5L Circular n United States Department of Agricultur Al) 'H I N lOMOl.i »OY. I III IV till DEPOSITORY : vrn i 1 1:1 i UOR1 RS. ; ii In t'luv Lmong the most troublesome of the insecl pests with fruit imi>\\ ers of the United States have to deal are two 9pecios ■ >Tl »• >r uil: beetles known,fTom 1 1 h • appearance o\ their larvie, as the round headed and flat-headed apple-tree borers. The firsl of these belongs to the family Cerambycida and the other to the Buprestida?. In ad tlit ion, there is a not her species called, after the adult form, the -|>nt ted apple-tree borer and to distinguish it from the round-headed borer, which it closel) resembles. The two species firs! mentioned are common and injurious throughout a wide extenl of country the former to Beed fruil trees, the latter also to stone fruil as well as to a great variet) of foresl and ornamental trees. The third is a com- parative!} rare insecl and rather exceptional!} injurious so fai as kn nun. THE ROUND-HEADED APPLE-TREE BORER. !.>!„ Fab. INTBODUCTOR1 BJEMABKS k.N"D DESCRIPTION The round-headed apple-tree borer i-. nexl after tin- codling moth, the worst enemy to apple culture in America. Tin" firsl intimation that the grower may have of the present this borer in his trees, unless he be forewarned. i< in their retarded 2 -07 growth and the sawdust-like castings, consisting of excrement itious matter and gnawings of woody fiber, which the larvae extrude from the openings into their burrows. This manifestation is usually accompanied by more or less evident discoloration of the hark and, in early spring particularly, by slight exudation of Bap. The parent of this borer is a beautiful heetle, measuring from three- fourths to nearly an inch in length, the male being perceptibly nar- rower than the female. The antennae are long, stout, and many- jointed, being somewhat shorter than the body of the insect itself. These organs and the legs arc gray, the undersurface of the body and the head arc silvery white, and the upper surface is light yellowish brown with two longitudinal white stripes extending through the thorax and elytra or wing-covers to the tip, as is shown in the accom- panying figure 1 . c. The larva, when mature, measures from three-fourths to a little over an inch in length <22-26 mm ). It is legless, fleshy, and some- what grub-like in appearance, cylindrical in form, and light yellow in color. The head is darker, particularly about the mandibles, which arc nearly black. The first thoracic segment is large and broad and bears on its summit numerous small tubercles, placed closely to- gether. The remaining joints of the body are narrower, the constric- tions between them being deep and conspicuous. The first seven abdominal segments bear on the upper surface of each a peculiar elevated process, as shown at figure 1, h. The pupa, illustrated at '/. i- nearly as long as the adult insect, which it resembles in a superficial manner, the head being bent down toward the breast, and the legs and long antenna' folded upon the ventral surface. Its color is similar to that of the larva. Saperda Candida was given its specific name by Fabricius in the year 1787, and was again described as new by Thomas Say, in 1824, under the name of S. bivittata, the latter remarking at the time that it injured apple trees by boring into the wood. DISTRIBUTION. This species is native to this country and is present in injurious numbers in practically every State of the apple-growing region east of the Rocky Mountains. It inhabits, like so many other injurious in- sects, the upper austral and transition life zones, comprising the better agricultural portion of all except the extreme southern States. It has been reported to occur in one locality, Agricultural College, Miss., which lies in what is considered the lower austral zone. As with many other noxious species, too, it is in the older States, particularly of New England and New York, where orchards have been long estab- lished, that injuries are most pronounced. Until recently this species [Cir. 32] B was not known as especially injurious aboul the District of Columbia, l>ui at the present time it has become verj abundant and destructive, whole orchards both of young and mature trees having succumbed to n - r:i\ ages. It- known distribution includes < anada, all of the Ke^ England States, \ew York, \ew Jersey, Pennsylvania, Delaware, Maryland, Virginia, West \ irginia, District of Columbia, Ohio, Illinois, Michigan, Iowa. Missouri, Kansas, and restricted localities in Texas, AJabama, and Mississippi. FOOD PLANTS IND NATURE Ol INFESTATION. This Koicr i- practical!} limited in its food to the apple and kindred wood} plants. It is most injurious to quince and apple, and Bome- w hat less so to pear. It infests also crab apple and thorns of different specie-, mountain ash, chokeberry, and juneberrj in short, practi- cally all except one or two kinds of trees and shrubs belonging to genera included in the family Pomaces?. The wild plants are its natu- ral Too. I. but certain varieties, at least, although often inhabited by tlii- insect, arc- for ason not so susceptible to ii> injur} as are our cultivated i rees. Tin- species inhabits more particularly the base of the trunk of trees, often being found lie low the surface i f the earth, especially in young nurser} stock. It is to such trees that it is most injurious, for it s ( .on works around the trunk, separating the wood from the hark, interfering with the flo'w of sap, and producing the effect of girdling, a result which is very apt to be produced even when no more than two or three larva' occur on tin- same tree. \ ei \ fre- quently four or live larva' dwell together in a single small tree and in a short time injure it quite beyond recovery . In old trees larva occur .somewhat higher up the trunk, in exceptional < a-e- at a distance of se\ era I fee! from t lie ha -e or even . -1 ill more rarely, in the lower linihs. As a rule, however, t key are seldom found except within a fool or two of the base. Tree- of all sizes are frequently killed or weakened bo such an extent that they are unable to mature a full crop of fruit. The experience of many years shows that injury follow- where grasses, weed-, or other rank vegetable growth are permitted to accu- mulate aboul the trunks of the trees, since the beetle, like all nocturnal insects, naturally seek- concealment, and the condition- thus afforded are most favorable for its attack on cultivated plants. I. IKK BISTORT. The beetles make their first appearance <<\ the season hue in May or in June, according to locality . During the night they come forth from the trunk- of the trees in which they have hied, and al this time may he seen in flight. During the day the\ bide away in some secluded [Cir place, under leaves or in similar situations, on the trees which they inhabil . Soon after their first appearance the sexes mate and eggs are de- posited. The female first makes an incisionin the hark probablyby means of her mandibles causing it to split slightly; then, turning head upward, she places an egg under the bark nearly a quarter of an inch from the incision, accompanying the deposition by the extrusion of "a gummy fluid which covers and secures it to its place and usually fills up the aperture. In young trees with tender hark the e«:g is usually thoroughly hidden, while in older trees it is sometimes so shallowly imbedded as to he readily seen.'' 'The egg is pale rust-brown in color, one-eighth of an inch long, one-third as wide at the middle, flattened so as to have a depth of about one-third the width."" Its shell is fairly tough and resistant, not sculptured, and sufficiently plastic, when laid, to receive impres- sions from the woody fibers between which it is forced. Oviposition has been observed from June to September in a single locality (Law- rence, Kansas), but June is the month in which most of the eggs are laid. Fitch and others observed the beetles in the trees, near Albany, X. Y.. as early as April. Regarding the duration of the egg stage, Mr. E. W. Junkins b states that a young borer larva was observed July 7 from e«;gs that were deposited June 15. This would give a period of twenty-two days, but Ave have no further data bearing on this point. The larva?, soon after hatching, tunnel under the hark and feed on the sap-wood, gradually working their way upward and afterwards downward, usually remaining within a short distance of. or below the surface of, the ground, particularly in young trees. By the heginning of the second year the larva', according to observations conducted by the writer, attain an average length of about five-eighths of an inch. The larval growth will naturally vary according to temperature, mois- ture, quantity of food available for consumption, and other condi- tions. With the approach of cold weather the larva' cease feeding, but with the beginning of warm spring weather— in the District of Columbia as early as the latter days of March they again commence forcing their excrement and castings, consisting of gnawed particles of wood, out through holes which they make in their burrows. By the end of the second year the larva- have increased considerably in size and have now penetrated deeper into the solid heart-wood, their burrows being closely packed behind them with castings. The third year the larva? gnaw- outward to the bark, form a pupal cell composed a Above quotations from account by Riley in New York Weekly Tribune, Feb. 20, 1878; Kans. Hort. Rept. for L879, pp. L96-201. frNew England Bomestead, .Ian. 3, 1885. [Cir. 32] partly of 1 1 leu' i astings and, with their headc pointin • toward the bark, transform to pupae. With the approach of Ma) and June thej cul their waj out l>\ means of their powerful mandibles and issue through ■ round hole as mature beetles. V larva was observed b) the writer ai the Department ol \ riculture thai pupated Maj 1 1 , and appeared as adult Ma\ 30, thus nineteen days for the pupal period, the uc;ii her being seasonable. \ \ i i i: \ i ENEMIES Concealed as this insect is during its three years of existence in its preparatory stages,it is nevertheless a prej to natural enemies which seek and devour it in its haunts under the bark. Of this number are woodpeckers and hymenopterous insect parasites. < M' the latter only • single species is known to the writer. Cenocaliw populato - \i 1. 1 B< IDS Ol < ON l ttOL. After borers have once entered a tree there is no better remedy known than to cut them oul with a knife or other sharp instrument. In the t reat men t of this insect an ounce of prevention is worth several pounds of cure. Cutting the borers out, unless practiced with the greatest care, is apt to resull in injury . and it is far better to prevent the parent insects from depositing their eggs upon the tree. This is not difficull of accomplishment, as oviposition is practically confined t<> two months in an\ -mule localit} . usuallj dune ami duly. The best preventives are impenetrable substances placed about the trunk and variou> washes of a repellent nature. Cutting out by hand. Little has Keen gained in the line of direct remedies for this borer until recent years. The early writers had noth- ing better to advise than cutting oul the larvae, either with a knife or gouge, or killing them l>y inserting a wire into their burrows. Thi ae remedies were in Use early in the presenl cent ur\ and are still I he ones most often practiced. It is do uncommon thing to find four or more larva' in a single small trunk, and t he cutting oul of all of them, if not practiced with the greatest caution, is apt to result m the girdling of the tree. if. indeed, this has not already Keen accomplished 1>\ the com- bined attack of the borers themselves. It would seem superfluous to add that it is hot to cut the borers out as soon as detected. Their presence may he known h\ a little experience, some persons being so ('Xpert m detecting t heir exact local ion as to be a hie to kill t hem with a knife thrust or hv the puncture of an awl or other sharp instrument. The fruit grower should institute a practice of inspection so that the borers may he removed as often as found. ■> Mentioned in [nseel Life, Vol. Ill nachus say da In! 6 To assist a tree in recuperating after it has been girdled, a bridge or two should be made by splitting a piece of apple twig (say of an inch or two in thickness), cutting it diagonally on the inside, and applying to the surface at the base of the tree. It should then be tied on and grafting wax applied to each end, after which a fertilizer should be applied and the whole hanked over with earth. It is also well to keep the tree watered for a few weeks after treatment. Mechanical jm rentives. — This is one of the borers that can readily be controlled by different sorts of mechanical barriers placed about the base of the tree. For this a few thicknesses of newspaper wrapped rather loosely about the trunk and extending about two feet from the base are all that is necessary. Tins covering should be tied, by pref- erence with cord, which will readily yield or break with the natural expansion of the tree in its growth, and also be tightly fastened at top ami bottom and hilled up with earth so thai the beetles can not obtain access to the tree from below. From the top of this covering upward it is best to use some deterrent alkaline or carbolated wash. Instead of newspapers, wire gauze or mosquito netting may be used, and should be put in place so as to loosely encircle the tree, that the beetles may be debarred from depositing their eggs between its meshes and that the growth of the tree may not be hindered. Both devices have been successfully employed for a long period of years, and there is abundant testimony to their value. If the netting or paper be put in place early in May, it will not only prevent the beetles from oviposit- ing during the next two months, but will also keep the insects which might be present in the trunk from issuing, and they will die in their burrows without being able to lay fertilized eggs. The paper wrap- ping must be removed each season, but the wire netting will last for several };ears. It is safe to remove either, ordinarily, after the first of September. Protective trashes. — Any one of several washes in general use against boring insects may be used as a deterrent. A good alkaline wash is prepared of soft soap reduced to the consistency of thick paint by the addition of caustic potash or washing soda in solution. A good fish- oil, or whale-oil, soap, or common soft soap, is often used, and in some cases any one of these is sufficient to deter the insects from depositing their eggs. The alkaline wash may be carbolated, if desired, by the addition of crude carbolic acid, at the rate of 1 pint to every 10 gal- lons of the wash. Such a wash not only affords protection against this and other borers, but against scale and fungous diseases at these points, and is, moreover, of positive benefit to the tree. Caustic pot- ash fish-oil soaps are among the best for insecticides. Whatever wash is used should be applied thoroughly, and in locali- ties where apple-tree borers are unusually troublesome the larger [Cir. 32] branches should also be covered as far a-- possible. The wash ma} be best applied with a whitewash brush and should be renewed al int< vnU of from i w " i" four weeks, as found necessary, the firsl applies tioii being made before the appearance of the insects in Ma} or June anil again during Jul} . Ii is well t" scrape old trees i" remove dead bark Bcales, care being taken n< >i to cause an} abrasion. Scraping is besl done some time before the application of tli«' wash so thai the wounds tliai mighl be made maj have opportunity to heal before the appearance of the beetles. The I ties are shy, and so seldom seen that il is doubtful if any method of destroying them ia feasible, The} are atl racted to lights al night to some extent, and some meel their end in this way. Keroseiu as n remedy. A great variety of substances has been recommended i<> kill the borers in the trees, but up t" the present time only a few have given satisfaction. For the benefil of those who have not hail experience with this borer it ma} he necessar} t" state that it is of no avail whatever to inject kerosene or an} other insecti- cide into the round holes made by the beetles in then- escape from the trees. A correspondent of this Bureau, Mr. 'I'. Ii. Ashton, who has had man} years' experience with this borer, states that there is no better wa} <<( effectually putting a stop to the depredations of this and similar borers than in the use of kerosene applied freely wherever the castings <>( the larvae are to he seen protruding through the hark. The kerosene is absorbed b} the castings and. carried by capillary attraction, permeates the entire burrow. It thus come- in contact with the larva, which soon succumbs. The amount of kerosene necessary i- so small that it doe- not endanger the health of the tree. Clean cultural methods. Finally, clean culture, the best preventive for insect injury of whatever kind, should not be neglected. The nursery should nol be started in new localities where crabapples, thorn.-, juneberry, and other wild food plant- of this species gro\< in greal profusion, nor in the vicinity of neglected orchards, nor should rank growths of weed-, grasses, bushes, and briars he permitted to accumulate about the trunk- of the tree-. When a tree i- -ecu to be injured beyond recover} it should be taken out and destroyed by burning before the following spring, so that the larva' which it eon- tain- ma} not have an opportunity to develop and infest healthy growth. THE SPOTTED APPLE-TREE BORER. A related insect very similar to the preceding, both in appearance and in habits, i- the -potted apple-tree borer. The beetle i- of nearly the same size and form, differing superficially by having two [Or. a.*) white spots on each elytron (fig. 2) instead of the longitudinal white lines which distinguish the latter (fig. 1, c). The larva and pupa are so similar that no description need be made of them. Although the species has a fairly wide distribution, corre- sponding somewhat closely to that of the com- mon species, specific injury by it has only been noted in two States, namely, in Michigan by Prof. A. J. Cook and in Iowa by Prof. H. Osborn. In the former State this borer is reported as quite as common and destructive as Saperda Candida. Its occurrence is recorded, also, in . fc _ Canada, Massachusetts, New York, Pennsylvania, male beetle eniargedone- Wisconsin, and Ohio, and there are specimens in the National Museum from northern Illinois and Texas. Apple and wild crab are the only plants which it has been observed to injure, but its occurrence has been noted on juneberiv and thorn. According to Osborn the "eggs are evidently laid in pairs, half an inch or more apart, along the branch, the larva 1 of each pair upon hatching working in opposite directions around the branch, at first just beneath the bark, afterwards (probably after the first year) entering the hard wood." The remedies for this species are the same as for the preceding with the extra precaution that the larger branches, also, he protected by the wash applied. THE FLAT-HEADED APPLE-TREE BORER. ( Chrysobothris femorata Fab. I GENERAL APPEARANCE AND NATURE OK INJURY. A much less dangerous, though more abundant, insect than an}* of the preceding, is the flat-headed apple-tree borer. It belongs to the short-horned wood-borers or metal- lic beetles of the family Buprestida?, and differs remarkably from the pre- ceding in all its stages as well as in its habits and life history. The adult insect (represented at b, fig. 3) measures from a little less to a little more than a half inch in length. It is flattened above and bears some resemblance to a snap- ping beetle, but, unlike the Elateri- dse, is not provided with jumping organs. The antenna 1 are short and serrate, the eyes large and conspicuous, and the forelegs are armed in front with a conspicuous tooth. The upper surface of the body is [Cir. 32] Fig. 3.— Chrysobothris femorata: a, larva; 6, beetle; e, bead of male; r. Euunilt Ent . Vol. XX. pp. 6 - [Or. 10 and cultivated redbud (Cerds chinensis)," from which the species has been reared by the writer, and currant.'' Cherry, Kerch, and white birch arc probable food plants, although the beetle has not been reared from tbem, and elm, tulip, and cotton- wood have been mentioned as such, but on what authority is not clear. Oak is without doubt the favorite natural Lost tree. The larva differs greatly from that of the round-headed borer. Its name, flat-beaded borer, is derived from the peculiar Hat expansion of tbe second thoracic segment which is close to the bead. Jn color it is light yellow and in length measures nearly twice that of the mature insect. It habitually rests in a curved position, more bent visually than shown in the illnst ration dig. 3, a). The pupa (d) shows the form of the future beetle and is of the same yellow color as the larva. This species inhabits practically the entire United States and the southern portion of Canada, being, like the preceding, a native of North America and injurious year after year. NATTKAI. HISTORY AND HABITS. The beetles make their appearance about the same time as the round-headed borer in regions infested by both species- after the middle of May in the principal apple-growing regions of the Northern States — and continue through the month of July and, it is said, even into September, the female depositing her eggs in cracks and grooves or under bark scales upon the trunks or branches of trees destined to be the future food of the larvae. Most frequently several eggs are found together. These are yellow in color, irregularly ribbed, and about one-fiftieth of an inch in length/ The larva differs from the round-headed borer in that only a single year is required for its devel- opment, pupation occurring in the spring shortly before the appear- ance of the beetles. It differs, also, in its manner of work, living for the most part just beneath the bark, where it excavates broad, flat, and very irregular channels. Sometimes, however, it enters more deeply into the sap-wood. Like many other borers, it will often girdle a small tree, a single individual being capable of killing a small tree in this manner. As it approaches maturity it generally eats deeper into the solid heart-wood, but in spring, just before transformation, it works back again into the bark and there constructs its pupal chamber. It is said to remain in the pupa state about three weeks,' whereupon the beetle cuts its way out, leaving in the bark an elliptical exit hole which distinguishes its work from that of the round-headed borers, which make round holes in their exit. These holes correspond to a cross-section of the beetle making them. In the North the winter o Formerly C. japoniea. 6 F. H. Hillnian. Nevada Expcr. Station, Bill. 36, p. 18. c C. V. Riley, Proc. Ent. Soc. Wash., Vol. Ill, p. 92. [Cir. 32] 1 1 months are passed as larvae, bul farther south, in the Districl of Columbia, according t" recent observation, pupation ma} take pi as earl] as November of the firsl yeai NATURA1 ENEMIES Among natural enemies, woodpeckers and ants are effective destroy- ers of thi> species, since thej devour larva? and pupa? under the bark, A number "f parasitic insects, also, prej upon il and assist greatrj in rest rid ing it s abundanci 1:1 mi mi - The remedies advised for the round-headed borer arc also of value and are generally employed against the present species It is neces- sary . however, that deterrent coverings and washes Bhould be applied farther up the trunk and to as man] branches a- can be conveniently reached. As this, however, necessitates additional labor and extra expense, other preventive measures are also recommended. '/'/• wood for tlu beetles. For this purpose anj sort of tree known tc» be freel] attacked l>\ this borer, e. \ burning before April or Ma\ of the following year. This plan has nol been practically tested, hut the writer has no doubt that it would prove useful in securing im- munity from this pest in the orchard, provided that no diseased fruit trees be left for food. Careful cultural until, hIs. Careful, clean methods of orchard man- agement are essential a- a measure of protection, and involve the cutting out of dead, dying, and injure. I deciduous forest ami shade as well a- orchard tree- known to he chosen a- food l>\ tin- species. Care should he exercised in transplanting, and especially in pruning; and fertilizers should be used in order that the trees may he thrifty and better able to withstand attack. Proper regard for these m< ure- should u'ive practical exemption from injury. Approved : James Wilson, s i . retary < The li>t includes the Brw onids, B - Riley and /• pallidtu Ashm., and the Ichneumonids / , and grallator S and en.' .. r more ~i" ■■ Lee • I « ihalcidid i I by Fitch ;i- occurring in New York and t>y Riley in Missouri. Nots. — First issue, July 1. 1898; revise, August 30, I [Cir. 32] o UNIVERSITY OF FLORIDA 3 1262 09216 4978