THE UNIVERSITY
OF ILLINOIS
LIBRARY
NATURAL HISTORY SURVEY
5705
ILL
v7cop.4
ILLINOIS BIOLOGICAL
MONOGRAPHS
Vol. VII October, 1922 No. 4
Editorial Committee
Stephen Alfred Forbes William Trelease
Henry Baldwin Ward
Published under the
Auspices of the Graduate School by
the University or Illinois Press
Copyright, 1923 by the University or Illinois
Distributed February 9, 1923
A CLASSIFICATION OF THE LARVAE
OF THE TENTHREDINOIDEA
WITH FOURTEEN PLATES
BY
HACHIRO YUASA
Contributions from the
Entomological Laboratories of the University of Illinois
No. 69
THESIS
SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE
OF DOCTOR OF PHILOSOPHY IN ENTOMOLOGY IN THE GRADUATE
SCHOOL OF THE UNIVERSITY OF ILLINOIS
1920
TABLE OF CONTENTS
I. Introduction 7
II. Morphology 14
III. Taxonomy 35
Superfamily Tenthredinoidea 37
Families of Tenthredinoidea 38
Family Xyelidae 39
Family Blasticotomidae 42
Family Tenthredinidae 42
Subfamilies of Tenthredinidae 43
Subfamily Diprioninae 45
Neodiprion Rohwer 46
Species of Neodiprion 47
Monoctenus Dahlbom 48
Diprion Schrank 49
Subfamily Emphytinae , 49
Genera of Emphytinae 50
Subfamily Selandriinae 51
Genera of Selandriinae 52
Thrinax Konow , 52
Species of Thrinax 53
Strongylogaster Dahlbom 53
Species of Strongylogaster 53
Selandria Leach 54
Subfamily Dolerinae 54
Dolerus Jurine 55
Species of Dolerus 56
Subfamily Phyllotominae 57
Tribe Phyllotomini 57
Genera of Phyllotomini 58
Endelomyia Ashmead 58
Caliroa Costa 58
Species of Caliroa 59
Tribe Phlebatrophini 59
Phlebatrophia MacGillivray 60
Subfamily Tenthredininae 60
Genera of Tenthredininae 61
Macrophya Dahlbom 62
Species of Macrophya 63
Subfamily Cimbicinae 64
Genera of Cimbicinae 65
Cimbex Olivier 65
Trichiosoma Leach 65
Abia Leach 65
Species of Abia 66
Subfamily Hoplocampinae 66
Genera of Hoplocampinae 67
Hemichroa Stephens 67
Marlattia Ashmead 68
Caulocampus Rohwer 68
Subfamily Dineurinae 69
Subfamily Cladiinae : 70
Genera of Cladiinae 71
Trichiocampus Hartig 71
Species of Trichiocampus 72
Priophorus Dahlbom 73
Species of Priophorus 73
Cladius Rossi 74
Subfamily Nematinae 74
Genera of Nematinae 75
Diphadnus Hartig 76
Pnstiphora Latreille 77
Species of Pristiphora 77
Micronematus Konow 79
Lygaeonematus Konow 81
Pachynematus Konow 81
Species of Pachynematus 82
Nematus Panzer 82
Species of Nematus 83
Croesus Leach 83
Amauronematus Konow 84
Species of Amauronematus 84
Pteronidea Rohwer 85
Species of Pteronidea 85
Pontania Costa 88
Species of Pontania 88
Subfamily Blennocampinae 91
Genera of Blennocampinae 92
Tomostethus Konow 92
Blennocampa Hartig 93
Erythraspiaes Ashmead 94
Monophadnus Hartig 94
Hypergyricus MacGillivray 94
Species of Hypergyricus 94
Monophadnoides Ashmead 95
Isodyctium Ashmead 95
Subfamily Fenusinae 96
Genera of Fenusinae 96
Kaliofenusa MacGillivray 97
Fenusa Leach 97
Subfamily Scolioneurinae 98
Metallus Forbes ;. ... 98
Species of Metallus 99
Subfamily Hylotominae 99
Hylotoma Latreille 100
Species of Hylotoma 100
Subfamily Schizocerinae 101
Schizocerus Lepeletier 102
Subfamily Acordulecerinae 103
Acordulecera Say 103
Species of Acordulecera 103
Family Pamphiliidae 104
Species of Pamphiliidae 105
Family Cephidae 108
Genera of Cephidae ...;•.. 109
Janus Stephens 110
Species of Janus 110
Adirus Konow 110
Trachelus Jurine Ill
Cephus Latreille ... Ill
Species of Cephus Ill
Hartigia Schiodte 112
Family Xiphydriidae 112
Xiphydria Fallen 113
Family Siricidae . 114
Tremex Jurine 115
Family Megalodontidae 116
Family Oryssidae 117
Oryssus Latreille 118
IV. Phylogeny 120
V. Summary 133
VI. Bibliography 135
VII. Explanation of Plates 141
VIII. Index 169
325J LARVAE OF THE TENTHREDJNOIDEA—YUASA
I. INTRODUCTION
That the cardinal principle of modern taxonomy is based on the funda-
mental facts of evolution and that the essential problem of classification
is the phylogenetic relationship of organisms need no argument. In order
to ascertain genetic affinities, it is not sufficient to investigate the morpho-
logical characters alone, but all other attributes, physiological and biolog-
ical, must be considered. It is also evident that the immature stages of
organisms should receive as thoro consideration as the adult if taxonomy
of insects is to attain that degree of comparative perfection obtained in the
classification of other organisms.
Systematic entomologists, dealing as they do with animals of such
diversity and complexity morphologically and biologically, have from
early times recognized, at least to some extent, the taxonomic significance
and value of the developmental stages of insects, but the practical difficul-
ties in obtaining necessary materials, accurately determined and adequate
in quantity and range, have made progress in this phase of insect taxonomy
very tardy. A good start, however, has been made by recent workers as
was pointed out by Brues (1919), and their results vindicate both the
possibilitity and practicability of such investigations. There is, moreover,
an urgent demand for such studies from economic entomologists, who are
constantly confronted by the problem of identifying the immature stages
of economic species.
The present study is an attempt to deal with the larvae of the Ten-
thredinoidea from the standpoint of synoptic and, to some extent, genetic
classification. The systematic significance of the morphological charac-
ters will be discussed in part two; the taxonomic treatment of the families,
subfamilies, genera, and species will constitute part three; and, as full a
discussion of the phylogenetic relationship of the families as is possible
with the data at hand, will form part four. No one appreciates the inade-
quacy of this study, both in thoroughness and comprehensiveness, more
than the author, but it is hoped that he has opened a way for those who
will advance our knowledge of this highly interesting group of insects to
a more satisfactory condition in the future.
The taxonomic literature dealing with the adults of the Tenthredinoidea
is extensive. The historical development of the subject is interesting to
students of this group of insects but a detailed account is out of place here.
However, a brief statement of the history of the group is desirable.
8 ILLINOIS BIOLOGICAL MONOGRAPHS [326
Linnaeus in the fourth edition of the Systema Naturae (1744) estab-
lished the order Hymenoptera under the name of Gymnoptera and applied
to the order its present designation in the first edition of the Fauna Suecica.
The name Piezata was proposed by Fabricius (1775) for the order, but
this name never came into general use. Latreille (1796), following Lin-
naeus, divided the order into two sections, Terebrantia and Aculeata.
The first section included two groups, Phytophaga, which comprises the
Tenthredinoidea, and the Entomophaga or parasitic Hymenoptera. The
Ditrocha and Monotrocha of Hartig (1837) correspond approximately
with the two sections of Latreille. Gerstaecker clearly recognized the
Tenthredinoidea as a unique compact group and proposed in 1867 to
divide the order Hymenoptera into two suborders. He used the name
Symphyta for the Tenthredinoidea and Apocrita for the remainder of the
order. The term Symphyta thus antedates Konow's (1890) subordinal
name Chalastogastra. Various terms have been proposed for this group
of Hymenoptera and the following are coextensive with the superfamily
name Tenthredinoidea as used in the present paper: Phytophaga, Ses-
siliventres, Securifera, Serrifera, Symphyta, and Chalastograstra. Rohwer
and Cushman (1917) proposed a third suborder of Hymenoptera, Idiogas-
tra, for the family Oryssidae and placed it between the Chalastogastra and
Clistogastra of Konow.
Early students of the Tenthredinoidea divided the superfamily into
two groups, Phyllophaga for the Tenthredinidae or "Tenthredo" of
Linnaeus and Xyllophaga for the Siricidae or "Urocerus" of Geoffroy.
With the exception of Stephens (1835) and Andre" (1879), who recognized
the additional families Xiphydriidae and Cephidae, respectively, besides
the two families mentioned above, the old system was followed for many
years. With the progress in studies of the world fauna of this group
of insects, modern writers h«).
Near the ventral end of each epicranial arm there is a thickening of the
surface and a pit. This pit is a pretenorina (/>«) and the thickened piece
corresponds to the clypealia (cl) of the larva of Corydalis. The preten-
torina and clypealia are constant in position and universal in occurrence in
the Tenthredinoidea. In the Siricidae the pretentorinae are distinct and
sometimes mistaken for ocellarae. In ecdysis the head is split along the
epicranial suture nearly to the ventral ends of the arms.
Vertex. — The large area on each side of the epicranial stem is the vertex
(v). It extends from the dorso-meson of the epicranium to the ventral
margin of the head, laterad of the epicranial arm, and cephalad of the
occipital suture when this is present, and bears an ocellara (o) and anten-
naria (ar). There is on the dorsal part of the vertex on each side a distinct
furrow which originates at the occipital foramen and extends cephalad
for some distance onto the lateral aspect of the head. This is the vertical
furrow (vf) and is characteristic of the larvae of the Tenthredinoidea.
It is wanting only in the leaf-miners and wood-borers. The nature of this
furrows is not known. There is a corresponding carina on the ental sur-
face of the head, and the major muscles of the retractor of the mandible
are attached to the ental surface of the vertex dorsad and ventrad of the
vertical furrow. The furrows usually converge at the cephalic end, but
sometimes are subparallel to each other.
Genae. — The portion of the vertex ventrad of an imaginary line drawn
ventrad of each ocellara parallel to the ventral margin of the head is a
gena (g). The extent of the genae varies, therefore, according to the
location of the ocularia. The setae on the genae are sometimes longer
than those elsewhere.
Ocularia. — The larvae of the Pamphiliidae, Xyelidae, Tenthredinidae,
and Cephidae possess a pair of ocellarae (e), one on each side of the head.
These organs of sight are remarkably uniform and constant in structure
and location. With the exception of Phlebatrophia and the Cephidae, the
ocellarae are usually clear, semiglobose or at least distinctly convex,
and are located on or near the center of the ocularia {ou), which are usually
circular and distinctly blackish. The ocularia are located on the vertex
dorsad of the antennariae in the Tenthredinidae and caudad of them
in the Pamphiliidae and Cephidae. In the Cephidae and Phlebatrophia
the ocularia are obsolete and the ocellarae are indicated by pigmented
335] LARVAE OF THE TENTHREDINOIDEA—YUASA 17
granules showing thru the cuticle. The ocellarae are obsolete in the
highly specialized families, Xiphydriidae and its allies. The life-habits
are correlated with the presence and the degree of development of the
organs of sight.
Front. — The area bordered by the epicranial arms on the cephalic aspect
of the head is the front ([/"). The ventral boundary is indicated by a
transverse depression connecting the ventral ends of the epicranial arms.
This depression is the fronto-clypeal suture (Jcs). The depression is
usually concave dorsad and often obsolete at each lateral end. The
front is usually flattened or only slightly convex and bears scattered setae
which vary in number and arrangement in different genera and in arrange-
ment in different individuals. The extent of the front is determined by
the length of the epicranial arms. The front is usually subquadrate,
often wider than 1 ong, but in some cases, as in Caliroa (Fig. 53), it is
much longer than wide. In the absence of the epicranial stem the lateral
boundaries are indicated by the pretentorinae as in Tremex (Fig. 46).
Phlebatrophia (Fig. 37) is unique in possessing a distinct median longi-
tudinal furrow on the dorsal half of the front.
Clypeus. — The area ventrad of the front is the clypeus (c). Its ventral
boundary is the clypeo-labral suture (ds), and the lateral margins are free,
oblique, and converge ventrad. The clypeus is usually much wider than
long and is divided usually into postclypeus (po) and preclypeus (pe) by a
difference in color and by a transverse row of setae. Sometimes the
clypeal suture (cs) is distinct, as in some Nematinae (Fig. 31). The clypeal
setae vary in number from two to eight or ten but are constant within a
genus and often within a subfamily. Four is the most common number.
Labrutn. — The small lobe attached to the ventral margin of the clypeus
is the labrum (l). It is usually transverse and has a median emargination
on the ventral margin. This emargination is usually shallow and broad
but occasionally very deep, as in Eriocampa and a few other Emphytinae.
Dolerus (Fig. 42) is characterized by the distinct asymmetrical median
emargination which makes the sinistral half of the labrum much smaller
than the dextral. The cephalic margin is nearly smooth and slightly
oblique in Tremex (Fig. 46). The labrum is very small in the Xiphydriidae
(Fig. 45). From two to several labral setae (Is) are borne on each side
of the meson, those near the meson being usually smaller than the lateral
ones. The number of labral setae are as a rule constant within a genus.
A row of setae which may be seen projecting from the ventral surface of the
labrum belongs to the epipharynx. The labrum is often divided into
halves by a distinct median longitudinal depression, as in Caliroa (Fig. 53),
Endelomyia (Fig. 48), and some Tenthredininae. This character is generic
in some subfamilies and only specific in others. The labrum in the Cim-
18 ILLINOIS BIOLOGICAL MONOGRAPHS . . (336
bicinae (Fig. 29) is unique in having a pair of longitudinal depressions on
each half which converge ventrad and bound a small median piece.
Postgenae. — The area mesad of the lateral boundary of the vertex on
the caudal aspect of the head is the postgena (pa). The dorsal boundary-
is the vertical furrow and the mesal the occipital foramen. The ventral
margin is concave and is connected with the labicoria (Ic). It is usually
more or less flat and glabrous. The occipital suture (os) is sometimes
distinct, as in Pteronidea.
Tortnae. — At each end of the clypeo-labral suture there is a chitinized
rod which extends onto the ventral surface as far as the epigusta. This is
the torma, present in all Tenthredinidae.
Occiput.— The narrow area on the dorsal third of the occipital foramen
between the vertical furrows is the occiput. The dorsal boundary is in-
distinct since the occiput merges with the vertex without any indication
of a suture.
Maxillariae. — The very narrow chitinized sclerites which form a sub-
circular collar around the dorsal and lateral margins of the occipital
foramen have been identified as the maxillariae (my). They are usually
only slightly developed and are continuous with the cervacoria. The
identity of these sclerites with the maxillariae of generalized adult insects
is uncertain, but they occupy the same position as the maxillariae and
consequently are considered as homologous with them. The dorsal third of
the maxillariae in the leaf-miners Metallus (Fig. 35), Phlebatrophia (Fig.
37) and Fenusinae (Fig. 34), are strongly chitinized, distinctly concave,
trough-like, and produced en tad. Along this ental margin a part of the
muscles which control the movement of the head are attached.
Occipital Foramen. — The large opening in the caudal aspect of the
head thru which the internal organs of the head are connected with those
of the body is the occipital foramen (of). The ventral margin of the
occipital foramen is membranous and connected directly with the laba-
coria and cervacoria (cc).
Precoila. — The strongly chitinized acetabulum located near the
ventro-mesal angle of the vertex or the dorso-lateral angle of the clypeus
is the precoila (pr). The preartis of the mandible (py) articulates at this
point. The precoila is distinct in all Tenthredinoidea.
Mandibularia. — The small transverse whitish or light-colored area
ventrad of the ventral margin of the head on the cephalo-lateral aspect is
the mandibularia (mb). It is usually only slightly chitinized and merges
with the mandacoria without any indication of a suture. The extensacuta
(ec) of the extensatendon of the mandible is usually distinct. The mandi-
bulariae are sometimes very large, as in the Xyelidae (Fig. 27).
Postcoila. — The cup-shaped acetabulum on the latero-ventral angle
of the postgena and caudal angle of the mandibularia is the postcoila
337] LARVAE OF THE TENTH REDINOIDEA-rYV ASA 19
{pit), where the postartis of the mandible articulates. The occipital suture
(os) when present originates in or near the postcoila. The postcoila is
always present.
Paracoila. — There is a slight projection at the mesal end of the caudo-
ventral margin of the head where the cardo of the maxilla articulates. This
is the paracoila (pi). It is not well developed but is present and discernible
in nearly all tenthredinid larvae. .
Odontoidea. — The lateral cervical sclerite is articulated with the head
capsule on the mesal margin of the postgena some distance ventrad of the
origin of the vertical furrow. This point of articulation is an odontoidea
(od) and is rather indistinct in the larvae of this group of insects.
Tentorium— -The tentorium is very simple in tenthredinid larvae.
It consists of the metatentoria (m/), corpo tentorium (ci), and pretentoria.
The supratentoria are apparently obsolete. The metatentorium is the
strongly chitinized conspicuous ental bar extending into the head capsule
from the ventro-mesal margin of each postgena. The two metatentoria
fuse on the meson and form the bridge, the corpotentorium, which gives
support to the caudo- ventral portion of the head. The position of each
metatentorina is indicated by a pit- or slit-like depression (mn). The loca-
tion of the pretentorinae (pn) has already been indicated. A strong
ental arm, much smaller than a metatentorium, extends yentro-mesad
from each pretentoria into the head capsule and fuses with the corpoten-
torium near the middle of the latter. This bar is a pretentorium. In
ecdysis the tentorium breaks in the middle of the corpotentorium, freeing
the mesal ends of the pretentoria and metatentoria. The tentorium in
the Xyelidae and Pamphiliidae is similar to that of the Tenthredinidae in
structure and location.
The movable parts of the head include all the appendages, that is, the
antennae, mandibles, maxillae, and labium.
Antennae. — The antennae are present in the larvae of all Tenthredin-
oidea, but their structure, size, position, and number of segments vary in
the different families and subfamilies. Each is borne by a distinct anten-
naria (ar) which is located in the ventrolateral portion of the vertex; in the
generalized families they are located cephalad of the ocularia; in the
specialized, ventrad of them. The antennariae are usually subcircular or
subquadrate. The antacoria (an) is usually extensive, distinctly convex,
and whitish in color (Figs. 143-153). It is only occasionally narrow and
confined to the periphery of the antennaria, as in certain Nematinae
(Fig. 154). The antennae of the Pamphiliidae (Fig. 26) are setiform,
one-half as long as the head is wide, with seven cylindrical segments.
There is a circular sensorium on the ventral aspect, of the distal portion of
the second, third, and fifth segments (Fig. 39). In the Xyelidae (Fig. 27) '
the segments are shorter but thicker, and vary in number from six to seven
20 ILLINOIS BIOLOGICAL MONOGRAPHS [338
according to the genus. The antennae of the Tenthredinidae (Figs-
145, 147, 149, 150, 153) apparently represent a specialization from those of
the Xyelidae. They are much shorter and vary in number of segments
from one to five. The antennae vary in shape and are conical in the
Emphytinae and other generalized subfamilies, with five ring-like or
limpet-shaped segments, with four more or less irregular, incomplete, often
partly fused segments in the Nematinae (Fig. 145), or flattened and fused
into a single segment in the Schizocerinae or button-like and one-segmented
in the Cimbicinae, Fenusinae, and Metallus (Fig. 147), or subconical or
irregular as in some Nematinae and Phlebatrophia (Fig. 150). When
the antennae consist of five segments, they are usually cylindro-conical
and remarkably uniform in shape. The antennal segments are usually
strongly chitinized, more or less ring-like, successively smaller in diameter,
and the distal segment is conical or occasionally erect and peg-like as in the
Diprioninae. The segments do not always form a complete ring; one
side may be reduced to a mere line, or be entirely wanting as in some
Nematinae, in which cases the segment is said to be incomplete. Some-
times fusion of all or some of the segments may take place. Certain
segments are sometimes setiferous and also bear some sensoria. The
number of segments is constant for a subfamily. The relative length and
shape of the segments vary, but are constant in species in some cases, and
in others constant in genera. The antennae of the Cephidae are small,
with four or five segments, while in the Xiphydriidae they are three-
segmented and in the Siricidae and Oryssidae single-segmented. It is
possible, therefore, to arrange the families of Tenthredinoidea in an as-
cending series according to the number and size of the segments of the
antennae. The tenacity of the antennae is well illustrated in the Oryssidae,
which in spite of the extreme modification of other structures still retains
one-segmented antennae.
Mouth-parts. — The larvae of the Tenthredinoidea possess well-devel-
oped mandibulate mouth-parts. They include the mandibles, maxillae,
and labium, and are remarkably uniform and constant in structure in the
different families. The modifications take place in the relative size of
parts and in the number of segments of the articulated parts.
Mandibles. — The mandibles (md) are always present, and are typically
thick, strongly chitinized, and sharply dentate, the dextral dissimilar to
the sinistral in the number and shape of the dentes, and in having one or
two and occasionally more mandibular setae on the lateral aspect. The
number and arrangement of the dentes, the number of mandibular setae,
and the relative size and shape of the mandibles are constant for certain
genera. The mandibles of the Schizocerinae are rather thin and flattened,
and in Phlebatrophia very thin and elongated with one triangular blade-
339] LARVAE OF THE TENTHREDINOIDEA—YUASA 21
like dentis. In this character the larvae of this genus are more specialized
than all other larvae, even including Oryssus.
Maxillae. — The maxillae (tnx) are always present and typically consist
of cardo, stipes, subgalea, palpifer, palpus (mp), galea (gl), and lacinia
(la). The cardo is usually more or less chitinized and is divided into a small
subcardo and a larger triangular alacardo. The subcardo articulates with
the head in the paracoila. On the lateral margin of the alacardo the large
stipes is attached. The stipes is usually less chitinized than the cardo,
submenbranous, convex on the lateral aspect, and attached to the lateral
margin of the alacardo. The cephalic aspect is membranous and is con-
tinuous with the maxacoria. The caudal aspect along the mesal margin
is strongly chitinized and continuous with the elongate triangular subgalea.
The line of fusion is indicated by a distinct oblique chitinized ridge which
extends from near the proximal end of the subgalea to the lateral angle of
the lacinia. The latero-ventral angle of the stipes is often produced as a
small triangular lobe, the stipal angle of Crampton (1921) as in the
Tenthredininae. The palpifer is a more or less membranous, mound-like
lobe attached to the distal end of the cephalic margin of the stipes and
often bears one or more setae. The palpus is borne by the palpifer and
typically consists of four more or less conical segments. The relative
size and shape of the segments vary and afford good characters for the
separation of genera and species. The galea is typically strongly chitinized,
digit-like, conical or slightly curved mesad, bluntly pointed, unsegmented,
and usually smaller than the palpus. The lacinia is located mesad of the
galea and cephalo-ventrad of the subgalea. It is usually subtriangular,
slightly flattened, lobe-like, and bears a row of setae on its oblique mesal
margin. It is sometimes distinctly flattened, strongly chitinized, with a
stiff row of setae, as in the Emphytinae, or rounded and with minute spi-
nous setae as in Diprion, or with a sharp triangular compressed seta in
addition to an ordinary row of setae as in the Xyelidae. The galea and
lacinia are always present except in Oryssus but are reduced in size in
Tremex. It is interesting to note that in the leaf-miners the palpi are
reduced but the galea are usually normal in size and larger than the palpi.
In Oryssus the maxillae are fleshy lobes with all the component parts
obsolete and with a brownish area in which a few sensory papillae are lo-
cated (Rohwer and Cushman, 1917). The palpi are apparently two-
segmented in the Xiphydriidae and Siricidae.
Labium. — The labium (li) consists typically of submentum, mentum,
stipulae, palpiger, palpi (Ip), and togaglossa — representing the fused
glossae and paraglossae. The submentum (sm) and mentum (w) is typ-
ically membranous, convex, with two or more setae, and very broad in
the larvae of most species. In some cases, as in the Diprioninae, part
of the mentum is chitinized. In the leaf-miners, such as Fenusa, Metallus.
22 ILLINOIS BIOLOGICAL MONOGRAPHS (340
and Phlebatrophia, the rrientum is strongly chitinized and flattened.
There is a distinct median longitudinal depression in Metallus. The
palpiger is practically wanting. The palpus is typically three-segmented
(Fig. 157). The relative size and structure of the segments vary, but are
usually constant for a subfamily or a genus. In Tremex and Phlebatrophia
the palpi are apparently two-segmented and very minute, while in Oryssus
they are obsolete. The stipulae are typically membranous, broad, some-
times bearing two setae, and fused with the mentum without any indication
of a suture. The stipulae are flattened and chitinized in Metallus and the
Fenusinae. Totaglossa is typically membranous, subglobose or bluntly
pointed, fused with the stipulae without any indication of a suture. It is
readily identified on account of its median position and characteristic
shape and structure. There is a slit-like opening for the duct of the silk-
gland, the sericos (crv) on the meson near the caudo-ventral aspect of the
totaglossa. The shape, size, and location of the sericos vary but it is
always present and chitinized. The cephalic or dorsal aspect of the
totaglossa is strongly convex, membranous, and sometimes bears a few
minute setae and sensoria.
Prepharynx. — The prepharynx, the so-called "hypopharynx" of the
larvae of the Tenthredinoidea, is very simple in structure and the bound-
aries of the parts that can be identified in generalized insects (Yuasa,
1920) are obsolete. The propharynx consists of the epipharynx and epi-
gusta. The epipharynx is membranous, is of the same size and shape as the
labrum, and bears an oblique row of a few setae on each side slightly
dorsad of the ventral margin. The epigusta is membranous and is sup-
ported on each lateral portion by a torma. The ambipharynx is restricted
and membranous. The parapharynx consists of the basipharynx and
hypopharynx (hx). The basipharynx is subglobose or convex, often
slightly chitinized on the sides, sometimes having a few minute setae,
and usually converges ventrad. The portion ventrad of the constriction is
considered as belonging to the hypopharynx, but is usually membranous
and continuous with the Cephalic surface of the totaglossa without any
indication of differentiation. The laciniae fit against the sides of the
constricted part Of the parapharynx. No striking modification in form of
the prepharynx appears in the different families.
Trunk. — The portion of the body caudad of the head is the trunk.
It consists of thirteen segments which connect with the head by means of
the cervacoria. The first three segments compose the thorax and the
remainder the abdomen.
Cervacoria. — The membrane (cc) which connects the thorax with the
head is rather broad and usually folded under the protruding cephalic end
of the prothorax. There is a chitinized sclerite on each side, the cephalic
end of which articulates with the head against the odontoidea and the
341] LARVAE OF THE TENTHREDINOIDEA—YUASA 23
caudal end with the epimeron and coxa. This is the lateral cervical sclerite
(les), which is always present and usually distinctly colored — brownish or
blackish. The cervacoria is continuous with the submentum on the
ventral aspect, and is often produced on the meson as a small mound-like
setiferous protuberance, as in Strongylogaster.
Thorax. — The prothorax is usually constricted on the cephalic portion,
the dorsal aspect is declivous, and the lateral aspect is produced. The
dorsum is typically divided into a narrow cephalic portion and a wide
caudal one, which in turn may be subdivided into two or more annulets
(Fig. 65). The first division is usually setiferous on the lateral aspect,
while the second division is setiferous on the dorsal aspect. On the middle
of the lateral aspect there is a large spiracle. This is the mesospiracle
(msp), which has migrated onto the prothorax. There is another setiferous
area cephalo-ventrad of the spiracle. The prothoracic leg is attached to
the latero-ventral margin of the segment, ventrad of the setiferous sub-
spiracular area, which is usually produced as a lobe and which Crampton
(1918) has designated as the surcoxal plate. There is a small, usually
strongly chitinized sclerite cephalad of the leg. This is the episternum-
epimeron, or the eupleuron of Crampton. The dorsal aspect of the pro-
thorax and often the lateral one may be chitinized and colored, forming
shield-like areas as in the Xyelidae and certain leaf-miners. The proster-
num is usually membranous, subdivided into two or more annulets, but
sometimes it is flattened and strongly chitinized as in Metallus. There is
usually a small pit or chitinized rod near the caudal part of the segment on
the ventral aspect. This is the profurcellina (Pfn) and marks the caudal
limit of the prosternum. The meso thorax and metathorax are more
or less similar in structure, frequently the largest segments in the body,
more or less ring-like and often distinctly annulate. The metaspiracles
(tsp) are located in the metacoria and are usually minute and functionless.
The mesothorax and metathorax resemble the prothorax in other details.
In the Fenusinae (Fig. 21) and Metallus (Fig. 22) the dorsum of the
mesothorax and metathorax is provided with an ovoid, fleshy, sucker-like,
low protuberance (scp) on each side of the meson. Its function is not
known. Dimorphopteryx is characterized by the presence of a pair of
prominent dorsal protuberances on the prothorax and a median protu-
berance on the mesothorax.
Thoracic Legs. — The larvae of the Tenthredinoidea, with the exception
of the Oryssidae, possess three pairs of thoracic legs. They are the most
persistent of all the thoracic and abdominal appendages and as a rule are
very similar in structure, both facts indicating a common origin. A typical
leg consists of five more or less well-chitinized segments: coxa, trochanter,
femur, tibia, and a distal segment representing the fused tarsus and tarsal
claw.
24 ILLINOIS BIOLOGICAL MONOGRAPHS [342
The coxa (ex) is usually the largest of all the segments, subconical, and
articulated to the ventro-lateral margin of the segment. The cephalo-
dorsal angle is strongly chitinized and articulates against the chitinized
end of the episternum-epimeron. There is a distinct oblique depression
extending from this angle to the middle of the dorso-distal margin of the
coxa. The distal ends of the coxae are usually chitinized and form ring-
like thickenings. The ventral half of the coxa is more or less mem-
branous. The trochanter (tr) is usually small, longer on the ventral
than on the dorsal aspect. The femur (fin) is usually cylindrical and is
often dilated at the distal end. Its ventro-distal portion is usually mem-
branous and is sometimes produced, forming a pointed projection, the
femoral process (//>), as in Dolerinae (Fig. 135) and in related subfamilies.
The tibia (/) is subcylindrical, narrower in diameter at the distal than at the
proximal end, and either longer or shorter, than the femur or subequal to it.
The distal segment is typically very short and claw-like. The apparent
claw (cw) represents a fusion of the tarsus and tarsal claw, and is usually
sharp and distinctly curved. The segments are usually setiferous and
more or less membranous on the ventral aspect and at the joints.
The general plan of structure of the legs is the same in a majority
of the larvae, but there are variations in the shape, size, arrangement of
setae, and in the number of apparent segments within the families and
subfamilies. The variations usually consist in the suppression of the
trochanter as in Phlebatrophia (Fig. 136) and the Fenusinae (Fig. 140),
or in the modification of the distal segment as in the Pamphiliidae (Fig. 130)
and Hylotominae, or in the reduction of the entire structure to a fleshy,
subconical, indistinctly segmented clawless protuberance as in Phleba-
trophia and certain highly specialized families. The absolute homology of
the segments in a modified leg can not be established, but when the number
of the segments is less than five it is probable that the trochanter is the
first one to disappear.
The Pamphiliidae are distinct from all other tenthredinoid larvae in
having setaceous legs with all segments cylindrical except the distal ones.
The distal segment is very slender, non-setiferous, straight, and sharply
pointed without indication of a claw. The Xyelidae (Fig. 131) possess
legs which are small but typical in structure and number of segments.
It is quite possible to derive the normal tenthredinid legs from those of the
Xyelidae. In the subfamilies of the Tenthredinidae, a series of modifica-
tions of the legs is found, altho the majority of the subfamilies and genera
are provided with typical five-segmented, well-developed claw-bearing
legs. The Phyllotominae (Figs. 141, 142) are characterized by very
short, stubby, chitinized legs which consist of four segments, including the
large strongly curved claw. Phlebatrophia (Fig. 136) is unique among the
Tenthredinidae in having fleshy, rudimentary clawless legs. The Fenusi-
343] LARVAE OF THE TENTHREDINOIDEA—YUASA 25
nae (Fig. 140) also possess small four-segmented legs but, unlike the
Phyllotominae, have simple and ring-like segments and claws normal in
form. The Hylotominae differ from the other subfamilies in possessing
apparently six-segmented legs. Their distal portion consists of a distinctly
separated tarsus and claw and bears an empodium-like fleshy lobe on the
caudal portion of the claw. The minimum number of segments is found in
the legs of the Schizocerinae (Fig. 139), where the mesothoracic and
metathoracic legs consist of only three simple cylindrical segments, while
the prothoracic legs are composed of four. There is a well-developed
fleshy subglobose lobe caudad of the claw. It is interesting to note that
the gall-makers, for example, Pontania have essentially the same type of
legs as the leaf-feeding Nematinae (Fig. 133), while the leaf-mining larvae
of the Fenusinae, Schizocerinae, and others, have modified legs. The
highly specialized families, Cephidae, Xiphydriidae, and Siricidae, possess
fleshy, indistinctly segmented rudimentary legs which are never provided
with claws. The most specialized family, Oryssidae, is entirely apodous.
The legs present, therefore, very good characters for differentiating the
families and the subfamilies of the Tenthredinoidea. The phylogenetic
significance of the thoracic legs is quite evident.
Abdomen. — The segments composing the abdomen, with the exception
of the two caudal segments, are more or less similar in structure, ring-like,
and usually subdivided into four to seven annulets. Segments 2-7 or 2-8
and 10 usually bear a pair of larvapods, the so-called "prolegs," on the
ventral aspect. The first and ninth abdominal segments never possess
larvapods except in the Xyelidae. The third abdominal segment is more
typical than the other segments and least modified, and for this reason
has been used as a type for description. In a typical larva this segment is
subdivided into a number of annulets on the dorsum and latus dorsad of
the spiracular line. The latus ventrad of the spiracular line is typically
lobe-like, setiferous, and distinguishable as two areas, the subspiracular
area (ssl) or the surpedal area (sdl) according to the location. When
these areas are distinctly lobe-like they are designated as subspiracular
lobe and surpedal lobe. The latter corresponds to the thoracic surcoxal
plate of Crampton. The subspiracular and surpedol lobes sometimes fuse
and extend the full length of the segment as an oblique fold, as in wood-
boring larvae and the Hylotominae. In the latter this lobe is conspicuously
produced laterad, making the segment distinctly flattened. The sub-
spiracular and surpedal lobes, when fused, are known as the sublateral
lobe (sll). The larvapods are located on the ventral aspect some distance
from the meson. The sternum is divided into two or more annulets, the
annulation being usually distinct but its exact limits difficult to determine
on account of the presence of the larvapods. The intersegmental coria
(cor) is distinctly indicated on the venter (Fig. 81). The segmentation
26 ILLINOIS BIOLOGICAL MONOGRAPHS " {344
is distinct but the limits of the somites are not so readily determined. The
cephalic limit of a segment is usually indicated by the distinct depression
on the dorsal and lateral aspects and by the short ventro-lateral depressions
which terminates at the cephalic end of the subspiracular lobe. Thus
the cephalic limit of a segment is not a straight line, but curves caudo-
ventrad and then slightly cephalo-ventrad of the subspiracular lobe.
The typical annulation and arrangement of setae, tubercles, and glandubae
on the typical abdominal segment are indicated elsewhere (Figs. 73-79).
The ninth abdominal segment is readily distinguishable because of its
location and shape, and by the absence of spiracles and larvapods. It is
typically smaller than the preceding segments, tapers more or less caudad,
and usually has one less annulet on the dorsum than have the preceding
segments. Its caudal limit is usually distinctly indicated by a deep
depression. The tenth, or the apparent ultimate, segment is modified and
differs from the other abdominal segments because of the presence of the
anus, anal larvapods, and other structures peculiar to this segment (Figs.
89-103).
Tenth Urotergum. — The tergum of the tenth abdominal segment is
usually convex and often setiferous. It sometimes bears numerous spinous
processes, as in the Blennocampinae and Dimorphopteryx, or paired suranal
protuberances as in certain genera of Nematinae, or a median suranal
process (srp), as in the Cephidae and its allies. In these highly specialized
families the tenth abdominal segment is produced cephalad and fits into
the deep semicircular emargination of the ninth segment. The tergum
possesses a distinct, deep, median longitudinal depression extending
from the cephalic end of the tergum to the proximal end of the median
suranal process. In the Xyelidae the tergum is produced distinctly hunch-
like on the meson of the cephalic third caudad of the deep, broad transverse
depression. The tergum is produced caudad in certain species of Pachy-
nematus and forms a distinct caudal projection. In this genus the gland-
ubae are very conspicuous. The size, convexity, number, and arrangement
of the spinous protuberances, caudal processes, and setae are useful
characters in recognizing different subfamilies and genera.
Suranal Lobe. — The membranous lobe (srl) of the Tenthredinidae,
which forms the dorsal wall of the anal slit may represent the rudiment of
the dorsal half of the ultimate segment, the so-called "telson." It bears
numerous setae of varying size and number and is usually fused with the
tergum of the tenth segment. In the larvae of the Xiphydriidae and its
allies, which possess a median suranal process, the suranal lobe is distinct,
more or less chitinized in part, usually separated from the tenth tergum by
a ridge or by an oblique suture which extends from the chitinized depres-
sion dorsad of the suranal process to the lateral end of the anal slit (au).
The area cephalad of this oblique suture is the pleuron of the tenth seg-
ment.
345] LARVAE OF THE TENTHREDINOIDEA—YUASA 27
Subanal Lobe. — The membranous lobe (sbl) which forms the ventral
wall of the anal slit may represent the rudiment of the ventral half of the
ultimate segment or "telson." It is never distinctly chitinized, always
indistinguishably fused with the tenth abdominal sternum, usually setifer-
ous, and is rather restricted in extent. In the Tenthredinidae the subanal
lobe is strongly convex and extends to the anal larvapods, the postpedes of
Crampton. If the subanal lobe represents a part of the telson, and if the
subanal appendages (sba) of the Pamphiliidae and Cephidae are the
appendages of the ultimate segment, then the subanal lobe possesses a
pair of genuine appendages. In the larvae of the Xyelidae there occur
sometimes distinct subglobose setiferous swellings dorso-caudad of the anal
larvapods. Their homology and function are unknown.
Tenth Urosternum. — The sternum of the tenth abdominal segment is
restricted in extent, more or less convex, and often glabrous. In the
Xyelidae and Tenthredinidae the anal larvapods occupy the greater part
of the caudal portion, which is thereby produced subconically ventrad.
This sternum is usually glabrous and more or less flattened in apodous
larvae. There are no annulations observable on this sternum.
Suranal Process. — In boring larvae, the ultimate segment is provided
with a strongly chitinized mesal suranal process (srp) on the suranal lobe.
This process, which has been variously designated by different writers, is
characteristic of the families Cephidae (Figs. 108, 109, 112, 114, 115)
Xiphydriidae (Figs. 107, 110), and Siricidae (Figs. 113, 120, 122). The
size, shape, number, and arrangement of the dentiform tubercles and
setae vary in different families but they are constant within species and
often also within genera. It is undoubtedly an adaptive structure devel-
oped in connection with the boring habit of the larvae. It is interesting to
note that in some of the gall-making larvae of Pontania and leaf-stem
boring larvae of Caulocampus, the tergum of the ultimate segment is
produced on the caudo-meson and forms a distinct protuberance provided
with chitinized points on its caudal end. The larvae of the Pamphiliidae
also possess a minute hook-like process on the caudo-meson of the ultimate
tergum. The genetic connection of this hook-like tubercle and the distinct
suranal process of highly specialized families is doubtful, but it is not difficult
to surmise a common origin for the suranal process of the Cephidae,
Xiphydriidae, and Siricidae. The suranal process corresponds to the
postcornu of Crampton.
Caudal Protuberances. — In certain genera of the Nematinae and in
a few other genera of the Tenthredinidae, the tergum of the ultimate
segment is provided with two or more protuberances which vary in size,
shape, number, and position in different genera. A typical condition in
nematid larvae is found in Pteronidea (Figs. 126, 127), which possess a
pair of conical, pointed, well-chintinized processes (srp), one on each side,
2S ILLINOIS BIOLOGICAL MONOGRAPHS [346
on the caudal margin of the tergum dorsad of the membranous suranal
lobe. These processes are always two in number and more or less constant
in position in nematid larvae, but vary in size and shape altho constant
within species. They are conical, subconical, sharply or bluntly pointed,
truncate, or distinctly swollen at the distal end as in Pteronidea trilineata.
The tenth abdominal tergum of the spinous larvae of the Blennocampinae
is provided with several symmetrically arranged conspicuous spinous
processes on the caudal portion and in part along the caudal margin. The
larva of Dimorphopteryx is unique among the Emphytinae in the possession
of four very distinct, sharply pointed spinous protuberances along the
caudal margin of the ultimate segment dorsad of the suranal lobe. In
certain of the gall-making species of Pontania the caudal end of the tenth
abdominal tergum is produced caudad and forms a median prominence
which usually has two minute strongly chitinized points close together on
the meson. A similar protuberance is found in the larvae of Caulocampus
acericaulis. In the Siricidae a pair of minute sharply pointed solid chitin-
ized spines occurs on the tergum of the ultimate segment, one on each
side of the median longitudinal depression (Fig. 113).
These protuberances have been variously designated. Crampton
(1919) considers the paired protuberances and spines to be homologous
with the cerci of Orthoptera and Ephemeridae. If they represent rudi-
mentary cerci they must belong to the eleventh abdominal segment,
the telson of embryologists, since the true appendages of the tenth segment
are transformed into the anal larvapods. But this homology is open to
question because these protuberances are mere projections of the surface
and not at all appendages in a morphological sense, and, furthermore,
because in other larvae the number and position of the protuberances vary
considerably. No one would suggest that the caudal tubercles and spinous
processes of Dimorphopteryx, Blennocampa, Hypergyricus, Caulocampus,
and others are homologous with the cerci of generalized insects; yet, there
is no reason to assume that the caudal tubercles of these larvae are differ-
ent in origin, structure, and function — whatever that may be — from the
suranal paired processes of the nematid larvae. These protuberances
may or may not be at all related genetically to the suranal median process
of the Cephidae and its allies. At any rate our present knowledge does
not permit any definite conclusion regarding the true nature or homology
of these structures. The interpretation advanced by Middleton (1921)
seems more reasonable. He named these protuberances pseudocerci.
Subanal Appendages. — The larvae of the Pamphiliidae (Figs. 91, 95)
and Cephidae (Figs. 108, 109, 111, 116, 117, 118, 119) possess a pair of
subanal appendages on the ultimate segment, one on each side ventrad
of the lateral ends of the anal slit. These appendages are long, setaceous,
and three-segmented in the Pamphiliidae, but are rudimentary, papilliform,
347) LARVAE OF THE TENTHREDINOIDEA—YUASA 29
and only indistinctly segmented in the Cephidae. When the appendages
are long and setiform, the relative length and color of the segments differ
in different species. In the Cephidae the appendages may or may not be
provided with accompanying setae near the proximal end, and these
setae may or may not form a continuous group with the setae on the
sternum.
That these structures are true appendages of the segment is indicated
by the segmentation and by the fact that they are invariably articulated
at the proximal end against the surface, not being mere protuberances
like the caudal processes of the tergum. Some embryologists consider these
appendages to be homologous with the cerci of generalized insects and the
anal "prolegs" of lepidopterous larvae, and, therefore believe them to be
true appendages of the eleventh abdominal segment. It is obvious that
they can not be homologous with the anal larvapods of other tenthredinoid
larvae. Crampton (1919) designated them as arthrostyli on the ground
that they are apparently homologous with the styli of the Ephemeridae
and other insects. The opinions of entomologists differ, for example
Middle ton (1921) homologizes the subanal appendages with the post-
pedes of Crampton. The homology and function of these appendages
need further investigation. However, it is significant that long distinctly
segmented appendages should occur in the Pamphiliidae and rudimentary
ones in the Cephidae.
Larvapods. — The embryological data seem on the whole to support
the view expressed by Korschelt and Heider (1899), who say that "the
abdominal appendages of the caterpillars of the Lepidoptera and Hymen-
optera are to be regarded as true limbs," and that "limb-rudiments first
form on all or most of the abdominal segments, but they very soon dis-
appear on those segments which in the larvae have no limbs, while on the
other segments they are transformed into the functional prolegs." Graber
(1890) has shown that the so-called anal prolegs of Hylotoma are the
appendages belonging to the tenth or true penultimate abdominal segment.
They are, therefore, not homologous with the anal "prolegs" of lepidop-
terous larvae, which are, according to Graber (1890), the appendages of
the ultimate segment.
The maximum number of larvapods (pig) occurs in the Xyelidae, where
each of the abdominal segments is provided with a pair. The first and
ninth pairs may be smaller than the others, as in Odontophyes, but they
are always discernible. The number of larvapods present in the Tenthredin-
idae varies from six to eight pairs. They are usually present on abdominal
segments 2-7 and 10 or 2-8 and 10, rarely on 2-6 and 10. In the Fenusinae
(Fig. 105) and Caulocampus the tenth pair is obsolete, and in Metallus
(Fig. 103) they are fused together forming a median protuberance.
Larvapods are entirely wanting in the other families of the Tenthredinoidea.
30 ILLINOIS BIOLOGICAL MONOGRAPHS [348
A typical larvapod is a fleshy subconical protuberance narrowed toward
the distal end, and is usually subdivided into a larger but shorter proximal
portion and a smaller but longer distal portion. Sometimes the distal
end is dilated and turned mesad, as in Neodiprion (Fig. 82), or the cephalo-
ventral angle is pointed, as in Tenthredo. The larvapods are well devel-
oped in most of the free-living larvae but in the leaf-miners and
fruit-borers they are reduced and smaller. They are very small in the Hylo-
tominae and rudimentary in the Fenusinae (Fig. 86) and Schizocerinae,
while they are obsolete in Phlebatrophia. The degree of development of
the larvapods is closely correlated with the habits of the larva. The
larvapods are usually located on the middle of each lateral half of the
sternum but occasionally are very close together near the meson, as in
Neodiprion. The number of pairs of larvapods present is a convenient
character for differentiating the subfamilies of the Tenthredinidae. The
larvapods often bear a few setae on the cephalic and lateral aspects.
The setae, when present, are confined to the mesal aspect. Lack of setae
on the larvapods is often a generic character and the number and arrange-
ment of the setae is typical of the species.
Crampton (1919), with good reasons, proposed to substitute the term
uropods for the long-used but misleading term prolegs. The term uropoda
has been employed by students of the Crustacea in designating the abdom-
inal appendages, especially one of the posterior pairs of pleopods, and
according to Smith's glossary of Entomology the term refers to "any of
the abdominal feet of Arthropoda." These facts indicate the necessity of a
distinctive term, and the new term larvapods following the suggestion of
Dr. MacGillivray, is used until a happier term is created for these true
abdominal appendages of insect larvae.
Metamerism. — Graber (1890) has shown that the number of somites
which compose the body of the larvae of Hylotoma is fourteen exclusive
of the head. The first three somites belong to the thorax and the remaining
eleven to the abdomen. The ultimate segment, or the telson of the embry-
ologists, is difficult to discern in larvae. It is probably represented by the
suranal and subanal lobes of the larvae, but the boundary between this
segment and the tenth somite is so obliterated, and the ultimate segment,
which is originally much smaller than the preceding somites, is in the
larval stage so much more reduced, that it is permissible and also con-
venient to speak of the abdomen as being composed of ten segments.
For this reason the tenth abdominal somite, which bears the so-called
anal prolegs, is designated as the ultimate segment in this paper. It is to be
noted that Nelson (1915:111) considers that there are eleven segments
and a telson in the abdomen of the embryos of Hymenoptera. In all the
larvae of the Tenthredinoidea examined, it is always possible to count
ten abdominal segments. The body is usually distinctly segmented.
349] LARVAE OF THE TENTHREDINOIDEA-^YUASA 31
The exact limit of the somite in a larva is not easy to determine.
Entomologists seem to have paid little or no attention to this point.
Castle (1900) has made an excellent study of the metamerism of the
Hirudinea, but his conclusions are not directly applicable to the case of in-
sect larvae tho they are pregnant with important suggestions. He found
that the natural and true limits of a somite coincide with the limits of the
neuromere, and that both reduction and increase in the number of rings,
which correspond to the annulets in the saw-fly larvae, take place at the
ends of the segment. The classical work of Lyonet (1762) and the recent
study of Forbes (1914) on the musculature of lepidopterous larvae, as also
a study of Boving (1914) indicate that the musculature affords a reliable
criterion for determining the limits of a somite. From a careful examina-
tion of the musculature of various types of tenthredinoid larvae (Fig. 129),
the author has come to the conclusion that in these larvae the natural
and accurate determination of the extent of the somites composing the
body is best based upon the musculature. A detailed discussion of this
subject is out of place here. It is sufficient to say that a majority of the
longitudinal muscles, including the dorsal, lateral, and ventral retractor
muscles, originate on the cuticular fold, or coria, which, on the exterior, is
usually indicated by a deep depression (is). Only a few muscles of impor-
tance cross this fold, nearly all the muscles being attached either to the
cephalic or caudal part of the coria. This cuticular fold, therefore, is con-
sidered as the cephalic limit of the somite, and the annulets into which
the somite is subdivided are numbered consecutively, commencing at its
cephalic end. To assume, a priori, the spiracular annulet, or the annulet
which bears the spiracle, to be the first annulet is arbitrary and inaccurate
inasmuch as this annulet, according to the criterion of musculature, cor-
responds to any one of the first three annulets of the somite. The position
of the spiracular annulet is constant and definite within a genus or sub-
family as long as the number of annulets of the somite is constant. Some
of the annulets are usually setiferous and often bear in addition transverse
rows of glandubae. The position of such setiferous annulets is constant within
the genus or subfamily when the annulation is constant. The number of
annulets on the ninth abdominal segment is always smaller than that on
the preceding segments. Since the setiferous annulets have a definite
order, it is possible to determine which annulets are obsolete on the penul-
timate segment. The first annulet to disappear is a caudal one, and
ordinarily it is only the caudal annulet that is missing. The number of
annulets of the sternum is less than that of the tergum. The length of
the annulets varies but their relative size is constant within a species.
The primitive number of annulets of the abdominal segments is unknown.
If the annulation of the generalized Tenthredinoidea is assumed to be
representative of the primitive condition, then four is the primitive num-
32 ILLINOIS BIOLOGICAL MONOGRAPHS [350
ber of annulets. In the specialized Tenthredinoidea the number varies
from one to seven, but five to seven is of the most common occurrence.
The number becomes smaller in the highly specialized families, being
reduced to a single annulet in the Siricidae and Orysidae.
Spiracles. — The spiracles (spi) are present on the prothorax and the
first eight abdominal segments in all Tenthredinoidea. The pair on the
prothorax are always the largest. The abdominal spiracles are usually
uniform in size and shape except the last pair, which are often larger than
the others. The spiracles are definite in location in regard to the annulets
and are always situated on some one of the first three annulets of the
segments. The spiracular line is usually located slightly ventrad of the
middle of the lateral aspect of the body, but sometimes it migrates ven-
trad to the latero- ventral line as in Caliroa. The spiracles (Fig. 155) are
usually very simple in structure, vertical in position, never circular in
outline but narrowly ovate, rounded or pointed at both ends. The peri-
treme is narrow but strongly chitinized and brownish or blackish. The
labiae are narrow and the spiracular opening is usually closed and appears
like a dark line. The peritreme is sometimes distinctly thickened as in the
Hylotominae. There is often a semicircular or irregular chitinized colored
area on each side of the spiracles, as in certain nematid genera. These
areas vary in size and shape but are constant within species, and their
presence is usually constant within genera and often within a subfamily.
When these areas are present, the spiracles are said to be winged.
The true prothoracic spiracles are considered as wanting in adult and
larval insects. The spiracles found on the prothorax of Tenthredinoid
larvae are the mesothoracic spiracles (msp) which have migrated from
the mesocoria onto the prothorax. The metathoracic pair (tsp) is usually
functionless, very small, and located in the metacoria, or obsolete. In the
Cephidae and Siricidae, however, the metaspiracles are distinct, functional,
and as large as the abdominal spiracles. It is difficult to explain the
rudimentary condition of this pair in the Xiphydriidae, since other charac-
ters indicate that they have a common origin with the Cephidae and
Siricidae. It is possible, however, in the course of evolution, to have one
structure of the body modified faster than another structure.
Setae. — The surface of the body is usually provided with some setae,
particularly on the head, thoracic legs, and the ultimate segment of the
abdomen on the suranal and subanal lobes. The number, size, arrange-
ment, and structure of the setae vary in different taxonomic units, accord-
ing to their location; and to some extent according to the stage of larval
growth. There is a tendency toward the loss of setae in the ultimate
stage or the last instar, as is Pteronidea, or to have fewer and smaller setae
in the leaf-mining and wood-boring larvae, as in the Fenusinae, Cephidae,
and others. There seem to be no definite setal patters, as in lepidopterous
351] LARVAE OF THE TENTHREDINOIDEA—YUASA 33
larvae, but when certain annulets of the segments possess setae their pres-
ence on these annulets in successive segments is constant if not in precisely
the same number and order. There is a tendency to have more and longer
setae on the lower half of the head than. on the upper half. The number
and arrangement of the setae are variable on the vertex and front but are
fairly constant on the clypeus, labrum, and mandibles.
A spinal formula is an abbreviated expression of the arrangement of
the tubercles or spines on the various parts of the body. The figures of
the formula indicate the number of branches of a spine and are arranged in
order, beginning with the mesal spine in the case of those on an annulet
and with the cephalic spine in the case of the subspiracular areas. The
spinal formula of the prothoracic segment represents the arrangement of
the spines on the large or second annulet, on the first or smaller lateral
annulet, on the subspiracular area, and on the postsubspiracular area
respectively. The spinal formula of the third abdominal segment indicates
the arrangement of the spines on the first tubercle-bearing (usually 2d)
annulet, on the next small annulet if this is present, on the third tubercle-
bearing (usually 4th) annulet, on the subspiracular area, and on the post-
subspiracular or surpedal area, respectively.
The number of branches of the spines sometimes varies and the arrange-
ment of the spines also may show minor variations. The spinal formulae
represent the most typical arrangement.
Glands and Glandubae. — There are many types of glands opening to the
exterior found on the various parts of the body of the larvae of the Tenth-
redinoidea. The larvae of the Nematinae and Cladiinae are provided with
a series of ventral glands on the ventro-meson of abdominal segments
1-7. Sometimes a pair of eversible glands is found in the cervical region,
as in Megaxyela major. The larvae of the Cimbicinae possess a spiracular
gland located dorsad of each spiracle of abdominal segments 2-8. It is from
these glands that the yellowish fluid of these larvae is poured out when
disturbed. A peculiar sucker-like protuberance with a depressed center
occurs in the larvae of the Acordulecerinae on the sublateral area of
abdominal segments 2-4 or 5 and 8. The function of this structure is not
known but it is not improbable that it is secretory in nature. The wax
glands of the wax-secreting larvae such as certain Tenthredininae, Emphy-
tinae, Selandriinae, etc., are minute and located on various parts of the
body of these larvae, but their detailed structure has not been studied.
The most common type of these glands is found in the larvae of the
Diprioninae, Emphytinae, Selandriinae, Tenthredininae, some Nematinae,
and others. The cutaneous glands of these larvae are provided with chi-
tinized rings about their external openings. These chitinized openings are
known as glandubae. They may be located at the end of tubular protu-
berances, and in such cases they are spoken of as being stalked, or they
34 ILLINOIS BIOLOGICAL MONOGRAPHS [352
may be found flush with the body surface, when they are spoken of as being
sessile. The glandubae are especially conspicuous in the larvae of the
Diprioninae and Pachynematus. The slime-glands of Caliroa have semi-
sessile glandubae which are few in number. The glandubae are constant
in their type, presence, general arrangement, and location, within genera
and subfamilies.
Formulae of Segmented Appendages. — For convenience in designating
the size and relationship of various segmented appendages, the resort
has been made to various so-called formulae. The segments of an appen-
dage are numbered, beginning with the proximal segment. In a formula
numbers of the segments are arranged in the descending order of magni-
tude, and those of equal dimensions are placed in a parenthesis. For
example, the expression "antennal formula: (2,5), 3, 4, 1" shows that the
antenna is composed of five segments and that segments 2 and 5 are equal
in length but longer than the others, and that segment 4 is shorter than
segment 3 but longer than the first or proximal segment.
353] LARVAE OF THE TENTHREDINOIDEA—YUASA 35
III. TAXONOMY
Strictly speaking no classification of the Tenthredinoidea based upon
larval characters has hitherto been proposed. Attempts have been
restricted to the characterization of the different subdivisions included in
the superfamily. Among the earlier writers Le Pele tier's (1823) work may
be mentioned. After a brief general account of the larvae, he gave a list
of eighteen divisions in which he grouped the species of the Tenthredinoidea
and stated whether the larvae of each division were known or unknown
and, if known, the number of the thoracic and abdominal legs present.
It is interesting to note that he mentioned a group of larvae the body of
which he characterized as "donkey-form" (aselliform) which he was
unable to place in any of his divisions. Dahlbom (1835) published careful
descriptions and a synopsis of larvae of sixty-three species. A synoptic
table for the larvae was compiled by Westwood (1840) from this work
and was published with additions. The characters used are the number of
abdominal legs and the feeding habits of the larvae. Norton (1867)
republished Westwood's table without additions. In the table given by
Cameron (1882) the larvae of more than ninety-five species are included.
The major groups are separated on the number of thoracic and abdominal
legs present. These subdivisions are segregated on biological characters
such as reflex bleeding, types of cocoons, and, finally, genera and species,
when known, are separated on the coloration, setae, food-plants, and feed-
ing habits. In 1895 Dyar, the most prolific and the only important Ameri-
can writer on the larvae of the Tenthredinoidea, published "A recognition
table for the known sawfly larvae of the North Atlantic States." The
larvae of one hundred and twenty-six species including forty-one not
specifically identified were considered in this synopsis. The characters
used are the number and location of abdominal legs, types of cocoon,
feeding habits, food-plants, and coloration. This last character was
employed extensively in separating different species. The next attempt
along this line was undertaken by Chester Young (1898), who was the
first to take into consideration the structural characters of the appendages
of the head. Unfortunately this work remains unpublished, but it is on
file as a baccalaureate thesis in the library of Cornell University. Konow
(1901) summarized the taxonomic information concerning the known
larvae of European and American species, four hundred and eighteen in
all, in the form of an analytical table. The presence or absence of abdom-
inal legs, number of antennal segments, and modifications and appendages
36 ILLINOIS BIOLOGICAL MONOGRAPHS [354
of the ultimate body-segment were used in separating the families and
subfamilies. The number and location of abdominal legs, the food-plants,
types of cocoon, and coloration furnished the basis for the separation of
tribes, genera, and species. Middleton (1915, 1917) has characterized the
larvae of the genus Dimorphopteryx and of the family Cephidae. It
must be noted that these writers were concerned only in the preparation
of recognition tables for the separation of the particular species they had
in hand, and, with the exception of Middleton, no one has attempted
to construct a synopsis of families, genera, and species as such.
In the following pages, the author has attempted to define and describe,
as far as possible with the materials at hand, families, subfamilies, genera,
and species by the use of larval characters. With a few exceptions, no
attempt has been made to incorporate data from previous writers for the
reason that the characters recorded by them were found in most cases of
little or no value for the present purpose — not because they were inaccu-
rate, altho that was true in many cases, but chiefly because they were not
of specific significance. For example, Dyar's descriptions of species are
usually very accurate and dependable but most of the characters noted
excepting coloration often proved to be only of family or subfamily sig-
nificance. The definitions given here are correct for the materials actually
studied, but it is not surprising if they do not hold good in many cases
when more materials become available for examination. It is obviously
impossible to attain perfection in the face of so many missing links in the
series of genera and species. These missing links will be filled in as rapidly
as accurately identified materials become available, but it must be remem-
bered that absolutely correct identification is only possible, in the majority
of cases, after carrying individual larvae of the species thru to the adult
stage, exuviae being saved for each instar.
In this study the classification of the Tenthredinoidea proposed by
MacGillivray in 1906, with later additions, has been adopted in the main
in arranging and restricting the families, subfamilies, genera, and species.
For generic synonymy, Rohwer's "Genotype of the Sawflies and Wood-
wasps" (1911) has been followed. In this section all references to the
bibliography of the different divisions and subdivisions have been omitted.
355] IARVAE OF THE TENTHREDINOIDEA—YUASA 37
SUPERFAMILY TENTHREDINOIDEA
Larvae with exposed, well differentiated head, trunk consisting of three
thoracic and ten visible abdominal segments; spiracles always present on
prothorax and first eight abdominal segments; antennae and chitinized
dentate mandibles always present; ocellarae, when present, always one on
each side of the head; thoracic legs, when present, always three pairs,
a pair to each segment; larvapods, when present, always six pairs or
more, and except the Xyelidae, are never on the first and ninth abdominal
segments, but always on the second abdominal segment, and never with
crochets; mouth-parts, when normal, with mandibles strongly chitinized
with distinct dentes, dextral dentes differing in number, shape, and
arrangement from sinistral; maxillae with cardo, stipes, palpifer, palpus,
galea, and lacinia present, palpus typically with four segments, galea
conical, digit-like, and lacinia usually flattened, its cephalic margin with a
fringe of setae; labium with submentum, mentum, palpi, stipulae, and
totaglossa, palpi typically with three segments, totaglossa membranous,
bulbose, with a sericos on its meso-distal portion; general appearance of
body caterpillar-like or grub-like; free leaf -feeders, leaf-miners, web-
spinners, leaf-rollers, wood- and stem-borers, and parasitic larvae.
Free Leaf -feeders. — Body caterpillar-like; thorax with well-developed,
distinctly segmented legs, typically with five segments, coxa, trochanter,
femur, tibia, and tarsus and tarsal claw; abdomen typically with a pair of
larvapods on segments 2-7 or 2-8 and 10; ultimate segment sometimes
with caudal protuberances but never with a distinct suranal process or with
subanal appendages; head typically semiglobose; antennae typically mul-
tisegmented, segments one to five in number; ocellarae always present,
usually located dorsad of antennariae; mouth-parts well developed and
typical in structure; abdominal segments usually with five to seven annu-
lets, some of which bear transverse rows of setae and often some glandubae;
head, thoracic legs, and anal area usually setiferous; majority of Tenthre-
dinidae and Xyelidae.
Leaf -miners. — Body somewhat depressed, head sometimes distinctly
depressed and mouth-parts directed cephalo-ventrad; thoracic legs small,
modified, number of segments reduced to four or to one, legs sometimes
entirely fleshy, conical, or mamma-like, with or without tarsal claws;
abdomen with very small larvapods or larvapods nearly obsolete; mouth-
parts sometimes modified, labial and maxillary palpi with reduced number
38 ILLINOIS BIOLOGICAL MONOGRAPHS (356
of segments; annulation sometimes obsolete. A few subfamilies of
Tenthredinidae.
Nest-builders. — Thorax with seta-like segmented legs; abdomen without
larvapods; antennae long, setaceous, seven-segmented; mouth-parts nor-
mal; ultimate segment with distinct subanal appendages and a minute
hook-like caudal process on caudo-meson of tergum; ocellarae present;
web-spining leaf-rollers, Pamphiliidae. -
Borers. — Thorax with rudimentary legs, tarsal claws never present;
abdomen without larvapods, ultimate segment with a distinct suranal
process or with a pair of subanal appendages; mouth-parts somewhat
modified, maxillary and labial palpi reduced in number of segments;
ocellarae wanting or with vestigial eye-spots; metaspiracles sometimes
functional, as large as abdominal ones; wood-borers and stem-borers.
Siricidae, Xiphydriidae, and Cephidae.
Parasites. — Body grub-like, thoracic and abdominal legs wanting;
mouth-parts modified, maxillary and labial palpi obsolete; ocellarae
wanting; antennae one-segmented; parasitic larvae, Oryssidae.
The larvae of the typical Tenthredinoidea are readily differentiated
from the larvae of other Entometabola by the presence of a single ocellara
on each side of the head and, usually, six or more pairs of larvapods, none
of which are provided with crotchets, and never occur on first and ninth
abdominal segments. The characteristic mouth-parts include four-
segmented maxillary palpi and three-segmented labial palpi. The character
of the antennae, the number of ocellarae and larvapods, the charac-
ter of the mouth-parts, especially maxillary and labial palpi, and the
presence of thoracic legs distinguish the leaf-miners and wood-borers of
the Tenthredinoidea from other leaf-miners and wood-borers, such as
certain Lepidoptera, Coleoptera, and Diptera. The larvae of Hymenop-
tera other than Tenthredinoidea are distinguishable from those of the
latter as follows: They are apodous, thoracic and abdominal legs being
always wanting; the mouth-parts are vestigial, maxillary and labial
palpi, if present, papilliform, never distinctly segmented; ocellarae are
never present; and suranal process and subanal appendages are always
wanting. The larvae of the Oryssidae are separable from other hymen-
opterous larvae on the basis of the characters used in the definition of that
family elsewhere.
FAMILIES OF TENTHREDINOIDEA
1(6) Thoracic legs present, either normal in form, distinctly segmented, or modified, if
modified, fleshy or conical, if conical, head and body distinctly depressed; larvapods
either present or wanting 2.
2(5) Thoracic legs normal in form, not seta-like, rarely mamma-like; larvapods usually
present; subanal appendages wanting; antennae usually with less than seven seg-
ments 3.
357] LARVAE OF THE TENTHREDINOIDEA—YUASA 39
3(4) Larvapods present on all abdominal segments; antennae with six or seven segments.
XYELIDAE.
4(3) Larvapods not present on all abdominal segments; antennae never with more than five
segments TENTHREDINIDAE.
5(2) Thoracic legs seta-like; larvapods wanting; subanal appendages present, setaceous;
antennae very long, with seven segments PAMPHILIIDAE.
6(1) Thoracic legs vestigial, not distinctly segmented, mamma-like or wanting, if mamma-
like, head and body never distinctly depressed; larvapods wanting 7.
7(12) Thoracic legs present; ultimate segment with suranal process 8.
8(9) Subanal appendages present, vestigial, papilliform; ocellarae present; antennae
with four or five segments CEPHIDAE.
9(8) Subanal appendages wanting; ocellarae wanting 10.
10(11) Antennae with three segments; metaspiracles functionless, very much smaller than
abdominal spiracles 11.
XIPHYDRIIDAE.
11(10) Antennae with one segment; metaspiracles functional, as large as abdominal spir-
acles SIRICIDAE.
12(7) Thoracic legs wanting; ultimate segment without suranal process and subanal
appendages ORYSSIDAE.
MacGillivray (1906) divided the superfamily Tenthredinoidea into
nine families. They are the Xyelidae, Pamphiliidae, Blasticotomidae,
Tenthredinidae, Xiphydriidae, Siricidae, Megalodontidae, Cephidae, and
Oryssidae. The first two families constitute his Generalized Tenthredinoi-
dea and the last six his Specialized Tenthredinoidea. Since the Blastico-
tomidae and Megalodontidae belong to the Palearctic fauna and are not
represented in North America, they are omitted from the foregoing table.
Family Xyelidae
Larvae (Fig. 6) of medium size, length 13-18 mm.; body caterpillar
like, subcylindrical, flattened on the ventral aspect, uniform in diameter'
except last two segments which are suddenly constricted, stout; segmenta-
tion and usually annulation distinct; cuticle smooth, tuberculate and
setiferous, but never slimy; color greenish, yellowish, whitish, or brownish;
tubercles, when present, brownish or blackish and setiferous; prothorax
sometimes with a pair of lateral eversible cervical glands in the cervacoria;
head circular in frontal contour, moderately large, width usually more
than one-half the diameter of the thorax; mouth directed ventrad; head
slightly overlapped by the prothorax, if any setae, sparsely and inconspi-
cuously setiferous; antennae long, conspicuous, with six, sometimes
seven, segments; ocularia about one-fifth the diameter of the antennaria
and located caudo-dorsad of it, elevated, ocellarae very small; epicranial
suture and vertical furrows present; mouth-parts normal in form; pro-
thorax with a large, often colored, shield-like area on the dorsum and
lateral aspects; legs in comparison with the size of the body very small,
normal in form, all three pairs subequal in size; larvapods present on all
40 ILLINOIS BIOLOGICAL MONOGRAPHS [358
abdominal segments including the first and ninth, where they are some-
times reduced in size; typical segments with four annulets; spiracles on the
second annulet; sublateral lobe produced ventrad, modified into a triangu-
lar lobe laterad of larvapod which it resembles in form; ninth abdominal
tergum with three annulets; tenth abdominal tergum constricted distinctly
and transversely on its cephalic fourth and with a distinct hump-like protu-
berance on the meson caudad of the cephalic constriction, concolorous with
the head and setiferous tuberlces; anal larvapods and ventral or subanal
lobes distinctly large, contiguous, forming a trilobate prominence on the
meson of the tenth sternum; subanal lobe with a pair of setiferous protu-
berances dorsad of larvapods; insects single-brooded, solitary, chiefly
exposed-feeders; pupate in earthen cells in the ground.
The Xyelidae is a small family consisting of seven genera and of
a limited number of species, most of which belong to the North American
fauna. The adults are readily distinguished from all other Hymenop-
tera by the presence of the free part of the vein R 2 in the wings. On
venational characters, MacGillivray (1906) considers the members of this
family to be the most generalized Hymenoptera known, having, "departed
from the type of the wing assumed for the original progenitor of the
Hymenoptera only in the loss of the free part of vein Cu2." The genera,
at the same time, possess many features of prominent progressive speciali-
zations which have proceeded in each case in a different sequence so that
a linear arrangement of the genera does not express their true affinities.
Over twenty-five species have been reported from boreal America.
Of this number, four species belonging to as many genera have been recog-
nized in the larval state. Another unidentified species, feeding on pecan,
is added in this paper. Dyar (1898) described the larvae of Megaxyela
major and Xyela minor and gave a definition of the family based on charac-
ters found in these species. He pointed out that they are most nearly
related to the Pamphiliidae. The larvae of Odontophyes aviingrata were
described by the same author (1899). Konow (1901) overlooked Dyar's
1898 paper and gave in his analytical table for the larvae Odontophyes
aviingrata as the sole representative of the subfamily Xyelini. That
Konow was unfamiliar with any xyelid larvae may be reasonably assumed
from the fact that he classified them with those larvae which had no
larvapods and that he placed a question mark before the analytical item
"ohne Afterborsten." The larvae of Pleuroneura, Paraxyela and Proto-
xyela are unknown. The described larvae feed on the foliage of hickory,
butternut, pecan, elm, and the staminate flowers of pine.
The most important materials that I had in the study of this family
were received from Professor R. W. Harned, of the Mississippi Agricultural
College, but, altogether, the material at hand is so limited that it does
359] LARVAE OF THE TENTHRED1N01DEA—YUASA 41
not permit a characterization of the genera. The following key will serve to
separate the species:
1 (8) Larvapods present on all abdominal segments, those on the first and ninth segment
sometimes rudimentary; thoracic legs normal in form; body tuberculate, tubercles
setiferous, concolorous with the head; head creamy or brownish or blackish; abdom-
inal segments typically with four annulets, first annulet smooth, non-tuberculate,
crescentic, and confined to the dorsal aspect, three following annulets convex, with
transverse row of setiferous tubercles; not on staminate flowers of conifers 2.
2(7) Head dark-colored, brownish or blackish; tenth abdominal tergum always and
prothoracic and ninth abdominal terga usually with dark-colored patches; tenth
tergum brownish or blackish; subanal lobe with a pair of wart-like brown tubercles
which bear blackish brown setae on the dorsal and lateral aspects, less densely on
the ventral aspect; dorsal tubercles arranged typically as follows: the second and
third annulets with four to five, the fourth annulet with two or three; the subspiracu-
Iar and surpedal lobes, each with a tubercle; the dorsal tubercles of the second annu-
let with one to three setae 3.
3(6) Tubercles of typical abdominal segment arranged as follows: second and third
annulets with four tubercles above the spiracular line, each tubercle bearing one
seta, the fourth annulet with two tubercles, one on the spiracular line with two setae,
the other, dorsad of the line, with one seta; on hickory and pecan 4.
4(5) Prothoracic tergum with a large dark brown, median patch whose lateral margins
converge toward the cephalic margin, which is one-half as long as the caudal margin;
the ninth abdominal tergum with a large dark brownish patch on each side of the
meson, the patches converging toward the caudal margin so that the caudal halves
are nearly confluent on the meson with a pair of brownish tubercles btween the
cephalic halves; tenth abdominal tergum almost completely dark brown in color;
the first annulet of typical segment with the dorsal pair of tubercles quadrate, one-
half as long as the annulet; abdomen with a brownish, cloudy, longitudinal dorso-
lateral line involving the dorsal pair of tubercles and extending usually from the
second abdominal segment to the seventh; on hickory and pecan; Y-226, G
Megaxayela major Cresson.
5(4) Prothoracic tergum without a large dark brownish median patch, but with a pair of
small blackish patches distinctly separated on the meson of the first and second
annulets, the cephalic pair larger, triangular, and their apices directed laterad, the
caudal pair subquadrate, further apart than the cephalic pair; the ninth abdominal
tergum without a pair of large dark brownish patches but with two pairs of small
blackish patches, distinctly separated on the meson, the cephalic pair smaller and
slightly further apart than the caudal pair; tenth tergum blackish, with its cephalic
constricted portion pale or creamy; first annulet of typical abdominal segment with
the dorsal pair of tubercles subcircular, one-third as long as the annulet; abdomen
without a brownish, cloudy longitudinal dorso-mesal lines; on pecan; Y-227
Megaxyela sp. 1.
6(3) Tubercles of a typical abdominal segment arranged as follows: second and third
annulets with four to five tubercles above the spiracular line, each tubercle bearing
two setae; the fourth annulet with three tubercles, one on the spiracular line and the
other two dorsad of it, each tubercle with two setae; on hickory and butternut;
Y-228 ; Odontophyes aviingrata Dyar.
7(2) Head light in color, creamy white or pale brown; the prothoracic and the ninth
and tenth abdominal terga without dark-colored patches; tenth tergum light brown;
subanal lobe with a pair of wart-like creamy tubercles which bear long light brown
42 ILLINOIS BIOLOGICAL MONOGRAPHS [360
setae, uniformly distributed on all aspects; tubercles arranged as follows: the second
and third annulets with four tubercles dorsad of the spiracular line, the second
tubercle dorsad of the ventral one sometimes rudimentary and often represented by
a single tiny seta, the fourth annulet with two tubercles, one on the spiracular line
and the other dorsad of it, the sublateral area divided into three lobes and each
with one tubercle; the dorsal pair of tubercles of the first annulet with four to five
setae; on Ulmus; G Macroxyda ferruginea Say.
8(1) Larvapods very small; thoracic legs rudimentary; body not tuberculate; head
creamy white ; abdominai segments typically with three annulets; on stamina te flowers
of pine (Dyar in 1898 described no larvapods) Xyda minor Dyar.
Family Blasticotomidae
The Blasticotomidae contains a single genus and species, Blasticotoma
filiceti Klug, which is confined to central and eastern Europe. It is an
archaic type. The systematic position of this unique species has been
considered differently by practically every writer who has studied it.
MacGillivray (1906) has shown, however, that it is in certain of its charac-
ters closely allied to the Xyelidae and Pamphiliidae, while in others it
approximates the Tenthredinidae, and that, it is intermediate in position
between these two groups.
Because of its taxonomic position, it is highly desirable to know the
characters of the larvae of this species, but unfortunately the literature is
void of information in regard to the immature stages, and this interesting
quest must await future discoveries.
Family Tenthredinidae
Larvae (Figs. 7-25) very small to very large, length 10-40 mm.; cater-
pillar-like, leaf -feeders, leaf-miners, or fruit-borers; body cylindrical,
thorax usually largest in diameter, body tapering caudad, sometimes
flattened on the ventral aspect, leaf-miners depressed; greenish or variously
colored with or without distinct markings; smooth, glabrous, setiferous,
tuberculate, or spinous; segmentation usually and annulation sometimes
distinct; third abdominal segment with 6, 7, 5, 4, 3, or 2 annulets, men-
tioned in the order of frequency; some of annulets usually setiferous and
often with glandubae; thoracic legs always present, usually well developed,
typically with five segments, sometimes with three, four, or six segments,
but always with distinct tarsal claws; legs rarely rudimentary, fleshy,
indistinctly segmented, and without tarsal claws; larvapods present
usually on abdominal segments 2-7 and 10 or 2-8 and 10, occasionally the
seventh and tenth pairs wanting, rarely with all larvapods obsolete; head
typically semiglobose, setiferous, with or without distinct markings or uni-
formly brownish, blackish, or greenish; antennae always present, never with
more than five segments; ocellarae always present, one on each side;
361] LARVAE OF THE TENTHREDINOIDEA—YUASA 43
maxillary and labial palpi typically with four and three segments respec-
tively, never obsolete, number of segments rarely reduced; clypeus usually
with two or three setae on each side; mandibles usually with one to four
setae; tenth abdominal tergum without suranal process and sometimes
with caudal protuberances; subanal appendages never present; epicranial
suture and vertical furrows usually present; metaspiracles functionless,
obsolete, or very much smaller than abdominal spiracles; various glands
sometimes present.
The family Tenthredinidae according to MacGillivray contains twenty-
four subfamilies of which five are not represented in the Nearctic
fauna. The subfamilies found in the United States and Canada are as
follows: Diprioninae, Emphytinae, Selandriinae, Dolerinae, Phyllotominae,
Lycaotinae, Tenthredininae, Cimbicinae, Hoplocampinae, Dineurinae,
Monocteninae, Cladiinae, Nematinae, Blennocampinae, Fenusinae, Sco-
lioneurinae, Hylotominae, Schizocerinae, and Acordulecerinae. Of these,
Lycaotinae and Dineurinae have not been available for study.
SUBFAMILIES OF TENTHREDINIDAE
1(42) Thoracic legs normal in form, five-segmented; if modified, tarsal claws always
present; larvapods usually well developed 2.
2(23) Larvapods present on abdominal segments 2-8 and 10; antennae elongate, conical,
usually with five segments 3.
3(20) Thoracic legs with five segments, normal in form 4.
4(11) Third abdominal segment with six annulets on dorsum 5.
5(10) Antennae conical, with five segments 6.
6(9) Labrum bilaterally symmetrical; legs with tibia shorter than femur, tarsal claws
short, strongly curved 7.
7(8) Body rather slender, tapering caudad, without small distinct tubercles; tenth
abdominal tergum without small tubercles; head never shiny, jet-black, body never
yellowish white EMPHYTINAE (in part).
8(7) Body rather robust, uniform in diameter thruout, with small distinct tubercles; tenth
abdominal tergum with several small protuberances, if without, head shiny, jet-
black, body yellowish white BLENNOCAMPINAE (in part).
9(6) Labrum not bilaterally symmetrical, but distinctly asymmetrical; legs with tibia
longer than femur, tarsal claws slender, only slightly curved DOLERINAE.
10(5) Antennae not conical, with three segments, the third segment erect and peg-like.
DIPRIONINAE.
11(4) Third abdominal segment with more or less than six annulets on dorsum 12.
12(19) Third abdominal segment with seven annulets on dorsum; body without conspicuous
branched spines or tubercles 13.
13(18) Antennae conical, with five segments; labrum without secondary longitudinal
sutures 14.
14(15) Larvapods setiferous; clypeus with three setae on each side; mandible with two
setae; labrum without a median longitudinal depression . . SELANDRIINAE (in part) .
EMPHYTINAE (in part).
15(14) Larvapods glabrous; clypeus with two setae on each side; mandible with 1-4 setae;
labrum with or without a median longitudinal depression 16.
44 ILLINOIS BIOLOGICAL MONOGRAPHS (362
16(17) Legs with tibia minute, distinctly shorter and smaller than femur; maxillae with
stipes without cephalo-ventral triangular projection; mandibles with two setae;
labrum without a median longitudinal depression 17.
SELANDRIINAE (in part).
17(16) Legs with tibia large, usually subequal to or longer than femur; maxillae with stipes
with cephalo-ventral triangular projection; mandibles with 1, 2, or 3-4 setae; labrum
with or without a median longitudinal depression TENTHREDININAE.
18(13) Antennae not conical, with one segment; labrum with secondary longitudinal
sutures; small but distinct crescentic glandubae dorsad of spiracles. CIMBICINAE.
19(12) Third abdominal segment with five, rarely three or four, annulets on dorsum;
body with conspicuous branched spines or tubercles. BLENNOCAMPINAE (in part) .
20(3) Thoracic legs with four segments, modified 21.
21(22) Tenth urotergum and prothoracic and mesothoracic tergites with conspicuous fleshy
pointed protuberances; body not tadpole-like EMPHYTINAE (in part).
22(21) Tenth urotergum and prothoracic and mesothoracic tergites without conspicuous
fleshy pointed protuberances; body often distinctly tadpole-like.
PHYLLOTOMINAE (in part).
23(2) Larvapods on abdominal segments 2-7 and 10, rarely on segments 2-7 or 2-6 and
10 24.
24(39) Thoracic legs with five segments, normal in form; larvapods on segments 2-7 and
either with or without anal larvapods 25.
25(36) Larvapods present on the ultimate segment, either normal and separated or fused
on the meson, forming a single prominence 26.
26(35) Anal larvapods normal and separated 27.
27(28) Antennae with five segments; third abdominal segment with six annulets; tenth
abdominal tergum with several caudal protuberances. HOPLOCAMPINAE (in part).
28(27) Antennae with four, rarely three, segments; third abdominal segment usually
with less than six annulets; tenth abdominal tergum with or without caudal protu-
berances 29.
29(32) Abdominal segments 1-7 on ventro-meson with an eversible gland; body often with
numerous conspicuous setae, setae arising from distinct tubercles; antennae with four
segments 30.
30(31) Body with numerous conspicuous multisetiferous tubercles, each tubercle bearing
several long setae, some of which are distinctly longer than others; third abdominal
segment with four annulets, annulet 1 with a transverse row of setae, annulets 2 and
3 with a transverse row of setiferous tubercles; tenth abdominal tergum never with
caudal protuberances altho with numerous long setae; setae barbed . CLADIINAE.
31(30) Body without numerous conspicuous multisetiferous tubercles, if tubercles present,
they do not bear several long setae some of which are distinctly longer than others;
third abdominal segment with varying number of annulets; tenth abdominal tergum
sometimes with caudal protuberances; setae not barbed NEMATINAE.
32(29) Abdominal segments 1-7 on ventro-meson without an eversible gland; body never
conspicuously setiferous; antennae with three or four segments; third abdominal
segment with three or five annulets 33.
33(34) Antennae with four segments; third abdominal segment with five annulets; abdom-
inal segments 2-4 and 8 or 2-5 and 8 without a postsubspiracular sucker-like pro-
tuberance HOPLOCAMPINAE (in part).
34(33) Antennae with one segment ; third abd ominal segment with three annulets ; abdominal
segments 2-4 and 8 or 2-5 and 8 each with a postsubspiracular sucker-like protuber-
ance ACORDULECERINAE.
363] LARVAE OF THE TENTHREDINOIDEA—YUASA 45
35(26) Anal larvapods united on the meson forming a single protuberance; antennae with
one segment; third abdominal segment with two annulets; prothorax often with
dorsal and ventral shields; vertical furrows wanting; head and body depressed,
glabrous SCOLIONEURINAE.
36(25) Larvapods wanting on ultimate segment; vertical furrows wanting 37.
37(38) Antennae with three segments; third abdominal segment with four annulets, annulets
2 and 3 setiferous; tenth abdominal tergum with a caudo-mesal protuberance; body
not depressed HOPLOCAMPINAE (in part).
38(37) Antennae with 1-2 segments; third abdominal segment with two annulets, annulets
glabrous; tenth abdominal tergum without a caudo-mesal protuberance; body
depressed FENUSINAE.
39(24) Thoracic legs with 3-4 or 6 segments; larvapods on abdominal segments 2-7 and 10
or 2-6 and 10, very small 40.
40(41) Mesothoracic and meta thoracic legs with six segments; prothoracic legs with six
segments; larvapods on abdominal segments 2-7 and 10 and occasionally with a
rudimentary eighth pair, or 2-6 and 10; body dilated laterad, sublateral lobe pro-
duced and conspicuous, often with numerous setiferous tubercles. HYLOTOMINAE.
41(40) Mesothoracic and metathoracic legs with three segments; prothoracic legs with
four segments; larvapods on abdominal segments 2-7 and 10 with an occasional
rudimentary eighth pair; body not dilated laterad, sublateral lobe not produced
and conspicuous; body never with numerous setiferous tubercles but with minute
protuberances SCHIZOCERINAE.
42(1) Thoracic legs not normal in form, but fleshy, indistinctly four-segmented, tarsal
claws wanting; larvapods vestigial on abdominal segments 2-8 and 10, ultimate
pair united on the meson, forming a single protuberance
PHYLLOTOMINAE (in part) .
Subfamily Diprioninae
Larvae (Fig. 7) moderately large, length 18-25 mm.; body cylindrical,
somewhat robust, tapering gradually caudad; segmentation and annula-
tion distinct; third abdominal segment with six annulets, annulets 1, 2,
and 4 or 2 and 4 with setae and glandubae; larvapods on abdominal
segments 2-8 and 10, close together on the meson; thoracic legs normal,
well developed, with five segments; prothoracic legs distinctly smaller than
other legs; color of body usually yellowish or greenish, with grayish, or
brownish stripes or rows of black spots; antennae with three segments, seg-
ments 1 and 2 minute, flat, irregular, incomplete, segment 3 erect, peg-like,
strongly chitinized; head and legs usually with spinous, stiff setae; glandu-
bae prominent and numerous; ventral glands wanting; spiracles not winged;
cuticle microscopically spinulate; larvae feed on conifers.
The subfamily Diprioninae is represented in North America by three
genera, Diprion, Neodiprion, and Monoctenus. The Neartic species
formerly placed in the genus Diprion (Lophyrus) are placed by Rohwer
(1918a) in Neodiprion. Diprion simile Hartig of Europe has recently
become established in the United States. With the exception of Mac-
Gillivray, systematists agree in associating the genus Monoctenus with
Diprion and its allies.
46 ILLINOIS BIOLOGICAL MONOGRAPHS [364
The three genera studied can be separated as follows:
1(2) Body large, stout, longer than 24 mm.; markings mottled with dark brown and
yellowish irregular spots, without brownish stripes or black spots; setae on head
small, slender, those on genae similar to other setae, not spinous; head blackish.
Diprion Schrank.
2(1) Body smaller, slender, usually shorter than 24 mm.; markings not mottled, but with
brownish longitudinal stripes or rows of black spots 3.
3(4) Third abdominal segment with annulets 1, 2 and 4 with setae and glandubae; setae
on head stiff, long, spinous, those on genae often very large and spinous
Neodiprion Rohwer.
4(3) Third abdominal segment with annulets 2 and 4 with setae and glandubae; setae on
head microscopic, and very few in number Monoctenus Dahlbom.
Neodiprion Rohwer
Larvae rather large; length about 19-24 mm.; body slender, with longi-
tudinal brownish stripes or rows of black spots along subdorsal, supra-
spiracular, and sometimes subspiracular lines; head round in contour,
cephalic and caudal margins parallel in profile; front flattened, subpenta-
gonal, as high as wide; ocularia large; antennaria subequal in diameter to
ocularia, their own diameter apart; lab rum semicircular, with small
crescentic median emargination; mandibles sharply dentate, the dextral
with four dentes and the sinistral with five; maxillary palpi large, four-
segmented, segments 1-3 ring-like, successively diminishing in diameter,
segment 4 suddenly and distinctly smaller than the preceding segment,
conical, bluntly pointed; galea chitinized, digit-like, smaller than palpi;
lacinia thick, lobate, bearing a minute triangular blade-like seta on ventro-
mesal angle, a stiff seta on dorso-mesal angle, and a row of three to five
minute setae on the oblique cephalo-mesal margin; labial palpi normal,
segment 2 usually longest, segment 3 conical, suddenly and distinctly
smaller than preceding segment; totaglossa with dorso-cephalic depression
on the meson and with several minute sensory pits; parapharynx distinct,
linguiform, constricted dorsad of the middle by a pair of chitinized pieces;
thoracic legs well developed, normal in form, usually blackish, segments
strongly chitinized, coxae largest, trochanter ring-like, chitinized on the
caudal two-thirds, with a whorl of setae, distad of setae membranous,
femur smaller than trochanter in diameter, entirely chitinized, wider than
long on dorsal aspect, increasing in diameter distad, tibia subequal in length
to femur but smaller in diameter, tarsal claws small, basal portion of claw
undeveloped, all segments of leg membranous on the ventral aspect,
prothoracic legs one-half the size of metalegs, mesolegs slightly smaller
than the latter; third abdominal segment with annulation formula, 2, 1,
(3, 5, 6), 5; spiracle on annulet 2, annulets 1, 2 and 4 with a transverse
row of slender, cylindro-conical glandubae, annulet 2 with a few micro-
scopic setae; substigmatal and surpedal lobes large, with several glandubae
365] LARVAE OF THE TENTHREDINOIDEA—YUASA 47
and a few setae; larvapods well developed, distal surface incurved mesad,
rather dilated, not pointed, distance between the pair at the base less
than the length of larvapod, venter with four annulets; tenth abdominal
tergum gradually convex, with glandubae; anal setae numerous, small;
spiracles elongate and oblong.
SPECIES OF NEODIPRION
1(10) Head black, light grayish or brownish, never uniformly reddish brown or orange;
body longitudinally striped or spotted 2.
2(3) Body with four longitudinal rows of black spots along subdorsal and supraspiracular
lines; tenth abdominal tergum with cephalic two-thirds entirely black; spots on each
side of dorso-meson elongate, wider at cephalic end; spots on supraspiracular line
large, subquadrate; spots onprothorax obsolete; body yellowish white; length, 22 mm. ;
on Pinus; Y-221, G-573, C-l, 1-4101 abbotii Leach.
3(2) Body without four longitudinal rows of black spots along the subdorsal and supra-
spiracular lines, but with longitudinal colored bands along each side of the dorso-
meson; latus with longitudinal row of independent segmentally arranged blackish
or brownish spots or with continuous brownish bands 4.
4(5) Body with a row of brownish spots along supraspiracular lines, spots segmentally
arranged, one on each segment, often those on middle segments obsolete, sometimes
all spots obsolete; tenth abdominal tergum with a pair of large blackish or brownish
spots which are all sometimes contiguous on meson; subdorsal bands narrower than
the distance between them; larvapods marked faintly along pedal line when supraspir-
acular spots are distinct; head black; length, 23 mm.; G-1686-2, -5. Neodiprion sp. 1.
5(4) Body with broad longitudinal bands along supraspiracular lines, instead of rows of
segmentarly arranged spots 6.
6(7) Subspiracular lines with broad brownish bands; head black; pedal lines also marked
brown; tenth abdominal tergum faintly marked; subdorsal bands much wider than
the distance between them; these bands much lighter in color than those on latus;
body dull greenish; length, 21 mm.; on spruce; G-791 abietis Harris.
7(6) Subspiracular lines without brownish bands; head light brown, brown, or pale
creamy yellow; subdorsal bands very narrow or very wide; pedal lines with or
without bands 8.
8(9) Pedal lines with distinct brownish bands; tenth abdominal tergum unmarked except
along caudal margin; subdorsal bands very much wider than the distance between
them, lighter in color; head blackish or brownish with brown marks on vertex and
front or pale brown; length, 19 mm.; G-156 Neodiprion, sp. 2.
9(8) Pedal lines without distinct brownish bands; tenth abdominal tergum marked,
entirely concolorous with head; subdorsal bands very narrow, usually narrower than
the distance between them; head light brown or pale creamy white with vertex
shaded grayish; length, 19 mm.; G-1686-3, -6, -7 Neodiprion sp. 3.
10(1) Head reddish brown or orange; body spotted; subdorsal and supraspiracular lines
with black spots 11.
11(12) Subspiracular and pedal lines with black spots; spots on subdorsal lines tapering
caudad, partly broken between annulets; spots along supraspiracular lines large,
subquadrate; spots on subspiracular lines smaller, sometimes very small but never
obsolete; spots on pedal lines very small, sometimes obsolete; tenth abdominal
tergum with a pair of large black spots which sometimes fuse on the meson; length,
25-28 mm.; G-1554, -1686-8, -593, C-cue-315, C-Young-37 lecontei Fitch.
48 ILLINOIS BIOLOGICAL MONOGRAPHS {366
12(11) Subspiracular and pedal lines without black spots; spots on subdorsal lines small,
often not distinctly tapering caudad; tenth abdominal tergum with a pair of large
black spots; length, 20 mm.; G-133 Neodiprion, sp. 4.
MONOCTENUS DAHLBOM
Larvae rather small; length about 15 mm.; body slender, dorsum
with diffuse brownish shade or with longitudinal stripes; third abdominal
segment with annulets 2 and 4 with setae and glandubae; head as in Neo-
diprion except that setae are minute and sparse; clypeus and lab rum with
two setae on each side; labrum with small crescentic median emargination;
maxillary palpi large, rather slender, segments 1-3 ring-like, subequal in
length but successively smaller in diameter; galeae and laciniae as in Neo-
diprion; labial palpi rather slender, its segments subequal in length; man-
dible with one mandibular seta; antennae with segment 1 complete, very
narrow, oval, segment 2 flat, incomplete, irregular, segment 3 peg-like,
erect; glandubae conical, distinct; setae microscopic; sublateral lobes not
well developed; annulation typically (1, 2), (3, 4, 5, 6), anal setae numer-
ous, short, and minute; telson with glandubae obsolete.
MacGillivray established in 1906 the subfamily Monocteninae for
the genus Monoctenus associating it with the Cladiinae and Nematinae,
thus deviating from the universal practice of regarding the genus Monoc-
tenus as a member of the subfamily Diprioninae or its equivalent. On
the basis of the venation, MacGillivray's contention is quite justifiable,
and it is most interesting to know what larval characters would indicate
in regard to the relationship between Monoctenus and Diprion and its
allies. Marlatt (1887) published notes on the immature stages of Monoc-
tenus unicolor but his descriptions do not touch the detailed anatomy
necessary for the definition of the genus. Recently, however, I was
fortunate enough, thru the courtesy of Mr. Rohwer, to examine a speci-
men belonging to the United States National Museum which Rohwer
considered to belong to a new species of Monoctenus. A careful study
of this larva convinced me that [so far as this species is concerned] there
are no essential differences between the larvae of Monoctenus and those
of the typical Diprioninae to justify the creation of a new subfamily.
For this reason I have followed the universal practice and decided to
treat Monoctenus as a member of the Diprioninae.
Monoctenus n. sp. Rohwer. — Length, 14 mm., head-width 1.5 mm.;
head brownish; body on dorsum dorsad of spiracular lines, segments of legs,
episternum and epimeron, deep brown; glandubae elongate, conical,
minute, brownish at tip; on cedar.
A specimen bearing the label "5419 Sawfly on cedar, Cadek, Mo.,
June 10, 1892."
367] LARVAE OF THE TENTHREDINOIDEA—YUASA 49
DlPRION SCHRANK
As far as known, only one species is represented in North American
fauna. An examination of D. simile shows that this genus is not very-
different from the other genera of Diprioninae but may be separated from
them by the characters of the setae and coloration of the head, and certain
minor points. It is not possible to characterize the genus with the material
at hand.
Diprion simile Hartig. — Body robust, length, 25 mm.; latus with a series
of yellowish or whitish spots on a uniformly grayish brown background,
dorso-meson with a narrow yellowish stripe bordered on each side by an
equally narrow grayish brown band; dorso-lateral lines broadly yellowish,
interrupted at each annulet by fine transverse lines; supraspiracular
lines with three yellow spots, size of spots increasing caudad; dorsad of these,
three smaller spots with the middle one largest and subequal to cephalic
spot of supraspiracular lines; three spots on subspiracular lines, the middle
one being the largest; pedal lines with a large spot on each segment;
larvapod with a brownish spot; tenth abdominal tergum and sternum
marked with grayish; the tergum with a deep constriction dorsad of suranal
lobe; head setae small, slender, hair-like, never spinous or stiff; setae on
genae similar to those on front, never stiff and spinous; legs with femur
sometimes longer than wide on the dorsal aspect; head black; body yellow-
ish gray, mottled; G.
Subfamily Emphytinae
Larvae (Fig. 8) small to moderately large, usually greenish, sometimes
striped; body cylindrical, slender, tapering caudad; segmentation distinct,
annulation fine, indistinct; third abdominal segment usually with six, rarely
seven, annulets, annulets 2 and 4 or 1, 3, 5 and rarely 1, 3, and 6 setiferous;
head greenish or brownish; sometimes with spots on vertex and front;
labrum with or without a mesal longitudinal depression, with 4-5 labral
setae on each side of the meson; clypeus with 2 or 3 setae on each side;
mandibles with one seta rarely with two; larvapods on abdominal segments
2-8 and 10, well developed, usually glabrous, rarely setiferous; ventral
glands wanting; glandubae small, conical, on annulets 1 and 3 or rarely
on 2 and 4; tenth abdominal tergum usually setiferous but without paired
caudal protuberances, rarely with conspicuous spines on the caudal margin,
if spines present, then prothorax and mesothorax on dorsum with two and
one protuberances respectively; antennae elongate-conical, with five seg-
ments, segments ring-like; thoracic legs usually normal in structure, with
femur subequal in length to or slightly longer than tibia, tibia well devel-
oped and normal, femur with its disto- ventral angle produced; legs, when
modified, short, stout, and trochanter obsolete; mouth-parts normal in form,
spiracles not winged; larvae leaf -feeders.
50 ILLINOIS BIOLOGICAL MONOGRAPHS [368
The Emphytinae is a large subfamily embracing a number of genera
and numerous species. MacGillivray considers this the second subfamily
of his generalized Tenthredinidae and places it between the Diprioninae
and Selandriinae. The larvae of this subfamily are found readily and in
general appearance and habitus resemble very closely the larvae of the
Selandriinae and Tenthredininae, but they can be separated by the number
of annulets, which in this subfamily, with the exception of Hemitaxonus
and Epitaxonus, is six, while in the other two subfamilies it is seven. The
two genera mentioned are characterized by the presence of seven annulets
on the typical abdominal segment and also by the setiferous larvapods,
thus resembling in these two particulars the larvae of the Selandriinae.
It is of interest to note that Rohwer would associate Hemitaxonus with
such genera as Selandria, Eriocampoides, etc., in the tribe Selandriini of
his subfamily Selandriinae. Middleton (1915) has published a definition
of the genus Dimorphopteryx together with a key for the separation of
three species.
The writer has collected a large number of larvae belonging to this
subfamily, but on account of the difficulty of breeding adults many
species remain unidentified. In the preparation of the synoptic key to the
genera and in discussions following, only bred or otherwise identified
species have been considered, the consequence being that future study may
require much modification in our conception of the various genera dealt
with.
GENERA OF EMPHYTINAE
1(4) Third abdominal segment with 7 annulets; larvapods setiferous 2.
2(3) Larvapods with 5-3-1 setae on cephalic, lateral, and caudal aspects respectively;
thoracic legs with femur longer than or subequal to tibia; labial palpi with segment
2 longer than segment 1 ; maxillary palpi with segments subequal in length
Hemitaxonus Ashmead.
3(2) Larvapods with 8-5-1 setae on cephalic, lateral, and caudal aspects respectively;
thoracic legs with femur shorter than tibia; labial palpi with segments subequal to
each other in length; maxillary palpi with segment 2 longer than segment 1
Epitaxonus MacGillivray.
4(1) Third abdominal segment with 6 annulets; larvapods glabrous 5.
5(26) Tenth abdominal tergum and prothoracic and mesothoracic tergites without con-
spicuous fleshy pointed protuberances; thoracic legs normal in form, with trochanters
distinct 6.
6(9) Annulets 1, 2, and 4 setiferous 7.
7(8) Antennae with segment 5 longest; legs with femur longer than tibia; head usually
without markings; labial palpi, if segments not subequal, segment 2 longer than
segment 1 Empria Lepeletier.
8(7) Antennae with segment 1 longest; legs.with femur subequal to tibia; head usually
with markings; labial palpi, if segments not subequal, segment 2 shorter than seg-
ment 1 Parataxonus MacGillivray
9(6) Annulets 2 and 4 setiferous 10.
369] LARVAE OF THE TENTHREDINOIDEA—YUASA 51
10(11) Clypeus with three setae on each side of meson; mandibles with two setae; maxillae
with palpifer produced dorsad as a triangular lobe; labrum with a deep median
emargination with a row of secondary setae caudad of the emargination
Eriocampa Hartig.
11(10) Clypeus with two setae on each side of meson; mandibles with one seta; maxillae
with palpifer not produced dorsad as a triangular lobe; labrum without a deep
median emargination 12.
12(13) Thoracic legs with trochanter longer than tibia. . . .Strongylogaslroidca Ashmead.
13(12) Thoracic legs with trochanter distinctly shorter than tibia 14.
14(15) Body spotted or transversely striped; head dorsad of ocellarae entirely blackish or
brownish; very large and robust larvae Macremphytus MacGillivray.
15(14) Body never spotted or transversely striped; head dorsad of ocellarae not entirely
blackish or brownish; smaller larvae 16.
16(17) Labial palpi with segment 1 longer than segment 2; legs with femur always longer
than tibia; tibia usually twice as long as trochanter; body rather robust; head not
marked distinctly with brown; annulet 4 longest on third abdominal segment
Monostegia Costa.
17(16) Labial palpi with segment 1 shorter than segment 2; legs with femur not always
longer than tibia; tibia always more than twice as long as trochanter; body rather
slender; annulet 4 not longest on third abdominal segment 18.
18(19) Head entirely pale, no markings; legs with femur longer than tibia; body on dorsum
not shaded darker than the venter; tenth abdominal tergum not marked
Monosoma MacGillivray.
19(18) Head not entirely pale, usually with brown spots or markings; legs with femur
not always longer than tibia, often subequal; body on dorsum sometimes shaded
darker than the venter; tenth abdominal tergum often marked 20.
20(21) Legs with femur always longer than tibia; tenth abdominal tergum usually marked ;
body on dorsum usually shaded darker than the venter Emphytus Klug.
21(20) Legs with femur subequal to or shorter than tibia; tenth abdominal tergum usually
unmarked ; body on dorsum not usually shaded darker than the venter 22.
22(23) Tenth abdominal tergum marked with a spot; body on dorsum shaded darker than
the venter; labial palpi with segment 2 longer than segment 1
Unitaxonus MacGillivray.
23(22) Tenth abdominal tergum unmarked; body on dorsum not shaded darker than the
venter; labial palpi with segment 2 subequal to or shorter than segment 1 24.
24(25) Labrum with a distinct median depression Taxonus Hartig.
25(24) Labrum without a distinct median depression Phrontosoma MacGillivray.
26(5) Tenth abdominal tergum and prothoracic and mesothoracic tergites with con-
spicuous fleshy pointed protuberances; thoracic legs not normal in form, with
trochanters obsolete Dimorphopteryx Ashmead.
Subfamily Selandriinae
Larvae (Fig. 9) small to fairly large, length 18-26 mm.; body cylindrical
and gradually tapering caudad; segmentation and annulation distinct and
fine; larvapods on abdominal segments 2-8 and 10; third abdominal
segment with seven annulets, annulets 1, 3, and 5 setiferous, annulets 3
and 5 with glandubae; thoracic legs normal in form except tibia sometimes
very minute; body uniformly greenish, without colored markings; head
with or without brownish spots; antennae with five segments, long, conical;
52 ILLINOIS BIOLOGICAL MONOGRAPHS [370
mouth-parts normal in form, well developed, palpi large; mandibles with
two setae; clypeus with three, sometimes four, setae on each side, rarely
with two; stipes of maxillae with triangular cephalo-ventral projection;
glandubae minute, stalked; spiracles not distinctly winged; larvapods
setiferous, with about ten setae, rarely glabrous.
The Selandriinae includes a limited number of genera. On the basis of
the venation this subfamily is placed next to the Emphytinae where
practically all systematists have placed it. Rohwer's conception of this
subfamily is somewhat different from that of MacGillivray and therefore
he differs from the latter in the disposition of some of the genera. For
example, Hemitaxonus is assigned to the tribe Selandriini while Mac-
Gillivray placed it, together with Epitaxonus, in the Emphytinae. It may
be said that the larvae of these two genera are very closely related to the
Selandriinae and differ from all other Emphytinae in the typical number
of annulets.
GENERA OF SELANDRIINAE
1(4) Thoracic legs with tibia normal in form, never greatly reduced, usually subequal
in length to femur; larvapods setiferous; clypeus with three or four setae on each
side 2.
2(3) Tenth abdominal tergum with brown spots; larvapods usually with ten or more
setae; clypeus usually with three and often four setae on each side; labium deep
brown, with four to six setae on each side; glandubae slightly longer than one-half the
length of adjacent setae; spiracles not winged; larger larvae; length more than
24 mm Tkrinax Konow.
3(2) Tenth abdominal tergum not marked with brown spots; larvapods usually with less
than ten setae; clypeus with three, rarely with four, setae on each side; labium pale
brown or whitish with three to six setae; glandubae usually subequal in length to
adjacent setae; spiracles faintly winged; smaller larvae; length less than 24 mm.
Strongylogaster Dahlbom.
4(1) Thoracic legs with tibia reduced, very much smaller than femur; larvapods glabrous;
clypeus with two setae on each side Sdandria Leach.
Thrinax Konow
Larvae comparatively large, long, length more than 24 mm.; body
slender, finely annulate, uniformly greenish; head and tenth abdominal
tergum with brown markings; thoracic legs normal, tibia and femur
cylindrical, tapering caudad, subequal in length; larvapods with about
ten setae, distributed as follows: 4-5 on cephalic and lateral aspects and
one on caudal; clypeus usually with three and often with four setae on each
side; labrum with four to six setae on each side, deep brown, without
median longitudinal depression; glandubae small, very short, slightly longer
than one-half the length of adjacent setae; spiracles not winged; maxillary
palpi with segments 2 and 4 subequal in length; labial palpi with segment 4
longer than segment 3 ; ninth abdominal tergum with six annulets, annulets
1, 3, and 5 setiferous, annulet 6 a little shorter than the second.
371] LARVAE OF THE TENTHREDINOIDEA—YUASA 53
SPECIES OF THRINAX
Head pale brown with vertex marked with brown on dorsum and caudad of ocellarae,
front with a round brown spot contiguous to ventral apex of the dorsal marking on
the vertex, frontal spot not reaching the fronto-clypeal suture; antennae, mouth-
parts, femur, tibia, and tarsal claw deep brown; tenth abdominal tergum with a
pair of small brown spots; annulation formula, 1, (5, 4, 3), 2, (6, 7); antennae, 5, 4,
3, 2, 1 ; labial palpi with distal two segments subequal; legs with trochanter, femur, and
tibia with lengths to each other as 12, 15, and 16 respectively; tarsal claws with the
proximal portion shorter than the distal narrow curved portion; length 26 mm.;
width of head 2 mm.; on fern; M-18 impressatus Provancher.
Head pale brown with vertex marked with brown on dorsum and caudad of ocellarae,
front with a subquadrate spot contiguous to the ventral apex of dorsal marking of the
vertex, frontal spot reaching the fronto-clypeal suture; antennae, labrum, mouth-
parts, femur, tibia, and tarsal claw deep brown; tenth abdominal tergum with a
pair of large brown spots; annulation, 1(5, 4, 3, 1), (6, 7); antennae, 5, 4, 1, 3, 2;
labial palpi with distal segment longer than the preceding; legs with trochanter,
femur, and tibia with lengths to each other as 12, 15 and 16 respectively; tarsal claws
with the proximal portion as long as the distal curved portion; length 25 mm.;
width of head, 2 mm.; on fem; Y-20-3-1, -20-1 pulatus MacGillivray.
Strongylogaster Dahlbom
Larvae small comparatively speaking, length less than 24 mm. ; body
slender, finely annulate, uniformly green; head pale or light brown or
sometimes with a few spots; tenth abdominal tergum never distinctly
marked; larvapods usually with less than ten setae; thoracic legs normal in
form, femur and tibia subequal to each other or one longer than the other;
labrum pale brown or whitish, with three to six setae on each side; glandu-
bae usually subequal in length to adjacent setae; spiracles often faintly
winged.
SPECIES OF STRONGYLOGASTER
1(2) Head with blackish brown markings, vertex with a pair of diverging spots over the
vertical furrows directed toward ocellarae and a spot caudad of each ocellara;
vertical markings sometimes faint, sometimes very distinct and large, merging into a
continuous vertical marking; front never with spot; antennae, labrum, and mouth-
parts light brown; tenth abdominal tergum usually without markings, rarely with a
pair of faint spots; annulation, 1, 4, (2,3, 5), (6, 7,) ; antennae, 1, 5, (2, 3, 4) ; maxillary
palpi, 2, (1, 4), 3; labial palpi with two distal segments equal in length to each other,
shorter than distal segment of maxillary palpi; labrum with three or four setae on
each side; mandible with two, rarely three, setae; legs with trochanter, femur, and
tibia with lengths to each other as 10, 10, and 12 respectively; uropods with about
eight or nine setae, five on cephalic, 3-4 on lateral, and one on caudal aspect; glandu-
bae long, slender, subequal in length to adjacent setae; spiracles not winged; length
18 mm.; width of head 1.8 mm.; on Pteris aquilina; Y-21 annulosus Norton.
2(1) Head without blackish brown markings, uniformly pale brown 3.
3(4) Trochanter distinctly shorter than femur; labial palpi with distal segment as long
as the preceding segment; head uniformly pale; body and legs uniformly green
without markings; annulation, 1, (3, 4, 5), (6, 7, 2); antennae slender, 5, 1, (4, 3, 2);
maxillary palpi, (2, 1), (4, 3), distal segment longer than that of labial palpi; labrum
54 ILLINOIS BIOLOGICAL MONOGRAPHS (372
and clypeus with four and three setae respectively on each side; larvapods with about
6-8 setae, 4-5 on cephalic, 2-3 on lateral aspect; glandubae subequal in length to
adjacent setae; spiracles with faint brown wings; thoracic legs with trochanter, femur,
and tibia with lengths to each other as 8, 13, and 15 respectively; length, 19 mm.;
width of head, 1.6 mm.; on Pteris aquilina; Y-168-4 tacitus Say.
4(3) Trochanter not distinctly shorter than femur; labial palpi with distal segment shorter
than the preceding segment; head uniformly pale, rarely with a pair of faint spots on
dorsal part of vertex; body uniformly green; legs distad of trochanter brownish;
annulation, 1, (5, 4, 3), (2, 6, 7); antennae, slender, conical, (5, 1), 4, (2, 3); maxillary
palpi, 2, (4, 1), 3, distal segment subequal to that of labial palpi; labrum and clypeus
with four and three setae respectively on each side; thoracic legs with trochanter little
shorter than femur, tibia usually almost as long as femur; length, 21-23 mm.; width
of head, 1.8 mm.; on Pteris aquilina ; Y-18-1, M-32 (in part), M-86. politus Provancher.
Selandria Leach
Larvae comparatively small, length less than 24 mm., usually about
15 mm.; body slender, finely annulate; head pale; body green; tenth
abdominal tergum unmarked; larvapods glabrous; legs very short, with
tibia conspicuously reduced in size, femur distinctly dilated at distal
end, bearing rudimentary tibia on dorsal margin; clypeus with two setae on
each side; mandible with two setae; labrum with three setae on each side;
glandubae very small; spiracles not winged.
Selandria flavipes Norton. — Legs with trochanter ring-like, femur dilated
at distal end, with ventro-mesal projection only slightly narrower in
diameter than trochanter; tibia very small, much smaller in diameter than
femur, appearing as if surrounded by fleshy part of the latter, deep brown
in color; trochanter, femur, and tibia with lengths to each other as 7, 11,
and 6, respectively; annulation, 1, 4, 2, (3, 5, 6, 7); antennae slender, coni-
cal, 5, (1, 2, 4, 3); maxillary palpi, (4, 1, 2), 3; labial palpi with distal
segment subequal in length to segment 1, longer than distal segment of
maxillary palpi; length, 15 mm.; width of head 1.3 mm.; on Pteris aqui-
lina: Y-168, M-70, C-S.f.
Subfamily Dolerinae
Larvae (Fig. 10) moderately large, length, 15-25 mm.; body slender,
cylindrical, tapering uniformly and gradually caudad, either uniformly
greenish or brownish, or dorsum colored darker than venter, never with
bright and distinct patterns; segmentation and annulation distinct; third
abdominal segment with six annulets, annulets 2 and 4 on dorsum seti-
ferous and with glandubae; larvapods on abdominal segments 2-8 and 10;
thoracic legs well developed; head large, as wide as thorax or nearly so;
vertical furrows distinct; antennae five-segmented, conical; labrum
distinctly asymmetrical, dextral part larger than sinistral; head, legs,
larvapods, tenth abdominal tergum, and sternum moderately setiferous;
glandubae present; spiracles not winged; cuticle distinctly, uniformly, micro-
373] LARVAE OF THE TENTHREDINOIDEA—YUASA 55
scopically verrucose on the dorsum and latus between spiracular lines; on
monocotyledonous plants.
The Dolerinae is a well-defined subfamily with a distinct habitus
and is closely allied to the Emphytinae and Selandriinae. The most
important adult character for differentiating the group from other sub-
families of the generalized Tenthredinidae is the coalescence of the cells
R 4 and R5 due to the atrophy of the free part of the vein R 5 . The sub-
family contains two genera, the old genus Dolerus and the recently de-
scribed genus Loderus. Leach separated, under the name of Dosytheus,
all those species having certain antennal peculiarities and, according
to Stephens, also having bright colors on the abdomen. This differen-
tiation was considered invalid by Hartig and his view was endorsed by
Norton and Cameron. Norton described a species under the name of
Dorytheus apricus var. albifrons which is now placed in the genus Loderus.
The monobasic genus Pelmatopus of Hartig, based on P. minutus, is now
considered as congeneric with Dolerus. Since the larvae of Loderus are
unknown, the genus Dolerus alone is considered here.
Dolerus Jurine
Head viewed from cephalic aspect circular in contour in mature
specimens, epicranium semiglobose, front distinctly flattened; mouth-
parts directed caudo-ventrad; antennaria never circular, with obtuse
corners at the angles of their dorsal side; antennae with formula, 5, (3, 4,
2), 1, distal segment conical, apex less chitinized and obtusely rounded,
never sharply pointed, segments 2-5 well chitinized, segment 1 narrow but
distinctly larger in diameter than distal segments; front distinctly wider
than high; labrum asymmetrical, dextral part always larger than sinistral
or with pointed ventro-mesal angle; mandible very thick, large, dextral
with four distadentes and one curved sharp proxadentis, sinistral with
four distadentes and mesal surface deeply emarginate; parapharynx with
apex dilated and chitinized; maxillary palpi, galea, lacinia, and labial
palpi normal in structure and well chitinized; thoracic legs with femur
often produced papilla-like on its disto- ventral angle, tibia long, cylindrical,
tapering uniformly distad, distinctly longer than femur, tarsal claw
rather slender and straight; abdominal segments with six annulets, typical
formula, (1, 2), 3, 4, (5, 6), 1 =5+6; spiracles on annulet 2; annulets 2 and
4 with conical glandubae and tiny cylindrical truncate setae with large
calices; tenth abdominal tergum semiglobose, anal setae numerous; ventral
glands never present.
The genus Dolerus is represented in North America by more than
thirty species but none of them had been identified in the immature stages
until the writer reared the adult of D. similis Nort. at Ithaca, N. Y. The
56 ILLINOIS BIOLOGICAL MONOGRAPHS [374
larvae of this genus are easily obtained and readily identified because of
the marked asymmetry of the labrum.
The following key will serve to separate the species studied:
SPECIES OF DOLERUS
1(6) Head uniformly pale, creamy, or pale brown; body uniformly whitish or greenish,
without distinct dorsal band 2.
2(3) Body with small black spots on each segment along supraspiracular and pedal lines;
head pale brownish yellow; spots on ninth abdominal segment much smaller than
preceding ones; length, 25 mm.; on wheat and grasses; Y-l 17-1-1, G-d-1. Dolerus sp. 1.
3(2) Body without small black spots on each segment along supraspiracular and pedal
lines; head creamy; length less than 25 mm 4.
4(5) Distance between antennaria and mandibularia subequal to distance between anten-
naria and ocularium; length, 20 mm.; on Carex trichocarpa; Y-24-5-2, -145-1(?),-147.
Dolerus sp. 2.
5(4) Distance between antennaria and mandibularia twice or more than twice the distance
between antennaria and ocularium; length of prothoracic spiracles in relation to
vertical diameter of antennaria variable; femur with or without disto-ventral pro-
jection; front with or without pale brown spot; length 18-20 mm.; on grasses, sedge,
timothy; Y-29- 11,-32-1, M-7, H,-41-l,-63,-225 Dolerus sp. 3"
6(1) Head spotted, banded, or distinctly brown, black, or purple; body uniformly longi-
tudinally banded or striped on dorsum, especially along dorso-lateral lines, rarely
uniformly whitish or greenish 7.
7(8) Head with a distinct blackish semicircular band extending from gena to gena dorsad
of front and involving ocellarae; body with a very fine brownish line along latero-
dorsal lines, more distinct on caudal segments; thoracic legs uniformly pale; length,
15 mm.; on grasses; Y-41-l-l,-41-2,-41-3,-8.47(?) M-41,-235 Dolerus sp. 4.
8(7) Head without distinct blackish semicircular band, but with spots or dark-colored
areas; thoracic legs with femur, tibia, and claws brown, not concolorous with coxa. .9.
9(12) Head pale brown, vertex with brown spots; body uniformly whitish or with light
dorsal band .. 10.
10(11) Vertex with two small spots, one dorso-mesad of each vertical furrow, variable in
size but never linear along the furrow; body uniformly whitish or creamy; length.
21 mm.; on Carpinus and Pteris aquilina (both doubtful); Y-74-1-1, M-82
Dolerus sp. 5.
11(10) Vertex with one minute spot at the origin of epicranial stem; light brown spot along
epicranial suture to ocellarae; body with dorsal band lighter on dorso-meson and
darker on supraspiracular lines, more distinct on caudal segments; length, 15 mm.;
on Equisetum arvense; Y-145-2 Dolerus sp. 6.
12(9) Head brownish with purplish or brownish markings on vertex, only rarely light
brown or yellowish, then vertical furrows with brownish streaks; body with distinct
dorsal band 13.
13(14) Head deep purplish black with following parts whitish: proximal half of epicranial
stem, vertical furrows, vertex caudad of ocellarae to the middle of epicranial stem
very narrowly, epicranial arms, clypeus, and labrum; dorsal band lighter on dorso-
meson; pedal lines with a row of grayish patches; legs with femora without disto-
ventral projection; length, 19 mm. ; on Equisetum arvense; Y- 146-1-2 . . si mil is Norton.
14(13) Head usually brownish or yellowish, vertex deeply brown, at least along vertical
furrows; typically pale on vertex ventrad of vertical furrows and caudad of ocellarae;
front with or without brownish spot; tenth abdominal tergum on both sides usually
375] LARVAE OF THE TENTHREDINOIDEA—YUASA 57
more brownish than on meson; legs with femora without disto- ventral projection;
length, 20-23 mm.; on sedges; Y-28-l,-27-l-l,-30,-210-l-8.32(?)-l-l, M-7,-8,-9,-35,
-64,-193,G-d-3. Dolerus sp. 7.
Subfamily Phyllotominae
Larvae (Fig. 11-12) small, length usually less than 15 mm.; body sub-
cylindrical or depressed, without colored patterns; larvapods on abdominal
segment with two or six annulets; antennae with 3-4 or 5 segments;
thoracic legs with four segments, short, stubby, with or without tarsal
claws.
The Phyllotominae can be divided into two distinct tribes on the basis
of the larval characters. The tribes can be separated as follows:
Thoracic legs with tarsal claws; head normal in form, not depressed; third abdominal
segment with six annulets; external feeders Phyllotomini.
Thoracic legs without tarsal claws; head depressed; third abdominal segment with
two annulets; leaf-miners Phlebatrophini.
The Phyllotominae is a distinct group and includes four genera, Phyl-
lotoma, Caliroa, Endelomyia, and Phlebatrophia. In the Nearctic region,
the last three genera are represented by a limited number of species.
MacGillivray considered this family as one of the five generalized sub-
families of the Tenthredinidae, quite apart from the Fenusinae and
Scolioneurinae, but Rohwer would associate them in his subfamily Mes-
sinae while Konow would include Hoplocampinae and Phyllotominae
in his tribe Hoplocampides. The subfamily is divisible into two distinct
groups according to the characters of the larvae. The remarkable speciali-
zation of structures due to the leaf-mining habit of the larva in one genus
where specialization has proceeded much further than in any of the other
leaf-miners, makes the division of the subfamily into two tribes desirable.
Tribe Phyllotomini
Body practically subcylindrical, thorax distinctly swollen, some-
times distinctly tadpole-like, tapering caudad; segmentation and annu-
lation indistinct, fine, subequal in length; third abdominal segment
with six annulets, annulets 2 and 4 microscopically and sparsely setiferous
or minutely tuberculate; tenth abdominal tergum with or without tubercles;
thoracic legs as long as head is wide, subequal in size, short, modified, with
four segments, stubby, with distinct tarsal claws, coxa conical, femur
cylindrical, as long as wide, tibia convex, wider than long, distal segment
very minute, with sharp incurved claw; larvapods on abdominal segment
2-8 normal in form, glabrous, distal lobe with a minute point on its cephalo-
ventral angle; ultimate segment with a pair of normal larvapods or without
any; head small, normal, not depressed, sparsely setiferous, longer than
58 ILLINOIS BIOLOGICAL MONOGRAPHS [376
wide, slightly pointed at dorsal apex; mouth directed slightly ventro-caudad;
antennae with four or five segments, slender, elongate, conical, or sub-
conical; mouth-parts normal in form; spiracles with or without wings;
ventral glands wanting; prothoracic glands sometimes present; glandubae
present, conical, tuberculate or sessile; cuticle usually microscopically
verrucose; larvae in life sometimes distinctly slimy; subgregarious; leaf-
skeletonizers.
GENERA OF PHYLLOTOMINI
Body without minute tubercles, tadpole-like, slimy; glandubae sessile Caliroa Costa.
Body with minute tubercles, not tadpole-like, not slimy; glandubae conical, tuberculate.
Enddomyia Ashmead,
Endelomyia Ashmead
Larvae small, length less than 15 mm., greenish yellow; body sub-
cylindrical, apparently almost glabrous, not tadpole-like, thorax
thickened, tapering caudad; third abdominal segment with six annulets,
annulets 2 and 4 tuberculate; tenth abdominal tergum with eight to ten
conical tubercles arranged approximately in three transverse rows; suranal
and subanal lobes with several rather long stiff setae; thoracic legs with
distinct tarsal claws; larvapods on ultimate segment normal in form,
separated; antennae with five segments, slender, elongate-conical; mandi-
bles with dentes; spiracles not winged; spiracles on sublateral lines; pro-
thoracic glands wanting; glandubae conical, tuberculate; body not slimy.
Endelomyia aethiops Fabricius. — Length, 13 mm. ; width of head, 1.2 mm. ;
head light brown; mouth-parts, labrum, and tarsal claws deep brown; body
greenish yellow to yellowish white; tubercles concolorous with body;
typical tubercular formula on pro thorax: 3-6 on first annulet, 2-3 on pro-
subspiracular lobe, 2-5 on annulet 2; third abdominal segment with 2 and
3 tubercles on annulets 2 and 4 respectively, 1 on annulet 3 near the spiracle,
1 each on subspiracular and surpedal lobe; annulation, 1, 2, 3, 4, (5, 6);
antennae, 1, (2, 3, 4), 5; maxillary palpi, (1, 2, 3), 4; labial palpi, 1, 2, or
(1, 2); subgregarious; on Rosa; Y-2, M-127.
Caliroa Costa
Larvae small, length 6-12 mm., whitish; body distinctly tadpole-like;
thorax conspicuously swollen, rounded on dorsum and flattened on venter;
tapering distinctly caudad; third abdominal segment with six indistinct
annulets, annulets 2 and 4 with a few glandubae; tenth abdominal tergum
without tubercles; suranal and subanal lobes often with a number of stiff
rather long setae; thoracic legs with distinct tarsal claws; larvapods on
ultimate segment obsolete, their position indicated by a small median
swelling; antennae with four segments, rather thick, elongate, distal
segment microscopic; mandibles with dentes; spiracles usually winged;
377] LARVAE OF THE TENTHREDINOIDEA—YUASA 59
spiracular line abnormally low in position, coinciding with latero-ventral
line; prothoracic glands present, large, triangular, fleshy, attached cephalo-
mesad of prothoracic legs; glandubae sessile;
SPECIES OF CALIROA
1(2) Anal setae not all of same type and length, longer ones arising from minute but
distinct tubercles, brown, apparently barbed, curved at tips, as long as labrum,
ten to twelve in number, arranged in a transverse row on suranal and subanal lobe;
spiracles distinctly winged, brown; clypeus light brown; head deep brown; thoracic
legs and antennae deep brown; smaller setae on anal area normal in form, much
shorter than the long barbed ones, scattered beyond the transverse rows; lengths of
front, clypeus, labrum, and width of labrum to each other as 23, 10, 8 and 12 respec-
tively; length of body, 11 mm.; width of head, 1 mm.; on cherry, plum, Crataegus;
Y-209, M-260,-249,-115, C-551,-552 cerasi Linnaeus.
2(1) Anal setae all of same type and length, none arising from distinct tubercles and
barbed, all of normal type, much shorter than labrum; spiracles usually not winged . 3.
3(8) Head blackish, deep brown, or brownish; legs brownish in part, not concolorous with
body 4.
4(7) Head blackish or dark brownish 5.
5(6) Head black or dark brownish black; anal setae scattered, pale, subequal in length,
about three-fifths as long as labrum; prothoracic legs distinctly lighter in color than
other legs, which are brownish; spiracles of cephalic segments faintly winged ; clypeus
whitish; lengths of front, clypeus, labrum, and width of labrum to each other as
22, 9, 8, and 11, respectively; length of body, 10.5 mm.; width of head, 1 mm.; on
oak; M-157,-200,-245, G-553c, Y-mck Caliroa sp. 1.
6(5) Head deep brown; anal setae scattered, subequal in length; prothoracic legs higher in
color than other legs; spiracles never winged; anal setae about one-third as long as
labrum; clypeus pale brown; lengths of front, clypeus, labrum, and width of labrum
to each other as 18, 10, 8, and 11 respectively; length of body 6 mm.; width of head,
.9 mm. ; on wild cherry; C obsoleta Norton.
7(4) Head brownish or light brown; all legs pale brownish; anal setae scattered, subequal
in length, about one-third as long as labrum; clypeus pale brown; lengths of front,
clypeus, labrum, and width of labrum to each other as 10, 9 ,7, and 11, respectively;
length of body, 8 mm.; width of head 1 mm.; on white oak and Crataegus; C-7,
M-230 quercus-alba Norton.
8(3) Head pale brown or whitish; legs whitish, concolorous with body; spiracles not
winged; anal setae scattered, subequal in length, about three-fifths as long as labrum;
lengths of front, clypeus, labrum, and width of labrum to each other as 21, 9, 7, and
10, respectively; length of body, 10.5 mm.; width of head, 1 mm.; Y-121, G-553c,
M-143,-201,-231,-236-242 quercus-coccinea Dyar.
Tribe Phlebatrophini
Body viewed from the side distinctly depressed, venter flattened,
thorax thickened, broadest on mesothorax, prothorax declivous cephalad,
caudal segments distinctly tapering; segmentation and annulation distinct;
third abdominal segment with two annulets, annulet 2 sparsely and incon-
spicuously setiferous; tenth abdominal tergum without tubercles; tenth
sternum small; thoracic legs modified, fleshy, indistinctly four-segmented,
60 ILLINOIS BIOLOGICAL MONOGRAPHS [378
tapering to distal end, distal segment microscopic, mamma-like, without
tarsal claw; larvapods vestigial, located on abdominal segments 2-8 and 10,
anal larvapods united on the meson, forming a single sucker-like pro-
tuberance; head distinctly depressed, pointed, sub triangular in contour,
partly overlapped by protruding pro thorax; mouth directed cephalad;
vertical furrows obsolete; antennae with 3-4 segments, segments 1 and 2
large and conical, segments 3 and 4 subcylindrical and much smaller and
less in diameter than proximal segments; mouth-parts modified, mandibles
slender, sharply pointed, without dentes, blade-like; labium flattened and
large; spiracles not winged; ventral and prothoracic glands wanting;
glandubae obsolete; body not slimy; leaf-miners.
Phlebatrophia MacGillivray
Larvae very small, whitish; length less than 10 mm.; body distinctly
depressed, tapering much caudad, broadest on mesothorax, prothorax
declivous cephalad; lateral lobes somewhat prominent; tenth abdom-
inal tergum convex, almost glabrous, about half as wide as mesothorax;
suranal and subanal lobes semiglabrous; third abdominal segment with
two annulets, caudal annulet about four times as long as the cephalic,
microscopically and sparsely setiferous; thoracic legs fleshy, tarsal claws
wanting; larvapods rudimentary; ocularia protruding, located laterad
of antennariae; epicranial suture in part obsolete; spiracles not winged;
spiracular line normal in position; maxillary palpi with four segments,
labial palpi with two segments; totaglossa roundly protruding; stipes
elongate, subgalea long, slender, with distinct chitinized carinae; labrum
flattened; mandibles slender, sharply pointed, without dentes, blade-like;
leaf-miners.
Phlebatrophia mathesoni MacGillivray. — Length, 7 mm. ; width of head,
1 mm.; mesothorax, 2.4 mm. wide; head light brown, mandibles and
carinae of subgalae deep brown; maxillary palpi typically 2, 1, 3, 4, distal
segment very minute; antennae with proximal segment or segments
larger in diameter and fleshy, conical, two distal segments together smaller
and shorter than the other two segments, but longer than labial palpi;
distal segment of labial palpus very minute; leaf-miners of birch; C and G.
Subfamily Tenthredininae
Larvae (Fig. 13) of medium to rather large size; body cylindrical,
slender, tapering uniformly and gradually caudad; segmentation and
annulation distinct, fine; third abdominal segment with seven annulets,
annulets 1, 3, and 5 setiferous and 3 and 5 with transverse row of glandu-
bae; abdominal segments 2-8 and 10 with larvapods; antennae with five
segments, slender, cylindro-conical; body uniformly greenish, with dark
37v>j LARVAE OF THE TENTHREDINOIDEA—YUASA 61
dorsal band or with complicated color-patterns; tenth abdominal tergum
convex, suranal or caudal protuberances wanting; ninth abdominal tergum
with six annulets, annulet 6 as long as annulet 2; thoracic legs normal,
well developed, femur with ventro-distal, conical membranous projection;
clypeus with two setae on each side; labrum with 3-5 setae on each side,
with or without a median longitudinal depression; maxillary palpi slender,
normal; galea digit-like, large; lacinia flattened, with a row of 10-15 setae
on the oblique, truncate cephalic margin; stipes with a sharp triangular
cephalo-ventral projection; labial palpi long, slender, with segment 2
longer than segment 1; mandible with 1, 2, or 3-4 setae; head variously
marked, distinctly and densely setiferous; spiracles on third annulet, not
winged; larvapods glabrous; glandubae distinct, slender, elongate cylindro-
conical, sometimes longer than adjacent setae; cuticle microscopically and
densely spinulate; ventral glands wanting; larvae free leaf-feeders.
The Tenthredininae constitutes, according to MacGillivray, the second
subfamily of the series of specialized Tenthredinidae. Rohwer (1911)
would divide the subfamily into two tribes, Perineurini and Tenthredinini,
using the position of the propodeal spiracles and shape of the cephalic
margin of the scutellum as characters for differentiating them. In many
cases the larvae resemble those of the Emphytinae.
GENERA OF TENTHREDININAE
1(4) Mandibles with more than one seta; labrum with median longitudinal depression;
legs with dorsal aspect of femur usually less than twice as long as trochanter, but
often subequal to it .2.
2(3) Mandibles with two setae Macrophya Dahlbom.
3(2) Mandibles with four, occasionally three, setae Tenthredo Linnaeus.
4(1) Mandibles with a single seta; labrum without median longitudinal depression;
legs with dorsal aspect of femur usually twice as long as trochanter 5.
5(6) Body with complexly patterned markings on the dorsum; distal segment of maxillary
palpi usually longer than that of labial palpi; head nearly black . . Tenthredo psis Costa.
6(5) Body without complexly patterned-markings on the dorsum; distal segment of
maxillary palpi usually not longer than that of labial palpi; head pale or light brown
Neopus MacGillivray
Tenthredo psis semilutea Norton. — Body on dorsum with complexly
patterned purplish-black markings extending to supraspiracular lines;
two lighter colored spots on dorso-meson, their apices directed cephalad,
cephalic one much larger than caudal; large spot with caudal emargination
on latus and contiguous to mesal triangles; subspiracular lobe with faint,
minute spots; otherwise ventral half of body including legs and larvapods
•whitish; head purplish black excepting the following parts, which are
white: genae including antennae and antennariae, lower fourth of front,
vertex narrowly, laterad of vertical portion of epicranial arms, clypeus,
labrum, and mouth-parts except tips of mandibles, which are black;
62 ILLINOIS BIOLOGICAL MONOGRAPHS [380
fronto-clypeal suture sometimes black; in young specimens, head grayish
and body entirely whitish-green; in life head and body coated with a waxy
bloom; annulation, (3, 5, 1), (2, 4), 6, 7; antennae, 5, 2, (1, 3, 4); maxillary
palpi, (4, 2), 3, 1; labial palpi with distal segment twice as long as the pre-
ceding segment, but subequal in length to or shorter than distal segment
of maxillary palpi; labrum usually with three setae on each side and
without median longitudinal depression; mandible with one seta; legs
with trochanter one-half as long as tibia, femur slightly longer than
tibia; glandubae half as long as adjacent setae; length, 18 mm.; width of
head, 1.8 mm.; on Thalictrum polygonum; Y-8,-92-1-1.
Neopus 14-punctatus Norton. — Head pale creamy-white with brown
spots on dorso-meson of vertex, caudad of ocellarae, and on front, frontal
spots much darker; body whitish green, dorsum with a grayish shade, bor-
dered along supraspiracular lines with narrow grayish bands, dorso-meson,
especially on thorax, with fine double bands; venter including legs and
larvapods whitish; annulation, (1, 5, 3), (2, 4, 6, 7); antennae, (5, 1), 2,
(3, 1); maxillary palpi, 4, 2, (3, 1); labial palpi with distal segment one-
fourth longer than preceding segment, but subequal to distal segment of
maxillary palpi; labrum with three setae on each side, median longitudinal
depression wanting; mandible with single seta; legs with trochanter nearly
one-half as long as femur, tibia equal in length to femur; glandubae more
than half the length of adjacent setae; length of body, 18 mm.; width of
head, 1.8 mm.; on Podophyllum pdtatum: Y-205-1-1.
Tenthredo bilineata MacGillivray. — Head whitish green with vertex
brown dorsad of genae except narrow line along epicranial stem, vertical
furrows, and caudad and dorsad of ocularia; body on dorsum with series of
triangular brownish markings; triangle with apex directed cephalad and
with minute deep brown spot at each basal angle, the triangle divided on
meson by a faint light line; supraspiracular line with light brownish in-
definite band; venter including legs and larvapods whitish; annulation,
(3, 1, 5), (7, 6, 2, 4); antennae, 5, (1, 2, 3, 4); maxillary palpi, (4, 2), 1, 3;
labial palpi with distal segment nearly twice as long as the preceding seg-
ment and shorter than distal segment of maxillary palpi; labrum with five
setae on each side and with median longitudinal depression; mandibles with
four setae; legs with trochanter nearly as long as femur, tibia longer than
femur; glandubae conical, large, subequal in length to adjacent setae;
length of body, 21 mm.; width of head, 2 mm.; on Geranium maculatum:
Y-175-2.
Macrophya Dahlbom
Body usually whitish green, on dorsum with or without grayish band,
latus sometimes with small black spots; head usually marked on vertex;
antennae with segment 1 or 2 longest or all segments subequal in length;
381] LARVAE OF THE TENTHREDINOIDEA—YUASA 63
maxillary palpi usually with segments 2 and 4 subequal in length; mandible
with two setae; labrum with three setae on each side, with median longitu-
dinal depression; trochanter distinctly shorter than femur; head and
body in life usually coated with a thin whitish waxy bloom; dorsal vessel
usually showing thru cuticle as a dark fine line; setae microscopic; gland u-
bae shorter or longer than adjacent setae; length, 16-21 mm.
SPECIES OF MACROPHYA
1(4) Head pale brown, with or without a minute brown spot at the caudal end of epi-
cranial stem; body on dorsum with light or pale grayish band, darker along supra-
spiracular lines, band sometimes obsolete; venter whitish, including legs and
larvapods; tenth abdominal segments unmarked; labial palpi with distal segment
twice as long as the preceding segment; glandubae very small, shorter than adjacent
setae; setae microscopic; head and body coated with thin waxy bloom; on Primus
serotina; subgregarious 2.
2(3) Larger species, length, 20 mm.; width of head, 1.8 mm. ; annulation, (1, 5), 3, (4, 6, 7),
2; antennae, (2, 1), (3, 4, 5); maxillary palpi, 2, (1, 3, 4); Y-126.-126-3-C-1
flicta MacGillivray.
3(2) Smaller species, length, 16 mm.; width of head, 1.8 mm.; annulation, (5, 1, 3), 4, 6,
2, 7; antennae, 2, (5, 1, 4), 3; maxillary palpi, (2, 4), (3, 1); Y-59-3-1,-59-4-1
fistula MacGillivray.
4(1) Head with a large blackish spot on dorsal part of vertex, often with black spots
caudad of ocellarae; body with or without distinct grayish dorsal band, on latus with
rows of black or yellowish spots; venter usually whitish; pedal line sometimes with
fine gray markings 5.
5(8) Body entirely whitish; head on vertex usually with a dorsal spot not expanding
distad; without spots caudad of ocellarae 6.
6(7) Body with a row of small black spots along supraspiracular lines, two spots to each
segment, cephalic spot larger than caudal; tenth abdominal tergum unmarked;
annulation, (1, 3, 5) (4, 7), (6, 2); antennae, (4, 1), 2, 3; legs with femur more than
twice as long as trochanter, tibia shorter than femur, coxa with grayish marking;
glandubae longer than adjacent setae; length of body, 22 mm.; width of head, 2.3
mm.; on Sambucus; Y-8.11,-11 tibiator Norton.
7(6) Body without a row of small black spots along supraspiracular lines, but with
yellowish spots on latus instead, which are obsolete in alcoholic specimens; annula-
tion, (3, 5, 1), (2, 7, 4, 6); antennae. 1, (2, 3, 4, 5); maxillary palpi, (4, 2), (1, 3);
labial palpi with distal segment only one-fourth longer than the preceding segments;
legs with trochanter slightly shorter than tibia, femur slightly longer than tibia;
length of body, 22 m.; width of head, 2.2 mm.; on Sambucus racemosa; Y-8.11
-2(?)-3 e.pinota Say.
8(5) Body not entirely whitish, dorsum with dark dorsal band; latus with one or more
rows of distinct black spots; head on vertex with a dorsal spot expanding distad,
broadly T-shaped, caudad of ocellarae with spots; tenth abdominal segment with a
minute black spot on caudo-meson; venter lighter in color 9.
9(10) Body on latus with grayish band darker in color than dorsal band and with only
one row of distinct black spots; supraspiracular lines with a row of distinct spots;
dorso-lateral lines with a row of smaller, inconspicuous spots; subspiracular line
with very faint grayish spots, nearly obsolete ; pedal lines with grayish linear markings ;
annulation, 1, (3, 5), (7, 2, 4), 6; antennae, (1, 2, 3, 4, 5); maxillary palpi, (2. 4),
1,3; labial palpi with distal segment not quite twice as long as the preceding segment;
64 ILLINOIS BIOLOGICAL MONOGRAPHS [382
legs with femur twice as long as trochanter and slightly longer than tibia; length of
body, 19 mm.; width of head, 2 mm.; on Aster prenanthoides ; Y-8, 81(?)
lineata Norton.
10(9) Body on latus with grayish band lighter in color than grayish-purple dorsal band and
with three rows of distinct black spots; dorso-lateral and supraspiracular lines with
rows of small spots, two spots to each segment, with caudal spot much smaller and
sometimes nearly obsolete; spots on supraspiracular line largest; pedal line with a
row of spots, two to each segment, with cephalic spots smaller than caudal; head
with black spots on vertex large, sometimes coalesced, covering entire vertex except
genae and vertical furrows; front with faint gray spot; annulation, (3,5, 1), (7,2,4,6);
antennae, 2, (1, 5), (3, 4); maxillary palpi, (4, 2), (1, 3); labial palpi with distal
segment not quite twice as long as the preceding segment; legs with trochanter more
than one-half as long as tibia, femur equal in length to tibia; length of body, 21.5
mm.; width of head, 2.1 mm.; on Solidago juncea and Rudbeckia laciniata; Y-160-2,
-160-1 pulchdla Klug.
Subfamily Cimbicinae
Body cylindrical (Fig. 14), tapering uniformly caudad, apparently
glabrous, prothorax narrowed; segmentation indistinct; annulation fine, 7,
(2, 3, 4), (1, 5, 6), annulets 2, 4, and 7 microscopically setiferous; thoracic
legs normal in form, with five segments, femur slightly longer than tibia;
larvapods on abdominal segments 2-8 and 10, divided into two unequal
lobes on the distal surface, few setae on the dorso-caudal aspect, and none
on the cephalic aspect as viewed from side; tenth abdominal tergum with-
out suranal protuberances; suranal and subanal lobes with several short
setae; head large, rather thickly setiferous, normal in form; labrum sub-
divided by diverging depression into median lobe and two lateral lobes,
sometimes asymmetrical; antennae with a single segment, button-like but
chitinized; ventral glands wanting; glandubae microscopic or minute and
stalked, sometimes distinct conical tubercles; spiracles distinctly winged;
conspicuous spiracular glands located dorsad of each spiracle of abdominal
segments 2-8; cuticle microscopically and densely spinulate or verrucose;
mouth-parts normal in form, maxillary and labial palpi rather slender,
galea very thick, curved mesad at distal end, sericos large, distinctly
chitinized, pear-shaped, U-shaped, or V-shaped; stipes with a distinct
triangular projection on the dorsal or cephalic margin; body covered
with waxy bloom in life; larvae ejecting yellowish fluid from spiracular
glands when disturbed; free leaf -feeders, sometimes semigregarious.
The Cimbicinae is a small compact subfamily consisting of few genera
and a limited number of species in the Nearctic region. Systematists are
in accord in the general conception of the group, but Konow includes the
Perginae in his subfamily Cimbicini. Cimbex americana, with its several
varieties, is a well-known representative of this subfamily.
383] LARVAE OF THE TENTHREDINOIDEA—YUASA 65
GENERA OF CIMBICINAE
1(4) Body in general whitish, without minute colored spots 2.
2(3) Dorsum of body with a black median stripe Cimbex Olivier.
3(2) Dorsum of body without a black median stripe Trichiosoma Leach.
4(1) Body in general not whitish, but with minute colored spots Abia Leach.
Cimbex Olivier
Larvae very large, distinctly robust, largest of all saw-fly larvae, 40-50
mm. in length; body whitish with a distinct dorso-mesal black line; labrum
distinctly asymmetrical, dextral portion larger than sinistral, median
cephalic or ventral emargination distinct and deep; body with distinct
minute warts or conical glandubae, cuticle microscopically verrucose;
spiracular glands semicircular; sericos of labium pear-shaped with its nar-
row neck directed dorsad or cephalad; lateral lobes small but prominent with
several conical tubercles; maxillary palpi, 2, 4, 3, 1; labial palpi, 1, 2;
antennae mound-like, wider than high
Cimbex americana Leach. — Length, 50 mm.; head, 5 mm. wide; head
white, creamy, microscopically brownish verrucose; black median stripe on
dorsum extending from prothorax to the middle of eighth abdominal
segment; conical tubercles or glandubae on sublateral lobes larger than
elsewhere and 4-7 in number; larvae solitary; on willow, elm, poplar,
maple, alder, linden, etc.; Y-68, -8, -182, M-99.
Trichiosoma Leach
Larvae very large, somewhat slender, entirely white; labrum slightly
asymmetrical, right side larger than sinistral, median ventral emargina-
tion deep, but not reaching the median lobe; body not warty; glandu-
bae microscopic, stalked, arising from very low swellings; cuticle micro-
scopically verrucose; spiracular glands semicircular; sericos of labium
U-shaped, narrower on dorsal or cephalic end; lateral lobes not prominent,
without conical tubercles; maxillary palpi 2, 4, 3, 1; labial palpi, 1, 2;
antennae conical, longer than wide.
Trichiosoma sp. — Length, 38 mm. ; width of head, 4 mm. ; head creamy
white, body whitish; solitary; on willow, poplar, alder, wild cherry;
M-78, -44.
Abia Leach
Larvae large, rather plump, greenish or grayish green with minute
yellowish or blackish spots; labrum symmetrical, median ventral emargi-
nation only slightly indicated, broad; body without warts or tubercles;
cuticle microscopically and densely spinulate; glandubae stalked and
minute, not arising from swellings; spiracular glands semicircular; sericos
of labium V-shaped, widest at dorsal or cephalic end; sublateral lobes
66 ILLINOIS BIOLOGICAL MONOGRAPHS [384
inconspicuous, with several glandubae; maxillary palpi, (4, 2) 3, 1; labial
palpi with segments subequal; antennae conical, usually as wide as long.
SPECIES OF ABIA
1(2) Body with a broad dorso-mesal yellowish stripe between subdorsal lines; dorsum
above supraspiracular lines shaded brownish gray; head brownish gray except
front, genae, clypeus, and labrum which are lighter; ocellarae white; body dorsad of
supraspiracular lines shaded grayish or brownish, venter pale whitish-green; dorsum
between subdorsal lines yellowish white; body with four rows of minute black
spots; middorsal row with a large spot on annulet 7 and a smaller spot on annulets 2
and 4; subdorsal row with a large spot on annulet 7, with a bright yellow spot between
two black spots mentioned above; supraspiracular row with a spot on annulets 2
and 4 and a very small spot on annulet 7; subspiracular row with a spot at the
ventral ends of annulets 3 and 4; a yellow spot caudad of each spiracle; length,
26 mm.; width of head, 2.7 mm.; on honeysuckle; semigregarious; Y-8.13
amerkana Cresson.
2(1) Body with a broad dorso-mesal yellowish stripe between subdorsal lines; dorsum
above supraspiracular lines not shaded brownish-gray, but body generally greenish . . 3.
3(4) Pedal line without distinct more or less continuous smoky brownish gray band;
black spots directly ventrad of spiracles never present; second annulet without minute
but distinct spots dorsad of lateral large spots; head grayish brown except front,
genae, and clypeus, labrum lighter; ocellarae white; body entirely grayish green,
dorsum between subdorsal lines concolorous with other parts, the dorso-meson
with a narrow yellowish line; five rows of minute black spots: meso-dorsal row with
a larger spot on annulet 7 and a smaller spot on annulets 2 and 4; subdorsal row with a
larger spot on annulet 7 and very minute and often obscure spot on annulet 2, and
larger, distinct, often subdivided, spot on annulet 4, the latter two nearer to meson
than the regular subdorsal spots; lateral row with a large spot between annulets
2 and 3; supraspiracular row with a smaller spot on annulets 4 and 7; subspiracular
with a larger spot at the ventral end of annulets 3 and 4; a bright yellow spot between
mesal and subdorsal black spots on annulet 7; length, 28 mm.; width of head, 2.8
mm.; on Triosteum aurantiacum; Y-8.13-2, M-196 injlata Norton.
4(3) Pedal line with distinct, more or less continuous smoky brownish gray band ; black
spots directly ventrad of spiracles always present, at least on majority of segments;
one or two minute black spots on second annulet dorsad of large lateral spots always
present; length, 30 mm.; width of head, 2.9 mm.; on honeysuckle; Y-104, G-583,
both from Urbana, HI. ; larvae resemble A . injlata in markings and general appearance
but differ as above Abia sp. 1.
Subfamily Hoplocampinae
Larvae (Fig. 15) small; body cylindrical, slender; segmentation and
annulation sometimes obsolete; third abdominal segment with four or five
annulets, annulets 2 and 3 or 2 and 4 setiferous or all annulets glabrous;
larvapods present on abdominal segments 2-7 and 10, glabrous or setiferous,
sometimes very rudimentary; ventral glands usually present on the meson
of abdominal segments 1-7; body greenish or yellowish, striped or spotted
or without any markings; tenth abdominal tergum with or without suranal
protuberances, if present, often more than two in number; antennae
385J LARVAE OF THE TENTHREDIN01DEA—YUASA 67
conical, with five segments, or flattened, with four, sometimes apparently
with three; larvae free leaf-feeders and borers in fruits or petioles of leaves.
The Hoplocampinae as defined by MacGillivray contains at present
five genera, Marlattia, Hoplocampa, MacGillivrayella, Hemichroa, and
Craterocercus, and represents, together with Dineurinae, a series in which
the anal veins have been modified before the loss of the radial cross-vein.
Formerly Rohwer (1910, 1911a, 1913b) considered Hoplocampa and
MacGillivrayella as constituting a subfamily Hoplocampinae but later
(1918c) he abandoned this idea and united these genera with six other
genera and subgenera to form the tribe Hemichroini of his subfamily
Nematinae, as others have done. With the exception of two genera,
Platycampus and Anoplonyx, Rohwer's tribe Hemichroini becomes
coextensive with our Hoplocampinae. Cameron (1883) considered this
subfamily as forming "a connecting link between the Selandrides and
Nematides." There are reasons for indicating a close relation between
this subfamily and Nematinae. A study of the larvae confirms the con-
tention of Rohwer (1918c) that the grouping of Caliroa and Phyllotoma with
the Hoplocampinae, as was done by Konow and Enslin, is untenable.
It must be stated here that since only three genera, each represented
by a single species, were available for this study, the preceding definition
of the subfamily is necessarily incomplete.
GENERA OF HOPLOCAMPINAE
1 (2) Tenth abdominal tergum without caudal protuberances Marlattia Ashmead .
2(1) Tenth abdominal tergum with caudal protuberances 3.
3(4) Caudal protuberances more than two in number; larvapods well developed; third
abdominal segment with five annulets; free leaf -feeders Hemichroa Stephens.
4(3) Caudal protuberances two in number on caudal projection; larvapods rudimentary;
third abdominal segment with four annulets; leaf-petiole borer. Caulocampus Rohwer.
Hemichroa Stephens
Larvae small, greenish; length less than 18 mm.; body slender, tapering
uniformly caudad; third abdominal segment with five annulets 2 and 4
setiferous; tenth abdominal tergum with several conical caudal protuber-
ances on its caudal margin; antennae distinctly conical, with five segments,
as long as the longest diameter of antennaria; antennal segment 1 cres-
centic, dorsal in position, extending nearly the entire length of antennaria,
segment 2 complete or incomplete, reduced to mere line on cephalic
aspect, segments 3 and 4 ring-like tho reduced in length on cephalic portion,
segment 5 conical or peg-like, bluntly pointed at apex; thoracic legs
with tibia subequal in length to femur; larvapods glabrous; spiracles faintly
winged; glandubae distinct and large; larvae free leaf -feeders.
Hemichroa dyari Rohwer. — Larvae yellowish green; length, 16 mm.;
head blackish; body with blackish dorso-lateral lines and interrupted
68 ILLINOIS BIOLOGICAL MONOGRAPHS [386
blackish lines on subspiracular and pedal lines; tenth abdominal tergum
with six to seven conical protuberances, suffused with brown; surpedal and
subspiracular lobes with two setae and two glandubae; glandubae with
diameter twice that of anal setae; annulation, (1, 2, 4) 3, 5; on alder; Y-39-
-1-1,-8.73 (?) -l,-8.73(?)-2, C-8.
Marlattia Ashmead
Larvae comparatively very small, greenish, with or without stripes
or spots; body cylindrical, tapering caudad; third abdominal segment
with five annulets, annulets apparently glabrous; tenth abdominal seg-
ment without caudal protuberances; antennae with four segments, flat-
tened; segment 1 small, incomplete; segments 2 and 3 complete but
reduced to narrow line on cephalic aspect; segment 4 minute, mamma-
like; head sparsely setiferous, setae increasing in length on the lower
portion; thoracic legs normal in form, tibia subequal in length to femur; lar-
vapods with a few setae; spiracles minute, un winged; glandubae micro-
scopic.
Marlattia laricis Marlatt. — Head pale yellowish, body greenish with
faint subdorsal lines; third abdominal segment with five annulets, (1, 2)
4, 3, 5; larvapods with three setae; suranal lobe with a few setae on caudo-
ventral aspect; small larvae, length, 10 mm.; M-57.
Caulocampus Rohwer
Larvae very small; length less than 10 mm. ; body subcylindrical, taper-
ing at prothorax, constricted suddenly on the ultimate segment, not
spotted or striped, but whitish, sparsely and microscopically setiferous;
third abdominal segment with four annulets, annulets 2 and 3 with very
minute setae; thoracic legs minute, with five segments, tibia longer than
femur; abdominal segments 2-7 with rudimentary larvapods represented by
spinulate swellings; tenth abdominal tergum much smaller in diameter
than preceding segments, strongly converging caudad, caudal margin
produced and chitinized, a pair of minute brownish caudal protuberances
on the caudal margin of the projection; head small, sparsely and minutely
setiferous; ocellarae represented by pigmented spots, distinct, ring-like,
ocularia wanting; antennae apparently with three segments, conical, seg-
ments 1 and 2 incomplete, segment 3 slender, peg-like; mouth-parts
normal and conspicuous tho small; spiracles not winged; glandubae
obsolete; in young specimens dorsum of abdominal segments 1-7, with a
pair of protuberances on annulet 2; larvae borers in leaf -petiole.
This genus is monotypic and unique in the reduction of larvapods
and ocellarae and in the possession of modified caudal projection on the
ultimate segment with rudimentary caudal protuberances. In this last
387] LARVAE OF THE TENTHREDINOIDEA—YUASA 69
character the larvae of this genus resemble those of certain species of
Pontania. The modifications of the body are undoubtedly correlated with
the boring habit of the larvae. MacGillivray still considers this genus
as without question belonging to the Cladiinae, but Rohwer regards it as
belonging to his tribe Hemichroini. It is dealt with here under the Hop-
locampinae because the larvae more closely resemble larvae of this sub-
family than they do those of the Cladiinae.
Caulocampus acericaulis MacGillivray. — Length, 8 mm.; width of head,
.8 mm.; head light brown, body straw-yellow; resembles larvae of weevils
in general appearance; mouth-parts normal in form; in young specimens
head yellowish and body whitish; annulation, 2, 1, 3, 4; maxillary palpi,
3, 2, 1, 4, segments brown, slender; galea digit-like, very small; thoracic
legs with very small tibiae, tibia subequal in length to maxillary palpus;
tenth abdominal tergum with many minute setae evenly and promiscu-
ously scattered, not concentrated on subanal lobe; larvae bore into the
petioles of maple-leaves; Y (generosity of Dr. W. E. Britton, New Haven,
Conn.).
Subfamily Dineurinae
Larvae small; body subcylindrical, flattened on venter or cylindrical,
usually tapering toward the caudal end, greenish or yellowish, often with
dorsum darker, never with bright-colored markings; glabrous or setiferous;
head small, light greenish or yellowish, never with distinct markings;
ocellarae blackish; mouth-parts usually brownish; thorax wider than the
remainder of body, thoracic legs well-developed, caudal pairs larger than
the cephalic, directed laterad; segmentation distinct; annulation indistinct;
larvapods on abdominal segments 2-7 and 10, sometimes rudimentary;
intersegmental coria often distinct and whitish; larvae feed on under side
or upper side of leaves, eating the parenchymatous layers only or feeding
on edges of leaves or mining in the leaves; ultimate stage glabrous and
yellowish; pupation in single-layered parchment-like cocoons in the
ground; some species with nauseating odor.
The Dineurinae as limited by MacGillivray contains three genera,
Dineura, Mesoneura, and Pseudodineura, and includes not over twenty-
five species, which are mostly distributed in Europe and North America.
This subfamily resembles in wing-type the Hoplocampinae. Systematists
do not agree in the exact position of the small European genus Pseudo-
dineura. Konow would place Dineura in his tribe Nematides but both
Mesoneura and Pseudodineura in his tribe Blennocampides. Rohwer,
on the other hand, would associate Dineura and Mesoneura in his tribe
Nematini, and is not quite certain whether Pseudodineura also belongs
to this tribe or not. Cameron, who described the larva of Pseudodineura
parvulus under the name of Dineura despecta, altho aware of the differences
70 ILLINOIS BIOLOGICAL MONOGRAPHS [388
between this species and its allies and other species of Dineura, hesitated
to agree with Thompson in associating it with Blennocampa. The vena-
tion certainly indicates close relationship between Dineura and Pseudo-
dineura. The latter is characterized in its larval stages by the leaf-mining
habit and structural modifications due to this mode of life, altho appar-
ently these do not constitute very striking distinctions if one may judge from
published records. Since previous authors failed to study the structures
of the head more carefully, and since these are of great taxonomic im-
portance, and also on account of the discrepancy between the larval
habits of the three genera in question, it is impossible to pass judgment on
their affinity until more is known with regard to their larval structures
and habits, particularly in the case of Pseudondineura.
The life history of the subfamily has been recorded by Girard, Cameron,
and Brischke and Zaddach. The larvae of the American species are un-
known, and as none of the European species have been available for study
the definition of the Dineurinae here given is tentative, and is based on
descriptions and figures published by Cameron (1882) and by Brischke
and Zaddach (1883).
Subfamily Cladiinae
Larvae (Fig. 16) of small to medium size; body rather flattened, wider
than high, slightly tapering caudad, conspicuously hairy, greenish or with
segmentally arranged spots on dorsum darkly shaded; segmentation and
annulation usually distinct; third abdominal segment with four annulets,
annulets 1, 2, and 3 setiferous, setae, especially on annulets 2 and 3,
arising from wart-like tubercles, long, often curved, always microscopically
barbed, never branched, some of the setae distinctly longer than others;
annulet 4 narrow and glabrous; larvapods present on abdominal segments
2-7 and 10 well developed, long, distal portion often dilated, appearing as if
subdivided, often curved mesad, always with few setae; ventral glands small
but always present on abdominal segments 1-7; tenth abdominal tergum
without caudal protuberances but with many setae of varying length;
thoracic legs spreading flat laterad; femur with a ventro-distal projection,
subequal in length to tibia; antennae with four segments, subconical, large;
segment 1 complete or incomplete, segment 2 complete, thicker, dorsal or
caudo-dorsal portion with clear spaces, segment 3 smaller and narrower
than segment 2, segment 4 minute, conical; spiracles never winged; glandu-
bae small or obsolete; sericos usually very wide, occupying nearly four-
fifths of the width of the totaglossa; larvae external leaf-feeders.
The Cladiinae is a small subfamily and according to MacGillivray
consists of six genera; Anoplonyx, Platycampus, Priophorus, Cladius, and
Trichiocampus. The first three genera are placed in the tribe Hemichroini
of his subfamily Nematinae by Rohwer (1911, 1918), who states that
389] LARVAE OF THE TENTHREDINOIDEA—YUASA 71
"the characters of both the adult and the larva point out subfamily
difference between Caulocampus and Priophorus" and that the former
superficially resembles Hoplocampa in all stages but is really related to
Craterocerus. The difference of opinion is due to the different value
placed by these two writers on the presence or absence of the radial cross-
vein in differentiating the subfamilies. The genus Caulocampus has been
discussed in connection with the Hoplocampinae because the larvae of this
genus are very different from those of the Cladiinae both morphologically
and biologically and because they are more naturally associated with the
larvae of the Hoplocampinae. Anoplonyx is represented in the Neartic
region by a single species. Platycampus includes four American species,
two of which have been recognized in the immature stages. P. americana
feeds on Populus and P. juniperi on juniper. None of these larvae have
been examined.
GENERA OF CLADIINAE
1(2) Body spotted, with a row of blackish or brownish spots on subdorsal, supraspiracular
or subspiracular lines; setae usually recurved exceedingly long, longest ones longer
than one-half the height of the head; annulet 1 usually with one seta on each side of
meson Trichiocampus Hartig.
2(1) Body never spotted; setae usually straight, long, but the longest ones never distinctly
longer than half the height of the head; annulet 1 always with more than one seta on
each side of meson, usually with four to six setae 3.
3(4) Head with spots, usually with blackish patches on dorso-meson of vertex and caudad
of each ocellara; body dorsad of spiracular lines usually shaded darker than the
venter; body sometimes pinkish; postsupraspiracular tubercles usually with three
setae, never with more than four Priophorus Dahlbom.
4(3) Head never with spots, usually uniformly greenish; body dorsad of spiracular lines
never shaded darker but concolorous with venter; body never pinkish but greenish
yellow or whitish; postsupraspiracular tubercles usually with six setae, never with
less than four Cladius Rossi.
Trichiocampus Hartig
Larvae small to moderately large, length from 10 to 25 mm., distinctly
hairy, with segmentally arranged spots; body with a longitudinal row of
blackish or brownish spots along subdorsal, supraspiracular, or subspiracu-
lar lines; annulet 4 shortest, annulet 1 usually with one and sometimes two
setae on each half of body, annulet 2 with tubercles bearing 2-5 setae,
annulet 3 with three warts, two dorsal ones bearing 4-5 setae and ventral
one with 6-9 setae, postspiracular tubercle usually with two setae, sub-
spiracular lobe with 8-9 setae, surpedal lobe with 6-10 setae; setae usually
recurved, variable in length, longest setae nearly subequal in length to
the height of head; warts or tubercles with setae of varying length, those
on annulet 1 among the shortest.
72 ILLINOIS BIOLOGICAL MONOGRAPHS [390
SPECIES OF TRICHIOCAMPUS
1(2) Body with three pairs of longitudinal rows of blackish or brownish segmentally
arranged spots along subdorsal, supraspiracular, and subspiracular lines; tenth
abdominal tergum not entirely black but white except a pair of minute spots; head
light brown with brownish spots, with following parts dark brown: dorso-meson of
vertex, dorsal two-thirds of front, and vertex dorso-caudad of each ocellara including
gena; preclypeus whitish, other parts pale, including occiput between vertical
furrows; a row of brownish spots from meso thoracic to ultimate segment along each
side of dorso-meson; a row of larger spots along supraspiracular line from pro thoracic
to penultimate segments; another row of much smaller spots along subspiracular
lines from mesothoracic to eighth abdominal segment; mesothoracic and metathoracic
subspiracular spots more than twice as large as supraspiracular spots of same seg-
ments; the former with circular white areas around the proximal end of setae;
prothoracic supraspiracular spots small and indistinct; third abdominal segment
with following setal map: 1, 3, 5, 1, 2, 5, 4, 8, 9-10, 8-9; tenth abdominal tergum
white, except a pair of minute spots; subdorsal spots not involving tubercles 2 and 3;
supraspiracular spot involving tubercles 4 and 5; subspiracular spot on caudal half of
subspiracular tubercle; maxillary palpi (2, 3), 1, 4; head in younger specimens black-
ish except near the mouth; body without spots; in older specimens, supraspiracular
spots appear first, then subspiracular, beginning with caudal segments, setae on tuber-
cles sometimes one or two less than in mature specimens; on Populus; length of
body, 12 mm.; width of head, 1.5-1.6 mm.; G-Onekama and Orono on oak, length of
body, 13 mm.; width of head, 1.7 mm., M-207. (The latter resembles the former
so closely and indistinguishably, altho its setae may be slightly fewer in number,
that they are considered as identical.) paetvius MacGillivray.
2(1) Body with two pairs of longitudinal rows of blackish or brownish segmentally
arranged spots along supraspiracular and subspiracular lines; tenth abdominal
tergum entirely black; head blackish, with paler areas 3.
3(4) Mesothoracic supraspiracular spots subequal in size to subspiracular spots; supra-
spiracular spots of abdominal segments not involving postsupraspiracular tubercles;
prothoracic supraspiracular spots minute and indistinct; preclypeus, labrum, and
genae blackish; metathoracic subspiracular spots with minute but distinct circular
whitish areas around proximal end of setae; head blackish, paler along vertical
furrows, epicranial arms, and postclypeus; body with a row of blackish spots from
mesothoracic to penultimate segment along supraspiracular and subspiracular lines;
tenth abdominal tergum black; third abdominal segment with the following setal
map: 1, 3, 3, 0, 2, 4, 4, 5-6, 8-9, 6-8; subspiracular spot involving few setae directly
ventrad of spiracles; head in younger specimens entirely blackish and spots on
subspiracular lines wanting; maxillary palpi, (2, 3), 1, 4; length of body, 18 mm.;
width of head, 1.3 mm.; on Salix; Y-151-1-1,-151-1-3; M-100,-261. (The specimens
in the Maine collection are practically identical with my specimens except in the
number of setae on subspiracular and surpedal lobes, which may exceed the number
given byoneortwo) ^o&Atae MacGillivray.
4(3) Mesothoracic supraspiracular spots not subequal to but distinctly larger, twice or
more, than subspiracular spots; supraspiracular spots of abdominal segments in-
volving postsupraspiracular tubercles; prothoracic supraspiracular spots large and
distinct; preclypeus, labrum, and genae not blackish but pale brown; metathoracic
subspiracular spots without minute but distinct whitish circular areas around the
proximal end of setae; head black, paler along vertical furrows, epicranial arms,
clypeus, labrum, and genae; body with a row of blackish or brownish spots from
prothorax to penultimate segment along supraspiracular and subspiracular lines:
391 LARVAE OF THE TENTHREDINOIDEA—YUASA 73
tenth abdominal tergum black; third abdominal segment with the following setal
map: 2, 2, 3, 1, 2, 4, 4-5, 7-8, 8-9, 9-10; mesothoracic supraspiracular spot more than
twice as large as subspiracular spot; prothoracic supraspiracular spots moderately
large and distinct; subspiracular spot involving few setae in caudal portion of sub-
spiracular tubercle; mesothoracic and metathoracic subspiracular spots without circu-
lar whitish areas around the proximal end of setae; maxillary palpi usually 3, 2, 1, 4;
head in young specimens pale brownish, with a row of very small supraspiracular
spots; head in older larvae blackish, body spotted like mature specimens but spots
smaller; on Populus; length of body, 21-23 mm.; width of head, 2-2.1 mm.; Y-172-1-1.
Trichiocampus sp. 1.
Priophorus Dahlbom
Larvae small, hairy; length less than 17 mm.; body with dorsal half,
at least in part, usually with grayish or olivaceous shade; never with
spots; annulet 1 with a transverse row of several setae; annulet 2 with
two warts, each bearing 4-5 setae; annulet 3 with three warts, dorsal two
bearing 5-6 setae each, ventral with 8-10 setae; postsupraspiracular
wart usually with three setae; subspiracular lobe with 12-15 setae and sur-
pedal lobe with 6-9; setae usually more or less straight, usually of two
different lengths, longer ones usually less than one-half the height of the
head; warts bearing setae of two varying lengths, those on annulet 4
being among the shortest setae.
SPECIES OF PRIOPHORUS
1 (2) Front with a distinct blackish or fuscous spot; vertex with a dorso-mesal fuscous spot
occupying nearly the entire space between vertical furrows; body never pinkish but
whitish; head caudad of ocellarae fuscous; body dorsad of spiracular lines from meso-
thorax to penultimate segment olivaceous or grayish, color becoming dilute on caudal
segments; third abdominal segment with following setal map: 4-5, 4, 5, 1, 3, 6, 8, 12,
13, 8-9; maxillary palpi 2, (3, 4), 1; in younger specimens dorsal grayish shade con-
fined to cephalic segments; on hazel; length, 15 mm.; width of head, 1.5 mm.; M-109.
modestius MacGillivray.
2(1) Front without a distinct blackish or fuscous spot, but with a light or pale brown spot;
vertex with a dorso-mesal fuscous or blackish spot, not nearly occupying the entire
space between vertical furrows; body sometimes pinkish; not on hazel 3.
3(4) Head brown; vertex with blackish spot occupying about one-half the distance between
vertical furrows; body pinkish; head with blackish spot caudad of ocellarae; dorsum of
mesothorax to first abdominal segment shaded gray, prothorax whitish; third
abdominal segment with the following setal map: 5, 4, 4, 1, 3, 5, 5, 10, 10-12, 6-2;
maxillary palpi, 2, (3, 4), 1; in younger specimens body whitish; length, 14 mm.;
width of head, 1.2 mm.; on Salix; Y-154-1-2 palliolatus MacGillivray.*
4(3) Head pale brown; vertex on dorso-meson with blackish spot occupying two-thirds
the distance between vertical furrows; spot also caudad of ocellarae; body not
pinkish but whitish, dorsad of spiracular lines from mesothorax to penultimate
*This species was described as Trichiocampus palliolatus n. sp. by Dr.MacGillivray in the
Entomological News, vol. XXXII, 1921, page 49, but the characters of the larva place it in the
genus Priophorus. Upon reexamination of the adult specimens, Dr. MacGillivray agrees
with me in the change I here make.
74 ILLINOIS BIOLOGICAL MONOGRAPHS [392
segment distinctly and uniformly olivaceous-gray; third abdominal segment with
following setal map: 5-6, 5, 5, 1-2, 3, 6, 6, 10, 15, 8-9; maxillary palpi, 2, 3, (4, 1);
in younger specimens black spots on head larger and olivaceous shade on dorsum of
body restricted to cephalic segments; length, 16 mm.; width of head, 1.6 mm.;
on Prunus virginicus; Y-138-3. (This species resembles P. solitaris according to Dyar's
description but the latter feeds on Alnus, Priopkorus sp. 1.
Cladius Rossi
Larvae rather small; length less than 15 mm.; body slightly flattened,
greenish or yellowish green; never with spots or shaded on dorsal half; annu-
let 1 with a transverse row of several setae, annulet 2 with two warts bearing
5-6 setae, annulet 3 with three warts, dorsal two bearing 6-7 setae, ventral
with 10 setae; postsupraspiracular tubercles with 5-6 setae; subspiracular
lobe with 14-17 setae, surpedal lobe with 10 setae; setae usually straight,
usually of two lengths, longer ones less than half the height of head; setae
on annulet 1 among the shortest.
Cladius pectinicornis Fourcroy. — Length, 12-14 mm.; head pale brown-
ish or yellowish, microscopically verrucose, with brownish spots; front
touched with light brown; body hairy, uniformly greenish or greenish
yellow; third abdominal segment with the following setal map: 5-6, 5, 6,
1, 5-6, 6, 7, 10, 14-17, 10; maxillary palpi, (2, 3), 1, 4; on Rosa; Y-3, M-244.
Subfamily Nematinae
Larvae (Fig. 18) small to moderately large; body cylindrical, slender, or
abdomen increasing in diameter; segmentation and annulation usually
distinct; third abdominal segment with 4, 5 or 6 annulets, annulets 1, 2, 3,
or 1, 2, 4, or more usually 2 and 4, setiferous; larvapods present on abdom-
inal segments 2-7 and 10, setiferous or sometimes glabrous; ventral glands
present on the meson of abdominal segments 1-7; thoracic legs normal in
form; body uniformly greenish or darker colored, striped or spotted,
tuberculate, setiferous or smooth; antennae with four segments, conical,
subconical, limpet-shaped, or flattened; antennal segments sometimes
incomplete or in part fused together; tenth abdominal tergum with or
without a pair of caudal protuberances; glandubae sometimes distinct,
conspicuous, and stalked; spiracles winged or not; larvae free leaf -feeders,
gall-makers, and leaf-rollers.
The Nematinae is a large subfamily of several genera and numerous
species and is characterized by the coalescence of the cells 2d A and 3d A
due to the atrophy of the free part of the 3d anal vein. The absence of the
radial cross-vein and the cell 1st 2d A distinguishes the adults of this
subfamily from those of the Hoplocampinae and Cladiinae respectively.
Rohwer (1912), who would unite the Nematinae, Hoplocampinae, and
three genera of the Cladiinae in one subfamily, Nematinae, states that the
393] LARVAE OF THE TENTHREDIN01DEA—YUASA 75
subfamily contains two types of larvae and that most of the aberrant larvae
belong to his tribe Hemichroini. It may be pointed out that the Nema-
tinae as denned by MacGillivray also contains two types of larvae, which
are separable on the presence or absence of the caudal protuberances on
the ultimate segment. There are, however, other morphological and
biological characters of the larvae which suggest that this subfamily con-
tains a number of genera of wide diversity, and that such genera as Ptero-
nidea and Pontania might profitably be subdivided into more genera.
GENERA OF NEMATINAE
1(18) Tenth abdominal tergum without caudal protuberances 2.
2(11) Antennae conical or subconical, antennal segments 2 and 3 always complete, segment
4 peg-like or conical, at least as long as wide at proximal end; third abdominal
segment always with six annulets 3.
3(4) Annulets 2 and 4 glabrous; larvapods glabrous; glandubae obsolete; thoracic legs
with coxae in part always colored brownish Nematus Panzer.
4(3) Annulets 2 and 4 not glabrous; larvapods usually not glabrous; glandubae usually
not obsolete; thoracic legs with coxae usually in part not colored 5.
5(6) Antennae with segment 3 ring-like, its cephalic portion subequal in length to caudal
portion, segment 2 complete, its cephalic portion not reduced to a mere line; body
increasing in diameter to abdominal segments 5-6; spiracles usually winged; larva-
pods glabrous or with 2-4 or more setae as viewed from lateral aspect.
Pristiphora Latreille.
6(5) Antennae with segment 3 not ring-like, its cephalic portion not subequal in length
to caudal portion; segment 2 usually complete but its cephalic portion reduced to a
mere line 7.
7(8) Body increasing in diameter to abdominal segments 5-6, not uniformly cylindrical;
spiracles usually winged; larvapods with 4-6 setae as viewed from lateral aspect.
Diphadnus Hartig.
8(7) Body not increasing in diameter to abdominal segments 5-6 but uniformly cylindrical;
spiracles never winged; larvapods with 1-2 setae as viewed from lateral aspect 9.
9(10) Thorax distinctly swollen; head pale brownish green; maxillary palpi with segment 2
as long on its lateral aspect as on its mesal aspect; legs with femur and tibia con-
colorous with body, whitish; body with dorsum not shaded bluish green
Pteronidea Rohwer (in part).
10(9) Thorax never distinctly swollen; head not pale brownish green but blackish; maxillary
palpi with segment 2 three times as long on its lateral aspect as on its mesal aspect;
legs with femur and tibia not concolorous with body but blackish; body with dorsum
shaded bluish green Lygaeonematus Konow.
11(2) Antennae not conical or subconical, but flattened; antennal segments 2 and 3 not
always complete, segment 4 never peg-like or conical, never as long as wide at
proximal end; third abdominal segment not always with six annulets 12.
12(13) Segments with four annulets, annulets 1, 2, and 3 setiferous; gall-makers
Pontonia Costa (in part) .
13(12) Segments with more than four annulets, annulet 1 not setiferous; not gall-makers. . 14.
14(15) Segments with five annulets, annulets 2 and 3 setiferous; antennae with all segments
fused together; larvapods with two setae as viewed from lateral aspect; body-setae
very long M kronematus Konow.
76 ILLINOIS BIOLOGICAL MONOGRAPHS [394
15(14) Segments with five or six annulets, annulets 2 and 4 setiferous; antennae usually not
with all segments fused together; larvapods usually with many more than two
setae as viewed from lateral aspect; setae on body not very long; gland ubae usually
conspicuous and stalked 16.
16(17) Segments with six annulets; larvapods with 7-10 setae as viewed from lateral aspect;
surpedal areas at least in part always marked with gray; latus of abdomen never
with numerous brownish spots; tenth abdominal tergum sometimes distinctly
pointed and produced caudad and with many conspicuous glandubae near the caudal
margin; larvae usually feeding on monocotyledonous plants. . .Packynematus Konow.
17(16) Segments with five annulets; larvapods with 3-5 setae as viewed from lateral aspect;
surpedal areas not marked with gray; latus of abdomen sometimes with numerous
brownish spots; tenth abdominal tergum never distinctly pointed and produced
caudad ; larvae usually feeding upon willow Amauronematus Konow (in part) .
18(1) Tenth abdominal tergum with a pair of caudal protuberances 19.
19(20) Gall-makers and leaf-rollers; segments with four annulets; annulets 1, 2, and 3
setiferous; antenae flattened; body setae more than twice as long as spiracles;
caudal protuberances normal in form and position or rudimentary or borne on a
small caudo-mesal projection, if normal in form and position, the tergum with
paired colored markings Pontania Costa (in part).
20(19) Free leaf-feeders; segments usually with five or six annulets, if four, annulets 2 and 4
usually setiferous; antennae conical or flattened 21.
21(22) Antennae conical, segment 2 complete, segment 3 ring-like, its cephalic portion
subequal in length to caudal portion; body on latus with eleven conspicuous blackish-
brown spots, surpedal and subspiracular areas of abdominal segments 1-9 and venter
between larvapods of abdominal segments 2-8 similarly marked; spiracles not winged;
caudal protuberances of ultimate segment small, blunt, not longer than wide at
proximal end; segments with five or four annulets, with annulets 2 and 3 or 2 and 4
setiferous Croesus Leach.
22(21) Antennae conical or flattened; if conical, segment 3 not ring-like but reduced in length
on cephalic aspect; body not marked as in Croesus; spiracles winged or not winged;
caudal protuberances of ultimate segments not blunt, minute, but usually much
longer than wide at proximal end 23.
23(24) Segments apparently with five annulets; annulets 2 and 3 setiferous; antennae
flattened, with segment 3 complete; body-setae subequal in length to spiracles; smaller
larvae, length, 13-15 mm Amauronematus Konow (in part).
24(23) Segments with four or six annulets; annulets 2 and 4, rarely 1, 2, and 3, setiferous;
antennae conical or flattened, segment 3 complete or incomplete; body-setae often
longer than the length of abdominal spiracles; small to moderately large larvae,
length, 15-23 mm Pteronidea Rohwer (in part).
DlPHADNTJS HARTIG
Larvae small, greenish; length less than 14 mm.; body cylindrical, in-
creasing in size to abdominal segments 5-6, tapering at each end; thorax not
swollen; tenth abdominal tergum without a pair of caudal protuberances;
third abdominal segment with six annulets, annulets 2 and 4 setiferous;
spiracles distinctly and usually equally winged; head marked with black or
brown streaks along epicranial stem and dorsad of ocellarae; somewhat
compressed cephalo-caudad ; labrum with median emargination broad and
deep and with median longitudinal depression; antennae distinctly conical,
395] LARVAE OF THE TENTHREDINOIDEA—YUASA 77
with four segments, segment 1 incomplete, segment 2 usually complete
tho reduced to a mere line on cephalic part, segment 3 narrowed on cepha-
lic part, segment 4 short, conical, or peg-like; larvapods setiferous, setae
4-6 in number as viewed from lateral aspect; anal larvapods rather large;
glandubae sessile; cuticle microscopically spinulate; suranal and subanal
lobes with numerous setae; larvae free leaf -feeders.
Diphadnus appendlculatus Hartig. — Length, 13 mm.; width of head,
1.35 mm.; body green, venter glossy white; tenth abdominal tergum not
marked; head greenish white with blackish brown streak along epicranial
stem, except near the occiput, and continuing to the dorsal two-thirds of
front, vertex dorsad of each ocellara not quite reaching the epicranial
suture; surface of head with minute brownish spots; following parts
brown: mandibles at apices, antennae, cervical sclerites, coxae at proximal
third, tarsal claws, and spiracles; setae minute, with conspicuous calices,
blackish; glandubae smaller at distal end than the calyx of seta; larvapods
on cephalic and lateral aspects with 4-6 setae and with a single ventral
glanduba; annulation, 1, (6, 2), (3, 5), 4; subspiracular lobe with 5-6
setae and without glandubae; surpedal lobe with about 4 setae and one
subsessile glanduba; on gooseberry; Y-158, -159, M-128.
Pristiphora Latreille
Larvae small, greenish; length less than 15 mm.; body cylindrical
usually slightly enlarged at abdominal segments 5-6, tapering at each
end; thorax not swollen; tenth abdominal tergum without the paired
caudal protuberances; third abdominal tergum with six annulets, annulets
2 and 4 microscopically setiferous, setae sometimes obsolete; annulet 1
always longest and annulet 3 and 4 always shortest; spiracles usually
winged, caudal wing usually much smaller than cephalic; head marked
usually with a blackish or brownish streak along epicranial stem, surface
with minute brown spots; labrum with distinct mesal emargination and
longitudinal depression; antennae conical or limpet-shaped, usually with
four distinct segments, segment 1 always minute, incomplete on caudal
side, segment 2 complete, but usually narrower on cephalic side, segment 3
uniform in length, segment 4 short, conical; larvapods usually glabrous
and with a single ventral glanduba, if setiferous, setae microscopic, 2-4
in number as viewed from side; anal larvapods rather conspicuous, glandu-
bae sessile or stalked; cuticle microscopically spinulate, suranal and
subanal lobes with numerous setae; tenth abdominal tergum as seen
from side notched dorsad of suranal lobe; free leaf -feeders.
SPECIES OF PRISTIPHORA
1(8) Larvapods setiferous; antennae always conical; head always with a brownish streak
dorsad of each ocellara; spiracles always with cephalic wing distinctly larger than
78 ILLINOIS BIOLOGICAL MONOGRAPHS (396
caudal wing; setae with calices surrounded by minute brownish areas; giandubae
always sessile, sometimes microscopic, diameter never more than half the diameter
of calices of setae 2.
2(3) Giandubae minute but distinct, about one-third as large as calices of setae or micros-
copic in smaller specimens; annulation, 1, (5, 6), 2, 3, 4; subspiracular area with 3-4
setae; surpedal area with 3-4 setae; larvapods with 2-4 setae as viewed from side;
head light brownish-green, marked with fuscous streaks on both sides of entire
length of epicranial stem, front with dorsal two-thirds light brown; following parts
light brown: labrum, antennae, mandibles, cervical sclerites, tarsal claws, and spir-
cles; body greenish, caudal segments pinkish or bluish, dorsal vessel dark green with
distinct fine white line on eash side; Length, 14 mm.; on Salix; Y- 143-2-2,-155, M-96.
murtfeldtiae Marlatt.
3(2) Giandubae microscopic, difficult to detect 4.
4(5) Second annulet of abdominal segments always longer than either fifth or sixth
annulet; larvapods with about two setae as viewed from side; subspiracular areas
with 4-5 setae, surpedal areas with 4 setae; annulation, 1, (5, 6), 2, 4, 3; on birch;
M-24 Pristiphora sp. 1.
5(4) Second annulet of abdominal segments always shorter than either annulet 5 or 6;
larvapods with 1-2 or 2-4 setae as viewed from side; subspiracular areas with four
setae; on alder or willow 6.
6(7) Larvapods with 1-2 setae as viewed from side; annulation 1, 2, (4, 5, 6), 3; surpedal
areas with 3-5 setae; body green, cylindrical; head pale brownish-green, marked with
brown streak along entire length of epicranial stem and dorsal two-thirds of front
and vertex, narrowly dorsad of each ocellara; following parts brown: antennae,
labrum, mandibles, maxillary palpi, cervical sclerites, tarsal claws, and spiracles;
antennae conical, segment 4 short, conical; spiracle with cephalic wing distinctly
longer than caudal; setae without brown areas surrounding calices; giandubae
minute, sessile, microscopic; M-74 Pristiphora sp. 2.
7(6) Larvapods with 2-4 setae as viewed from side; surpedal areas with 3-5 setae; annula-
tion, 1, 2, 6, 5, 4, 3; on wolly willow; M-90 Pristiphora sp. 3.
8(1) Larvapods glabrous; antennae conical or limpet-shaped; head with or without a dark
streak dorsad of each ocellara; spiracles winged or not winged, if winged, wings
subequal in size, or cephalic wings larger than caudal; setae usually with calices
surrounded by minute but distinct brownish areas; giandubae sessile or stalked,
sometimes microscopic 9.
9(10) Head distinctly and uniformly brownish; spiracles indistinctly winged; all setae
ventrad of subdorsal lines with calices surrounded by minute brownish areas; an-
tennae conical; giandubae subequal to calices in diameter; annulation, 1, 5, 6, 2, 3, 4;
on birch; M-132 Pristiphora sp. 4.
10(9) Head never distinctly and uniformly brownish 11.
11(12) Body on dorso-meson from prothorax to fifth abdominal segment with a distinct
blackish line; spiracles winged, cephalic wings usually larger than caudal; all setae
ventrad of subdorsal lines with calices surrounded by minute brownish areas; an-
tennae conical; giandubae minute, about half as large as calices in diameter; head
with distinct line along epicranial stem; vertex without a dark streak dorsad of each
ocellara; annulation, 1, 2, (5, 3, 4, 6) or 1, 2, (3, 4, 5, 6); on Prunus; M-128
Pristiphora sp. 5.
12(11) Body on dorso-meson from prothorax to fifth abdominal segment without a distinct
blackish line 13.
13(14) Head entirely pale or light brown; vertex without dark streak along epicranial stem.
antennae distinctly conical; spiracles winged, wings subequal in size; setae never with
397] LARVAE OF THE TENTHREDINOIDEA—YUASA 79
calices surrounded by distinct brownish areas; glandubae probably obsolete, micro-
scopic; annulation, 1, 5, 6, 2, 3, 4; on oak; M-20 Pristiphora sp. 6.
14(13) Head never entirely pale or light brown; vertex always with a dark streak along
epicranial stem, sometimes indistinct but never entirely wanting 15.
15(22) Spiracles winged ; setae ventrad of spiracular lines with calices surrounded by distinct
minute brownish areas; antennae always conical; vertex with or without a dark
streak dorsad of each ocellara 16.
16(19) Spiracles with cephalic wings always larger than caudal; glandubae always sessile;
gland os microscopic, difficult to detect; setae on latus dorsad of spiracular lines
with calices surrounded or not surrounded by distinct brownish areas 17.
17(18) All setae on latus dorsad of spiracular lines with calices surrounded by brownish
areas; vertex dorsad of each ocellara with a brownish streak; annulation, 1, (5, 6),
2, 4, 3; body green; head marked as in P. bivittata; length of body, 12-13 mm.; on
Salix; M-72 sychophanta Walsh.
18(17) All setae on latus dorsad of spiracular lines with calices not surrounded by brownish
areas; vertex dorsad of each ocellara without a brownish streak, uniformly pale;
annulation, 1, (2, 5, 6), 4, 3; body enlarged on abdominal segments 5-6, greenish,
with dorsal vessel dark green with white line on each side; head greenish with brown-
ish streaks along entire length of epicranial stem, expanding on the dorsal half of
front; following parts brown: labrum, mandibles, antennae, cervical sclerites, tarsal
claws, and spiracles; antennae conical, segment 4 elongate, conical; on Spiraea latifolia
and S. tomentosa; M-4 Pristiphora sp. 7.
19(16) Spiracles with wings subequal in size; glandubae stalked ; glandos subequal in diameter
to calices; setae on latus dorsad of spiracular lines never with calices surrounded by
distinct brownish areas 20.
20(21) Vertex with a distinct dark streak dorsad of each ocellara; annulation, 1, 2, (5, 6), 4, 3;
length, 16-17 mm.; body cylindrical, increasing in size to abdominal segments 5-6,
green, dorsal vessel dark green with fine white line on each side of it; head green,
slightly brownish, with fuscous streaks; following parts light brown : dorsal two- thirds
of front, labrum, maxillary palpi and galea, labial palpi, and cervical sclerites; follow-
ing parts brown: antennae, mandibles, spiracles, glandubae, and setae; antennae
conical, distinctly with four setae, segment 4 conical; spiracles with wings; ven-
tral glands subequal in size to larvapods; glandos in diameter subequal to or larger
than calices of setae; setae on dorsum very minute; on Spirea; Y, M-14,-88
bivittata Norton.
21 (20) Vertex without a distinct dark streak dorsad of each ocellara; annulation, 1, 2, 6, 5, 3,
4; on Potentilla; M-10 Pristophora sp. 8.
22(15) Spiracles not winged; setae ventrad of spiracular lines never with calices surrounded
by distinct minute brownish areas; antennae limpet-shaped, segments indistinguish-
ably fused; vertex always with a brown streak dorsad of each ocellara; glandubae
sessile; glandos microscopic, difficult to detect; annulation, 1, (2, 5, 6), (3, 4); length
12-13 mm.; body green, with broad dark green dorsal vessel bordered on each side
by a fine white line; head greenish brown; setae stiff, comparatively long, without
brown areas surrounding calices; on Geum canadensis; Y-212. .Pristiphora sp. 9.
MlCRONEMATUS KONOW
Larvae small; length less than 15 mm.; body subcylindrical, tapering
at both ends; mesothorax distinctly and metathorax slightly swollen;
lateral lobes prominent and swollen; segmentation distinct; annulation
indistinct; third abdominal segment with five annulets, annulets 2 and
80 ILLINOIS BIOLOGICAL MONOGRAPHS {398
3 setiferous; thoracic legs spreading laterad, normal in form; larvapods
setiferous, normal in form, except the anal pair, which is reduced in size,
only one-half as large as the other pairs; tenth abdominal tergum with-
out the paired caudal protuberances; head circular, smaller than thorax
in width and height, front flattened; antennae apparently with four seg-
ments, flattened, all segments fused together; ventral glands very large;
setae sparse, very long; spiracles not winged; suranal and subanal lobes
multisetif erous ; glandubae subsessile; free leaf -feeders.
Konow in 1905 listed three species of Micronematus: abbreviates,
califomicus, and monogyniae. The second species properly belongs to
Diphadnus. Of the two remaining species, M. abbreviates was recognized
in the larval stages a long time ago by Snellen von Vollenhoven (1868).
This genus is European and is represented in North America by a single
species, Micronematus gregarius Marlatt. That this species does not
belong to Pachynematus can be readily seen from the structure and
biological characters of the larvae as was suggested by Dyar (1897)
in his original description of the immature stages. Three facts distinguish
this species from all other known species of Pachynematus: (1) the larva
has five annulets instead of six; (2) the anal larvapods are very much reduced
in size; and (3) the larva feeds on willow instead of grasses. On the other
hand M. gregarius has certain characters in common with M. abbreviates
as recorded by Vollenhoven. Since this species can not be referred to
Pachynematus or to any other known American genus, and since it has
characters which are peculiar to Micronematus, and since the adult
characters, according to Ashmead (1898), would place it in this genus,
this species is here considered as belonging to Micronematus. If future
study should prove this position untenable, a new genus should be erected.
Micronematus gregarious Marlatt. — Length, 12 mm.; body shiny,
yellowish white; alimentary canal showing thru as green tube; head pale
testaceous with a broad blackish band across the front between ocellarae
and a narrow band dorsad of each ocellara to and along vertical furrow;
mouth-parts, cervical sclerites, and legs except coriae brownish; abdominal
segments 1-8 with postspiracular and subspiracular areas swollen, mound-
like, and tinted fuscous; abdominal segments 2-7 with colored postspiracu-
lar areas larger than subspiracular areas; those on segments 1 and 8 much
smaller; thoracic segments with two colored patches on latus, one larger
and more ventral than the other; larvapods with about two setae on the
cephalo-lateral aspect; ventral glands nearly three times as large as larva-
pods; setae slender, at least twice as long as spiracles; spiracles not winged;
subspiracular area with two setae and single glanduba, surpedal area
with 3-4 setae and single glanduba; larvae gregarious; on Salix; Y.
399] LARVAE OF THE TENTHREDINOIDEA—YUASA 81
Lygaeonematus Konow
Larvae comparatively speaking moderately large, length 18-20 mm.;
body cylindrical, tapering uniformly and slightly caudad; thorax not
swollen; abdomen never swollen; dorsum grayish green and venter pale,
head shiny black, only slightly narrower than thorax; antennae conical,
with four distinct segments, segment 1 minute, incomplete, and with single
sensory pit, segments 2 and 3 narrower on cephalic part than on caudal
part, segment 4 conical; labrum with mesal emargination shallow and broad;
maxillae with galea larger than labial palpi; maxillary palpi with segment 2
three times as long on lateral margin as on mesal; third abdominal segment
with six annulets, annulet 1 largest, annulets 2 and 4 setiferous; larvapods
well developed, setiferous, with 1-2 setae and single ventral glanduba;
glandubae sessile; glandos smaller than calyx of a seta; ventral glands
subequal to or larger than larvapods in size; spiracles not winged; tenth
abdominal tergum as seen in profile not notched dorsad of suranal lobe and
without caudal paired protuberances; setae usually arising from minute
fleshy mound-like protuberances; cuticle microscopically spinulate; free
leaf-feeders.
Lygaeonematus erichsoni Hartig. — Length, 18-20 mm.; body somewhat
shiny, greenish gray dorsad of spiracular lines, ventrad of them opaque
bluish- white, head black; following parts fuscous to blackish: mouth-parts,
cervical sclerites, femur, tibia, and claws; following parts grayish: surpedal
areas, coxa, and trochanter in part, swellings between legs, and abdominal
surpedal areas faintly; annulation, 1, 2, 6, (3, 5, 4); glandos half as large
in diameter as calices of adjacent setae; surpedal areas on abdomen with
8-10 setae and two glandubae; subspiracular area with 6-7 setae, usually
without glandubae; cuticle with distinct microscopic brownish spinulae;
on larch; Y-162, M-105, -165.
Pachynematus Konow
Larvae comparatively speaking moderately large; length, 15-23 mm.;
body cylindrical, tapering uniformly and distinctly caudad; thorax rarely
and abdomen never swollen; third abdominal segment with six annulets,
annulets 2 and 4 setiferous, annulet 1 longest, annulet 4 usually shortest;
tenth abdominal tergum without a pair of caudal protuberance, and without
a notch dorsad of suranal lobe as seen in profile; the tergum sometimes
produced distinctly caudad and pointed; suranal and subanal lobes with
numerous setae; head brownish or greenish, sometimes with fuscous
streak along epicranial stem, semiglobose, subequal in width to thorax
or only slightly narrower; labrum with median longitudinal depression,
cephalic emargination shallow; maxillae with galea always larger than
labial palpi, sometimes more than twice as large; antennae with four seg-
ments, flattened, never distinctly conical, segment 1 usually minute, in-
82 ILLINOIS BIOLOGICAL MONOGRAPHS [400
complete, segments 2 and 3 with cephalic parts distincty reduced to mere
lines, sometimes all four segments fused; larvapods always setiferous, with
8-11 setae on cephalic and lateral aspects and a single ventral glanduba;
glandubae conspicuous, cylindro-conical, at least twice as long as wide
at proximal end; spiracles usually not winged, if winged, rather indistinctly;
setae stiff, brown, arising from fleshy mound-like minute tubercles; in
younger specimens third abdominal segment with five annulets, annulets
1, 2, and 3 with stiff brown setae; glandubae obsolete; cuticle microscopi-
cally spinulate; larvae usually feed upon grasses.
This generic description is based upon two identified and several un-
identified species. The known species can be separated as follows:
SPECIES OF PACHYNEMATUS
Head with narrow fuscous or blackish streak along epicranial stem and vertical furrows;
tenth abdominal tergum with a broad fuscous streak on the meson and the caudal margin
produced distinctly caudad and bluntly pointed, with many conspicuous glandubae; antennae
with four fused segments; annulation, (2, 1), 6, (3, 4, 5); larvapods with 7-9 setae on cephalic
and 1 seta on lateral aspect; subspiracular lobe with 5-6 setae and 1-2 glandubae; surpedal
lobe with 5-7 setae and 1-3 glandubae; body on dorso-lateral lines with narrow, interrupted
longitudinal fuscous, bands; head as wide as thorax; length, 20 mm. width of head, 2 mm.;
on Carex; Y-150 subalbattu Norton.
Head with narrow fuscous or blackish streak along epicranial stem and vertical furrows;
tenth abdominal tergum without a broad fuscous streak on the meson, the caudal margin
only slightly produced caudad, rounded, with many glandubae; antennae with four segments
not fused ; annulation, (1, 2), 6, (3, 4, 5) ; larvapods with about ten setae on cephalic and one se-
ta on lateral aspect; subspiracular lobe with about six setae and a single glanduba; surpedal
lobe with six setae and three glandubae; head as wide as thorax; length, 16 mm.; width of
head, 1.6 mm.; on Carex; Y-177 repertus MacGillivray.
Nematus Panzer
Larvae comparatively small, length about 10 mm.; body cylindrical,
uniform in diameter thruout the entire length excepting the caudal end,
where it is tapering, dull green, apparently glabrous; annulation indis-
tinct; third abdominal segment with six annulets, annulets glabrous,
formula: 1, 5, 2, 6, 3, 4; thoracic legs normal in form; coxa usually fus-
cous on proximal half; larvapods small, diminishing in size gradually on
the caudal segments, not setiferous; ventral glands subequal in size to larva-
pods; tenth abdominal tergum without a pair of caudal protuberances,
with a notch dorsad of suranal lobe as seen in profile, caudal margin trun-
cate or slightly emarginate on the meson, not produced; suranal lobe with
several minute setae on ventral aspect; subanal lobe with moderately
numerous minute setae; abdomen with lateral lobes inconspicuously
swollen; head circular in outline, rounded in profile on dorsal half, front
flattened; ventral half of head with several longer and larger setae; dorsal
half nearly glabrous or with microscopic setae; vertex usually with a fuscous
401] LARVAE OF THE TENTHREDINOIDEA—YUASA 83
streak caudad and dorsad of each oceJlara; antennae four-segmented,
subconical or sublimpet-shaped, sometimes in part fused; segment 1
minute, segments 2 and 3 reduced to mere line on cephalic aspect, segment
4 minute, subconical; mouth-parts and cervical sclerites fuscous to black-
ish; maxillary palpi with two distal segments distinctly smaller than
segment 2, which is sometimes longer than all the other segments taken
together; galea larger than labial palpus; sericos distinct, circular; sub-
spiracular and surpedal lobes with a few microscopic setae; glandubae
probably microscopic, usually obsolete; spiracles usually winged; cuticle
microscopically spinulate; free leaf-feeders.
SPECIES OF NEMATUS
1(4) Vertex with a fuscous streak caudad and dorsad of each ocellara; maxillary palpi
with segment 2 shorter than all the other segments taken together 2.
2(3) Vertex with fuscous streaks extending dorsad of vertical furrows; antennae with all
segments fused and almost completely filling antafossae; spiracles distinctly winged;
tenth abdominal tergum with caudal margin shallowly emarginate on the meson;
head with dorsal half entirely glabrous ; length, 1 1 mm. ; on oak ; M-2 1 . . chloreus Norton.
3(2) Vertex with fuscous streaks not extending dorsad of vertical furrows; antennae with
all segments distinct, but not nearly completely filling antafossae; spiracles not
distinctly winged; tenth abdominal tergum with caudal margin not emarginate on the
meson; head with dorsal half sparsely setiferous; length, 9 mm.; Y-133. Nematus sp. 1.
4(1) Vertex without a fuscous streak caudad and dorsad of each ocellara; maxillary palpi
with segment 2 slightly longer than all the other segments taken together; antennae
with four distinct segments; spiracles winged; length, 10.5 mm.; on oak; M-2.
Nematus sp. 2
Croesus Leach
Larvae moderately large, length about 25 mm., body cylindrical tapering
caudad on abdominal segments 7-10 and also at cephalic end of prothorax;
segmentation distinct; annulation indistinct; third abdominal segment
with four or five annulets, annulets 2 and 3 setiferous; tenth abdominal
tergum with a pair of low, conical, bluntly rounded caudal protuberances,
usually as wide as or wider than high; head flattened on front, rounded,
shiny black; antennae distinctly conical with four segments: segment 1
incomplete, three times as long as wide, segments 2 and 3 usually complete
and not reduced to mere lines on the cephalic aspect, segment 4 peg-like,
bluntly pointed, longer than wide at proximal end; maxillary palpi with
segment 1, 3, and 4 subequal in length, segment 2 twice as long as segment
1 ; larvapods setiferous; spiracles not winged, indistinctly colored; glandubae
subsessile or with a short stalk, very wide in diameter more than three
times the diameter of shaft of setae; maxacoria developed into a distinct
triangular swelling dorso-caudad of cardo, and covered with dark spinulae.
Croesus latitarsus Norton. — Length, 25 mm.; annulation, 3, 2, 1, 4 or
2, 1, 5, 3, 4; larvapods with 4-5 setae and a single glanduba as viewed
from side, no markings; tenth abdominal tergum with dark-colored area
84 ILLINOIS BIOLOGICAL MONOGRAPHS [402
contiguous to concolorous suranal protuberances; suranal and subanal
lobes with numerous setae, which increase in length with the distance
from the anus; body yellowish green or brownish, with colored patches on
subspiracular and surpedal areas and on subdorsal line from mesothorax
to ninth abdominal segment; abdominal segments 2-8 on ventro-meson
each with a large colored patch; in younger stages body fuscous with
few distinctly delimited colored patches or none; M-1,-26,-50,-51,-48.
Amauronematus Konow
Larvae small to moderately large; length 15-20 mm.; body cylin-
drical, often tapering distinctly caudad; latus with subspiracular and
surpedal areas colored or with numerous, minute colored spots; head
blackish, brownish, or greenish; third abdominal segment with five annu-
lets, annulets 2 and 3 or 2 and 4 setiferous; tenth abdominal tergum with
or without caudal paired protuberances; body setae much longer or
shorter than the length of spiracles; larvapods with 2-3 or 3-5 setae as
viewed from side; spiracles not winged; larvae free leaf -feeders.
The larval stages of five species of Amauronematus have been described
by Dyar. Of these, larvae of luteotergum, dyari, oregonensis, and similis
have not been available for study, but according to Dyar's descriptions,
the last three apparently lack the caudal paired protuberances. I have a
large number of larvae collected on willow by Dr. MacGillivray which
also lack the paired caudal protuberances and probably belong to this
genus. The species may be separated as follows :
SPECIES OF AMAURONEMATUS
1 (4) Tenth abdominal segment with paired caudal protuberances 2.
2(3) Abdomen on ventro-meson with a row of blackish spots; caudal paired protuberances
and head blackish; gregarious; on alder luteotergum Norton.
3(2) Abdomen on ventro-meson without a row of blackish spots; paired caudal protuber-
ances and head not blackish but pale; solitary; on Azalea azaleae Marlatt.
4(1) Tenth abdominal segment without paired caudal protuberances 5.
5(6) Mature and also younger larvae with antennae flattened and their segments fused
in part, with no discernible or with very small antacoria; younger larvae (14 mm. or
less) with annulets 1, 2 and 4 setiferous; annulets 2 and 4 with transverse row of
warty protuberances each bearing 2 or 3 stiff stout setae; older larvae (14 mm. or
more) without numerous brownish spots on dorsum and latus and without brownish
interrupted and diffuse dorso-mesal and dorso-lateral lines; on sweet fern; M-85.
Amauronematus sp. 1.
6(5) Mature larvae with antennae whose segments are all distinctly separated by distinct
antacoria; young larvae with antennae like those of preceding species; younger larvae
(14 mm. or less) with annulets 1, 2, and 4 setiferous; annulets 2 and 4 without
transverse row of warty protuberances the setae being minute and arranged singly;
older larvae (14 mm. or more) with numerous brownish spots on dorsum and latus
with brownish, interrupted, and diffuse dorso-mesal and dorso-lateral lines; on willow;
M-10 virendus MacGillivray.
403] LARVAE OF THE TENTHREDINOIDEA—YUASA 85
Another species, resembling the preceding very closely and, difficult to distinguish except
by the colored spots which are more or less darker and slightly more numerous than in
virendus; M-l 12 vescus MacGillivray.
Pteronidea Rohwer
Larvae small to moderately large; length 15-25 mm.; greenish, often
spotted or banded transversely or longitudinally; body cylindrical, slender,
uniformly tapering caudad, thorax rarely conspicuously swollen; head and
trunk setiferous, often tuberculate; head blackish, brownish, or greenish;
antennae with four segments, sometimes with segments in part fused,
conical, subconical, or flattened; third abdominal segment with 4-6
annulets, more commonly 5-6, annulets 2 and 4, rarely 1, 2, and 3 setiferous;
tenth abdominal tergum with or without a pair of small but distinct suranal
caudal protuberances, if without, body swollen on thorax, protuberances
pointed, bluntly rounded, truncate, or swollen at distal end; larvapods
setiferous, setae few in number; spiracles winged or unwinged; glandubae
subsessile or obsolete; leaf -feeders, sometimes gregarious.
The genus Pteronidea is rich in number of species. The author has
examined a large number of specimens representing at least thirty species
and including much bred material, and has prepared the following synoptic
key for differentiating species. It may be stated here that Pteronidea,
together with a few allied genera, is readily separated from all other Tenth-
redinidae by the presence of a pair of suranal caudal protuberances on the
lateral portion of the caudal margin of the ultimate tergum. Pteronidea
thoracica Harrington is unique in lacking the caudal paired protuberances,
but is easily distinguished by its characteristic, somewhat elongate, tad-
pole-like body, and also by its white head and body and its spreading legs.
The color and coloration and the presence of setiferous tubercles and their
arrangement are useful characters in separating species.
SPECIES OF PTERONIDEA
1(2) Tenth abdominal tergum without suranal processes; thorax conspicuously swollen;
thoracic legs spreading out flat laterad; body entirely greenish white; on Prunus
virginiana; Y-141 thoracica Harrington.
2(1) Tenth abdominal tergum with suranal processes; thorax not conspicuously swollen. 3.
3(50) Head black or brown; body usually with numerous colored patches 4.
4(5) Body entirely blackish with distinct yellowish spots on latus; on Salix, Populus
balsamifera, etc.; Y-8.45, M-104, M-182, Y-5-2 ventralis Say.
5(4) Body not entirely blackish, without distinct yellowish spots on latus 6.
6(7) Body entirely green; head light brown; suranal processes short, mere swellings; on
Ribes sp.; Y-l ribesi Scopoli (ultimate stage)
7(6) Body not entirely green; suranal processes usually distinctly pointed, more than
mere swellings 8.
8(9) Body yellowish with 11 transverse black markings extending between subdorsal
lines across the venter. Young collection 55 Pteronidia, sp. 1.
9(8) Body not yellowish, without 1 1 transverse blackish markings 10.
86 ILLINOIS BIOLOGICAL MONOGRAPHS [404
10(17) Body without numerous small tuberculate areas, usually without fine longitudinal
series of sub-adjacent patches; thorax, at least, always suffused on dorsum with
darker shade 11.
11(12) Body shiny metallic fuscous; dorsum of all segments grayish brown; tenth abdominal
tergum uniformly black; Y-132-2-1 (on Carpinus caroliniana) , Y-132m-l-2 (on
Mows alba), Y-193 (on Alnus rugosa), erythrogastra Norton.
12(11) Body not shiny metallic fuscous; dorsum of none of segments grayish-brown; tenth
abdominal tergum not uniformly black 13.
13(14) Abdomen on dorso-meson with a fine longitudinal line; tenth abdominal tergum
fuscous on dorso-meson; suranal processes distinctly fuscous; on Alnus; M-114.
Pteronidea sp. 2.
14(13) Abdomen on dorso-meson without a fine longitudinal line; tenth abdominal tergum
not fuscous on dorso-meson; suranal processes not distinctly fuscous 15.
15(16) Tenth abdominal tergum with a fuscous triangular mark on each side of meson; head
more or less uniformly brown; on Salix rostraia; Y-169, C-427-45. .Pteronidea sp. 3.
16(15) Tenth abdominal tergum without a fuscous triangular mark on each side of meson;
head not uniformly brown but epicranial stem, vertex dorsad of ocellarae, front in the
center, and labrum distinctly darker; on hazel (?); M-153 Pteronidea sp. 4.
1 7(10) Body with numerous small blackish tuberculate areas; sometimes with fine interrupted
longitudinal lines composed of irregular subadjacent colored areas; thorax on dorsum
never suffused with darker shade 18.
18(27) Body on dorso-meson with a fine more or less continuous black line independent of
greenish or pale dorsal vessel, line occasionally faint but never entirely obsolete;
latus usually with fine more or less continuous longitudinal lines 19.
19(20) Abdomen on ventro-meson with fuscous spots; larvapods on cephalic surpedal
areas never with fuscous spots; on Alnus; M-232 Pteronidea sp. 5.
20(19) Abdomen on ventro-meson never with fuscous spots; larvapods on cephalic surpedal
areas often with fuscous spots 21.
21(24) Antennae with antacoriae distinct, not limited to periphery of an ta fossae; antennal
segment 1 very minute, never more than twice as long as wide; segment 2 usually
incomplete, if complete, ventral portion never more than a mere faint line; segment 3
usually complete, cephalic portion reduced to a line 22.
22(23) Larvapods on cephalic aspect with minute irregular blackish or brownish spots near
setae; on Salix; Y-8.48(?)-l Pteronidea sp. 6.
23(22) Larvapods on cephalic aspect without minute irregular black spots near setae; on
Salix spp.; Y-6-1,-6-6,-44-1-1, M-156 (in part), C-140, C-649 odoratus Dyar.
24(21) Antennae with antacoriae indistinct, limited to periphery of antafossae; antennal
segment 1 complete, or if incomplete, never less than twice as long as wide; segments
2 and 3 always complete, their cephalic and dorsal portions never reduced to mere
lines; segment 4 cylindro-conical; all four segments often fused together in part and
filling antafossae almost completely; larvapods on cephalic aspect with irregular
black spots near setae, spots sometimes very minute but never wanting from all
larvapods 25.
25(26) Antennae with all 4 segments fused together in part and filling antafossae almost
completely; on Salix spp.; Y-95-1-1, Y-8.45 (?)s-l-l corneUi Marlatt.
26(25) Antennae without all 4 segments fused together in part; segment 1 always dis-
tinctly separated from the other segments; antacorriae always distinct; on Populus;
M-156 (in part) Pteronidea sp. 7
27(18) Body on dorso-meson never with a fine more or less continuous black line independent
of greenish or pale dorsal vessel; latus usually without fine more or less continuous
longitudinal lines 28.
405] LARVAE OF THE TENTHREDINOIDEA—YUASA 87
28(29) Latus with distinct more or less continuous longitudinal lines; venter on meson
without black spots; C-713 Pteronidea sp. 8.
29(28) Latus without distinct more or less continuous longitudinal lines; venter on meson
usually with black spots 30.
30(31) Larvapods always with black spots on cephalic aspect; dorsum with setiferous
black tubercles more or less uniform in size; abdomen on ventro-meson without
black spots; on Ribes sp.; Y-l; M-135 ribesi Scopoli.
31(30) Larvapods never with black spots on cephalic aspect; dorsum with setiferous black
tubercles never uniform in size; abdomen usually with black spots on ventro-meson.32.
32(33) Larvapods on abdominal segments 4-7 usually with minute black spots on mesal
aspect, those on sixth abdominal segment never wanting; abdomen on ventro-
meson without black spots; on Salix; Y-95-1; M-155 (in part); M-140
Pteronidea sp. 9.
33(32) Larvapods on abdominal segments 4-7 without minute black spots on mesal aspect;
abdomen on ventro-meson with black spots 34.
34(47) Abdominal segments 7-9 on ventro-meson with black spots 35.
35(40) Ninth abdominal tergum with colored patches on first three annulets, 4, 6, and 4
patches respectively 36.
36(39) Dorsum not shaded grayish-brown 37.
37(38) On Populus; G-14; M-158 efeta MacGillivray.
38(37) On hazel; M-110 effusa MacGillivray.
39(36) Dorsum shaded grayish-brown; on Salix; Y-8.45(?)-2-l Pteronidea sp. 10.
40(35) Ninth abdominal tergum with colored patches on first three annulets .41.
41(44) Colored patches on first three annulets 2, 6 and 4 in number respectively 42.
42(43) Body small, less than 13 mm. in length; Young-49 Pteronidea sp. 11.
43(42) Body large, more than 15 mm. in length; on Populus balsamifera; M-182; G-pop.
Pteronidea sp. 12.
44(41) Colored patches on first three annulets 2, 4, and 4 in number respectively 45.
45(46) On birch; M-139 emcrita MacGillivray.
46(45) On Populus; Y-45 lombardae Marlatt.
47(34) Abdominal segments 2-8 on ventro-meson with black spots 48.
48(49) Large larvae, 20-23 mm. in length; dorsum without dark shade; head much smaller
than thorax in width and height; on Salix; Y-8.45(?)s-5-2. .fulvicrus Provancher.
49(48) Moderately large larvae, less than 20 mm. in length; dorsum always with dark shade;
head comparatively large, only slightly smaller than thorax in width and height; on
Salix;M-119 evanida MacGillivray.
50(3) Head not black or brown, usually greenish with few linear markings; body usually
without numerous colored patches 51.
51(54) Body with a pair of distinct fine latero-dorsal lines; larvapods with 1-2 setae as
viewed from side 52.
52(53) Head with a black line extending the entire length of epicranial stem to the occiput;
on Salix; M-12 erudita MacGillivray.
53(52) Head without black line extending the entire length of epicranial stem to the occiput;
on Salix; M-190 Pteronidea sp. 13.
54(51) Body without a pair of distinct fine dorso-lateral lines; larvapods usually with 3-5
setae as viewed from side 55.
55(58) Head entirely green 58.
56(57) Suranal process sharply pointed; on Rhododendron canadense; M-46
Pteronidea sp. 14.
57(56) Suranal processes bluntly rounded; on Salix; M-133 Pteronidea sp. 15.
88 ILLINOIS BIOLOGICAL MONOGRAPHS [406
58(55) Head not entirely green, usually with a blackish or brownish line along epicranial
stem and one dorsad of each ocellara 59.
59(64) Suranal process sharply pointed 60.
60(61) Body tapering caudad uniformly and slightly; uniformly green; on Salix cordala;
Y-153-1-1,-153-? mendka Walsh.
61(60) Body not tapering caudad uniformly and slightly; abdomen swollen on segments
5-7; body not uniformly green 62.
62(63) Latus of each segment with a large fuscous patch; tenth abdominal tergum with
caudal margin between suranal processes straight; on Alnus; M-71
equina MacGillivray.
63(62) Latus of each segment without a large fuscous patch; tenth abdominal tergum with
caudal margin between suranal processes convex; on birch; M-61. Pteronidea sp. 16.
64(59) Suranal processes never sharply pointed but enlarged at distal ends 65.
65(66) Antennae with segment 3 complete, altho reduced to a mere line on cephalic aspect;
on birch; M-60 Pteronidea sp. 17.
66(65) Antennae with segment 3 incomplete; Y-120 (on Gleditsia triacanthos); Y-143-1
on Salix cordata trilineata Norton.
Pontania Costa
Larvae comparatively small, whitish or greenish, usually 10-15 mm.
in length; gall-makers or leaf-edge-rollers; body cylindrical, thorax usually
not swollen; tenth abdominal tergum usually with a pair of suranal pro-
tuberances; when the paired caudal protuberances are normal in position,
i. e., near the lateral ends of caudal margin of the segment, the tergum
usually with paired blackish or brownish markings; caudal protuberances
sometimes very minute and borne on the caudal margin of the produced
median projection; spiracles winged or not winged; third abdominal
segment with four annulets, annulets 1-3 setiferous; head usually dark
brown or blackish in younger specimens and yellowish or pale brown in
older specimens; labrum with mesal emargination shallow or obsolete;
maxillary palpi with segment 2 longest, usually nearly equal in length to
segments 3 and 4 taken together; antennae with four segments, segments
fused or separate, segments 1 and 2 usuallly incomplete and separate,
segment 3 sometimes complete, often fused with segment 4; larvapods
setiferous, with four or more setae.
Most Nematinae with gall-making or leaf-folding larvae belong to this
genus. The different types of galls are supposed to be specific and are
considered of systematic value. Many species are indistinguishable in the
immature stages except by the morphology of the galls they produce.
SPECIES OF PONTANIA
I. Gall-Makers
1(18) Tenth abdominal tergum with or without the paired caudal protuberances, if present,
small, blunt, usually not longer than wide at proximal end, sometimes borne on
caudal projection of suranal lobe; tergum without paired blackish or brownish
markings; ninth abdominal tergum with distinct paired markings or transverse rows of
minute spots 2.
407] LARVAE OF THE TENTHREDINOIDEA—YUASA 89
2(3) Tenth abdominal tergura without paired caudal protuberances; tibia distinctly
longer than femur; head brownish or yellowish with space between ocellarae across
the front paler; Y-8-4- 1,-8-4-3,-8-6-1, C-y67, M-212; on Salix pomum Walsh.
3(2) Tenth abdominal tergum with paired caudal protuberances; tibia not distinctly
longer than femur 4.
4(5) Suranal lobe not produced caudad, as a small mesal projection, but with a pair of
caudal protuberances, small but normal in position, near the lateral ends of the
caudal margin; head blackish or blackish brown, space along epicranial suture paler;
spiracles usually not winged; dorsum of segments not transversely marked with
gray; on Salix; Y-7-1,-7-4-1,-8.8, C-cu 201, M-92 hyalina Norton.
5(4) Suranal lobe produced caudad, forming a small mesal projection which bears rudi-
mentary paired protuberances; head light brown with front and vertex dorsad of
each ocellara darker; spiracles usually winged; dorsum of segments transversely
marked with gray; antennae with segments 3 and 4 fused; labrum with mesal emar-
gination obsolete 6.
6(7) Gall not transected by the leaf, but attached to one surface, point of attachment
showing as discolored scar; greater part of gall free from the leaf; two or more galls
sometimes adjacent; woolly small-leaved willows; M-148 Pontania sp. 1.
7(6) Gall transecting the leaf; usually only one gall on a leaf 8.
8(9) Gall involving the midrib; surface of gall irregularly constricted; sometimes 2 or
more galls adjacent; M-226 devincta MacGillivray.
9(8) Gall not involving the midrib tho extending to it 10.
10(15) Long axis of gall parallel to midrib; leaf transecting the gall into two subequal
parts 11.
11(12) Gall kidney-shaped, strongly convex, about 14 mm. in length; M-213. Pontania sp. 2.
12(11) Gall not kidney-shaped 13.
13(14) Gall bean-shaped, slightly convex; 12-14 mm. in length; Y- 191-1-1
demissa McGillivray.
14(13) Gall bean-shaped, strongly convex; 14-15 mm. in length; M-262. .Pontania sp. 3.
15(10) Long axis of gall transverse to midrib 16.
16(17) Gall transected by leaf into two subequal semiglobose parts, surface not constricted
by a furrow; M-211,-216 Pontania sp. 4.
17(16) Gall transected by leaf into two unequal parts; surface constricted by a furrow;
M-93 Pontania sp. 5.
2. Leaf-folders
18(1) Tenth abdominal tergum always with the paired caudal protuberances
which are sharply pointed, normal in position, and longer than wide at proximal
end; tergum usually with paired blackish or brownish markings; ninth abdominal
tergum with or without distinct paired markings or transverse rows of minute
spots 19.
19(20) Tenth abdominal tergum without distinct paired blackish or brownish markings;
head entirely yellowish; M-150 Pontania sp. 6.
20( 1 9) Tenth abdominal tergum with distinct paired blackish or brownish markings 21.
21(26) Ninth abdominal tergum without any markings or spots; antennae with segment 3
sometimes incomplete 22.
22(25) Tenth abdominal tergum with markings extending entire length and dumbbell-
shaped ; antennae with segments 2 and 3 usually complete 23.
23(24) Folded portion of leaf irregularly wrinkled; usually both edges folded; M-175.
1-1 Pontania sp. 7.
24(23) Folded portion of leaf not irregularly wrinkled; usually one edge folded; Y-31-1-1,
-8, 46(?)-2-2 Pontania sp. 8.
90 ILLINOIS BIOLOGICAL MONOGRAPHS [408
25(22)
26(21
27(32
28(29
29(28
30(31
31(30
32(27
33(34;
34(33
35(36
36(35
37(42
38(39
39(38
40(41
41 (40
42(37
Tenth abdominal tergum with markings not extending the entire length and not
dumbbell-shaped; antennae with segments 2 and 3 incomplete; folded portion of leaf
irregularly wrinkled; often both edges folded; Y-139-1-1 Pontania sp. 9.
Ninth abdominal tergum with some markings or spots; antennae with segment 3
usually complete . , 27.
Ninth abdominal tergum with two transverse rows of minute colored spots 28.
Tibia longer than femur; front concolorous with vertex; setae on abdominal terga
more than three times as long as spiracles; Y-166-1-1 Pontania sp.10.
Tibia subequal in length to femur; front not concolorous with vertex but darker; setae
on abdominal terga less than three times as long as spiracles 30.
Head blackish; mature larvae 9 mm. in length; on Salix; Y-8.46(?)-l-2
Pontania sp. 11.
Head brownish; mature larvae 11 mm. in length; on Populus; M-166
Pontania sp. 12.
Ninth abdominal tergum without two transverse rows of minute colored spots .... 33.
Ninth abdominal tergum with two pairs of transverse blackish or brownish markings,
interrupted on meson; head brownish with area along epicranial suture distinctly
clear and paler; Y-142-1 derosa MacGillivray.
Ninth abdominal tergum with one pair of transverse blackish or brownish markings,
interrupted on meson; head blackish or brownish in younger specimens, yellowish
or light brown in older specimens with area along epicranial suture not distinctly
paler 35.
Tenth abdominal tergum with markings not reaching the paired caudal protuberances
but broken on caudal half into minute spots; head yellowish with two minute brown
spots on front; leaf-edge folder, folded edges not irregularly wrinkled; M-146.
Pontania sp. 13.
Tenth abdominal tergum with markings reaching the paired caudal protuberances,
not broken on caudal half into minute spots; yellowish or brownish without two
minute brown spots on front 37.
Ninth abdominal tergum with paired markings on its cephalic half 38.
Ninth abdominal tergum with a transverse row of minute spots caudad of paired
markings; leaf-edge-folder; both edges often folded and folded portion irregularly
wrinkled; M-145 Pontania sp. 14.
Ninth abdominal tergum without a transverse row of minute spots caudad of paired
markings 40.
Antennae with segment 3 incomplete; only one edge of leaf-folded, folded portion not
irregularly wrinkled; M-89,-147 Pontania sp. 15.
Antennae with segment 3 complete; both edges of leaf folded, folded portion irregu-
larly wrinkled; M-116,-144 Pontania sp. 16.
Ninth abdominal tergum with paired markings on caudal half; antennae with
segment 3 complete; single edge-folder, folded portion not irregularly wrinkled;
Y-8.46(?)-2-2 (in part) Pontania sp. 17.
Nematid genus 1. — Larvae small, greenish; body cylindrical, tapering
uniformly toward caudal end; segmentation distinct; annulation indistinct;
third abdominal segment apparently with four annulets, annulets 1, 2, and
3 setiferous; thoracic legs conspicuously long, nearly as long as thorax,
slender, with trochanter longer than femur; larvapods well developed,
setiferous; tenth abdominal segment without the paired caudal protuber-
ances; head circular, front flattened, smaller than thorax in width and
409] LARVAE OF THE TENTHREDINOIDEA—YUASA 91
height; antennae with four segments, segments small, incomplete, with
large sensory (?) pits, segments sometimes fused in part; spiracles not
winged.
This genus is represented by a single unidentified species collected by
Chester Young on Salix at Ithaca, New York. The larva is unique in the
character of the legs in that the trochanter is longer than the femur.
That this species belongs to the Nematinae is unquestionable but it is not
closely related to any genus in particular except perhaps to Pontania.
It may represent an undescribed genus.
Species 1. — Length, 10.5 mm.; body greenish; head brownish with dorsal
half of front dark fuscous; labrum semicircular with slight mesal emar-
gination; maxillary palpi with segment 1 nearly as long as segment 2
which is cylindrical and as wide at distal end as at proximal, segment 3
much smaller, segment 4 minute, peg-like, two distal segments curved
mesad; galea conical, only slightly larger than labial palpi; thoracic legs
with coxae subequal in length to tibiae, with trochanter slightly shorter
than coxa, and as long on dorsal margin as on ventral, femur shorter
than trochanter, cylindrical, three-fourths as wide as long, tarsal claws
slightly curved; larvapods with 1-2 setae near cephalic aspect; setae
slender, not stiff, rather sparse; tenth abdominal tergum rounded on
caudal margin, with few setae; subanal lobe with several setae; abdominal
segments with subspiracular areas with two setae and surpedal areas with a
single setae; on Salix nigra; C-c.y.-77.
Subfamily Blennocampinae "m
Larvae (Figs. 19-20) moderately large; body subcylindrical, sometimes
rather robust, tapering uniformly caudad, venter more or less flattened,
usually distinctly spinose; segmentation distinct; annulation indistinct;
third abdominal segment with five or six annulets, rarely apparently with
four; thorax sometimes thickened; thoracic legs well developed, normal,
tibia shorter than or subequal to femur; femur produced ventro-distad as
pointed membranous projection; larvapods on segments 2-8 and 10, normal
in form, glabrous, subsegmented, distal lobe truncate on distal margin
and often curved mesad; tenth abdominal segment usually with several
spines arranged in a transverse row along caudal margin; suranal and sub-
anal lobes with several setae; head small, sparsely setiferous, narrower than
thorax, front slightly convex; antennae with five segments, slender, elon-
gately conical; ventral glands wanting; glandubae sometimes present;
spiracles rarely winged; spines often very long, furcate, with two, three, or
five branches, barbed, or represented by conical tubercles or sometimes
reduced to short bifurcate tubercles; cuticle microscopically and densely
spinulate; ultimate stage occurs, in which all setae and spines are lost and
92 ILLINOIS BIOLOGICAL MONOGRAPHS [410
body becomes colorless and glabrous; free leaf -feeders; sometimes gregari-
ous.
The Blennocampinae as restricted by MacGillivray is a large sub-
family rich in genera and species, and is related to Fenusinae and Scolion-
eurinae. This is in agreement with Konow's statement altho this author
makes his tribe Blennocampides the third in his subfamily Tenthredinini.
Rohwer would group the majority of the genera under consideration in
his subfamily Empriinae, but take out the genera Phymatocera and Tomos-
tethus from the subfamily and place them in a subfamily by themselves.
This arrangement has an advantage in classifying the larvae because of
the fact that the larvae of Tomostethus lack the characteristic spines which
readily distinguish the Blennocampinae from all other groups in the larval
stages. The following key will separate the genera examined, with two addi-
tional ones, Erythraspides and Periclista, whose diagnostic characters
are taken from Dyar's paper (1898b).
GENERA OF BLENNOCAMPINAE
1(2) Body without spines; with six annulets, annulets 2 and 4 each with a transverse
row of minute but stalked glandubae Tomostetltus Konow.
2(1) Body with spines 3.
3(10) Third abdominal segment with six distinct annulets; spines usually unbranched but
conical if branched, very short and minute, tenth abdominal tergum with small
conical unbranched spines 4.
4(7) Body spines conical and not bifurcate, blackish 5.
5(6) Spiracles with distinct black wings M onopkadnus Hartig.
6(5) Spiracles without distinct black wings Hypergyricus MacGillivray
7(4) Body-spines not conical but bifurcate, blackish or whitish 8.
8(9) Spines whitish; tenth abdominal tergum not marked Blennocampa Hartig.
9(8) Spines black; tenth abdominal tergum marked with black. .Erythraspides Ashmead.
10(3) Third abdominal segment with five annulets, rarely apparently with four; spines in
part usually bifurcate, long, never short and conical 11.
11(12) Tenth abdominal tergum with a mesal spine cephalad of caudal marginal row of
spines; subdorsal spines of prothorax with five branches; prothoracic spinal formula:
5-2-1:5:1-2; third abdominal segment:2-2-2K):3-2-2:2-l:l-2; ultimate tergum 1-1-1:
2:2 Monophadnoides Ashmead.
12(11) Tenth abdominal tergum without a mesal spine cephalad of caudal marginal row of
spines; subdorsal spines of prothorax with three branches at most 13.
13(14) Second annulet of third abdominal segment with three spines dorsad of spiracular
line; host-plants not confined to Quercus species; prothoracic spinal formula: 2-2-2:
2-3:1-2; third abdominal segment 2-2-2:1:2-2-2:2-1:1:1 Isodictium Ashmead.
14(13) Second annulet of third abdominal segment with two spines dorsad of spiracular
line; host-plants confined to species of Quercus; otherwise resembling the preceding
genus Periclista Konow.
Tomostethus Konow
Larvae moderately large, length 17-21 mm., rather robust, yellow-
ish white; body subcylindrical, tapering little caudad, venter flattened,
411] LARVAE OF THE TENTHREDINOIDEA—YUASA 93
without spines, sparsely and microscopically setiferous; head black, shiny,
much smaller than thorax; third abdominal segment with six annulets,
annulets 2 and 4 each with a transverse row of few stalked glandubae;
tenth abdominal segment without spines, truncate on caudal margin;
spiracles not winged, but with a pair of faint ventral crescentic brown
marks; antennae, (5, 4, 3), 2, 1 in older larvae and 5, (4, 3), 2, 1 in younger
larvae; maxillary palpi, 4, 2, 1, 3, pointed; labial palpi rather slender, (1, 2);
ultimate stage entirely whitish.
Tomosthethus bardus Say. — Length, 18 mm.; width of head, 1.9 mm.;
body whitish with yellowish tinge, in older specimens yellowish white;
head shiny black with clypeus alone lighter in color; legs blackish brown;
larvae gregarious; on ash; G-2, Y-8.14.
Tomostethus multicinctus Rohwer. — According to Sasscer's description
(1911) the larvae of this species are indistinguishable from the preceding
species but the bred adults have been assigned to this species by Rohwer.
Larvae have not been examined.
Blennocampa Hartig
Larvae rather small, length 15-20 mm.; greenish; body subcylin-
drical, slender, tapering uniformly caudad; spines small, bifurcate, tubercle-
like or conical; head very small, third abdominal segment with six an-
nulets, annulets 2 and 4 spinose; tenth abdominal segment spinose, spines
conical, unbranched, numerous, arranged in four rows, 1: 1: 1-1-1:
1-1-1-1-1; typical prothoracic spinal formula: 2-2-1-1-1: 1-1-1: 1: 1-1;
third abdominal segment, 2-2-1: 1:2-2-1: 1-1-1: 1-1-1; antennae, 5, (1, 2, 3,
4); maxillaray palpi, (2, 3, 4), 1, slender, pointed; labial palpi (1, 2),
nearly equal to two distal segments of maxillary palpi taken together;
legs with femur longer than tibia; larvapods normal in form, more or
less rounded at distal end.
Blennocampa spiraeae Dyar. — Length, 16.5 mm.; width of head, 1.2
mm.; body greenish; head pale brown; legs concolorous with body; ocel-
larae entirely black, tips of mandibles and tarsal claws brown; maxillary
palpi with segment 4 and labial palpi with segment 2 deep brown; pro-
thoracic formula of spines variable, 2-2-1-1-1 or 2-3-1-1, or 2-1-1-1; ab-
dominal segment on surpedal lobe with from 2-1 to 2-2 spines; tenth
abdominal tergum with small, short, conical spines arranged in four rows
as follows: (1) two pair of spines on each side of meson, (2) two spines on
each side of the meson, near the center of the tergum, (3) lateral pairs
sometimes with additional spines, and (4) the last and caudal row of
five spines on each side of meson along the caudal margin of tergum, the
three lateral spines closer together than the others; on Spiraea; not bred:
M-28.
94 ILLINOIS BIOLOGICAL MONOGRAPHS 1412
Erythraspides Ashmead
Larvae comparatively speaking small, inconspicuously spinose,
greenish; third abdominal segment with five annulets, annulets 2 and 4
each with three minute bifurcate spines.
According to Dyar's Key (1898) the larvae of Erythraspides pygmaeae
is distinguished from those of Blennocampa spiraeae by the black head
and spines of the former. Record is meager, and without specimens no
adequate diagnosis can be given.
MONOPHADNUS HaRTIG
Larvae rather small, length less than 15 mm., spotted; body rather
robust, only slightly and uniformly tapering caudad; tubercles conical,
small, blackish, not furcate; third abdominal segments with six annulets,
annulets 2 and 4 tuberculate; tenth abdominal tergum with two rows of
tubercles, some of which are bifurcate; pro thoracic spinal formula:
1-1:1:1:1; third abdominal segment, 1-1-1:1:1-1-1:1:1; antennae 5, (4, 3,
2), 1; maxillary palpi (4, 2), 1, 3; labial palpi (1, 2); palpi rather thick and
conical; spiracles with distinct black wings.
Monophadnus nubilipennis Norton. — Length, 14 mm.; width of head,
1.3 mm.; head blackish brown, clypeus alone lighter; body dirty white
with yellowish tinge; legs grayish; on hellebore; Y-42,-8.42.
Hypergyricus MacGillivray
Larvae rather large and robust, spotted; length 16-20 mm., body
subcylindrical, tapering but slightly and uniformly caudad; tubercu-
late, tubercles conical, short, stout, usually not furcate; third abdominal
segment with six annulets, annulets 2 and 4 tuberculate; tenth abdominal
segment with two rows of few tubercles; prothoracic spinal formula
variable, but with a single tubercle on supraspiracular area and two tubercles
ventrad of it; third abdominal segment also with variable number of
tubercles, only two on subspiracular area; tubercles not furcate; spiracles
with faint ventral crescentic brown marks but without definite wings;
antennae rather obtusely rounded, segments decreasing in diameter from
proximal to distal, but increasing in length; suranal and subanal lobes
strongly convex, with numerous short recumbent setae; legs with femur
distinctly longer than tibia; distal portion of femur dilated and produced
vehtro-mesad.
SPECIES OF HYPERGYRICUS
Head black, genae, antennariae, ventral half of front and clypeus lighter in color; tubercles
blackish; body whitish, faint grayish shade and yellowish tinge in older stages;
legs grayish brown; antennae with segment 3 and 4 subequal in length; prothorax
with spines, 2-2:1:1:1; third abdominal segment, 1-1:0:1-1:1:1; latus of body along
supraspiracular lines with broken band of grayish shade, marks distinct and square
413] LARVAE OF THE TENTHREDINOIDEA—YUASA 95
dorsad of each spiracle; on leaves and fruits of Smilacina racemosa; length, 18 mm.;
width of head, 1.8 mm.; Y-73,-29-10,-8.73, M-181 fumipennis Norton.
Head brownish yellow; length, 17 mm.; width of head, 1.9 mm.; spots on dorsum variable;
body whitish with faint yellowish tinge; legs concolorous with body; supraspiracular
lines without smoky-black band; prothoracic spines 1-1-1 or 1-1-1-1:1:1:1 or 3; third
abdominal segment with 1-1 ; 1:1-1-1 :1 :1 ; any of the dorsal tubercles may be wanting;
otherwise similar to the preceding species; Y; 20 specimens collected by Mr. J. R.
Malloch on Smilacina in Illinois Hypergyricus sp. 1.
MONOPHADNOIDES ASHMEAD
Larvae small, distinctly spinose, greenish; length less than 17 mm.;
body subcylindrical, tapering caudad, rather slender; spines furcate,
with two, three, or more branches; third abdominal segment with five,
apparently four, annulets, annulets 2 and 3 spinose; prothorax with spines,
5-2-l:(5 or 3):1:2; third abdominal segment, 2-2-2:0:(3 or 2)-2-2:2-l:l-2;
tenth abdominal tergum with a mesal furcate spine cephalad of caudal
marginal row of spines; legs rather slender, femur slightly longer than
tibia, not dilated at distal end; spiracles unwinged; maxillary palpi,
(1, 4), (2, 3); labial palpi, (1, 2); maxillary and labial palpi slender, pointed;
antennae, 5, (1, 2, 3, 4), sharply pointed and slender; semigregarious.
Monophadnoides rubi Harris. — Length, 16 mm.; width of head, 1.6 mm.;
head pale brownish green, distinctly setiferous, spines whitish, branches
sometimes light brown; length of longer branches subequal to the width
of head as seen in profile; tenth abdominal tergum with mesal spines with
2-3 branches, on the caudal third of the tergum cephalad of the marginal
row of spines, sometimes another smaller unbranched spine cephalad of
the furcate mesal spines; marginal row of spines, beginning with mesal
spine, consists of two simple, one bifurcate and lower, and lateral simple
spine on each side of meson; on Rubus and also on giant Ragweed; Y-8.17,
M-19,-183, G-562, 500-3.
ISODYCTITJM ASHMEAD
Larvae rather small, usually distinctly spinose; length less than 17 mm.;
body subcylindrical, tapering caudad, rather slender; third abdominal
segment with five annulets, annulets 2 and 4 spinose, sometimes appar-
ently four-annulate, with annulets 2 and 3 spinose; spines furcate, usually
with two to three branches, branches usually conspicuously long, some-
times small, short, but always sharply pointed at distal end; spiracles never
winged; thoracic legs normal, femur subequal in length to or longer than
tibia; head blackish or spotted on vertex and front or uniformly greenish;
spines on prothorax, 2-2-2-1:2-2:1:2; on third abdominal segment 2-2-2:1:
2-2-1:1:1; tenth abdominal segment with a marginal row of spines, usually
four on each side of meson.
96 ILLINOIS BIOLOGICAL MONOGRAPHS [414
Several species have been examined. None of the material has been
identified altho the following larva may belong to /. subgregarium.
Isodyctium sp. 1. — Length, 15.5 mm.; head, 1.5 mm. wide; head marked
on vertex and front with large confluent brownish spots, those on front
sometimes separate; body uniformly greenish; legs concolorous with
body, femur subequal in length to tibia; spines blackish, very long and
furcate, with large proximal end, those ventrad of spiracular lines whitish;
those one-half as long as head are wide as seen in profile; prothorax with
spines, 2-2-2-1:2-2:1:2; third abdominal segment, 2-2-2:1:2-2-2:2-1:1-1;
tenth abdominal tergum, 2-1:2:2, the mesal pair sometimes with confluent
bases; maxillary palpi, (4, 2), 3, 1 ; labial palpi, 1,2; ultimate stage: entirely
whitish, vertex pale brown, third abdominal segment with five distinct
annulets, setiferous but not spinose; on oak; M-6.
Subfamily Fenusinae
Larvae (Fig. 21) very small; body semicylindrical, venter flattened,
depressed, tapering caudad, glabrous; segmentation distinct; annulation
indistinct; third abdominal segment with either one or apparently 2-4
annulets; thorax slightly swollen, prothorax sometimes with dorsal and
ventral shields; legs small, short, apparently with four segments, spreading
cephalo-laterad; larvapods on abdominal segments 2-8, vestigial, merely
mound-like; anal larvapods obsolete; tenth abdominal tergum glabrous
without suranal processes or caudal protuberances, sometimes with small
mesal projections; suranal and subanal lobes glabrous; head sparsely
setiferous, depressed, subtriangular in outline, wedge-shaped in profile
narrower than thorax and overlapped on caudal third by prothorax; ver-
tical furrows wanting; antennae apparently with single segment; antacoria
large; ocellarae minute, located dorso-caudad of antennariae; ventral
glands wanting; glandubae wanting; spiracles indistinctly winged; cuticle
sometimes with microscopic but distinct chitinized dentiform spines;
larvae, leaf-miners.
The Fenusinae is a small subfamily represented by four genera in the
Nearctic region. Systematists have always considered this group as
closely related to the Scolioneurinae and Blennocampinae. MacGillivray
is the only one who would assign them subfamily rank. Konow listed three
European species, dohrni, nlmi, and pumila, under the old generic name
Kaliosysphinga. The first two are now considered as types of distinct
genera. They have been introduced into this country and are liable to do
considerable damage at times. The genera studied are separable as follows:
GENERA OF FENUSINAE
Caudal end of body rounded, without a mesal suranal protuberance; sternum of ninth abdom-
inal segment with a pair of swellings covered with distinct microscopic dentiform spines:
415] LARVAE OF THE TENTHREDINOIDEA—YUASA 97
tenth sternum strongly convex, much shorter than ninth sternum
Kaliofenusa MacGillivray.
Caudal end of body truncate, with a mesal suranal protuberance; sternum of ninth abdominal
segment flattened, uniformly and microscopically spinulate; tenth sternum slightly
convex, nearly as long as the ninth sternum Fenusa Leach.
Kaliofenusa MacGillivray
Larvae very small, greenish white; length less than 12 mm.; thorax
broadest on meso thorax; declivous on dorsum from metathorax toward
the head; head only slightly depressed, front convex; mouth-parts normal
except labium, which is flattened; mandibles rather thick in profile;
dorsum and venter covered with brownish, irregular, microscopic dentiform
spines, larger on the center of segment and larvapods; caudal end of body
rounded; tenth abdominal tergum without mesal protuberance; sternum
of ninth segment with a pair of microscopically dentate swellings; tenth
sternum strongly convex, much shorter than ninth sternum.
Kaliofenusa ulmi Sundevall. — Length, 10 mm.; width of head, .9 mm.;
head light brown, legs brown, ocularia, mandibles, maxillary palpi, deep
brown; sternum of ultimate segment with transverse depression on the
caudal third distinct; leaf -miners, on Ulmus, feeding on all tissues except
upper and lower epidermis; Y-4-1, -4-2,-8.4.
Fenusa Leach
Larvae very small, length less than 12 mm., greenish white; body rather
uniform in width except at caudal end which tapers suddenly and dis-
tinctly; head strongly depressed; front flattened; mouth-parts protruding
beyond the distal end of mandibles; body uniformly and microscopically
spinulate; no distinct localized microscopic dentiform spines; caudal
end of body truncate; tenth abdominal tergum with a distinct mesal coni-
cal suranal protuberance; sternum of ninth segment rather flattened,
without microscopically dentate swellings; tenth sternum slightly convex,
nearly as long as ninth.
Fenusa dohrni Tischbein. — Length, 10-11 mm., width of head, 1.1 mm.;
head brown; prothorax with dorsal and ventral shields indicated; thoracic
legs light brown, trochanter wanting, femur subequal in length to tibia;
tibia with proximal end subequal in diameter to distal end of femur;
tenth abdominal sternum with transverse depression in caudal fourth
indistinct; body often greenish, green adipose tissues being visible thru
the cuticle; dorsal vessel showing thru as light-colored line; leaf -miners on
Alnus vulgaris, feeding habit similar to that of Kaliofenusa ulmi; Y-4. A,
-43-1-2.
98 ILLINOIS BIOLOGICAL MONOGRAPHS (416
Subfamily Scolioneurinae
Larvae (Fig. 22) very small; body semicylindrical, somewhat de-
pressed, flattened on venter, broader on thorax, tapering caudad, glabrous,
greenish, never with bright patterns; segmentation distinct; annulation
indistinct, third abdominal segment with two annulets; larvapods rudi-
mentary, mere swellings on abdominal segments 2-7, the anal pair adjacent
on meson, forming a single protuberance; thorax thickened, prothorax
often with distinct dorsal and ventral chitinized shields; thoracic legs
small, slender, distinctly five-segmented, directed laterad; head depressed,
sub triangular, wedge-shaped in profile, narrower than thorax; mouth-
parts flattened and protruding, labium large, with submentum and mentum
strongly chitinized; antenna one-segmented; vertical furrows usually
wanting; tenth abdominal tergum abbreviated, glabrous; spiracles usually
winged; glandubae obsolete; ventral glands wanting; cuticle often with
minute dentiform tubercles; leaf-miners.
The Scolioneurinae is a small subfamily containing six genera, four of
which are peculiar to the Nearctic region. All six genera are represented
in the North American fauna. Prior to the recognition of the subfamily
by MacGillivray, the species belonging to it were referred to the genera
Fenusa and Blennocampa. Konow first segregated a species of Entodecta
and later more of Scolioneura from Blennocampa, placing them, together
with Fenusa and its allies, in other genera of his tribe Blennocampides.
Rohwer would separate the genera of the Scolioneurinae from those of
the Blennocampinae but unite them with those of the Fenusinae in the
tribe Messini of his subfamily Messinae. The close affinity of the Fenu-
sinae and Scolioneurinae is evident from the fact that all known larvae
of these subfamilies are leaf-miners and that they possess similar types of
structural modifications. The definitions here given are based on obser-
vations on two American species of Metallus supplemented by writings of
European students — Cameron, Brischke, and Zaddach.
Metallus Forbes
Larvae small, length 10-13 mm., whitish or pale brownish; body de-
pressed, rather stout, mesothorax broadest; pleuron of each segment
tuberculate; cuticle with microscopic irregular chitinized dentiform
tubercles, those on center of dorsum and venter largest; head directed
ventro-cephalad, much narrower than thorax, attached to the ventral
part of prothorax; vertical furrows wanting; front twice as long as wide,
labrum subtriangu'ar, small; antennae mamma-like; ocellarae incon-
spicuous, about one-fifth the diameter of the antennaria; mouth-parts
small but distinct, slightly modified; mandibular dentes sharp; maxillary
palpi three-segmented, stipes elongate, galea digit-like, slightly curved
417] LARVAE OF THE TENTHREDINOIDEA—YUASA 99
mesad and subequal in size to palpi, lacinia thin, small, plate-like; labium
comparatively large, flattened; labial palpi inconspicuous, apparently
2-segmented; ligula globose and proturding; thoracic legs with coxa large,
stump-like, following segments suddenly smaller and slender, trochanter
ring-like, femur as long as wide, tibia longer than femur, cylindrical,
chitinized, tapering gradually to distal end, tarsal claws broadly curved,
sharp; mesothorax and metathorax with a dorsal membranous swelling
on each side of the meson; spiracles distinctly and semicircularly winged;
tenth abdominal tergum small, convex; anal setae wanting; subanal lobe
small, prominently convex.
SPECIES OF METALLUS
Head brownish, not concolorous with body, epicranial suture very distinct; dorsal and ventral
shields distinct and brown; dorsal shield transverse, covering dorsum of prothorax,
proventral shield very large, occupying entire venter between prothoracic legs caudad of
and continuous with brown cervacoria, mesoventral and metaventral shields small,
transverse, triangular between legs; labium with submentum strongly chitinized, brown
with dark carina on meson and along caudal margin, mentum brown, longer than wide;
larvapods with crescentric brownish band on cephalic aspect; length, 11-12 mm.; on
Rubus; Y rubi Forbes.
Head pale or whitish, concolorous with body, at least not distinctly colored ; dorsal and
ventral shields obsolete, only rarely faintly indicated; labium with submentum broad
and without dark median longitudinal carina, depression on meson rarely present,
never dark and distinct; larvapods without crescentric brownish band on the cephalic
aspect; length, 10 mm.; on Rubus; Y bethunei MacGillivray.
The larvae of Metallus rubi were described by Forbes, but the original
specimens are apparently lost. The description given here is based on
specimens in the Cornell Collection. Forty-three larvae of M. bethunei
were examined thru the courtesy of Mr. H. G. Crawford of Guelph,
Ontario, Canada.
Subfamily Hylotominae
Larvae (Fig. 23) moderately large; body semicylindrical, venter
flattened, distinctly wider than high, widest on abdominal segments 1-3,
tapering caudad, caudal segments only one half the width of widest seg-
ments; yellowish green, spotted or not; segmentation distinct; third
abdominal segment with three annulets, all setiferous, often tuberculate;
thoracic legs large, spreading laterad, apparently six-segmented inclusive
of claws; claws sharply curved, large, distinctly separated from fifth
segment by suture and with a large pulvillus-like swelling; larvapods
setiferous, on abdominal segments 2-6 and with rudimentary 7th pair, or on
2-7 and 10 with rudimentary 8th pair; antennae one-segmented, either
conical or button-like, if conical, larvapods on abdominal segments 2-6
and 10; spiracles distinctly winged; glandubae obsolete; tenth abdominal
tergum without suranal processes.
100 ILLINOIS BIOLOGICAL MONOGRAPHS [418
The Hylotominae in the adult stage is closely allied to the Schizocerinae.
but in the larval stages their affinities, if extant, are not so manifest,
The laravae are peculiar in possessing six-segmented -thoracic legs and
varying numbers of larvapods. The shape and general appearance of the
larvae are so characteristic that they alone are sufficiently reliable for
identification in the field. Two genera are represented in the Nearctic
region, the genus Atomacera, which includes only a few species, has not
been studied.
Hylotoma Latreille
Head, conspicuously shiny black, brown or yellowish, or with a brown
median streak; body with minute blackish tuberculate setiferous spots
forming interrupted longitudinal rows along some or all of the subdor-
sal, latero-dorsal, supraspiracular, subspiracular, and pedal lines; annu-
lation usually 2, 3, 1; annulet 1 with a few minute setae, annulets 2 and
3 with a transverse row of a few stiff brown setae together with very
minute setae scattered around the larger setae; subspiracular tubercles
obsolete; pedal area prominent, produced laterad and oblique, extending
entire length of segment; maxillary palpi normal, four-segmented, segment
1 flattened, with distinct mesal projection, segments 2 and 3 cylindrical,
segment 4 minute, peg-like; labial palpi normal, three-segmented; larva-
pods located close together near the meson, proximal portion chitinized, seti-
ferous, distal portion small, membranous, non-setiferous, bluntly rounded,
those on seventh or eighth abdominal segment lacking membranous
distal portion.
The genus is divisible into two sections by the structure of antennae and
number of larvapods. Owing to the incompleteness of published records
of larvae of this genus, involving in some cases confusion in specific identi-
fication, it is not possible to determine many of the specimens collected.
The following key will separate the species represented in the collections
studied.
SPECIES OF HYLOTOMA
1 (10) Antennae distinctly conical or peg-like, twice as long as wide; larvapods on abdominal
segments 2-6 and 10, seventh segment with rudimentary pair; head always uniformly
blackish, brownish, or yellowish; body always with numerous minute blackish spots
arranged longitudinally along subdorsal, dorso-lateral, supraspiracular and pedal
lines f 2.
2(5) Head always black, thoracic legs with all segments blackish; tenth abdominal tergum
blackish 3.
3(4) Tenth abdominal segment on ventral half blackish; area between larvapods with
minute colored spots; area ventrad of pedal folds with minute spots; latus of each
segment with a few very minute secondary setiferous spots besides regular tubercu-
late spots; on Crataegus Y-194-3 194-2; on Prunus? Y- 194-5 Hylotoma sp. 1.
4(3) Tenth abdominal segment on ventral half unmarked, whitish; area between larvapods
without minute colored spots; area ventrad of pedal folds without minute spots;
419] LARVAE OF THE TENTHREDINOIDEA—YUASA 101
latus of each segment without minute setiferous spots; on Alnus: Y- 194-4
Hylolonia sp. 2.
5(2) Head not always blackish but usually yellowish or brown; thoracic legs not with all
segments blackish, segments distad of coxa usually brownish or brownish yellow;
tenth abdominal tergum not always blackish 6.
6(7) Head blackish; tenth abdominal tergum yellowish; subanal lobe yellowish; spots
between larvapods numerous and brownish; latus of each segment with many very
minute secondary setiferous spots; tuberculate spots of body yellowish with brown
border; on oak; Y-214-1-2 Hylotoma sp. 3.
7(6) Head yellowish or reddish brown; tenth abdominal tergum blackish; subanal lobe
whitish 8.
8(9) Area ventrad of pedal folds with many minute setiferous spots; area between larva-
pods sometimes with spots; spots on body not uniformly blackish or brownish but
blackish on cephalic and also usually on caudal portion of the body those on middle
portion brownish or yellowish with brown border sometimes spots all pale yellowish
brown; head reddish or yellowish brown; on Crataegus; Y-222
scapularis Klug.
9(8) Area ventrad of pedal fold without spots; area between larvapods never with spots;
spots on body uniformly blackish or brownish; head yellowish or yellowish brown;
on elm; C-C.U. 668 Y-29-24 Hylotoma sp. 4.
10(1) Antennae button-like, usually wider than long; larvapods on abdominal segments
2-7 and 10, eighth segment with rudimentary pair; head blackish brownish or with a
distinct median streak from occiput to front; body sometimes not spotted except
on each side of the meson on cephalic segments 11.
11(14) Head blackish or brownish; body distinctly and regularly spotted; tenth abdominal
tergum and subanal lobe usually blackish; thoracic legs usually with coxae blackish
or brownish and other segments brownish or grayish 12.
12(13) Tenth abdominal tergum and subanal lobe whitish; all colored areas or spots of body
brownish; area between larvapods with few setiferous spots; area ventrad of pedal
fold with many setiferous spots; on Salix discolor; C-Young 61. . . .Hylotoma sp. 5.
13(12) Tenth abdominal tergum and subanal lobe blackish or brownish; all colored areas
or spots blackish or brownish; area between larvapods usually without setiferous
spots; area ventrad of pedal fold with varying number of spots; on Prunus; Y-1946-1
G-Onekama No. 23; Maine 1915; C-C.U. 656 C.U. sub. 64 Hylotoma sp. 6.
14(11) Head yellowish or light brownish with brown streak along epicranial stem; body not
regularly and distinctly spotted except along dorso-meson on cephalic segments;
tenth abdominal tergum never blackish or brownish; thoracic legs always con-
colorous with body; Y-185-1-2 (Azalea) Y-185 (Willow) M-113 (birch bred) M-108
(hazel) macleayi Leach.
Subfamily Schizocerinae
Larvae (Fig. 24) small; body subcylindrical, flattened on venter,
tapering caudad, mesothoracic and metathoracic segments somewhat
swollen, prothorax distinctly tapering cephalad; whitish or creamy white,
never spotted or striped; segmentation and annulation indistinct; third
abdominal segment with three annulets, all annulets provided with a
transverse row of tubercles; spiracles on annulet 1; tenth abdominal
tergum without suranal or caudal protuberances; larvapods on abdominal
segments 2-8 and 10, the venter of ninth segment with a pair of minute
102 ILLINOIS BIOLOGICAL MONOGRAPHS (420
protuberances; thoracic legs modified, pro thoracic legs apparently four-
segmented, distal segment pad-like, tarsal claws wanting; mesothoracic
and metathoracic legs apparently three-segmented, distal segment pad-
like with a sharp claw on cephalic side; antennae apparently one-segmented,
segment large with several clear spots; antennaria ventrad or slightly
caudad of ocularium; spiracles winged; glandubae obsolete; in younger
specimens larvapods sometimes very indistinct; tubercles often indistinct;
leaf-miners.
The Schizocerinae is represented in the Nearctic region by a single
genus, Schizocerus, and includes a limited number of species. Modern
systematists have always associated this subfamily with the Hylotominae,
the two being separated by the presence or absence of the free part of
Scj in the front wing. The larvae of this subfamily are unique in having
thoracic legs and maxillary and labial palpi modified by reduction in the
number of segments.
Schizocerus Lepeletier
Larvae small, length less than 15 mm., creamy- whitish; head small,
pale brown, higher than wide, sparsely and microscopically setiferous;
annuJation 1, 2, 3; annulets above spiracular b'nes with tubercles, 2 on
annulet 1, four on annulet 2, and three on annulet 3, annulet 1 with a row
of tubercles on venter; a row of tubercles between larvapods and surpedal
area; subspiracular area not tuberculate or warty; tenth abdominal
tergum small, only slightly convex, tubercules almost obsolete, with
several stiff short setae on caudal margin; venter of ultimate segment
with distinct anal larvapods, subanal lobe with a pair of long and short
tubercles on each latero-caudal margin; maxillary palpi apparently three-
segmented, distal segment very minute, formula, 2, 1, 3; labial palpi
apparently two-segmented; mandibles as viewed from side narrow and
slender; totaglossa of labium large; spiracles winged, wings small, oblong;
spiracular line dividing the latus into two subequal dorso-ventral parts.
Schizocerus zabriskiei Ashmead. — Head pale brownish-green, body
whitish; in younger specimens head brownish, body with minute tubercles
touched with brown; legs, and venter between legs brownish; tubercles
ventrad of surpedal area and dorsad of larvapods usually three in number
in mature larvae and two in younger larvae; mature specimen, length,
13 mm.; width of head, 1.3 mm.; on Portulaca; Y, G.
Schizocerus sp. 1. — Larvae indistinguishable from the preceding species.
This species was collected at Muncie, HI., by Dr. Edna Mosher, who
bred adults. It is considered by Dr. MacGillivray to be a new species.
421] LARVAE OF THE TENTHREDINOIDEA—YUASA 103
Subfamily Acordulecerinae
Body (Fig. 25) subcylindrical, tapering caudad, venter flattened,
thorax distinctly swollen; segmentation distinct; annulation indistinct,
third abdominal segment with apparently three annulets, all annulets
tuberculate, setiferous; thoracic legs 5-segmented, spreading laterad, distal
segment consisting of a sharp recurved claw and caudal membranous
globose swelling; pro thoracic legs one-half as large as meta thoracic;
larvapods rudimentary on abdominal segments 2-7 and 10, increasing in
size from cephalic pair to sixth pair; tenth abdominal segment truncate,
small, without suranal processes; antennae flattened, apparently 1-seg-
mented; abdominal segments 2-4 or 2-5 and 8 with crescentic sucker-like
protuberances, one on each postsubspiracular protuberance; ventral
glands wanting; spiracles not winged; glandubae wanting.
The Acordulecerinae, according to MacGillivray (1906), is represented
on the North American continent by a single genus, Acordulecera. Rohwer
would divide the subfamily into two tribes, Acordulecerini and Conocoxini,
the former including besides Acordulecera, Pantherix and possibly
Thulea and the latter Conocoxa and Nithulea. A radically different
arrangement is that of Konow who regarded Acordulecera as one of
fourteen genera included in his tribe Lobocerotides which was one of four
tribes constituting his subfamily Lophyrini. Konow seems to have been
unfamiliar with the larvae of the Nearctic genus Acordulecera, for he
speaks of the larvae of Lophyrini as "mit 16 Abdominalbeinen ; an Coni-
feren." — a characterization not at all applicable to the genus under
consideration. The host-plant of two species of Acordulecera have been
recorded, and one species recognized in the larval stage. I have examined
larvae of several unbred species.
Acordulecera Say
Larvae very small, length less than 12 mm., greenish, never spotted or
striped; head usually brownish or pale; annulation, 3, (2, 1); prothorax
constricted; annulets with transverse row of slight tubercles, each bearing
slender peg-like setae; lateral lobes distinct; tenth abdominal tergum with
several setae; suranal and subanal lobes with several setae; maxillary palpi
rather slender, uniformly tapering distad; mandible thick; labial palpi
small; ligula dilated, rounded; free leaf-feeders; gregarious.
SPECIES OF ACORDULECERA
1(4) Sucker-like protuberances on abdominal segments 2-5 and 8 2.
2(3) Head with vertex blackish brown, front distinctly lighter in color; legs whitish
concolorous with body; sucker-like protuberances with three marginal setae; length
9.5 mm.; width of head 1.2 mm.; on butternut; Y-8.93(?)-2-2. . .Acordulecera sp. 1.
3(2) Head with vertex light brown, epicranial stem deep brown, front sometimes deep
brown; in young specimens head entirely dark brown; legs brown; sucker-like
104 ILLINOIS BIOLOGICAL MONOGRAPHS [422
protuberances with three marginal setae; length 11 mm.; width of head 1.3 mm.;
on chestnut and butternut; Y-93 C-cu 667 Acordulecera sp. 2.
4(1) Sucker-like protuberances on abdominal segments 2-4 and 8 5.
5(8) Sucker-like protuberances with three marginal setae; on oak 6.
6(7) Head light brown with epicranial stem deep brown or brownish with vertical furrows
lighter in color; legs brownish; length 9 mm.; width of head 1.2 mm.; Y-131 -137,
C-cu 680, M-37 Acordulecera sp. 3.
7(6) Head yellowish or light brown, with epicranial stem concolorous with body; length,
7 mm.; width of head, 1.1 mm.; M-239, M-243, C-yll dorsalis Say.
8(5) Sucker-like protuberances with five marginal setae; head deep brown, vertical
furrows and epicranial arms lighter in color; legs whitish, concolorous with body;
length, 9 mm.; width of head, 1.2 mm.; on hickory; Y-144-5 tnusta MacGillivray.
Family Pamphiliidae
Larvae (Fig. 1) of medium size; body subcylindrical, slightly flattened
on the ventral aspect; sublateral lobe on the ventro-lateral margin dis-
tinct, moderately large; body slender to robust; segmentation and annula-
tion distinct; cuticle microscopically setiferous, appearing smooth, often
delicate, transparent; color usually greenish or creamy white; head semi-
globose, prominent, as wide as thorax; color creamy or brownish or blackish;
mouth directed ventrad; head completely exposed, sparsely setiferous;
epicranial suture and vertical furrows present; antennae extremely long,
setaceous, conspicuous, seven-segmented; ocularia located ventro-laterad
of antennariae; mouth-parts normal, sericos produced and prominent;
prothorax with shield-like, usually brownish, broad patches on the dorsal
and lateral aspects; thoracic legs modified, setiform, sharply pointed,
segments cylindrical, distal segment very long, slender, straight; third
abdominal segment with four annulets on dorsal and ventral aspects;
spiracles on the second annulet; larvapods wanting; eighth abdominal
segment on the venter mesad of the lateral lobe with a fleshy protuber-
ance resembling a larvapod, ninth segment cylindrical, smaller than the
preceding; tenth segment depressed, rounded on the caudal margin,
usually setiferous, sometimes conspicuously so, often with colored patches,
always with a median hook-like suranal process near the caudal margin
of the tergum; subanal lobe with a pair of setiform, three-segmented
conspicuous subanal appendages; insects one- or two-brooded; spinning
silken web or rolling leaves for their nests; solitary or gregarious; pupate in
the ground.
The Pamphiliidae is an easily circumscribed family of eight or nine
genera and a large number of species which are peculiar to the Northern
hemisphere. The adults differ from all other Hymennoptera except the
Xyelidae in the preservation of the subcostal vein in the hind wings.
In this character it is more generalized than the Xyelidae altho it is
more specialized than this family in other features of venation. Brischke
423] LARVAE OF THE TENTHREDINOIDEA—YUASA 105
and Zaddach (1865) discussed the immature stages and biology of eleven
European species of the Pamphiliidae and pointed out that certain of
their habits may be of taxonomic significance. The larvae of these species
fall into one or the other of two groups according to the type of nests they
build. The first group contains those whose larvae build nests by tying the
leaves of their food-plants together with threads of silk and are either
solitary, as Lyda, or gregarious, as Cephaleia and Neurotoma. The
second group consists of those whose larvae build nests by rolling the
edge of the leaves of their food-plants and live inside the tubes so formed,
as Pamphilius. Some of this latter group make portable nests out of
detached pieces of leaves, as Pamphilius inanitus on Rosa. The adults,
however, are so closely related to each other that Rohwer (1911) con-
sidered such a subdivision impractical. Konow (1901), in his analytical
table of the larvae, included sixteen species, representing four genera, but
did not register any Nearctic species. According to this writer (1905) the
larvae of Lyda and Cephaleia feed on coniferous plants while those of
Neurotoma and Pamphilius attack deciduous plants. Nothing is known
concerning the biology of Anoplolyda. Dyar (1895) included in his table
ten Nearctic pamphilids but, excepting Pamphilius ocreatus, all were uni-
dentified and many were taken from descriptions given by Packard (1890).
Of about fifty-five Nearctic species representing seven genera, Acan-
tholyda, Itycorsia, Cephaleia, Caenolyda, Neurotoma, Pamphilius, and
Anoplolyda, only five species have been identified in the larval stage,
and the food-plants of about six species recorded.
Four identified and several unidentified species have been examined.
It is not possible to define the genera with this limited material; the
species studied can be separated as follows.
SPECIES OF PAMPHILIIDAE
1(14) Subanal appendages with the second segment longer than or subequal to the third
segment, never distinctly shorter; head usually dark-colored ; tenth abdominal tergum
with colored patches 2.
2(3) Subanal appendages with the second segment subequal in length to the third, all
segments black; first segment longer than the two distal segments taken together;
head black; body olive-green with yellowish lateral lobes; on spruce; Packard
(1890)-35 Pamphiliid sp. 1.
3(2) Subanal appendages with the second segment longer than third, the third usually
darker in color than the others; first segment longer than or nearly equal to the two
distal segments taken together; head dark brown to green 4.
4(5) Head green; tenth abdominal tergum without colored patches; body green; subanal
appendages with the second and third segments black; on Pinus strobus; Packard-83.
Pamphiliid sp. 2.
5(4) Head not green, usually brownish; tenth abdominal tergum with or without colored
patches; body not greenish, sometimes reddish or olivaceous; subanal appendages
usually with segments brownish; on Pinus and Abies 6.
106 ILLINOIS BIOLOGICAL MONOGRAPHS [424
6(13) Head brown to yellowish 7.
7(12) Head dark brown 8.
8(9) Head paler along epicranial arms; subanal appendages with first segment as long as
all the other segments taken together; all segments pale to light brown; length,25 mm. ;
width of head, 3 mm.; body robust, large; following parts dark brown: head except
along epicranial arms, prothoracic shields, thoracic surpedal lobe, coxae, sterna
between thoracic legs, cervical sclerites, markings on the tenth abdominal segment,
median suranal process, and antenae; ocellarae black; suranal process short and
erect; tenth abdominal tergum with a pair of lateral patches, not connected along
caudal margin; tenth abdominal sternum with a median brown patch, distinctly
rounded on cephalic margin; subanal appendages light brown, first segment equal
in length to other two taken together, segment 2 longer than 3; thoracic legs with
fifth segment as long as fourth, and third taken together; antennal formula: (2, 5),
3, 6, 1, (4, 7); cuticle distinctly reticulate, each area brownish; three specimens in
MacGillivray collection bearing label "Cephalaeia sp. No. 839? Maine." (The
identification is open to question, but, since these larvae are readily distinguished
from the larvae of Pamphilius and Neurotoma by the characters used in the table
here, they may be considered, tentatively at least, as representing the genus Cephal-
eia.) Cefhalcia sp. 1.
9(8) Head not paler along epicranial arms, but uniformly brownish 10.
10(11) Head pitch-brown; body pinkish to reddish brown; on spruce; Packard-36
Pamphiliid sp. 3.
11(10) Head horny brown; body horny brown; subanal appendages with first segment
longer than other two taken together, third segment brown; on Pinus strobus;
Packard-84 Pamphiliid sp. 4.
12(7) Head yellowish to brownish yellow; body pale brick-red or yellowish, each segment
with a large reddish spot on the spiracular line; subanal appendages with first segment
nearly equal in length to other two taken together; all segments blackish; on Pinus
strobus; Packard-85 Pamphiliid sp. 5.
13(6) Head pale red, with a black spot on the front; body reddish olive-green with purplish
meso-dorsal line; on Austrian pine; closely related to Lyda campestris; Packard-82.
Pamphiliid sp. 6.
14(1) Subanal appendages with the second segment distinctly shorter than the third; head
variously colored, blackish to pale; tenth abdominal tergum either with or without
colored patches IS.
15(18) Tenth abdominal tergum with a colored patch on each side, median triangular patch
between the cephalic ends of the lateral patches wanting; lateral patches connected
along the caudal margin of tergum; sternum with a large colord patch 16.
16(17) Head blackish or dark brownish, in younger specimens pale brown; subanal append-
ages with first segment longer than other two segments taken together, third longer
than second, all segments brown, the third darker; cervical sclerites pale brown,
dorsal and lateral shields of pro thorax pale to light brown, patches on the ultimate
segment brownish; body with a pink dorsal line on the meson; antennae in mature
specimens with formula, (2, 3, 5), 1, 7, (4, 6) ; ocularium about one-third the diameter
of antennaria; ocellarae small, eccentric, near the mesal margin of ocularium;
mouth-parts brownish; length, 19 mm.; width of head, 1.9 mm.; on wild cherry;
G Neurotoma fasciata Norton.
17(16) Head lighter in color, yellowish, sometimes brownish yellow; subanal appendages with
first segment nearly equal to other two taken together, all segments black; following
parts blackish: prothoracic shields, thoracic legs, markings on ultimate segment,
subanal appendages, ocularia, thoracic sterna; the black markings of tenth abdominal
425) LARVAE OF THE TENTHREDINOIDEA—YUASA 107
tergum connected along the caudal margin; black marking of tenth sternum large,
completely covering the sternum, and with its cephalic margin between the subanal
appendages straight; antennae with formula, (3, 5), 2, 1, 7, (6, 4); length, 18 mm.;
width of head, 1.7 mm.; on plum; G NeurolomainconspicuaNorton.
18(15) Tenth abdominal tergum either with a colored patch on each side and with a median
triangular patch between the cephalic ends of the lateral patches always present, the
lateral patches sometimes not connected along the caudal margin of the tergum,
the sternum with a large colored patch; or the tergum without colored patches and
the sternum either with a pair of small round spots or without markings 19.
19(22) Tenth abdominal tergum with two lateral triangular patches and one mesal patch
and sternum with a large colored patch 20.
20(21) Head blackish; body greenish-white; subanal appendages with the first segment longer
than the other two taken together, all segments pale brown, the third sometimes
darker; following parts blackish: head uniformly, antennae, prothoracic shields,
thoracic lateral lobe, markings on ultimate segment, suranal hook, cervical sclerites,
and coxae; antennae with formula, (3, 2), 5, 1, 7, (4, 6); eighth uromere with a pair
of marginal ventral glands near caudal portion of the sublateral lobe, both pale
brown; in life, body glossy white with diffused fleshy-reddish tint; antennae and
subanal appendages whitish; length, 19 mm.; width of head, 1.9 mm.; on Cornus;
nests made by rolling edges of leaves cut across from the margin to the midrib;
gregarious; Y-125 Pamphilius sp. 1.
21(20) Head light brown, with a black spot on the apex of front; subanal appendages with
the first segment nearly equal in length to the other two taken together, two proximal
segments creamy, third deep brown; body whitish green; ocularia brown, a black spot
at the origin of the epicranial arms; following parts brown: thoracic shields, cervical
sclerites, and markings on the ultimate segment; tenth abdominal tergum with a
median cephalic triangular patch between the lateral patches; subanal appendages
with second segment longer than half the length of the third; thoracic legs pale or
creamy; antennae, beyond the first segment, deep brown, with formula: (2, 3, 5),
1, 7, (4, 6); length, 19 mm.; width of head, 1.8 mm.; on blackberry; G
Pamphilius dentatus MacG.
22(19) Tenth abdominal tergum without colored patches 23.
23(26) Tenth abdominal sternum without a pair of small colored patches 24.
24(25) Head uniformly pale brown; subanal appendages with the first segment as long as
other two taken together, the second shorter than the third, all segments pale brown;
ocularia large, about one-third the diameter of antenaria, black; following parts
blackish brown: narrow prothoracic shields, cervical sclerites, and antennae; suranal
hook brown without colored base; antennae with formula, (2, 3), 5, 1, 7, (4, 6);
length, 12 mm.; width of head, 1.5 mm.; host unknown; Y-163-3. (This species
closely resembles P. persicus MacG.) Pamphilius sp. 2.
25(24) Head not uniformly pale brown, vertex brown, front with a brown spot; subanal
appendages with the first segment as long as the other two taken together, distal
two segments brownish; following parts brown: prothoracic shields, cervical sclerites,
antennae, and suranal process; legs pale brown, darker in young specimens; length,
17 mm.; width of head, 1.8 mm.; on blackberry; M-69 Pamphilius sp. 3.
26(20) Tenth abdominal sternum with a pair of small colored patches; head pale to light
brown, front sometimes with a brown spot, usually without it; subanal appendages
with the first segment nearly equal in length to other two taken together, the second
segment shorter than the third, all segments pale to brownish; ocularia and mandible
at distal end blackish brown; suranal process brown with its base pale; antennae
108 ILLINOIS BIOLOGICAL MONOGRAPHS {426
brown; tenth abdominal sternum with small brown round spot on each side; length,
16 mm.; width of head, 1.6 mm.; larvae solitary, leaf-edge rollers on Cornus; M.
Pamphilius ocreaius Say.
Family Cephidae
Body (Fig. 2) cylindrical, sometimes slightly depressed, enlarged at
thorax, slightly arid uniformly tapering caudad, slender or moderately
stout; segmentation usually distinct; annulation sometimes indistinct;
cuticle smooth or verrucose, microscopically and very sparsely setiferous;
color generallly pale or creamy white, never with distinct bright marks;
head circular in contour, semiglobose, moderately large, narrower than
thorax, caudal portion concealed by prothorax, pale brown or concolorous
with body, sparsely setiferous; mouth-parts directed ventrad, normal
in form, brownish; antennae with four or five segments, conical; oceliarae
small, with ocularia less than one-fifth the diameter of antennaria and
located latero-caudad of it; epicranial suture and vertical furrows present;
mesothorax distinctly, and metathorax with dorsal and lateral aspects
somewhat swollen; thoracic legs vestigial, fleshy, mamma-like, tarsal
claws wanting; third abdominal segment with two or three annulets,
sometimes indistinct; venter with three annulets; larvapods wanting,
sometimes with slight swellings in normal position of larvapods; lateral
lobes prominent, extending the entire length of the segment; tergum of
ultimate segment with mesal longitudinal broad depression and distinct
suranal process; sternum of ultimate segment with a pair of inconspicuous
vestigial, papilliform subanal appendages ventrad of the cephalic end of
the anal slit; internal feeders, boring into the stem of monocotyledonous
and herbaceous plants and bushes; pupation in tunnels in the host-plants.
The Cephidae contains about fourteen genera and is moderately rich
in number of species, some of them of intercontinental distribution.
Nine genera are represented in North America. Practically all systematists
have considered this group as a distinct aggregate worthy of family rank.
Rohwer (1911), however, has expressed the opinion that future studies
may possibly make it advisable to unite this group with the Xyelidae
and to treat each of them as subfamilies. There have so far been no facts
or reasons brought to light which call for such a step. On the other hand,
MacGillivray's study has emphasized the fact that "so far as the wings
are concerned, they (Cephidae) are the most distinct of any group of the
Tenthredinoidea, and are only indirectly related to any of the other
families." They are generalized in the manner of the origin of media
but are specialized in other features of the wings. On the basis of larval
characters this family is related to the Pamphiliidae and is quite unrelated
to the Xyelidae.
The systematic position of the osculant genus Syntexis is unsettled.
In the original description Rohwer (1915) stated that this genus has
427] LARVAE OF THE TENTHREDINOIDEA—YUASA 109
affinities with both the Cephidae and Xiphydriidae and on the basis of
venation, it probably belongs to the latter as denned by MacGillivray.
Certain features other than venation, however, led Rohwer to place it in
the Cephidae. It is not safe to venture any opinion without careful
examination of the larvae, but their antennae and their lack of papilliform
subanal appendages suggest close affinity with the Xiphydriidae.
At least six out of sixteen American species have been recognized
in the larval stages and their host-plants recorded. Janus integer and
Cephus cinctus are economic pests. Konow's tribe Macrocephides includes
the species whose larvae bore into the pith of shrubs and woody twigs,
and his tribe Cephides embraces those whose larvae bore into the stalks
of Graminaceae.
Middleton (1917) published descriptions and keys for distinguishing the
larvae of five species representing four genera, Adirus, Janus, Cephus, and
Hartigia together with a definition of the groups based on "characters
common to all the genera studied and probably to the family." He
reserved for future discussion the question of the systematic position of
the Cephidae, but pointed out the obvious affinity of this group with the
Siricidae on one hand and the Pamphiliidae on the other. Gahan (1920)
described the larva of Tracheitis tabidus (Fab.) and added a key for sepa-
rating this larva from that of Cephus cinctus and C. pygmaeus.
GENERA OF CEPHIDAE
1(10) Papilliform subanal appendages present on the ultimate abdominal segment 2.
2(3) Suranal process depressed on the distal portion, oval in cross-section, with strongly
chitinized dentiform tubercles on the proximal portion; antennae five-segmented.
Janus Stephens.
3(2) Suranal process not depressed on the distal portion, circular in cross-section, with or
without strongly chitinized dentiform tubercles on the proximal portion; antennae
four-segmented 4.
4(5) Suranal process proximad of distal cylindrical portion with strongly chitinized
dentiform tubercles Adirus Konow.
5(4) Suranal process proximad of distal cylindrical portion without strongly chitinized
dentiform tubercles 6.
6(7) Terga of eighth and ninth abdominal segments setiferous, each with a transverse row
of distinct setae; tenth abdominal tergum as viewed from side strongly convex and
truncate on the caudal aspect; suranal process with stiff setae not arising from distinct
chitinized bases Trachelus Jurine.
7(6) Terga of eighth and ninth abdominal segments glabrous, each without a transverse
row of distinct setae; tenth abdominal tergum as viewed from side not strongly
convex and not truncate on the caudal aspect but gradually declivous caudad;
suranal process with stiff setae arising from distinct chitinized bases 8.
8(9) Suranal process with distal chitinized portion very short and ring-like, or very
long and cylinder-like, more than twice as long as wide; suranal process with a
single transverse row of setae proximad of the distal chitinized portion or with two or
more whorls of setae; the distal margin of the distal chitinized portion not distinctly
serrate Cephus Latreille.
110 ILLINOIS BIOLOGICAL MONOGRAPHS [428
9(8) Suranal process with distal chitinized portion, as long as wide, cylinder-like; suranal
process proximad of the distal chitinized portion with two or more whorls of setae;
distal margin of the distal chitinized portion minutely but distinctly serrate
Hartigia Schiodte.
10(1) PapQliform subanal appendages on the ultimate abdominal segment wanting.
Syntexis Rohwer.
Should Cephus and Hartigia (Middleton, 1917) and Tracheitis (Gahan,
1920) prove to possess five-segmented antennae, as reported, contrary to
the observations of the present writer, the genus Janus can be separated
from them by the chitinized dentiform tubercles and Trachelus by the
glabrous eighth and ninth abdominal terga.
Jantjs Stephens
Antennae distinctly with five segments; segments 1 and 2 short,
ring-like, segment 3 longer, but half as wide as segment 1, segment 4
cylindrical, longer than wide, segment 5 elongate-conical, twice as long as
wide, subequal in length to or shorter than segment 4; suranal process
short, strongly chitinized, nearly as long as wide at proximal end, denti-
form tubercles with circular rows of stiff setae on the proximal half, distal
half small, depressed, narrowly oblong in cross-section; subanal appendages
peg-like, with a minute seta at the distal end, apparently segmented,
without setae near the proximal end; lateral area of suranal lobe with
2-3 setae; mandible with four dentes.
SPECIES OF JANUS
Subanal appendages distinctly two-segmented, segment 1 ring-like, much larger in diameter
than segment 2; antennae with segment 5 about one-half as long as segment 4; bores in
Salix and Populus abbreviaius Say.
Subanal appendages indistinctly two-segmented, segments subequal in diameter; antennae
with segment 5 subequal in length to or only slightly shorter than segment 4; bores in
Ribes species (currant); C integer Norton.
Adirus Konow
Antennae distinctly with four segments; segment 4 long, peg-like,
bluntly pointed, nearly three times as long as wide, twice as long as
segment 3; suranal process large, distal fourth strongly chitinized, sud-
denly constricted, circular in cross-section, with chitinized dentiform
tubercles; subanal appendages peg-like, fleshy, apparently unsegmented,
with setae near the proximal end, these setae separated from the remainder
of the setae on the sternum; lateral area of suranal lobe with 20-28 setae.
Adirus trimaculatus Say. — Middleton has described the larvae in
detail. They bore in the stems of blackberry and rose. Thru the kindness
of Dr. E. P. Felt, one mature and two young damaged specimens from
429] LARVAE OF THE TENTHREDINOIDEA—YUASA 111
the New York State Museum, labeled "a 2766" and "a 2261" were exam-
ined by me.
Trachelus Jurine
Antennae apparently with four segments — according to Gahan five
segments present; body thickest dorso-ventrad in mesothorax, second
and third abdominal segments widest, the ninth and tenth tapering
suddenly; suranal process rather short, tapering caudad gradually, chit-
inized dentiform tubercles wanting, with or without stiff short setae,
if setae present they do not arise from chitinized bases; ultimate tergum
setiferous on both sides of the median depression, convex as viewed from
side, truncate on the caudal aspect, not declivous caudad; third abdominal
segment with three annulets, annulet 2 largest and with a transverse row
of setae; subanal appendages peg-like, unsegmented.
Trachelus tabidus Fabricius. — Suranal process without distinct con-
striction, with or without brownish setae, if present, setae arranged in a
irregular circle in the proximal half; subanal appendages brownish with 2
minute setae at the distal end, and with 1 or 2 setae which are separated
from the remainder of the setae on the sternum; lateral area of suranal
lobe with 5-7 setae; antennae with segment 4 bluntly rounded, segments
2 and 3 ring-like, segment 1 narrow but large in diameter with a seta on
the dorsal margin, segments all brown; bore in the stalks of wheat, rye,
and barley (Gahan 1920).
Cephus Latreille
Antennae apparently with four segments — according to Middle-
ton five segments present — segment 4 less than twice as long as wide;
abdominal segments 5-8 with ventral swellings corresponding in position
to larvapods; suranal process without chitinized dentiform tubercles, either
with a narrow ring-like distal chitinized portion and a semicircular row of
setae or with a long cylindrical distal portion and two or more irregular
rows of whorls of setae on the proximal portion, the distal margin of the
distal chitinous portion entire and smooth; subanal appendages papilla-
like, cylindrical, more than twice as long as wide, bluntly rounded at the
distal end, with one or more setae near the proximal end; lateral area of
suranal lobe with 7-15 setae; mandible with three dentes. .
According to Rohwer (1917) only two species of this genus are known
to occur in North America. They can be separated as follows:
SPECIES OF CEPHUS
Suranal process with the distal chitinized portion cylindrical, twice as long as wide, setae on
the proximal portion arranged in two or three irregular whorls; subanal appendages with
several setae; lateral area of suranal lobe with about 15 setae; the only true Nearctic
species known; bores in stalks of Elymus, Agropyron, Phleum, and wheat, cinctus Norton.
112 ILLINOIS BIOLOGICAL MONOGRAPHS [430
Suranal process with distal chitinized portion ring-like, shorter than wide, setae on the
proximal portion arranged in a semicircular row on the dorsal aspect; subanal append-
ages with one or rarely two setae, lateral area of suranal lobe typically with seven setae;
introduced from Europe; bores in stalks of wheat pygmaeus Linnaeus.
Hartigia Schiodte
Antennae apparently with four segments — according to Middleton
(1917) with five segments — segment 4 longer than segment 3, elongate,
conical; suranal process twice as long as wide at proximal end, without
strongly chitinized dentiform tubercles, with several whorls of spinous
setae; subanal appendages two-segmented, sometimes segmentation
indistinct, with accompanying setae separated from the remainder of
setae of the sternum; lateral area of suranal lobe with 15-20 setae.
Hartigia cressoni Kirby. — The larvae of this species have been described
in detail by Middleton. They bore in the stems of Rubus in California.
The preceding generic definition was based upon specimens obtained thru
the courtesy of Mr. Harry S. Smith, of Sacramento, California, and does
not quite agree with that given by Middleton (1917).
Family Xiphydriidae
Larvae (Fig. 3) small; body subcylindrical, thorax and two caudal seg-
ments distinctly swollen; segmentation distinct; annulation obsolete;
creamy white, no markings; glabrous; thoracic legs rudimentary, fleshy,
mamma-like, without tarsal claws; larvapods wanting; ultimate segment
with distinct suranal process, without subanal appendages; ocellarae
wanting; mouth-parts modified; maxillary palpi apparently two-segmented;
antennae apparently with three segments; metaspiracles functionless, very
much smaller than abdominal spiracles; cuticle on dorsum smooth, on
venter microscopically, sharply, and densely spinulate; tenth abdominal
tergum with deep meso-dorsal depression; wood-borers.
The Xiphydriidae contains four genera, Derecyrta, Brachyxiphus,
Xiphydria, and Konowia, which may be divided into two groups on
the presence or absence of the radial cross-vein in the wings. Systematists
have generally considered this group as a subfamily of the Siricidae, but
MacGillivray (1906) has elevated it to its present standing on the vena-
tional characters, which he has proven to be the most generalized of the
specialized Tenthredinoidea. Rohwer (1911) would divide the family
into two subfamilies, Xiphydriinae and Derecyrtinae, the latter being
monobasic. Of the four genera, two are represented in the Nearctic fauna.
In a recent synopsis of the Nearctic wood- wasps, Rohwer (1918b)
tabulates eight species of Xiphydria. He considers that X. walshii West-
wood, which MacGillivray (1916) assigned to the genus Konowia belongs
to the original genus, although the species was unknown to him, and
states that "it is possible that it is provancheri Cresson." Rohwer suggests
431] LARVAE OF THE TENTHREDINOIDEA—YUASA 113
that the specimens which Patten (1878) reared from Betula nigra and
regarded as X. attenuata Norton do not belong to this species but are
similar to an undescribed female bearing a Bradley manuscript name.
Nothing is known concerning the immature stages of Konowia basalts
Say. The larvae of Xiphydria are wood-borers and confine their attacks
to dead and decaying wood of deciduous trees. European species infest
willows, poplar, elm, and birch, and American species, maple, hickory,
and birch. Konow (1901) listed four species, Xiphydria prolongata, X.
camelus, X. longicollis, and X. abdominalis in his key to the larvae of
Tenthredinoidea.
Xiphydria Fallen
Larvae comparatively small; thorax distinctly swollen, the meta-
thorax being the largest segment of the body; abdominal segments 1-2
cylindrical, subequal in diameter; third abdominal segment with a single
annulet; two caudal segments somewhat globose; sublateral lobe moder-
ately large, extending the entire length of the segment; suranal process
comparatively long, with dentiform tubercles near the base; tenth ab-
dominal sternum much smaller than the tergum; head and ultimate
segment with long setae; head semiglobose, vertical furrows present;
epicranial suture in part indistinct; antennariae distinct; antennae three-
segmented, segments 1 and 2 ring-like, segment 3 conical, longer but of
much smaller diameter than the preceding segments; labium very small,
without median emargination; mandibles with distinct dentes; maxillae
with small modified palpi, apparently two-segmented; galea conical,
smaller than palpi, lacinia fleshy, tubercle-like, with several setae; labium
with submentum and mentum large, convex, membranous, palpi appar-
ently with three segments, small, median lobe large, flattened on venter,
suboblong; spiracles large, oblique, not winged; glandubae wanting.
Xiphydria provancheri Cresson. — Length, 12 mm.; width of head,
1.6 mm.; body yellowish white; head creamy white; mouth-parts brownish;
suranal process arising from large brownish strongly chitinized suranal
lobe, deep brown, at proximal end, more than twice as long as wide,
distal two-thirds suddenly and distinctly smaller in diameter than proximal
third, with two circular rows of dentiform tubercles and setae on the
proximal third and two distinct ventral dentiform tubercles on the distal
third, one caudad of the other, these without setae; on birch.
This description is based upon a rare specimen collected at Saranac
Inn, New York State, Aug. 20, 1900, and generously loaned by Dr. E. P.
Felt. The larva bores into partly decayed heartwood of standing birch
and makes a gallery about 2.5 mm. in diameter. The burrows are invari-
ably filled with the borings, except a short curved portion thru which the
adult makes its way to the surface. A parasite, Pammegischia xiphydriae
Ashmead, was reared by Dr. Felt from larvae of this species.
114 ILLINOIS BIOLOGICAL MONOGRAPHS [432
Dr. Felt (1906) also found another larva making moderately large
cylindrical burrows in decaying birch and considered it as probably
belonging to X. attenuata. He refers to the rearing of this species by
Patton and suggests Rhyssa humida Say as its parasite. Since the identity
of Patton's specimen is questioned and since the adult was apparently
not reared, it is not possible to identify the specimen under consideration.
If it were really X. attenuata, then it should be known as X. abdominalis
as proposed by Konow (1905) and Rohwer (1918).
Family Siricidae
Body large, 30-40 mm., cylindrical, uniform in diameter thruout
(Fig. 4), fleshy, plump; integument smooth, transparent, non-setaceous,
light in color; head circular, half as high as thorax; mouth directed ventrad,
mostly exposed, but slightly overlapped by prothorax; antennae incon-
spicuous, apparently one-segmented; ocellarae wanting; epicranial suture
wanting and vertical furrow indistinct; mouth-parts not normal in form,
light in color; prothorax large; mesothorax and metathorax short in
comparison with abdominal segments; legs rudimentary, mamma-like,
subequal in size, borne on fleshy conical lobes; larvapods wanting; typical
segment with two indistinct annulets, sublateral lobe distinct but not
prominent; tenth abdominal segment semiglobose in profile; tenth tergum
distinctly depressed by a median furrow; suranal lobe on the meson with
dark colored, chitinized, suranal process; subanal appendages wanting; in-
ternal-feeder, bores in the trunks of deciduous and evergreen trees.
The Siricidae contains five genera and about fifty species, most of
which are confined to the northern hemisphere. The recognition of the
fact that these insects constitute a well-circumscribed group dates back
to the time of Linnaeus (1758) who described five species of Siricidae among
those of his heterogeneous genus Ichneumon, three of the five having
become the types of three modern genera. Systematists have universally
agreed in considering this group worthy of family rank. The family
falls into two natural divisions, Siricinae, including three genera, Sirex,
Urocerous, and Xeris, and Tremecinae, embracing two genera, Tremex
and Teredon. The genus Xeris was associated with the genera composing
the Tremecinae both by Ashmead (1898) and Konow (1905), but Rohwer
(1911) proposed a more natural arrangement, placing this genus in the
Siricinae. Bradley (1913) definitely divided the two groups on the number
of segments of labial palpi and the retention of cerci in the adults.
According to Bradley (1913) there are twenty species reported for
North America, representing all the known genera. The specific charac-
ters of some common species, as Sirex nigricornis, Urocerus cressoni, and
Tremex columba, are subject to a wide range of variation and several
varieties have been described. So far as known, the larvae of the Siricinae
433] LARVAE OF THE TENTHREDINOIDEA—YUASA 115
are wood-borers attacking conifers, those of the Tremecinae boring in
deciduous trees. Tremex columba, or three races of this species which
infest maple, elm, apple, pear, beech, oak, and sycamore, are the best-
known examples. The food-plants of only three American species are
known, these including Sirex cyanens and Urocerus albicornis. Larvae of
the Siricinae have not been examined.
Tremex Jurine
Larvae conspicuously large; body cylindrical, slightly flattened on
the venter; large, robust, usually bare except on head and tenth abdominal
segment; whitish or creamy white; setae microscopic; head semiglobose,
slightly wider than high on cephalic aspect, semicircular in profile, pro-
duced to the ventral half of the front, then suddenly truncated, pale brown-
ish; mandibles and coilae deep brown; antennae apparently one-segmented,
conical; antacoria partly chitinized and bearing a few small setae; ocel-
larae wanting; depression mesad of antennaria which is sometimes called
the "eye" is a pretentorina; vertical furrows concealed by overhang-
ing pro thorax; clypeus small, light in color; labrum transverse, con-
vex, thick, asymmetrical, without median emargination, but with a
notch on the right third of slightly oblique cephalic margin; mandibles
strong; mandacuta distinct, brown; mandibularia narrow, inconspicu-
ous, maxilla fleshy except subgalea, stipes large; palpi two-segmented,
small; galea conical, brown, small, arising from broad shoulder which
bears a few tiny setae on the lateral portion; lacinia round, lobe-like,
bearing three rows of brown setae, which decrease in length on cephalic
or dorsal side; labium compact, submentum narrow, transverse, mem-
branous, mentum convex, lobe-like, deeply emarginate on cephalic margin,
ligula round, fitting into the emargination of mentum, palpi small, two-
segmented, second segment much smaller than first, conical and brown,
sericos large, transverse, distinct, crescentic; prothorax large, produced
dorsad and cephalad, overlapping the caudal third of the head; mesothorac-
ic and metathoracic segments about one-half the length of abdominal seg-
ments except the first abdominal which is only little longer than the meta-
thorax; thoracic legs rudimentary, mamma-like, short, tipped with tiny
chitinized spot, borne on fleshy conical pedal lobe; cervical sclerites want-
ing; sternum with transverse subtriangular lobes which meet on the meson
in front of median lobe between and slightly cephalad of prothoracic legs;
metaspiracles as large as abdominal spiracles; abdomen slightly and uni-
formly tapering to the caudal end; annulation indistinct on dorsum,
apparently with but one annulet, the venter with two annulets, the
second annulet larger than the first; sublateral lobe prominent, extending
the entire length of segment as a single oblique elevation; spiracles large,
brown; ninth abdominal segment a little shorter than the eighth; tenth
116 ILLINOIS BIOLOGICAL MONOGRAPHS [434
tergum convex, lateral area of suranal lobe broad, suranal process promi-
nent, deep brownish, strongly chitinized, compressed, with two pairs of
small but distinct teeth.
The foregoing definition of the genus is based on one species, Tremex
columba.
Tremex columba Linnaeus. — Length, 40 mm.; width of head, 4 mm.;
ultimate segment with setae as follows: tergum near the caudal margin
on each side of the median furrow with a small, brown, sharp, hook-like
spine, with tiny setae which arise from large calices; ventral side of suranal
lobe with such setae; tenth sternum small; small brown spot at the lateral
end of anal slit; subanal lobe non-setiferous; subanal appendages wanting;
1-8396; G-.
The eggs of the Pigeon Tremex are oblong-oval, pointed at both ends
about 1.2 mm. in length, deposited singly, but in limited area, close to each
other; oviposition takes place in early summer, female sometimes fails to
withdraw ovipositor and dies in situ; larvae on hatching in the wood make
a gallery and feed for probably one season; transformation takes place in
the burrow; adults emerge thru circular hole, about 8 mm. in diameter.
The larvae are parasitizec by Thalessa lunator and also by Megarhyssa
atrata Fabricius, according to Champlain (1921).
Felt (1906) suggests as remedial measure against this insect, the cutting
down and burning of all trees badly infested. Keeping the trees in vigor-
ous health is supposed to be sufficient to prevent injury as the larvae work
only in weakened or partly decaying wood.
Family Megalodontidae
Antennae long, conspicuous, multisegmented, located above or near
the ocellarae; larvapods wanting; last abdominal segment rounded, with a
pair of bristle-like segmented subanal appendages; larvae feed on herba-
ceous plants.
This family contains four genera, Rhipidioceros, Megalodontes,
Melanopus, and Tristactus, and about thirty-five species, which are
distributed in Europe,' Asia, and North Africa. Systematists have invari-
ably associated this family with the Pamphiliidae, but that this position is
unnatural has been conclusively shown by MacGillivray. He has pointed
out that it represents a line of specialization very similar to that found
in the Siricidae, and that while it is more closely related to this family
than to any other, an abundance of characters justify one in considering
it as a distinct group.
Only one species, Megalodontes spissicornis Klug has been recognized
in the larval stage. The larvae, according to Hiendlmayr (1878), are found
on Lasperfritium latifolium L. in central Europe from the end of July to
435] LARVAE OF THE TENTHREDINOIDEA—YUASA 117
the beginning of August. In the younger stages, they are gregarious
and live in a common nest like many Pamphiliidae, but they spin an
individual web when half-grown. There is one generation a year.
This interesting species was not available for study, and the foregoing
definition is abstracted from Konow (1901) and may be found by later
students of little value in defining the family. This family, so far as the
recorded larval characters are concerned, seems to be closely associated
with the Pamphiliidae in possessing the bristle-like subanal appendages
and long conspicuous antennae. Future observations, however, may
possibly reveal more important characters, not given in the brief synopsis
of Konow.
Family Oryssidae
Body (Fig. 5) eruciform, grub-like, subcylindrical, slightly depressed,
swollen in the middle of the abdomen, tapering at each end; segmentation
distinct; annulation obsolete; creamy white, without colored markings;
spiracles on prothorax and first eight abdominal segments; thorax increas-
ing in size caudad, thoracic legs obsolete; larvapods wanting; fourth
abdominal segment largest in diameter, size of segments decreasing rapidly
caudad, last segment smallest; suranal process and subanal appendages
wanting; head white, compressed cephalo-caudad, circular in frontal
contour, narrower than thorax; antennae with a single segment, papilla-
like; mandibles tridentate; maxillae and labium vestigial, fleshy, lobe-like,
without palpi; ocellarae wanting; larvae parasitic on wood-boring larvae of
Coleoptera; pupation in the pupal cells of the hosts.
The Oryssidae contain six genera and a limited number of species
distributed thruout the world. The genus Oryssus alone is represented
in the Nearctic region. In former years the family has been associated
with the Siricidae, but recently writers are in accord in regarding it as an
extremely specialized compact group. MacGillivray (1906) came to the
conclusion that "so far as their wings are concerned the presence of the
second anal cell in the front wings is the only structure that would place
the genus Oryssus in the superfamily Tenthredinoidea" ; The group is
not only highly specialized in the adult characters but a recent discovery
of the parasitic habit of the larvae isolates these Hymenoptera from all
other Tenthredinoidea as a unique class. In fact Rohwer and Cushman
(1917) have gone so far as to propose a new suborder, Idiogastra, placing it
"intermediate between the suborder Chalastogastra — where adult would
place it — and the suborder Clistogastra — with which the larva would ally
it." Whether this arrangement is acceptable or not, the fact that this
group is remarkably well circumscribed and that it represents the summit
of an extremely isolated line of specialization in the Tenthredinoidea
can not be doubted.
118 ILLINOIS BIOLOGICAL MONOGRAPHS [436
Only one species, Oryssus occidentalis Cresson, has been recognized in
the immature stages. The definitions given here are based on the descrip-
tions and figures of this species published by Rohwer and Cushman (1917).
It is quite possible that future studies may prove them inadequate for
the identification of the larvae of other genera and species yet to be dis-
covered.
Oryssus Latreille
Larvae small; epicranial suture faint, arms obsolete; clypeus cres-
centic, narrow; fronto-clypeal and clypeo-labral sutures distinct; labrum
more than twice as wide as long, with shallow mesal emargination; an-
tennaria distinctly elevated, antacoria extensive, mound-like; antennae
small, mamma-like; mandibles strongly chitinized, curved, narrow mesal
dentis larger than lateral dentes, these subequal in size, sharp; maxillae
fleshy, sub triangular, unsegmented lobes; annulation on dorsum indistinct,
with apparently two annulets, venter with one; sublateral lobes distinct,
extending the entire length of the segments; spiracles visible from dorsal
aspect; segments transversely raised and with a few minute tubercles.
Oryssus occidentalis Cresson. — Color white with mandibles and chit-
inized ridges near the mouth brown; head one-third as wide as the widest
segment of the body — the fourth abdominal segment; maxillae with minute
brownish spots bearing about three sensory papillae; labium with about
four stout setae on each side of meson; prothorax declivous toward the
head, forming straight line with the latter in profile, on dorsum subequal
in length to mesothorax; metathorax half as long as mesothorax; lengths
of abdominal segments as follows: 8, (1, 9), (2, 7), (4, 6), 5, 10 on dorsum,
(6, 7, 8), 5, 1, 3, (2, 4), 9, 10 on venter, 8, 7, 4, (1, 2, 5, 6), 3, 9, 10 on latus;
tenth abdominal segment one-fourth as wide and one-third as high as the
fourth and sixth segments respectively; dorso-cephalic margin of mesothor-
acic and eighth abdominal segments distinctly, and of metathoracic and
abdominal segments 5, 6, 7, 9, 10 slightly convex, and of abdominal
segments 2 and 3 concave; ventro-cephalic margin of abdominal segments
1, 6, 7, 8 distinctly, and of 2 and 9 slightly, concave, of 3, 4, and 5 convex,
of 1 and 6 with a distinct convex emargination on each side of meson;
abdominal segments with the distance from spiracles to dorsal surface
uniform on lateral aspect and much shorter than the distance from spiracles
to the ventral surface, the latter variable and increasing caudad to the sixth
segment and diminishing thereafter; "each thoracic and abdominal segment
has dorsally at each side of the middle a low, transverse elevation sur-
mounted by a transverse row of four or five short, stout back-pointing
spines"; setiferous elevations on abdominal segments 1-7 and 9 and on
metathorax near the caudal margin of the segments, those of prothoracic
437] LARVAE OF THE TENTHREDINOIDEA—YUASA 119
and mesothoracic and eighth abdominal segments being in the middle;
tenth abdominal segment with small pointed protuberances directed cau-
dad; venter of segments with brownish spots in place of legs; larvae para-
sitic on the larvae of Buprestis confluens Say, B. laeventris Le Conte, and
possibly other species of Buprestidae.
120 ILLINOIS BIOLOGICAL MONOGRAPHS [438
IV. PHYLOGENY
A classification based on phylogeny is one of the essential concerns of
philosophical taxonomy. In order to ascertain the genetic relationship
of organisms, synthetic as well as analytic, consideration of evidence
drawn from all the branches of biological science is imperative. The
indissoluble relation of morphology, embryology, and paleontology to tax-
onomy is so manifest and familiar that no comments are needed. The
time has come, however, when a critical examination of the phylogenetic
significance and the taxonomic value of the physiological and biological
attributes of animals must be made. Whatever evidence comparative
physiology, biochemistry, and genetics may offer should be incorporated
as far as possible with the data obtained in other more commonly ex-
ploited fields of research. Only in this way is it possible to arrive at a
comprehensive, systematic and complete summation of knowledge of
animals. This is the primary function of philosophical taxonomy, and in
this sense the saying of W. S. Jevons that "science can extend only so far
as the power of accurate classification extends," is true.
There are good reasons to believe, however, that even to-day morphol-
ogy, as of old, holds its supreme place in systematic investigations as it
offers fundamental assistance in determining the genetic affinities of
organisms. The success of a study of phylogeny based on morphological
evidences depends on the ability of the investigator to select the proper
structures, to determine the direction and nature of changes undergone by
these structures, and to draw legitimate conclusions by judicious interpre-
tation of the facts observed. Data obtained from studies of the external
anatomy of the larval stages of entometabolous insects are of necessity
incomplete of themselves for determining the phylogeny of the group;
yet, in the absence of other means of approach to the problem, they
constitute essential facts significant enough to merit careful consideration.
The opinions of scientists in regard to the systematic importance of
the characters based upon the immature stages of Entometabola have
been divided. There are some who ascribe no importance whatsoever to
them and entirely ignore this phase of taxonomy. There are others who
recognize the importance of the larvae from the viewpoint of synoptic
classification as they are primarily interested in the practical purpose of
439] LARVAE OF THE TENTHREDINOIDEA—YUASA 121
synoptic descriptions and keys. There are still others who believe in the
intrinsic importance of the immature stages in the study of phylogeny.
The reasonableness of the oft-repeated objection which was voiced by
Comstock (1918) that the larvae of insects exhibit a cenogenetic develop-
ment and, therefore their ontogeny bears little or no relation to the phylog-
eny of the race, must be admitted in regard to certain structures which
are entirely too adaptive and too much modified by environmental factors
in meeting the trophic requirements of particular species or genera. But
admission of this fact is not incompatible with a belief in palingenesis
of other structures. Besides, the warning that the cenogenetic peculiari-
ties, which may be of value as distinguishing characters, are of no phylo-
genetic significance and must, therefore, be judiciously and discriminately
distinguished from more important palingenetic characters, applies not
only to the classification of the larvae but to the taxonomy of the adults as
well. This objection alone does not invalidate a belief in the intrinsic
importance of the immature stages from the phylogenetic point of view.
While the writer does not minimize the danger of a too confident expecta-
tion of finding phylogenetic indices in the successive ontogenetic stages in
entometabolous insects, yet he is equally reluctant to abandon his hope in
regard to the taxonomic value of the characters of immature insects.
The present study is a partial justification of his contention.
Students of the Tenthredinoidea have recognized the practical im-
portance of the larvae in determining the systematic position of different
taxonomic units. Norton (1867) stated that "Mr. Walsh has shown
that in some species of Euura and Nematus bred by him, it was almost
impossible to detect any difference in the imago, while the larvae varied
greatly. Doubtless our opinion will be greatly modified by future dis-
coveries." Cameron (1882) was of the opinion that the larvae were of
great value in differentiating the tribes and subtribes altho they appeared
to be of little use in regard to the genera. MacGillivray (1913) goes further
and states that "it was hoped from a study of the immature stages of the
Tenthredinoidea that some information might be obtained as to the
validity of the species based on obscure anatomical details." Rohwer
also often uses the characters of the larvae as collateral evidence in decid-
ing the systematic position of certain subfamilies and genera.
Nothing definite is known in regard to the ancestors of the Hymenop-
tera beyond the probability that they have somehow arisen from a primi-
tive type of some neuropteroid-like Palaeodictyoptera. The order is
considered to be one of the most, if not the most, highly specialized of all
insects. Systematists are unanimous in regarding the Tenthredinoidea
as the most generalized of the Hymenoptera. It is difficult, if not impossi-
ble, to conjecture the primitive larval type of the Tenthredinoidea.
Judging, however, from what are universally considered to be generalized
122 ILLINOIS BIOLOGICAL MONOGRAPHS {440
conditions in insects in general and in the Tenthredinoidea in particular,
the probable ancestral type of larva may be characterized as follows:
body cylindrical; segmentation distinct; annulation indistinct, annulets
few in number; head exposed, subglobose, distinct from the trunk; thorax
and abdomen more or less similar in structure excepting the three pairs of
thoracic legs, which are well developed and consist of five segments,
tarsal claws distinct; abdomen with twelve segments including the telson;
larvapods present on abdominal segments 1-10; antennae long, composed
of several segments; ocellarae present, one on each side of head; mouth-
parts well developed, maxillary and labial palpi segmented; tenth abdom-
inal tergum without caudal protuberances or suranal process; eleventh
abdominal sternum with a pair of segmented subanal appendages; ten
pairs of functional spiracles present, including metaspiracles; larvae free
leaf-feeders.
There are, as was pointed out by Comstock (1893), two kinds of char-
acters of phylogenetic importance. "First, characters indicating differ-
ence in kind of specialization; and second, characters indicating difference
in degree of specialization of the same kind. The former will indicate
dichotomous divisions of lines of descent; the latter merely indicate
degrees of divergence from a primitive type."
In determining the probable genetic affinities of the families of the
Tenthredinoidea, the following structures have been taken into considera-
tion: thoracic legs, larvapods, subanal appendages, ocellarae, antennae,
mouth-parts, suranal process, and metathoracic spiracles. The list does
not by any means exhaust the structures which might be employed for
this purpose, but it is believed that the structures listed offer the most
reliable and essential basis for the determination of a phylogeny based
upon larval characters. The significant changes in these structures are:
addition or reduction of parts; difference in degrees of development of
existing parts; and modifications in length, size, shape, and degree of
chitinization of the parts. These modifications have been interpreted
according to the Comstockian principles quoted above.
The thoracic legs are among the most persistent structures in the
adult and larval stages of insects in general, and their absence is unques-
tionably an indication of specialization by reduction. It is likewise
reasonable to assume that any modification of the typical, simple, cylin-
drical, five-segmented condition as regards the form or the number of
segments is a sign of specialization. The legs of the larvae of the Pam-
philiidae approximate most closely the primitive condition in the number,
shape, and structure of the segments. The tarsal claw is straight and
very slender. In the Xyelidae the legs assume a condition different from
that of the Pamphiliidae. The differentiation of segments in size and shape
has proceeded further and the tarsal claws have become distinctly claw-
441] LARVAE OF THE TENTHREDINOIDEA—YUASA 123
like. The legs are very small compared with the size of the body. The
Tenthredinidae present a series of conditions which illustrate beautifully
cases of modification both by reduction and addition. The typical, well-
developed, five-segmented legs undoubtedly represent the normal sequence
in development from the condition found in the Xyelidae. The apparently
six-segmented condition of the Hylotominae, four-segmented legs of the
Fenusinae, and three-segmented condition of the Schizocerinae, together
with the development of distal fleshy lobes in the first- and last-named
subfamilies are cases of specialization. The fact that the specialization
by reduction of segments has not proceeded at the same rate in the last
two subfamilies is indicated by the difference in the structure of the
segments. It is interesting to note that the prothoracic legs of the Schizo-
cerinae still retain four segments in spite of the fact that in the two caudal
pairs the number of segments has been reduced to three. The osculant
genus Phlebatrophia is unique among all other Tenthredinidae in having
the legs modified to such an extent as to lose all resemblance to normal
segmented legs. They have become mere fleshy, indistinctly segmented,
clawless protuberances. In this character this genus resembles highly
specialized families such as the Cephidae and its allies. The Cephidae,
Xiphydriidae, and Siricidae represent a series of modifications in which the
changes have resulted in fleshy, vestigial, entirely clawless legs with or with-
out indication of segmentation. Judging from the size and degree of
segmentation, the Xiphydriidae is more generalized than the Siricidae
and more specialized than the Cephidae. The Oryssidae is entirely apo-
dous, and the fact that it is parasitic on buprestid larvae leaves no doubt
as to its extreme specialization.
The larvapods are considered as true appendages of the abdominal
segments. Their presence is highly significant from a phylogenetic point
of view. The larvae of the Tenthredinoidea are divisible into two types
according to the presence or absence of the larvapods. The Xyelidae
and Tenthredinidae represent the type with polypodous larvae and the
other five families represent the type with apodous larvae. In the first
group the Xyelidae possess the maximum number, or ten pairs, of larva-
pods, while the Tenthredinidae are provided with six to eight excepting
certain specialized genera which possess very vestigial or no larvapods.
It has not been possible to determine the reason for the invariable absence
of larvapods upon the first and ninth uromeres in the Tenthredinidae. It
may be that the same mechanical factors which have caused the fusion
of anal larvapods in boring larvae like Caulocampus are also responsible
for this condition. The size and, to some extent, the structure and position
of the larvapods vary within the Tenthredinidae as in the Schizocerinae,
Hylotominae, and Fenusinae. It is interesting to note that the gall-making
genus Pontania retains normal larvapods as well as thoracic legs, while the
124 ILLINOIS BIOLOGICAL MONOGRAPHS f442
leaf-miners have both thoracic and abdominal legs reduced in the number
and size of their segments. The small size and reduced number of seg-
ments are correlated with the well-developed thoracic legs of the Hylo-
tominae. In this subfamily the claws are very large, sharply curved, and
provided with empodia-like distal structures, indicating a great adapta-
tion for clinging to leaves. This fact is sufficient to account for the reduc-
tion of the larvapods. The Pamphiliidae and four specialized families
in the same line of development are entirely without larvapods. It is
highly desirable to determine whether this apodous condition signifies
a common origin of all five families. Upon this question hinges much of
the interpretation of the phylogeny of the Tenthredinoidea.
In characterizing the larvae of the hypothetical primodial Ten-
thredinoidea the abdomen was considered as provided with the maximum
number of appendages, including ten pairs of larvapods and a pair of
subanal appendages. This assumption is based upon the fundamental
fact that the progenitor of insects having evolved from a typical arthro-
podan organism possessed the typically arthropodan character, abdominal
appendages. This assumption is justifiable in view of the following facts:
(1) the possession of appendages on all of the abdominal segments is a
fundamental arthropodan characteristic; (2) the embryos of practically all
insects exhibit at some time during their development rudiments of
abdominal appendages; (3) appendages are present on all or some of the
abdominal segments in the postembryonic stages of the Apterygota;
(4) the gonapophyses of the Exometabola represent the true abdominal
appendages in this group of insects; (5) the larvapods and other appenda-
ges are present in the larvae of the Mecoptera, Lepidoptera, generalized
Hymenoptera, and, possibly, in some other orders, — all these facts indi-
cating the wide occurrence and fundamental continuity of abdominal
appendages in the Hexapoda. It is, therefore, not unreasonable to assume
that the progenitor of insects, at least in some stage of its development,
possessed appendages on all of the abdominal segments. The same
argument supports the contention that the ancestors of the Hymenoptera
undoubtedly closely resembled the remoter ancestors of the Insecta.
The larvae of the progenitor of the Hymenoptera for this reason have
been considered as provided with the maximum number, or ten pairs,
of larvapods, a pair on each of the first ten abdominal segments and a
pair of subanal appendages on the eleventh abdominal segment. If this
assumption is true, the larvae of the Xyelidae, which possess ten pairs of
larvapods, must be considered as representing the most primitive condition
found in the Hymenoptera. Graber (1890) has shown that in the larvae
of Hylotoma the larvapods arise from the embryonic limb-rudiments and
are directly evolved from them during the development and, therefore,
the larvapods are the true appendages of the abdomen, homodynamous
443J LARVAE OF THE 7 ENTHREDINOIDEA—YUASA 125
with the thoracic legs and homologous with the abdominal appendages of
generalized insects. There is no reason for considering the larvapods of
the Xyelidae as embryologically and morphologically different from those of
Hylotoma, consequently the larvapods of the Xyelidae must be the
true appendages of the abdomen; and since the larvae of this family
are provided with the maximum number of larvapods, they must be
considered as the most generalized of the Tenthredinoidea. The Ten-
thredinidae with six to eight pairs of larvapods and certain other mor-
phological and biological characters are unquestionably related to the
Xyelidae and probably represent a line of evolution from a xylelid-like
ancestral stock. Among the Tenthredinoidea with apodous larvae, the
Pamphiliidae, with a pair of segmented subanal appendages, is undoubtedly
the most generalized of all five families. The origin of the Pamphiliidae
is consequently an important question. For the reasons already stated
in connection with the larvapods, the progenitor of the Hymenoptera has
been considered as possessing a pair of subanal appendages on the caudal
segment of the body. In this character as well as in all others the Pamphilii-
dae approach most nearly the primitive condition and, except for the
absence of larvapods, unquestionably represents the most generalized
condition found in the Tenthredinoidea, outranking even the Xyelidae.
The loss of larvapods in this case is just as difficult to explain as the loss
of subanal appendages in the case of the Xyelidae. These structures, the
larvapods and subanal appendages, must have been lost during the course
of phylogeny since the progenitor undoubtedly possessed both of these
structures, and these two families, in spite of their generalized conditions,
must represent the end-products of evolution in their particular lines.
It is, then, natural and proper to assume that there have taken place two
distinct lines of development from the ancestral type of the Hymenoptera.
In the one, the specialization consisted in the suppression of the develop-
ment of larvapods, as in the Pamphiliidae, and in the other in the suppres-
sion of the development of subanal appendages, as in the Xyelidae. These
two families, then, represent two independent lines of evolution and are
the most generalized families not only of the Tenthredinoidea but of the
Hymenoptera. Whether the Xyelidae is more generalized than the
Pamphiliidae, or vice versa, must, from the very nture of the case, remain
a question till the advancement of our knowledge shall perhaps make the
answer possible. There are, however, a few things that should be pointed
out regarding this question. If the suppression of the development of
larvapods is considered of equal phylogenetic significance with the sup-
pression of the development of the subanal appendages, and if the head
and the appendages of these two families alone are compared, there is no
doubt that the Pamphiliidae are more generalized than the Xyelidae.
But since the subanal appendages are true abdominal appendages homo-
126 ILLINOIS BIOLOGICAL MONOGRAPHS {444
dynamous with the larvapods, and since it is natural to believe that the
process of reduction has taken place very slowly by gradual suppression
of the appendages, it is not unreasonable to assume that the apodous
condition found in the Pamphiliidae represents a much later stage of
specialization than the condition of the polypodous larvae of the Xyelidae.
The biology of the Pamphiliidae also indicates that this family is perhaps
more specialized than the Xyelidae. However, these considerations
counterbalance each other, and, when all is said, it is difficult to decide
between the two families as to their relative degrees of specialization.
This somewhat drawn-out discussion leads to the following conclusions:
(1) the progenitor of the Hymenoptera possessed a pair of larvapods on
each of the first ten abdominal segments and a pair of segmented subanal
appendages on the eleventh segment; (2) the progenitor gave rise to dis-
tinct stocks which resulted in the production of larvae with larvapods in
one case and with subanal appendages in the other; (3) the Xyelidae
represents the former line of evolution and the Pamphiliidae the latter;
and (4) the question as to whether the Pamphiliidae is more generalized
than the Xyelidae or vice versa is by its nature unanswerable. To the
above conclusions it may be added that it is only natural and reasonable to
consider the Tenthredinidae as representing the further evolution of the
primitive stock from which the Xyelidae had evolved, and the Cephidae,
Xiphidriidae, Siricidae, and Oryssidae, in turn, as evolving from the
original stock which gave rise to the Pamphiliidae.
The subanal appendages are present only in the Pamphiliidae and
Cephidae. In the former they are rather long, setiform, well developed,
distinctly three-segmented; in the latter they are minute, vestigial, often
fleshy, papilla-like, and indistinctly segmented. Since the embryonic
history of these appendages has not been studied, their true nature is not
known. There is little doubt but that they are true appendages. If they
represent the appendages of the ultimate segment, as has been suggested
by certain writers, and correspond to the so-called style of generalized
insects, then their presence is an indication of a primitive condition. There
is hardly any question as to the common origin of the subanal appendages
in the Pamphiliidae and Cephidae, and if these structures represent what
they are assumed to represent these two families must have a close affinity.
The ocellarae are present in the Pamphiliidae, Xyelidae, Tenthredin-
idae, and Cephidae. They are well developed, and are usually accompanied
by well-defined ocularia in the first three families. In the Cephidae the
ocellarae are vestigial and represented by localized pigmented granules,
and lack ocularia. It is significant that the ocellarae are unmodified in
the gall-makers and leaf-miners of the family Tenthredinidae, except in
Phlebatrophia, where they are reduced in size and the ocularia indistinct.
The atrophy of the ocellarae is undoubtedly correlated with the mining
habit of the larvae.
445] LARVAE OF THE TENTHREDINOIDEA—YUASA 127
The antennae are present in all larvae of the Tenthredinoidea. Judg-
ing from the condition obtaining in generalized insects, it is reasonable to
consider the antennae of the Pamphiliidae as representing the primitive
ancestral type. They are long and setiform in this family and consist of
seven cylindrical well-chitinized segments. The Xyelidae is closely
related to the preceding family in antennal characters altho a shortening
of the length has taken place. In the Tenthredinidae the antennae undergo
much modification both in the number and form of the segments. They
may be conical, limpet-shaped, or flattened, and the number of segments
varies from five to one. The antennae of the Cephidae resemble those of
the Xyelidae and some of the Tenthredinidae in shape and number of
segments. The antennae undergo steady reduction in size and number of
segments in the three remaining families, reaching the extreme of reduc-
tion in the Oryssidae, where each is represented by a button-like swelling.
The trend of specialization in the antennae is orthogenetic so far as the
families are concerned but quite diverse in the subfamilies of the Ten-
thredinidae.
The mouth-parts, which include the mandibles, maxillae and labium,
afford a fertile field for characters which are of interest from a systematic
point of view. The mandibles, like the antennae, are the most persistent
and ever-present structures in the head of all larvae of the Tenthredinoidea.
The maxillary and labial palpi are typically four-and three-segmented
respectively. The change is in the reduction in number and size of the
segments. The Cephidae is normal in this respect but gradual change
takes place in the Xiphydriidae and Siricidae, while in the Oryssidae the
change has proceeded so far as to completely obliterate the maxillary and
labial palpi. The palpi of Phlebatrophia resemble those of the specialized
families. The families represent different stages of specialization, and
their relative systematic position can be indicated by the degree of changes
in the mouth-parts.
The suranal process which is located on the meson of the suranal
lobe or the tenth urotergum is characteristic of the larvae of the Cephidae,
Xiphydriidae, and Siricidae. It should not be confused with the caudal
protuberances of certain Tenthredinidae, as these two structures are
of an entirely different nature. There is a minute hook-like process on the
caudo-meson of the tenth abdominal tergum of the Pamphiliidae. It
should be noted that in certain larvae of Pontania and Caulocampus the
caudal portion of the ultimate tergum is produced caudad as a blunt more
or less strongly chitinized protuberance which undoubtedly serves the
same function as the suranal process of the specialized families. These
two structural modifications of the caudal end of the body, however, are
not homologous with each other. The suranal process is undoubtedly
128 ILLINOIS BIOLOGICAL MONOGRAPHS [446
an adaptive structure which has arisen in response to the habit of the
larvae and does not represent the true appendages of the segment, to
which the suranal lobe belongs. For this reason the caudal process is of
less significance phylogenetically than the subanal appendages of the
Pamphiliidae and Cephidae.
The metathoracic spiracles of the larvae are either obsolete or vestigial
in the majority of the Tenthredinoidea. The larvae of the Cephidae and
Siricidae differ from all others in that the metaspiracles are functional
and as large as the abdominal spiracles. It is important to ascertain the
original condition of the metaspiracles in these families because upon the
interpretation of their primitive condition depends their phylogenetic
value and hence the relationship between these two families and also
between them and other families. It is considered reasonable to assume
that the progenitor of insects and hence the ancestor of the Hymenoptera
possessed functional spiracles on all the segments of the body including the
metathorax, and that their metaspiracles must have been as large as the
abdominal spiracles. The closed minute functionless metaspiracles found
in the Pamphiliidae, Xyelidae, and others, indicate a condition of atrophy
rather than a rudimentary condition, and so far as this character is con-
cerned the Cephidae and Siricidae represent the unmodified primitive
condition and some sort of relation between these two families must be
assumed. But on the basis of other characters it is not conceivable that
these two families evolved one from the other in a linear sequence, apart
from and independent of other families; they must have descended from
a common stock which also gave rise to other families which exhibit
vestigial metaspiracles. If this is true there must have taken place a
series of dichotomies starting with functional metaspiracles, one line of
development resulting in the loss of this primitive character and the other
line of evolution retaining the original condition. By assuming four such
successive dichotomies in the line of evolution, the origin and significance
of the metaspiracles of the Cephidae and Siricidae can be reasonably
explained. At each of the four successive dichotomous divisions which
produced respectively the pamphiliid-like progenitor and Xyelidae,
Pamphiliidae and the cephid-like progenitor, Cephidae and the xiphydriid-
like progenitor, and Xiphydriidae and Siricidae, one line of descent always
carried the original character and the other line lost it until this peculiarity
was generally sifted out, being retained unmodified only in the Cephidae
and Siricidae. In this way the metaspiracles are here considered to be
the direct descendant of the primitive structures which remained unmod-
ified thruout the course of evolution of these families. The two families
are generalized in this respect indicating a close genetic relation.
447]
LARVAE OF THE TENTHREDINOIDEA—YUASA
129
The morphological characters discussed are summarized in the following
table:
Comparison of Various Structures in the Families o* the Tenthredinoidea
Structure
Pamphi-
liidae
Cephidae
Xiphy-
driidae
Siricidae
Oryssidae
Xyelidae
Tenth-
redinidae
Thoracic legs
5-seg-
mented
Fleshy
Fleshy
Fleshy
Wanting
5-seg-
mented
S-, 4-, 3-
segmented
Larvapods
Wanting
Wanting
Wanting
Wanting
Wanting
10 pairs
6-8 pairs
Subanal
appendages
Distinct,
long
Vestigial
Wanting
Wanting
Wanting
Wanting
Wanting
Ocellarae
Distinct
Vestigial
Wanting
Wanting
Wanting
Distinct
Distinct
Antennae
7-seg-
5- and 4-
3- seg-
1 -seg-
1 -seg-
7- and 6-
5-, 4-, and 1-
mented
segmented
mented
mented
mented
segmented
segmented
Mouth-parts
Typical
Typical
Modified
Modified
Vestigial
Typical
Typical, rare-
ly modified
Suranal process
Wanting
Distinct
Distinct
Distinct
Wanting
Wanting
Wanting
Meta thoracic
spiracles
Vestigial
Functional
Vestigial
Functional
Vestigial
Vestigial
Vestigial
The Pamphiliidae, with its long seven-segmented antennae, setiform
three-segmented subanal appendages, setiform five-segmented thoracic
legs, well-developed typical mouth-parts, together with the absence of
larvapods, is unquestionably one of the most generalized families of the
Tenthredinoidea. This family differs from the hypothetical type only
in the absence of larvapods and reduced metaspiracles.
The Xyelidae, with its fairly long seven-and six-segmented antennae,
five-segmented thoracic legs, well-developed typical mouth-parts, together
with the presence of ten pairs of larvapods and the absence of subanal
appendages, is undoubtedly a very generalized family, quite different
from the preceding. The only striking difference from the hypothetical
type is the absence of the subanal appendages and functional metaspiracles.
The Tenthredinidae, with its one- to five-segmented antennae, well-
developed thoracic legs, and six to eight pairs of larvapods, together with
the absence of the subanal appendages, is unquestionably related to the
Xyelidae, and if it has not been evolved directly from the latter the two
families must have arisen from a common stock. The Tenthredinidae is a
phylogenetic complex in itself, and some of the more specialized genera are
further removed from the more generalized genera, biologically as well as
morphologically, than the latter are from the Xyelidae or their xyelid-
like ancestors.
The Cephidae, with its segmented antennae, vestigial subanal append-
ages, vestigial thoracic legs, normal mouth-parts, absence of larvapods,
presence of suranal process, vestigial ocellarae, and large functional
metaspiracles, is considered an offshoot of the ancestral stem from which
130 ILLINOIS BIOLOGICAL MONOGRAPHS [448
the Pamphiliidae had previously evolved. The specialization is indicated
by the vestigial condition of the ocellarae, subanal appendages, and
thoracic legs, on the one hand, and the development of suranal processes
on the other. The presence of the functional metaspiracles is of phy-
logenetic importance. So far as the head characters are concerned, this
family resembles the Tenthredinidae to a limited extent, and in some of
the generalized genera of the latter the thoracic legs and the caudal portion
of the tenth abdominal segment undergo some modifications which in a
remote sense simulate the condition in the Cephidae. But since this
family differs from the Tenthredinidae, and resembles the Pamphiliidae in
the absence of larvapods and the presence of subanal appendages, it is
considered more reasonable to ascribe to it a closer relationship to the
Pamphiliidae than to the Tenthredinidae.
The Xiphydriidae, with its somewhat modified mouth-parts, three-
segmented antennae, fleshly thoracic legs, suranal process, absence of
larvapods, the general shape of the body, and its biology, resembles the
Cephidae but differs from it in theabsence of subanal appendages, ocellarae,
and in the vestigial functionless metaspiracles. The absence of the subanal
appendages may point to one of the two possibilities in regard to the origin
of the Xiphydriidae. This family might have evolved from the cephid-
like ancester but have lost the subanal appendages by the completion of
the process of atrophy which had already reduced the original distinctly-
segmented appendages (similar to those of the Pamphiliidae) to the
vestigial papilliform appendages of the Cephidae. The two families
under consideration might, on the other hand, have had a common stem
which possessed subanal appendages, ocellarae, and vestigial metaspiracles.
In the absence of positive support for the first possibility, it is more
expedient to consider the second possibility as nearer to the true rela-
tionship of the two families, Xiphydriidae and Cephidae.
The Siricidae, with its greatly reduced thoracic legs and mouth-parts
together with certain other characters, is considered more specialized
than the Xiphydriidae. The presence of the functional metaspiracles
and its genetic significance have already been discussed. For the same
reason which suggests a common origin for the Cephidae and Xiphy-
driidae, the Siricidae is considered to have arisen from a common stock
which gave rise also to the Xiphydriidae. In the degree of specialization
by reduction as well as by addition, this family outranks the Xiphydriidae.
The Oryssidae, with its vestigial mouth-parts, absence of ocellarae,
thoracic and abdominal legs, subanal appendages, suranal process, caudal
protuberances, and functional metaspiracles, together with its parasitic
habit, is unquestionably the most highly specialized family of the Ten-
thredinoidea. Its morphological and biological characters are so different
from other families that it is not easy to ascertain the systematic position
449] LARVAE OF THE TENTHREDINOIDEA—YUASA 131
of the family. There are, however, certain considerations which suggest
a possible relationship between this family and the Siricidae. Morpho-
logically the oryssid larvae are more closely related to the apodous boring
larvae of the Cephidae, Xiphydriidae, and Siricidae than to the polypodous
free-living larvae of the Xyelidae and Tenthredinidae. The siricid larvae
are more closely related to those of the Oryssidae than to those of the
Cephidae and Xiphydriidae. The parasitic habit also suggests a closer re-
lation to the wood-boring larvae since it is more plausible to imagine the
possibility of a wood-boring larvae becoming parasitic on other wood-
boring insect larvae under some unknown but not entirely inconceivable
circumstances than to imagine the development of a parasitic habit de novo
in free-living leaf-feeders. Since the oryssid larvae are parasitic on the
larvae of Buprestis inhabiting plants which are also infested by the larvae
of the Siricidae, if any transformation of habit of the larvae has taken
place, it is more natural to expect the larvae of the Siricidae or some
siricid-like insect to become parasitic than any other larvae. The recent
investigation by Baumberger (1919) on the role of microorganisms in
the physiology of insect nutrition offers a valuable suggestion in regard to
the possibility of radical changes in food habits. For these reasons it is
considered reasonable to ascribe a common progenitor to the Siricidae
and Oryssidae, at least for the time being. It may be added that it is
not entirely unreasonable to assume an independent line of evolution
for the Oryssidae apart from all other Tenthredinoidea and consider
this family as having no close relation to any of the modern families of the
Tenthredinoidea. In that case, the Oryssidae must have arisen from the
ancestral stock before the Pamphiliidae and Xyelidae had their origin.
There is, however, no clear evidence in support of such relation and
since the relation is reasonably explained by associating the Oryssidae
with the Siricidae, the former is considered the most highly specialized
family of the Tenthredinoidea with a common origin with the ancestor of
the Siricidae.
The conclusions on the systematic position and relationship of the
different families of the Tenthredinoidea based exclusively on larval
characters and derived entirely independent of the opinions of the spe-
cialists who have paid more attention to the adults are of necessity not
the final words on the subject. The true significance of such conclusions
lies in their complemental and collateral value. It is interesting on this
account to compare the writer's opinion with the conclusions of the
modern authorities on this group of the Hymenoptera.
The relationship suggested here supports in its essential points the
three more important systems of classification proposed by Konow (1905),
MacGillivray (1906), and Rohwer (1911). MacGillivray considered the
Xyelidae the most primitive because of the venational character but
132 ILLINOIS BIOLOGICAL MONOGRAPHS [450
recognized the Pamphiliidae as the most generalized from his study (1913)
of the immature stages. Had he placed the Pamphiliidae before the
Xyelidae and the Cephidae before the Xiphydriidae and Siricidae, his
system would coincide exactly with the system based exclusively on the
immature stages. Konow and Rohwer both associate the Cephidae
with the Pamphiliidae and Xyelidae. This arrangement is partly supported
if the affinity between the Pamphiliidae and Cephidae, as suggested in
this study, is upheld. The genetic continuity of the Xyelidae and Ten-
thredinidae is clearly recognized by MacGillivray (1913). The true
systematic position of the Tenthredinidae or its equivalent is difficult
to express in linear arrangement. The important point to be noted is the
fact that these authors and also Morice (1919) consider the Xyelidae and
Tenthredinidae as different and apart from the other families of the
Tenthredinoidea. The Oryssidae unquestionably merits at least separate
family rank. In the absence of requisite knowledge of the larval characters
of the Hymenoptera other than the Tenthredinoidea, it is not expedient
to venture any opinion on the suggestion made by Rohwer and Cushman
(1917) to establish a third suborder, Idiogastra, for the reception of the
Oryssidae. Enslin (1911) differs from the authors already mentioned
not only in his arrangement of the groups in a descending order but also in
treating the Xyelidae and Pamphiliidae as subfamilies of his Tenthredini-
dae, on a level with the Cimbicini, Lophrini, and others. This study does
not support his arrangement. Morice (1919) suggested that "the Lydini
(Pamphiliidae Ensl.) may represent a primitive group of Tenthredinidae
which had branched off from the main stock before it had developed
certain characters," such as abdominal legs. Handlirsch (1908) considered
the Siricidae as having evolved from the osculant Juracic group, Pseudo-
siricidae. The antiquity of the Siricidae is accepted by Morice who
expresses his idea of the relationship of the families of the Tenthredinoidea
as follows: "We may suppose that the Siricidae are the earlier group,
but whether the Tenthredinidae and Lydini had Siricid ancestors, or
whether the Siricidae-f-Cephini-f-Oryssidae and Tenthredinidae+ Lydini
are respectively earlier and later branches of a common stock are questions
which must be left unanswered."
451] LARVAE OF THE TENTHREDINOIDEA—YVASA 133
V. SUMMARY
The larvae of the Tenthredinoidea have proved to be of great value in
affording important evidence in regard to the probable phylogenetic
relationship of the families included in this superfamily. The more
significant conclusions reached in this study are summarized in the form
of a synoptic key as follows:
FAMILIES OF TENTHREDINOIDEA
Larvapods present, thoracic legs present, well developed, distinctly segmented.
Larvapods present on all abdominal segments Xyelidae
Larvapods never present on 1st and 9th abdominal segments Tentkredinidae
Larvapods wanting, thoracic legs present or wanting.
Thoracic legs present.
Thoracic legs and subanal appendages well-developed and distinctly segmented.
Pamphiliidae.
Thoracic legs vestigial, indistinctly segmented.
Subanal appendages and ocellarae present Cephidae.
Subanal appendages and ocellarae wanting.
Metaspiracles vestigial, much smaller than abdominal spiracles. . . Xiphydriidae.
Metaspiracles functional, as large as abdominal spiracles Siricidae.
Thoracic legs wanting Oryssidae.
A synopsis such as the foregoing is necessarily inadequate and some-
what misleading in indicating the affinities of the families. A better idea
is gained by means of the customary phylogenetic tree, altho such a
scheme also has its limitations. In the following diagram the relation
between the families of the Tenthredinoidea is shown. Here the relative
vertical positions are intended to represent approximately the degree
of specialization; and the continuous lines, the affinities.
The larvae of the Tenthredinoidea are thus divisible into two distinct
groups. The first group includes the larvae characterized by the presence
of both the thoracic and abdominal legs, and by the absence of the subanal
appendages and suranal process, and is represented by the Xyelidae
and Tenthredinidae. The second group consists of the five families,
Pamphiliidae, Cephidae, Xiphydriidae, Siricidae, and Oryssidae, and is
divisible into two subgroups. The first subgroup contains the first four
families and is characterized by the absence of abdominal legs, by the
134
ILLINOIS BIOLOGICAL MONOGRAPHS
[452
presence of vestigial clawless thoracic legs in the last three families, and
by the presence of either subanal appendages or suranal process or both.
The second subgroup contains a single family, Oryssidae, which is charac-
terized by the absence of both thoracic and abdominal legs, suranal
Highly
Specialized
Tenthredinidae
(specialized)!
Oryssidae
Siricidae /
/ /
Xiphydriidae / /
Specialized
Tenthredinidae 1
(generalized) 1
/ // Oephidae
Generalized
Xyelidae \l
/ / i'amphiliidae
Primitive
Pro-
-Symphyta
Fbylogenetic tree indicating the probable affinities of various families of the Tenthredinoidea
process, subanal appendages, and segmented maxillary and labial palpi.
The Xyelidae and Pamphiliidae are undoubtedly the most primitive of the
first and second groups respectively.
The Tenthredinoidea, therefore, is considered to have developed
from a common ancestral stock along two distinct lines of evolution.
The first line of development led to the evolution of the Xyelidae and
Tenthredinidae and the second line produced the Pamphiliidae, Cephidae,
Xiphydriidae, Siricidae, and Oryssidae.
453] LARVAE OF THE TENTHREDINOIDEA—YUASA 135
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1823. Monographia Tenthredinetarum, synonymia extricata. Paris.
1836. Histoire naturelle des Insectes. Hymenopteres. Vol. TV. Paris.
Linnaeus, C.
1744. Systema Naturae. 4th ed. Paris.
1746. Fauna Suecica sis tens animalia Sueciae regni, etc.
1758. Systema Naturae. 10th ed. Homiae.
Lyonet, P. ■»
1762. Traite anatomique de la Chenille, qui rouge le Bois de Saule, etc. La Haye.
MacGillivray, A. D. •
1906. A study of the wings of the Tenthredinoidea, a superfamily of Hymenoptera.
Proc. U. S. Nat. Museum, 29, 569-654.
1913. The immature stages of the Tenthredinoidea. Ann. Rept. Ent. Soc. Ontario,
44: 54-75.
1916. Tenthredinoidea. Conn. Geol. Nat. Hist. Survey. Bull. No. 22:25-175.
Marlatt, C. L.
1895. The hibernation of nematids, and its bearing on inquilinous species. Proc. Ent.
Soc. Wash., 3, 263-267.
1887. Notes on a red cedar sawfly. Trans. Kansas Acad. Sci., 1885-6, 10:80-83.
1890. The final molting of tenthredinid larvae. Proc. Ent. Soc. Wash., 2 :115-117.
Merian, Maria S.
1730. Histoire des Insectes de l'Europe, dessinSs d'apres nature et expliquds par Marie
Sibille Merian, etc. La Haye.
Middleton, W.
1915. Notes on some sawfly larvae belonging to the genus Dimorphopteryx. Proc.
U.S. Nat. Mus. 48: 497-501.
1917. Notes on the larvae of some Cephidae. Proc. Ent Soc. Wash., 19:174-179.
1921a. LeConte's sawfly, an enemy of young pines. Jour. Agr. Res., 20:741-760.
1921b. Some notes on the terminal abdominal structures of sawfly. Proc. Ent. Soc.
Wash., 23:139-144.
1921c. Some suggested homologies between larvae and adults in sawflies. Proc. Ent.
Soc. Wash., 23:173-192.
1922. Sawflies injurious to rose foliage. U. S. Dept. Agr. Farmers' Bull. 1252.
Morice, F. D.
1919. Notes on Australian sawflies, especially the "authors' types" and other speci-
mens in the British Museum of Natural History and the Hope Collections of the
Oxford University Museum; with diagnostic synopsis of the genera and species,
and photographs illustrating their structural characters. Trans. Ent. Soc.
London, 1918: 247^33.
457] LARVAE OF THE TENTHREDINOIDEA—YUASA 139
MOUFET, T.
1634. Insectorum sive minimorum animalium theatrum, etc.
Nelson, J. A.
1915. The embryology of the honey-bee. Princeton Univ. Press.
Norton, E.
1867-69. Catalogue of the described Tenthredinidae and Uroceridae of North America.
Trans. Am. Ent. Soc, 1867-69, 1: 31-84, 193-280; 2:211-242, 321-368.
Packard, A. S.
1883. Third Report U. S. Ent. Comm., 307, 324, 435.
1890. Fifth Rept. U. S. Ent. Comm., being a revised and enlarged edition of Bull.
No. 7, on insects injurious to forest and shade trees.
Parrott, P. J., and Fulton, B. B.
1915. Cherry and hawthorn sawfly leaf-miner. Jour. Agr. Res., 5:519-528.
Pearsall, R. F.
1902. Life history of Lyda fasciala (Norton), Fam. Tenthredinidae. Can. Ent., 34:
214-216.
POLETAJEW, N.
1885. Ueber die Spinndriisen der Blattwespen. Zool. Anz., 8:22-23.
Riley, C. V., and Marlatt, C. L.
1891. Wheat and grass sawflies. Insect Life, 4:168.
Rohwer, S. A.
1910. Hoplocampa. Can. Ent., 42:242-244.
1911. A classification of the suborder Chalastogastra of the Hymenoptera. Proc.
Ent. Soc. Wash., 13:215-226.
1911a. Genotypes of the sawflies and wood wasps, or the superfamily Tenthredinoidea.
Bull. Tech. Series, U. S. Bur. Ent. No. 20, Part 2.
1911b. Additions and corrections to "the genotypes of the sawflies and woodwasps, or
the superfamily Tenthredinoidea." Ent. News, 22:218-219.
1912. Notes on sawflies, with descriptions of new species. Proc. U. S. Nat. Mus.,
43:205-251.
1915. A remarkable new genus of Cephidae. Proc. Ent. Soc. Wash., 17:114-117.
1917. The American species of the genus Cephus Latreille. Proc. Ent. Soc. Wash.,
19:139-141.
1918a. New Sawflies of the subfamily Diprioninae. (Hym.). Proc. Ent. Soc. Wash.,
20:79-90.
1918b. Notes on, and descriptions of the Nearctic woodwasps of the genus Xiphydria
Latreille (Hym.) Ent. News, 29:105-111.
1918c. Notes on, and descriptions of sawflies belonging to the tribe Hemichroini (Hym.).
Proc. Ent. Soc. Wash., 20:161-173.
Rohwer, S. A. and Cushman, R. A.
1917. Idiogastra, a new suborder of Hymenoptera with notes on the immature stages
of Oryssus. Proc. Ent. Soc. Wash., 19:89-98.
Sasscer, E. R.
1911. Notes on a sawfly injurious to ash. Proc. Ent. Soc. Wash., 13:107-110.
Schwarz, E. A.
1909. Illustrations of the life history of a sawfly (Hylotoma pectoralis Leach) injurious
to willow. Proc. Ent. Soc. Wash., 11:106-108.
Snellen von Vollenhoven.
1868. Die inlandsche Bladwespen. Tijdschr. voor Ent., 11:
Stephens, J. F.
1835. Illustrations of British entomology; or synopsis of indigenous insects, etc.
London.
140 ILLINOIS BIOLOGICAL MONOGRAPHS (458
SWAMMERDAM, J.
1737. Biblia naturae, etc. Leydae.
Swenk, M. H.
1911. A new sawfly enemy of the bull pine in Nebraska. 24th Ann. Rept. Neb. Agr.
Exp. Sta., 1911.
Townsend, H. T.
1894. Notes on the Tenthredinid gall of Euura orbitalis on Saliz and its occupants.
Jour. N. Y. Ent. Soc., 2:102.
Walden, B. H.
1912. A new sawfly pest of the blackberry, Pomphttius denkUus MacGfllivray. Rept.
Conn. Agr. Exp. Sta., 1912, 236-240.
Walsh, B. D.
1866. Imported insects; the gooseberry sawfly. Pract. Ent, 1:117-125.
Webster, F. M.
1900. The purslane sawfly, Schizocerus zabriskei Ashm. Can. Ent., 32:51-54.
Westwood, J. O.
1840. An introduction to the modern classification of insects. London.
Young, Chester.
1898. The larvae of the Tenthredina. Baccalaureate thesis, Cornell University.
1899. Descriptions of sawfly larvae. Can. Ent., 31:41-43.
Yuasa, H.
1920. The anatomy of the head and mouth-parts of Orthoptera and Euplexoptera. Jour.
Morph., 33:251-307.
459] LARVAE OF THE TENTHREDINOIDEA—YUASA 141
PLATE I
142 ILLINOIS BIOLOGICAL MONOGRAPHS (460
EXPLANATION OF PLATE
LARVAE OF TENTHREDINOIDEA
Fig. 1— Pamphiliidac. Pamphilius sp. Y-125.
Fig. 2 — Cephidae. Janus integer.
Fig. 3 — Xiphydrudae. Xiphydria sp.
Fig. 4 — Siricidae. Tremex columba.
Fig. 5— Oryssklae. Oryssus occidentalis
(After Rohwer and Cushman, 1917).
au anus
msp mesothoracic spiracle
sba subanal appendage
sp* abdominal spiracle
srp suranal process
tig* mesothoracic leg
tsp me ta thoracic spiracle
ILLINOIS BIOLOGICAL MONOGRAPHS
VOLUME VII
• • '0 m
YUASA LARVAE OF THE TENTHREDINOIDEA PLATE I
461] LARVAE OF THE TENTHREDINOIDEA—YUASA 143
PLATE II
144
ILLINOIS BIOLOGICAL MONOGRAPHS
[462
EXPLANATION OF PLATE
LARVAE OF XYELIDAE AND TENTHREDINIDAE
Fig. 6 — Xyelidae.
Fig. 7 — Tenthredinidae.
Fig. 8— Tenthredinidae.
Fig. 9 — Tenthredinidae.
Fig. 10 — Tenthredinidae.
Megaxyela major.
Diprioninae. Neodipriron lecontei.
Emphytus apertus.
Strongylogaster anmtlosus.
Dolerus similis.
anus
mesothoracic spiracle
larvapod
abdominal spiracle
mesothoracic leg
metathoracic spiracle
Emphytinae.
Selandriinae.
Dolerinae.
msp
Pig
spi
tig 1
tsp
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YUASA LARVAE OF THE TENTHREDINOIDEA PLATE II
463] LARVAE OF THE TENTHREDINOIDEA—YUASA 145
PLATE III
146
ILLINOIS BIOLOGICAL MONOGRAPHS
[464
Fig. 11 — Phyllotominae.
Fig. 12 — Phyllotominae.
Fig. 13 — Tenthredininae.
Fig. 14 — Cimbicinae.
Fig. 15 — Hoplocampinae.
EXPLANATION OF PLATE
LARVAE OF TENTHREDINIDAE
Caliroa cerasi.
Phlebatrophia mathesoni.
Tenthredo sp.
A bia in flat a.
Hemichroa americana.
au anus
tnsp mesothoracic spiracle
pig larvapod
spi abdominal spiracle
tig 2 mesothoracic leg
tsp metathoracic spiracle
ILLINOIS BIOLOGICAL MONOGRAPHS
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YUASA LARVAE OF THE TENTHREDINOIDEA PLATE III
465] LARVAE OF THE TENTHREDINOIDEA—YUASA 147
PLATE IV
148
ILLINOIS BIOLOGICAL MONOGRAPHS
m
Fig. 16 — Cladiinae.
Fig. 17 — Nematinae.
Fig. 18 — Nematinae.
Fig. 19 — Blennocampinae.
Fig. 20 — Blennocampinae.
EXPLANATION OF PLATE
LARVAE OF TENTHREDINIDAE
Cladius pectinicornis.
Pkronidea ventralis.
Pkronidea ribesi.
Monophadnoides rubi.
Tomostethus bardus.
an anus
msp mesothoracic spiracle
pig larvapod
spi abdominal spiracle
srp suranal process
tig 1 mesothoracic leg
tsp metathoracic spiracle
ILLINOIS BIOLOGICAL MONOGRAPHS
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YUASA LARVAE OF THE TENTHREDINOIDEA PLATE IV
4671 LARVAE OF THE TENTHREDINOIDEA—YUASA 149
PLATE V
150
ILLINOIS BIOLOGICAL MONOGRAPHS
[468
EXPLANATION OF PLATE
LARVAE OF TENTHREDINTDAE
Fig. 21 — Fenusinae.
Kaliofenusa ulmi.
Fig. 22 — Scolioneurinae.
Meiallus rubi.
Fig. 23 — Hylotominae.
Hylotoma sp.
Fig. 24 — Schizocerinae.
Schizocerus zabriskei.
Fig. 25 — Acordulecerinae.
Acordulecera sp.
au anus
msp mesothoracic spiracle
pig larvapod
scp sucker-like protuberance
spi abdominal spiracle
tig * mesothoracic leg
tsp meta thoracic spiracle
ILLINOIS BIOLOGICAL MONOGRAPHS
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YUASA LARVAE OF THE TENTHREDINOIDP:A PLATE V
469] LARVAE OF THE TENTHREDINOIDEA—YAUSA 151
PLATE VI
152
ILLINOIS BIOLOGICAL MONOGRAPHS
(470
EXPLANATION OF PLATE
CEPHALIC ASPECT OF THE HEAD
Fig. 26 — Pompkttius sp.
Fig. 27 — Megaxyda major.
Fig. 28 — Neodiprion lecontei.
Fig. 29 — Abia americana.
Fig. 30 — Pteronidea ribesi.
Fig. 31 — Lygaeonematus erichsoni.
Fig. 32 — Endelomyia aethiops.
a
antenna
an
antacoria
or
antennaria
c
dypeus
cl
clypealia
els
clypeo-labra) suture
crv
sericos
cs
clypeal suture
ea
epicranial arm
es
epicranial stem
f
front
fes
fronto-clypeal suture
gl
galea
hx
hypopharynx
inl
line of invagination
I
labrum
IP
labial palpus
Is
labral setae
Fig. 33 — Macremphytus variatms.
Fig. 34 — Kaliofenusa ultni.
Fig. 35 — MetaUus rubi.
Fig. 36 — Schizocerus zabriskei.
Fig. 37 — Phlebatrophia mathesoni.
Fig. 38 — Dolerus similis.
ma muscular attachment
mb mandibularia
mi mandible
mds mandibular setae
mp maxillary palpus
mx maxilla
o ocellara
ou ocularia
pe preclypeus
pn pretentorina
po postclypeus
pr precoila
py preartis
v vertex
»/ vertical furrow
ILLINOIS BIOLOGICAL MONOGRAPHS
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YUASA LARVAE OF THE TENTHREDINOIDEA PLATE VI
471] LARVAE OF THE TENTHRED1N0IDEA—YUASA 153
PLATE VII
154
ILLINOIS BIOLOGICAL MONOGRAPHS
[472
EXPLANATION OF PLATE
VENTRAL ASPECT OF THE HEAD AND PROTHORAX
Fig. 39 — PamphUus sp.
Fig. 40 — Megaxyda major.
Fig. 41 — Koliofenusa ulmi.
Fig. 42 — Dolerus simttis.
Fig. 43 — Neodiprion lecontei.
Fig. 44 — Macremphytus varianus.
a
antenna
an
antacoria
c
clypeus
cc
cervacoria
d
clypealia
ds
clypeo-labral suture
en
sericos
cw
tarsal claw
ex
coxa
ea
epicranial arm
cc
extensacuta
es
epicranial stem
f
front
fes
fronto-clypeal suture
fm
femur
g
gena
gl
galea
hs
hvpopharynx
Fig. 45 — Xiphydria sp.
Fig. 46 — Trernex columba.
Fig. 47 — Lygeonematus ericksoni.
Fig. 48 — Enddomyia adhiops.
Fig. 49 — Met alius rubi.
1
labrum
la
lacinia
les
lateral cervical sclerite
li
labium
IP
labial palpus
mb
mandibularia
md
mandible
mp
maxillary palpus
mx
maxilla
ocellara
Pin
profurcellina
pn
pretentorina
Pr
precoila
py
preartis
t
tibia
tr
trochanter
Ug l
prothoracic leg
V
vertex
ILLINOIS BIOLOGICAL MONOGRAPHS
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YUASA LARVAE OF THE TENTHREDINOIDEA PLATE VII
473] LARVAE OF THE TENTHREDINOIDEA—YUASA 15$
PLATE VIII
156
ILLINOIS BIOLOGICAL MONOGRAPHS
[474
EXPLANATION OF PLATE
VENTRAL AND DORSAL ASPECTS OF HEAD AND PROTHORAX
Fig. 50 — Janus integer.
Fig. 55 — Dolerus similis.
Fig. 51 — Schizocerus zabriskei.
Fig. 56 — Megaxyela major.
Fig. 52 — Phlebatropkia mathesoni.
Fig. 57 — Caliroa cerasi.
Fig. 53 — Caliroa cerasi.
Fig. 58 — Neodiprion lecontei.
Fig. 54 — Pamphilius sp.
Fig. 59 — Endelomyia nethiops.
a
antenna
la
lacinia
c
clypeus
Ic
labicoria
cc
cervacoria
li
labium
eg
cervical gland
IP
labial palpus
els
clypeo-labral suture
m
mentum
erv
sericos
mb
mandibularia
em
tarsal claw
md
mandible
ex
coxa
tnp
maxillary palpus
M
epicranial arm
msp
mesothoracic spiracle
ec
extensacuta
mx
maxilla
es
epicranial stem
ocellara
f
front
Pfn
profurcellina
fm
femur
pn
pretentorina
1
gena
i
tibia
gi
galea
^
prothoracic leg
hx
hypopharynx
m
tarsus
is
intersegmental line (limit of somite) v
vertex
I
labrum
*f
vertical furrow
ILLINOIS BIOLOGICAL MONOGRAPHS
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YUASA LARVAE OF THE TENTHREDINOIDEA PLATE VIII
475] LARVAE OF THE TENTHREDINOIDEA—YUASA 157
PLATE IX
1S8
ILLINOIS BIOLOGICAL MONOGRAPHS
[476
EXPLANATION OF PLATE
DORSAL AND LATERAL ASPECTS OF HEAD AND PROTHORAX
Fig. 60 — Macremphytus varianus.
Fig. 61 — Monophadnoides rubi.
Fig. 62— Metallus rubi.
Fig. 63 — Patnphilius sp.
Fig. 64 — Megaxyela major.
Fig. 65 — Neodiprion lecontei.
Fig. 66 — Dolerus similis.
Fig. 67 — Macrcmphytus varianus.
Fig. 68 — Endelomyia aeikiops.
Fig. 69 — Caliroa cerasi.
Fig. 70 — Pteronidea ribesi.
Fig. 71 — Lygeonematus ericksoni.
Fig. 72 — Abia americana.
a
antenna
let
lateral cervical sderite
c
clypeus
li
labium
cc
cervacoria
IP
labial palpus
eg
cervical gland
mb
mandibularia
cw
tarsal claw
md
mandible
ex
coxa
rnp
maxillary palpus
ea
epicranial arm
msp
mesothoracic spiracle
ec
extensacuta
mx
maxilla
es
epicranial stem
ocellara
f
front
Pr
precoila
fm
femur
py
preartis
t
gena
t
tibia
kx
hypopharynx
tr
trochanter
it
intersegmental line (limit of somite)
V
vertex
I
labium
4
vertical furrow
la
lacinia
ILLINOIS BIOLOGICAL MONOGRAPHS
VOLUME VII
YUASA LARVAE OF THE TENTHREDINOIDEA PLATE IX
477| LARVAE OF THE TENTHREDINOIDEA—YUASA 159
PLATE X
160
ILLINOIS BIOLOGICAL MONOGRAPHS
1478
EXPLANATION OF PLATE
LATERAL AND VENTRAL ASPECTS OF THIRD ABDOMINAL SEGMENT
Fig. 73 — Pamphilius sp.
Fig. 74 — Endelomyia atthiops.
Fig. 75 — Dolerus similis.
Fig. 76 — Megaxyela major.
Fig. 77 — Neodiprion lecontei.
Fig. 78 — Macremphytus varianus.
Fig. 79 — Caliroa cerasi.
Fig. 80 — Pamphilius sp.
Fig. 81 — Dolerus similis.
Fig. 82 — Neodiprion lecontei.
Fig. 83 — Endelomyia aethiops.
Fig. 84 — Megaxyela major.
Fig. 85 — Caliroa cerasi.
Fig. 86 — Kaliofenusa ulmi.
Fig. 87 — Metallus rubi.
Fig. 88 — Macremphytus varianus.
al-al annulets 1, 2, 3, 4, 5, 6, 7.
ch chitinized area.
cor intersegmental coria
pig larvapod
sdl surpedal lobe or area
spi abdominal spiracle
ssl subspiracular lobe or area
ILLINOIS BIOLOGICAL MONOGRAPHS
VOLUME VII
YUASA
LARVAE OF THE TENTHREDINOIDEA PLATE X
479] LARVAE OF THE TENTH REDINOIDEA—YU ASA 161
PLATE XI
162
ILLINOIS BIOLOGICAL MONOGRAPHS
[480
EXPLANATION OF PLATE
LATERAL AND VENTRAL ASPECTS OF CAUDAL ABDOMINAL SEGMENTS
Fig. 89 — Megaxyda major.
Fig. 90 — Megaxyda major.
Fig. 91 — Pamphilius sp.
Fig. 92 — Macremphytus varianus.
Fig. 93 — Macremphytus varianus.
Fig. 94 — Caliroa cerasi.
Fig. 95 — Pamphilius sp.
Fig. 96 — Dolerus similis.
Fig. 97 — Caliroa cerasi.
Fig. 98 — Endelomyia atthiops.
Fig. 99 — MetaUus rubi.
Fig. 100 — Neodiprion lecontei.
Fig. 101 — Neodiprion lecontei.
Fig. 102 — Dolerus similis.
Fig. 103— M etallus rubi.
Fig. I04r—Phlebatrophia mathesoni.
Ventral aspect of third ab-
dominal segment.
au
anus
al
annulet 1
a2
annulet 2
o6
annulet 6
ck
chitinized area
PH
larvapod
sba
subanal appendage
sbl
subanal lobe
sdl
surpedal lobe or area
spi
abdominal spiracle
srl
suranal lobe
ssl
subspiracular lobe or area
ILLINOIS BIOLOGICAL MONOGRAPHS
VOLUME VII
YUASA LARVAE OF THE TENTHREDINOIDEA PLATE XI
481] LARVAE OF THE TENTHREDINOIDEA—YUASA 163
PLATE XII
164
ILLINOIS BIOLOGICAL MONOGRAPHS
(482
EXPLANATION OF PLATE
CAUDAL ASPECT OF HEAD, ABDOMEN, ABDOMINAL APPENDAGES
Fig. 105 — Kaliofenusa ulmi. Ventral Fig.
aspect of caudal abdominal segment.
Fig. 106— Phkbatrophia mathesoni. Fig.
Fig. 107— Xiphydria sp.
Fig. 108 — Cephas Pygmaeus. Fig.
Fig. 109 — Adirus trimaculatus.
Fig. 110 — Xiphydria sp. Fig.
Fig. Ill — Hartigia cressoni.
Fig. 112 — Janus integer. Fig.
Fig. 113 — Tremex columba.
Fig. 114 — Cephas pygmaeus. Caudal end Fig.
of the abdomen enlarged.
Fig. 115 — Adirus trimaculatus. Fig.
Fig. 116 — Adirus trimaculatus. Subanal ap-
pendage enlarged. Fig.
Fig. 117 — Hartigia cressoni. Subanal
appendage enlarged. Fig.
Fig. 118 — Janus sp. Subanal appendage
enlarged. Fig.
Fig. 119 — Cephus Pygmaeus. Subanal
appendage enlarged.
120 — Tremex columba. Lateral aspect of
suranal process enlarged.
121 — Janus integer. Lateral aspect of
suranal process enlarged.
122 — Tremex columba. Dorsal aspect of
suranal process enlarged.
123 — Janus integer. Dorsal aspect of
suranal process enlarged.
124 — Pteronidea ribesi. Ventral aspect
of third abdominal segment.
125 — Pteronidea ribesi Lateral aspect
of caudal end of abdomen.
126 — Pteronidea ribesi. Lateral aspect
of caudal end of abdomen.
127 — Pteronidea ribesi. Dorsal aspect of
caudal end of abdomen.
128 — Abia americana. Caudal aspect of
the head.
129 — Neodiprion lecontei. Musculature
of third abdominal segment, semidia-
grammatic. Annulets numbered.
au anus
cc
ch
cht
cervacona
chit inized area
chitinized tubercle
cor cona
ct corpotentorium
e s epicranial stem
li labium
lp labial palpus
1st lateral area of suranal lobe
nib mandicoria
mc maxacoria
mn metatentorina
tnp maxillary palpus
ml metatentorium
mx maxilla
my
maxillaria
od
odontoidea
of
occipital foramen
OS
occipital suture
pa
postgena
Pgr
postgenal ridge
PI
paracoila
Pig
larvapod
pa
postcoila
pa
postgena
sba
subanal appendage
sbl
subanal lobe
sU
sublateral lobe
spi
abdominal spiracle
srp
suranal process
ILLINOIS BIOLOGICAL MONOGRAPHS
VOLUME VII
129
127
YUASA LARVAE OF THE TENTHREDINOIDEA PLATE XII
483| LARVAE OF THE TENTHREDINOIDEA—YUASA 165
PLATE XIII
166 ILLINOIS BIOLOGICAL MONOGRAPHS [494
EXPLANATION OF PLATE
ANTENNAE, LEGS, SILK-GLANDS
Fig. 130 — Patnphilius sp. Metathoracic leg.
Fig. 131 — Megaxyda major. Metathoracic leg.
Fig. 132 — Macremphytus varianus. Metathoracic leg.
Fig. 133 — Pteronidea ribesi. Mesothoracic leg.
Fig. 134 — Neodiprion lecontei. Metathoracic leg.
Fig. 135 — Dolerus sitnilis. Metathoracic leg.
Fig. 136 — Phlebatrophia mathesoni. Metathoracic leg.
Fig. 137 — Metallus rubi. Metathoracic leg.
Fig. 138 — Pteronidea ribesi. Mesothoracic leg. Dorsal aspect.
Fig. 139 — Sckizocerus zabriskei. Metathoracic leg.
Fig. 140 — Kaliofenusa ulmi. Metathoracic leg.
Fig. 141 — Caliroa cerasi. Metathoracic leg.
Fig. 142 — Endelomyia aethiops. Metathoracic leg.
Fig. 143 — Megaxyela major. Antena.
Fig. 144 — Adirus Irimaculatus. Antenna.
Fig. 145 — Sckizocerus zabriskei. Antenna.
Fig. 146 — Cephus pygmaeus. Antenna.
Fig. 147 — Metallus rubi. Antenna.
Fig. 148 — Tremex columba. Antenna.
Fig. 149 — Kaliofenusa ulmi. Antenna.
Fig. 150 — Phlebatrophia mathesoni. Antenna.
Fig. 151 — Janus integer. Antenna.
Fig. 152 — Hartigia cressoni. Antenna.
Fig. 153 — Thrinaximpressatus. Antenna.
Fig. 154 — Pteronidea ribesi. Antenna.
Fig. 155 — Tremex columba. Mesothoracic spiracle.
Fig. 156 — Abia americana. Silk-glands.
Fig. 157 — Abia americana. Labium, hypopharynx, and portion of silk-glands, enlarged.
Fig. 158 — Abia americana. Lateral aspect of cephalic portion of silk-glands.
Fig. 159 — Abia americana. Dorsal view of silk-press, hypopharynx removed.
Fig. 160 — Abia americana. Cephalic view of labium and hypopharynx.
al-a6 antennal segments 1, 2,
3, 4, 5, and 6
an antacoria
li
labium
crv cericos
IP
labial palpus
cw tarsal claw
M
arrow pointing mesad
ex coxa
sd
duct of silk-glands
D arrow pointing dorsad
s&
cells of silk-gland
fm femur
sgd
small duct of silk-glands
fp femoral process
slpr
silk-press
k* hypopharynx
ILLINOIS BIOLOGICAL MONOGRAPHS
VOLUME VII
YUASA LARVAE OF THE TENTHREDINOIDEA PLATE XIII
4853 LARVAE OF THE TENTHREDINOWEA—YUASA 167
PLATE XIV
168 ILLINOIS BIOLOGICAL MONOGRAPHS \486
EXPLANATION OF PLATE
Chart representing graphically the relationship of various taxonomic units or groups
according to the more important modern systems of classification of the Tenthredinoidea as
proposed by Konow (1905), MacGillivray (1906), and Rohwer (1911-1918).
ILLINOIS BIOLOGICAL MONOGRAPHS
VOLUME VII
MORF. IMPORTAHT MODERN SYSTEMS OF CLASSIPICAnOHOFIHKTRmHKEPinOIDEi
KONOW
1903
MACGILLIVRAY
1906
ROHWER.
HJM ~-'l 8
CHALASTOGASTKA TENTHREDINOIDEA CMALASTOGASTRA
I LYD1DAE
Lydioi
Meb«cerin»e
Acorduleccrinae^
Pt€ry3i>fl>orioae v
^Penjinaff
,V. XIPHYDRJIDA1
W.SIRjaDAE
Siricinatf
1Wmecin»f
VHMEGALODOIITIDAE
YICEPHIDAE
IX.ORVSSIDAE
MEGALODONTOIDEA I
flEGALOOOHTIDAE.
Meq^Jo.tontiixvp
Paatpbiliirtae
XYEUBAE
CEPHIDAE
ORYSSOipEA-ipiO^ji
SIRECOI
XIPHYDRIIDAE
XipWdriinac
Dcrecystinae
SIRECIDAE
5irecir»a?
Sirccioi
_. Ktr\ I ni
TENTHREDINOIDEA
CIMBECIDAE
Cimbecinae
dmbecini
PK e "At o pc i^in i
Z&r&rinae
RtruAs|i>)iri>v.'
ARGIDAE
\BUSTICOTOM»DAE
1THREDIMIDAE
1 Pfpriooioae (»«m»;
AllantipAc
TtXAonini
Er-iocampini
A|la»rrHr>i
Dolerinatf
Tcntbrcd ininae
(Vrincurini
Trnthrvdlnini
Mrssin&c
FfcyUatotnirti
. rtossini
Ath»liiru\c
Enpt-ii"*^
Emu iini
L Lyi Aotini
fMennoc»mpini
PKymatocvi inAf
6VI Aiutt-iinae
Selandriini
Struts yl<*jstern»i
l.vliinac
N«rnAtinA*'
Of Jialini . . , _ _,
Hemict*romt (i«»ia)
'PTERYGOPHOKI DAE
\
Ptery^orhorh
Acorduleceri
Ph yl&<- t<->pK«giri«<>
Acordulecerin&eiz
turiinac (2,
PERGIDAE
'LOBOCERIDAE
YUASA LARVAE OF THE TENTHREDINOIDEA PLATE XIV
487]
LARVAE OF THE TENTHREDINOIDEA—YUASA
169
INDEX
Page
abbotti 47
abbreviates 110
abdominalis 113
Abia 65
Abia, species of 66
abietis 47
abdomen 25
acericaulis 69
Acordulecera 103, 104
Acordulecera, species of 103
Acordulecerinae 44
Acordulecerinae, subfamily 103
Adirus 109, 110
aethiops 58
albifrons 55
americana 65, 66
Amauronematus 76, 84
Amauronematus, species of 84
annulosus 53
antennae 19, 127
appendiculatus 77
apricus 55
arthrostyli 29
attenuata 114
aviingrata 41
azaleae 84
bardus 93
basalis 113
bethunei 99
bilineata 62
biviltata 79
Blasticotoma 42
Blasticotomidae, family 42
Blennocampa 92, 93
Blennocampinae 43, 44
Blennocampinae, genera of 92
Blennocampinae, subfamily 91
borers 38
Caliroa 58
Caliroa, species of 59
caudal protuberances 27
Caulocatnpus 67, 68, 69
Page
Cephaleia 106
Cephidae 129
Cephidae, family 108
Cephidae, genera of 109
Cephus 109, 111
Cephas, species of Ill
cerasi 59
cervacoria 22
chloreus 83
Cimbex 65
Cimbicinae 44
Cimbicinae, genera of 65
Cimbicinae, subfamily 64
cinctus 109, 111
Cladius 71, 74
Cladiinae 44
Cladiinae, genera of 71
Cladiinae, subfamily 70
clypeus 17
columba 116
cornelli 86
corpotentorium 19
cressoni 112
Croesus 76, 83
demissa 89
dentatus 107
derosa 90
despecta 69
devincta 89
Dimorphopteryx 51
Dineura 69
Dineurinae, subfamily 69
Diphadnus 75, 76, 77
Diprion 46, 49
Diprioninae 43
Diprioninae, subfamily 45
dohrini 97
Dolerus 55
Dolerus, species of 56
Dolerinae 43
Dolerinae, subfamily 54
dorsalis 104
170
ILLINOIS BIOLOGICAL MONOGRAPHS
[488
Page
Dorytheus 55
dyari 67
ej&eta 87
efflusa 87
emeriia 87
Emphytus 51
Emphytinae 43, 44
Emphytinae, genera of 50
Emphytinae, subfamily 49
Empria 50
Endelomyia 58
epicranial suture 15
epinota 63
EpUaxonus 50
equina 88
erichsoni 81
Eriocampa 51
erudiia 87
Erythraspides 92, 94
erythrogastra 86
evanida 87
fasciata 106
Fenusa 97
Fenusinae 45
Fenusinae, genera of 96
Fenusinae, subfamily 96
ferruginea 42
flicta 63
filiceti 42
fistula 63
flavipes 54
formulae of segmented appendages — 34
free leaf-feeders 37
front 17
fuivicrus 87
fumipennis 95
gall-makers 88
genae 16
glands 33
glandubae 33
gregarious 80
Hartigia 110, 112
head 14
Hemichroa 67
Hemitaxonus 50
Hoplocampinae 44, 45
Hoplocampinae, genera of 67
Hoplocampinae, subfamily 66
kyalina 89
Hylotoma 100, 101
Page
Hylotoma, species of 100
Hylotominae 45
Hylotominae, subfamily 99
Hypergyricus 92, 94, 95
Hypergyricus, species of 94
impressatus 53
inanitus 105
inconspicua 107
inflata 66
integer 110
Isodictium 92, 95
Janus 109, 110
Janus, species of 110
Kaliofenusa 97
Konowia 113
labium 21
labrum 17
laricis 68
larvapods 29, 123
latitarsus 83
leaf-folder 89
leaf-miners 37
lecontei 47
lineata 64
lombardae 87
longicollis 113
luteotergum 84
Lygaeonematus 75, 81
macleayi 101
M acremphytus 51
Macrophya 61, 62
Macrophya, species of 63
M acgillivrayella 67
Macroxyela 42
major 41
mandibles 20
mandibularia 18
Marlattia 67, 68
mathesoni 60
maxillae 21
maxillariae 18
Megalodontes 116
Megalodontidae, family 116
Megaxyela 41
mendica 88
MetaUus 98
Metallus, species of 99
metamerism 30
metatentoria 19
metathoracic spiracles 128
LARVAE OF THE TENTHREDINOIDEA—YUASA
171
Page
Micronematus 75, 79, 100
minor 42
minutus 55
modeslius 73
Monoctenus 46, 48
Monophadnoides 92, 95
Monophadnus 92, 94
Monosoma 51
Monostegia 51
mouth-parts 20, 127
mulUcinctus 93
murtfeldtiae 78
musta 104
Nematus 75, 82
Nematus, species of 83
Nematinae 44
Nematinae, genera of 75
Nematinae, subfamily 74
Neodiprion 46, 47, 48
Neodiprion, species of 47
Neopus 61, 62
nest-builders 38
Neurotoma 106, 107
nubilipennis 94
obsolete 59
occidentalis 118
occipital foramen 18
occiput 18
ocellarae 126
ocreatus 105, 108
ocularia 16
Odontoidea 19
Odontophyes 41
odoratus 86
Oryssidae 130
Oryssus 118
Oryssidae, family 117
Pachynematus 76, 81
Pachynematus, species of 82
paehdus 72
pattiolatus 73
pamphiliid 105
Pamphiliidae 129
Pamphiliidae, family 104
Pamphiliidae, species of 105
Pamphilius 105, 107, 108
parasites 38
paracoila 19
Parataxonus 50
parvulus 69
Page
patchiae 72
pectinicomis 74
Periclista 92
Phlebatrophia 60
Phlebatrophini 57
Phlebatrophini, tribe 59
Phrontosoma 51
Phyllotominae 44, 45
Phyllotomini 57
Phyllotomini, genera of 58
Phyllotominae, subfamily 57
politus 54
pomum 89
Pontania 75, 76, 88, 98
Pontania, species of 88
postcoila 18
precoila 18
postpedes 29
pretentoria 19
prepharynx 22
Priophorus 71, 73, 74
Priophorus, speciesof 73
Pristiphora 75, 77, 78
Pristiphora, speciesof 77
prolegs. 29, 30
prolongata 113
postgenae 18
provancheri 113
Pseudodineura 69
Pteronidea 75, 76, 85, 86
Pteronidea, species of 85
pulatus 53
ptdchella 64
pygmaeae 94, 109, 112
quercus-alba 59
quercus-coccinea 59
14-punctatus 62
repertus 82
ribesi 85, 87
rubi 95,99
scapularis 101
Schizocerinae 45
Schizocerinae, subfamily 101
Schizocerus 102
Scolioneurinae 45
Scolioneurinae, subfamily 98
Selandria 52, 54
Selandriinae 43, 44
Selandriinae, genera of 52
Selandriinae, subfamily 51
172
ILLINOIS BIOLOGICAL MONOGRAPHS
[490
Page
scmilutea 61
setae 32
simile 49
similis 55, 56
Siricidae 130
Siricidae, family 114
spiracles 32
spiraeae 93, 94
spissicornis 116
Strongylogasler 52, 53
Strongylogaster, species of 53
Strongylogastroidea 51
subalbatus 82
subanal appendages 28, 126
suranal lobe 26, 27
suranal process 27, 127
sychophanta 79
Syntexis 110
tabidus Ill
tacitus 54
Taxonus 51
Tenthredinidae 129
Tenthredinidae, family 42
Tenthredinidae, subfamilies of 43
Tenthredininae 44
Tenthredininae, genera of 61
Tenthredininae, subfamily 60
Ten three! inoidea, families of 38, 133
Tenthredinoidea, superfamiry 37
Tenthredo 61, 62
Tenthredopsis 61
tenth urosternum 27
Page
tenth urotergum 26
tentorium 19
thoracica 85
thoracic legs 23, 122
thorax 23
Thrinax 52
Thrinax, species of 53
tibiator 63
Tomostethus 92, 93
tormae 18
Tracheitis 109, 111
Tretnex 115, 116
Trichiocampus 71, 73
Trichiocampus, species of 72
Trichiosoma 65
trilineala 88
trimaculatus 110
trunk 22
ulmi 97
unicolor 48
Unitaxonus 51
ventralis 85
vertex 16
vescus 85
virendus 84
Xiphydria 113
Xiphydriidae 130
Xiphydriidae, family 112
Xyela 42
Xyelidae 129
Xyelidae, family 39
zabriskiei 102
UNIVERSITY OF ILLINOIS-URBANA
S70.SILL C004
ILLINOIS BIOLOGICAL MONOGRAPHS URBANA
7 1922
3 0112 017753531