UNIVERSITY OF ILLINOIS
Agricultural Experiment Station.
URBANA, JULY, 1899.
BULLETIN No. 56.
RECENT WORK ON THE SAN JOSE SCALE IN ILLINOIS.
The work of this office on the San Jose scale for the years 1897 and
1898 has been in part purely practical and in part scientific. It has
included a continuation of the search for infested Illinois localities and
a thoroughgoing examination of those detected, as begun in 1896; the
inspection of Illinois nurseries and nursery stock as a basis for official
certificates issued to nurserymen; the insecticide treatment of infested
premises in Illinois, undertaken to arrest the spread of the scale in this
State; the collection, study, cultivation, and introduction, into orchards
of two fungus parasites of this scale; field experimentation with special
insecticides and insecticide apparatus; and a study of certain minor
points in the life history and cecology of this insect.
The search for infested Illinois localities has resulted in the dis-
covery of six * points not on the list given in ‘my last biennial Report,
thus making twenty-five} such localities now known in Illinois. 29,.°97) HESS: 1.50 1.50
P.S. Peterson & Son. .|/Chicago ....|Mar. 7, 8, ’98| H. E.S. 8.75 8.75
JW. Miller Cowss.c;. Freeportte ihe pee 8 Ob riaeo ae 6.50 6.50
Piminewoettavocna be Freeportec co) ci") 10,5 O82 sss, 6.50 6.50
Lebkicher'& Spitler,..|Freeport.42 0" 931,09] Eis eS. | ee ee 6.50
Hoe Cotta. aes on see cnt Nursery.) 2 12, OSH Eos, 8.95 8.95
ease Vaughan. ss Chica goy, U..)-e ee 14s Ooela tees. Fas 7.752
I, DCUYOEd ert hanes Bloomington |April 4, ’98) H. E.S. 6.66 6.66
R. Douglas’Sons...... Waukegan ..| ‘‘ 19,98] E. B. F. 18.76 18.76
Rob't C. Uecke....... Harvard 723s} -# (225; 298i) Bale 21.07 21.07
foGe Vaughan. sn 2 Chicago..... Aug. 25, '98| E. B. F. L1.03 11.93
R. Douglas’ Sons..... Chicagov;+:. i> 27, “OS -E=Bar- 13.73 13593
Spaulding Nurs. & Orch. Co..../Spaulding ../ ‘‘ 30, ’98) R.W.B. 10,92 10.92
Phoenix Nursery Co../Bloomington |Sept. 1-4, '98; R W. B ater 30°94
W.W. Thomas...... Makanda. i) 5,- 98] E. B..F: 3.04 3 04
Ass ELGOTAGLY. mc sete et Makanda: «Sabb og ee ba 3.04 3.04
Di We Leib & Son. < Makandas., ste" OGG) rs oe Ee 4.51 4.51
W. A. Watson & Co.../Normal.... LO>6 27%.1 OO, avy. i, 8.54 8 54
Kop ts. Uecke > ..0 = Harvard sci 7 ST both, Gas 2.00 2.00
Galeener & Thacker ..|Vienna..... im Gr Bes LG 10.09 10,09
Pon Gul Noenis 7 ge Bloomington; ‘' 8, Jos RIVY eB: 6.00 6.00
Augustine & Co... ..3. Normal. nS 9g, '98| R.W. B. 6.10 6,10
Arthur Bryant & Son..|Princeton...| ‘'15,16, ’98| R W. B. 16.50 16.50
Alpha Nursery Co. ../Alpha.. ; 17, 98) R.W. B. 7.59 7.59
L. 8. Frese (Forest Oak Nursery).|Coatsburg. . . | 19, 98; RW B. 12.69 12.69
GustavKlarner(Quincy
Star Nurseries)..... Oumcy>, 44 21, '98| R.W. B. 13.44 13.44
PIOUATO. E iatas Gs ee Melville Sai 396-26; os. te Coats 3.29 3.29
SUELO Ce ON ee aye Upper Alton| ‘ 26, ’98| E. C.G. 3.29 3.29
Theo. Bechtel........ Staunton» jee SNe, PORT me Geta 2.00 2.00
P. S. Peterson & Son..|Chicago.....j/Oct. 4, 5, °98| E B. F. 19.66 19.66
Custer Brothers...... Normal..... RBS Ooh kee VV aks. Faere Goi 0
Missing Link AppleCo.|Clayton..... We 522 OO 15 nr 19.25 19 25
DiveeAI LS S015 oo hee Meee Dundee..... «8.20.0 QoL rosubee ks: 20.81 20.81
In nearly all cases the nursery stock examined was still standing in
the rows; a fact which made it usually impossible to ascertain anything
directly with regard to the condition of the roots.
cable inspection of large nurseries can give at best only a rather loose
approximation to a knowledge of injurious insects infesting them—at
least on a small scale and to an obscure extent.
Indeed, any practi-
Our inspectors could
only walk through the nursery plats back and forth at intervals of
several rows of trees, judging of the general condition of the planta-
-
1899. ] WORK ON THE SAN JOSE SCALE IN ILLINOIS. , 251
tion, stopping now and then to examine an individual tree, and giving
careful attention only to trees whose general appearance indicated the
possibility of insect injury. Of course no premises were found entirely
free from insects commonly classed.as injurious. In the great majority
of cases, however, those present were kinds which would necessarily be
left behind in the shipment of clean young nursery trees, and without
exception all were common widespread insects of the region or of the
state at large.
It is clear, however, that no certificate, however carefully it may be
drawn, or however thoroughgoing may be the inspection upon which it
is based, should be taken as more than presumptive evidence of the
entire absence of seriously injurious insect pests. Indeed, in the hands
of any except a thoroughly reliable and honest nurseryman it is
entitled to no credit whatever, but may be even worse than no certifi-
cate at all, since it would be perfectly easy for an unscrupulous dealer
to deceive first the inspector and then his customer, and this with little
or no danger of detection. The inspector, of course, must take the
word of the nurseryman as to the extent of his property, and can only
presume that he has seen all the stock from which the owner is likely to
draw for sale, for if deceived in this regard he has usually no means
of detecting the deceit. On the other hand, there is no certain means
of limiting the use of the certificate to stock actually grown by the nur-
seryman or on the grounds where the inspection was made. Duplicates
of it may be used, with perfect security from detection, upon any stock
from any source, received perhaps long after the last inspection was
made. So far as the official certificate tends to give a sense of security
to the customer in dealing with a nurseryman he does not know or in
whom, if known, he does not have full confidence, it is undoubtedly an
evilinstead of a benefit; but notwithstanding these drawbacks to its use,
it will be difficult, I think, to devise any satisfactory substitute for it,
as it is now commonly worded and as it should be generally understood.
INSECTICIDE TREATMENT.
Heretofore and in other states under circumstances such as existed
in Illinois in 1897, either nothing has been done in the general behalf,
the San Jose scale being left to the care of individuals acting in their
own interest, or laws have been passed establishing some state authority
competent to deal with the economic situation. In Illinois an attempt
was made to secure such thoroughgoing legislation at the biennial ses-
sion of the state legislature for 1897. A bill establishing a state board
of horticulture with ample powers of inspection and police was intro-
duced in both houses and passed the senate by a unanimous vote,
252 BULLETIN NO. 56. [ July,
but was vigorously opposed while in the house and finally failed in
committee, the only immediate result of the effort being an item in the
general appropriation for the expenses of the state government appro-
priating $3,000 to the State Entomologist ‘‘ for experiment, publication,
and instruction concerning the San Jose scale, and for the inspection
and disinfection of orchards and nurseries.”
It thus became a part of the duty of the Entomologist to do every-
thing possible to exterminate the San Jose scale in Illinois wherever it
had been or might be detected or, if destruction should prove impracti-
cable, at least to check its multiplication and spread as vigorously as
possible, and to give to owners of infested premises full instruction with
respect to precautionary and remedial measures. It was also clearly
intended that the office should act to protect the state as far as practi-
cable against the dispersal of the scale through the nursery trade.
With a view to the discharge of these duties the following circular was
issued in July, 1897: :
An appropriation of $3,000 was made to the State Entomologist of Illinois by the
General Assembly at its last session, ‘‘ for experiment, publication, and instruction
concerning the San José scale, and for the inspection and disinfection of orchards
and nurseries.” It is the earnest desire of the Entomologist that this sum may be
used to the best advantage to disclose the present condition of the fruit interest of the
state with reference to this pernicious insect; .to exterminate the scale promptly
wherever in Illinois it has been or may be found; to protect the nurseryman and
fruit grower as far as practicable against the chance of future invasion; and to assure
the customers of Illinois nurserymen and of other dealers in fruit plants that Illinois
stock offered for sale is free from this pest.
It was the evident intention of the legislature to trust the control of this important
matter to the public spirit and enlightened business enterprise of the private citizen,
aided in every practicable way by the official Entomologist. It is the purpose of this
circular to make to allinterested a cordial offer of information, advice, aid, and super-
vision of insecticide operations, as far as the resources at our disposal will permit; and
also to ask early and full information from all concerned with reference to the occur-
rence or introduction, known or suspected, of the San José scale in Illinois.
LOCATION OF COLONIES.
It must be our first endeavor to discover promptly and to locate exactly all the
colonies of this insect now established in the state. Eighteen such colonies have
already been found, nearly all by an inspection of premises to which we have had
reason to believe that nursery stock was imported at a time when the nurseries from
which it came were infested by this scale. It is of great importance that we have at
once full information concerning all importations into the state from places and at
times such as to make it possible that the San José scale was conveyed by their means.
I consequently earnestly request all to whom this notice may come that they will send
to this office prompt and precise information with regard to the importation into
Illinois of nursery stock or other trees or plants subject to its attack, which were
grown in any of the following localities within the time mentioned after each: Cali-
fornia, since 1873; eastern New Jersey, between 1886 and 1894; Maryland since 1887;
1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. 253
Florida, since 1889; Washington State and Ohio, since 1890; Georgia and Louisiana,
since 1891; Long Island, N. Y., since 1892; Delaware and eastern Massachusetts,
since 1893.
The plants thus far found subject to injury by the San José scale are the apple,
pear, peach, apricot, plum, cherry, quince, grape, raspberry, blackberry, gooseberry,
currant, and persimmon, among our fruits; the chestnut, hickory, pecan, English
walnut, black walnut and almond among the nut-bearing trees; the oak, basswood,
elm, catalpa, birch, poplar, and willow among our shade and forest trees; and a large
miscellaneous list of trees and shrubs, including the rose, thorn-apple or red haw,
crab-apple, wahoo, spirza, loquat, cotoneaster, flowering quince, flowering currant,
acacia, alder, and sumach. This insect also seriously infests the osage orange,
spreading with the greatest facility through the thick growth of the wayside hedge.
It is very important that all supposed or possible cases of the appearance of the
San José scale in Illinois be reported at once to this office, accompanied by twigs or
pieces of bark illustrating the supposed attack. To all communications accompanied
by such specimens prompt reply will be made, and energetic measures for its
destruction will be taken wherever the scale is thus detected.
EXTERMINATON OF THE SCALE.
To owners of premises on which this scale is found the Entomologist will give all
information and assistance necessary to the prompt extermination of the pest, sending
an agent to inspect: the situation and surroundings, to give personal instruction as to
methods of procedure, and to supervise and direct insecticide operations, An effi-
cient spraying apparatus will also be furnished for use where this cannot otherwise
be readily obtained. This proposition is made on the sole condition that the owner
will destroy stock hopelessly diseased and will provide the necessary insecticide and
the labor for its preparation and for its distribution to infested stock, and that the
whole operation will be carried on and continued to the satisfaction of a representative
of this office. Experience elsewhere has shown that expert assistance of this sort is,
as a rule, necessary to insure success; and expenditure of public money in such an
interest can be justified only on condition that everything is done needful to the
accomplishment of the end desired. A
The San José scale is commonly regarded by those best informed concerning it
as the most dangerous and injurious insect enemy of American fruits. It now occurs
in Illinois in comparatively small colonies, where in most cases it can probably be
exterminated at small expense. Considering the enormous loss which is likely to fall
upon the horticulture of the state if this highly destructive insect is allowed to spread
generally throughout our orchards and to infest our nurseries, it is to be hoped that
every person upon whose property it appears will regard the situation in the light of
the public welfare as well asin that of his private interest, and that he will take
without hesitation such measures as may be necessary to protect both.
BULLETIN OF INFORMATION.
An illustrated bulletin of information concerning the San José scale and its dis-
tribution in Illinois has been published by the State Agricultural Experiment Station
{Bulletin No. 48), and will be furnished on application to Prof. Eugene Davenport,
Director of the Station. A later and more comprehensive article upon the subject
will appear in the forthcoming biennial report of the State Entomologist, which will
probably be ready for distribution this fall. *
* For omitted section see page 248.
254 BULLETIN NO. 56. [ July,
In accordance with the propositions of this circular, preparations
were made during the summer of 1897 for a thorough and general in-
secticide treatment of all infested premises, to begin as soon as the
leaves had fallen from the trees, this postponement being essential to
any reasonable assurance that all the scales on an infested tree would
actually be reached.
DESCRIPTION OF APPARATUS.
The principal apparatus used is a large and complicated machine
sprayer consisting of a one-horse power gasoline engine, a three-cylinder
force pump, and a large double galvanized-iron tank with a powerful
gasoline heater beneath for making the solution of whale-oil soap.
Besides this apparatus, intended for use in large orchards or in com-
munities where a considerable number of infested places were separated
by short distances, we had in use from one to three hand-sprayers of
the kind ordinarily used in orchard work.
The machine sprayer (Plate II.) is mounted on a two-horse baggage
wagon, under the seat of which are placed the battery and the gasoline
tank to supply the burners. Immediately back of these, on the first
third of the floor space, is the engine. The large heating tank comes
next. It is set close to the right side that there may be room on the
left for the belt which connects the engine with the pump. The pump
occupies the remaining room in the back. The wagon thus loaded
weighs 2,400 lbs.
The gasoline engine (Plate III., Fig. 1) which drives the pump was
manufactured in the University Shops. It has a four-inch cylinder witha
four-inch piston stroke. The gasoline vapor is made by the flow of air
over a gasoline jet from a needle valve on the right side, this jet being
caused by gravitation from a supply tank placed higher than the engine and
above the wagon seat. Gas is drawn into the cylinder from the vapor
chamber to fill the partial vacuum caused by the previous explosion, a
valve to allow this being opened each time the piston passes the center.
The vapor when under a back pressure of forty pounds is exploded by
an electric spark caused by an inter-cylinder contrivance making and
breaking the current from a sixteen-cell battery. The pulley wheel is
nine inches in diameter and makes about four hundred revolutions per
minute. The engine is rated at one-horse power.
Just back of the engine is the tank, firmly attached to a three-
eighths by one and a fourth-inch iron frame raised sixteen inches from
the floor of the wagon. - There are six legs of the same material as the
frame, each bolted to the floor. Beside these legs two braces extend
forward from the upper part and are bolted to the flour, one on either
1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. oD gies
side of the base of the engine. The tank is of heavy galvanized iron,
fifty-six inches long by twenty-six inches wide, and twenty-seven inches
deep. Its capacity is one hundred and seventy gallons. A partition
runs crosswise through the middle, and each section thus made has a
twelve-inch opening in the top and a cap for the same. In the left-hand
corner, toward the rear, each section empties through an inch pipe into
the system leading to the pump. A valve on this pipe admits the shut-
ting off of the section from the feeding system at will. Another valve
allows the direct emptying of the section without passing its material
through the pump. Each section of the tank is provided with like valve
and arrangements, and contains a strainer so placed that all liquid pass-
ing to the outlet must run through it.
Beneath the tank are two sets of gasoline burners (Plate III., Fig. 2),
each set having twelve burners, all constructed on the same principle as is
the common plumber’s torch. Gasoline comes to them through a pipe
on the right side of the wagon from a tank under the seat. To this tank is
attached an air pump and a pressure gauge. While in use a ten-pound
pressure is maintained. By means of valves, one or both sets of burners
may be in use at one time, and the construction is such that each burner
may be shut off or caused to burn low. The floor of the wagon under
the tank is thickly covered with asbestos and cement, which protects the
wood and forms a foundation for the pipes which support the sets of
burners. Within the iron frame are two side- and two end-strips of gal-
vanized iron which protect the burner flames from wind and help retain
the heat beneath the tank.
The pump is of the triplex type, having three one and three-quarter
-inch-cylinders capable of a two and a half-inch-piston stroke. The
pumping capacity is 0.07 gallon per revolution of crank shaft, or from
2.8 gallons to 4.2 gallons per minute when run within recommended
speeds, and the pump will operate against one hundred and fifty pounds
per square inch. A one-inch feed-pipe enters from the tank, which is
elevated, in the manner stated, above the body of the pump. The dis-
charge may be through a one-inch pipe or through the series of four
quarter-inch cocks arranged on a cross-pipe which is connected with
the one-inch discharge. The belt runs on a twelve-inch pulley with a
two and a half-inch face. There are two pulleys, one loose on the
shaft.
A three-eighths inch pipe is connected up with the discharge and
the water jacket of the engine cylinder, and this cylinder again with the
“feed-pipe, thus allowing a flow through the water jacket. ‘The rate of
this flow is governed ‘by a shut-off valve on the jacket feed-pipe near
the cylinder. When only two quarter-inch hose are in use this valve
256 BULLETIN NO. 56. [ July,
may be opened sufficiently to cause not only the circulation in the water
jacket, but also to relieve the increased pressure on the two hose.
Beside the main parts of the outfit, as above mentioned, there are
two tool boxes, about one hundred and fifty feet of three-ply quarter-
inch rubber hose, poles and extension rods for spraying higher parts of
the trees, pails for carrying water, and gasoline cans.
The larger tool box is 8.5 in. x 41 in. x 32 in. outside measure,
and was made in this form that it might occupy the space between the
tank and wagon box, on the left, when moving from place to place. In
this box are the work clothes, a spade, hatchet, nozzles, reducers,
wrenches, wire-cutters, packing, screw-driver, and other articles used
in connection with the spraying operation. The smaller box is 12 in.
xX Ig in. x 20 in., and was made to occupy the space between the engine
and the tank. It contains the oils and smaller renewal parts for the
engine.
A large tarpaulin covers the whole apparatus, and by means of
short ropes attached to its edges may be securely fastened to the wagon-
box, so that in shipping, engine, tank, and machinery are all under
shelter and protected from the weather.
DETAILS OF TREATMENT, WITH RESULTs.
At Dundee, Kane county, all the trees (apple, peach, and mountain-
ash) upon which the San Jose scale could be discovered were dug out
and destroyed in the presence of my Assistant, Mr. R. W. Braucher,
November 20, 1897. Everything in the block of trees in which this in-
fested stock was found was, in fact, so destroyed at this time except
some shade trees—black walnut, horse chestnut, white elm, hard maple,
birch, and basswood, and these were thoroughly sprayed with whale-oil
soap. A few white-ash seedlings in this block were not sprayed. The
apple-, cherry-, and pear-trees in the vicinity, and scattered soft maples,
rose-bushes, and syringas next the infested block were sprayed, leaving
without treatment only the ornamental shrubbery farthest from the trees
infested.
These premises were very carefully inspected again September 7,
1898, by Mr. E. C. Green, of my office, and still more fully, October
28 and 29, 1898, by Mr. E. B. Forbes, the first inspection to ascertain,
for my own information, the effect of the insecticide procedure there,
and the second, made at the request of the owner, to serve as a basis
for a certificate of freedom from the San Jose scale and other injurious
insects and fungous diseases. Both these skilled and careful observers
reported after this interval of nearly a year from the time of treatment
that there was no trace of the San Jose scale to be found on these
1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. Log OST
grounds; but to make assurance doubly sure I required the destruction
of all stock on the infested premises which could possibly harbor and
maintain the scale, designating the various lots and kinds of trees and
shrubbery objected to. This requirement had been made good by January
16th, and an unqualified certificate of apparent freedom from the San Jose
scale and from all other dangerous insects and from fungous diseases
capable of being transported with nursery stock to the injury of cus-
tomers was issued under that date.
At Monroe Center, in Ogle county, the single pear-tree originally
first infested had been cut off close to the ground and burned by the
owner, and the bark had been removed from the stump for some dis-
tance below the surface. Two shoots three or four feet high which
afterward grew up from this stump in the summer of 1897, showed no
signs of the scale November 18th of that year. Traces of the scale were
found, however,-on two eight-year old Rocky Mountain cherry-trees
and on some sprouts of another pear-tree near by. All the infested
bushes and trees on this lot and everything near by were thoroughly
sprayed at this time with whale-oil soap—one hundred and fifty trees
- and shrubs in all, including peach, pear, cherry, apple, and plum, grape,
goosebery, currant, Rocky Mountain cherry, etc., and not a scale could
be found on these or on any of the surrounding vegetation by Mr. Green,
who visited this place September g, 1898, for the purpose of ascertain-
ing the effect-of the treatment.
On Mr. Jacob Winzeler’s place, two and a half miles south of Tre-
mont, everything on the premises lable to attack by the scale was
sprayed with whale-oil soap by Mr. Green March 28, 1898. Nine hun-
dred and forty fruit-trees and shrubs were thus treated, and also fifteen
large maple-trees about forty feet high. Ona visit of inspection made
nearly six months later (September 14th) Mr. Braucher reported that he
found a few living young San Jose scales, about half grown, on three
large peach-trees, but that otherwise the premises seemed free from the
- scale. The large maple-trees had been badly damaged by the spray,
many of the lower branches having been-killed, evidently by the drip
from the branches above. *
On Mr. P. B. Stem’s place, three and a half miles north of Manito,
two hundred peach-trees and twenty-five apple- and quince-trees were
cut out, and also twenty rods of osage-orange hedge. Nine hundred
trees were treated in this orchard, ranging in age from six to ten years.
As none of these had ever been trimmed, about three days’ work of four
men was required to prepare them for treatment. The spraying upon
the 7th and 8th of April, 1898,. was followed by a heavy shower in the
_ * All infested trees since destroyed.
258 BULLETIN NO. 56. [ July,
night, and the whole orchard was consequently sprayed again, the work
being finished April 11th. Five months later, September 14~16, 1898, a
critical inspection of this whole orchard was made by Mr. Green. On
one peach-tree six living scales were found on new wood; on eight other
peach-trees one or two scales each were found; and on each of six
others from one to seventeen scales remained—mostly on new wood but
some under bits of bark on the older growth. Ona single peach-tree a -
colony of one or two hundred scales was found upon a branch, a part
of which had evidently escaped the spray. Except for this single colony
the total number of scales found on a very careful search of everything
in and near this orchard which had been previously infested resulted in
the discovery of about fifty living scales.
According to the report of Mr. Braucher, as summarized in my
last entomological Report (page 15), about ninety-nine per cent. of the
San Jose scale in the orchard of Mr. Kiem, near Quincy, had been
killed by two successive sprayings with whale-oil soap, made in the fall
of 1896 and the spring of 1897. That this was not an overestimate of
the efficiency of the treatment is shown by the report of Mr. Green,
who visited this orchard April 13, 1898, and upon a rigid examination
could find no living scales on the premises except on the trunk of one
small apple-tree. He proceeded, according to his instructions, to treat
thoroughly a third time all the trees (twenty in number) which had
originally been badly infested, first scraping the trunks and removing
the earth from about the bases. Hot soap solution was brushed on with
stiff brooms up to the uppermost twigs, and these were sprayed except
in a few cases where they were perfectly fresh and bright, evidently
never having had any scale upon them. A very critical examination of
this orchard made September 20, 1898, by the acute and careful in-
spector, Mr. R. W. Braucher, showed that the San Jose scale in this
orchard was, however, far from being exterminated, living scales being
detected on several apple- and peach-trees which had been badly infested
when the treatment of this orchard began. One apple-tree had been so
badly incrusted with the scale that especial pains was taken to treat it
thoroughly. The limbs were cut back to a few short stubs, the bark
was scraped, and the tree was thoroughly coated with strong soap solu-
tion by means of a brush. Pieces of bark clipped from this tree showed,
nevertheless, that it was still slightly infested by the scale.
At Paloma, visited April 17th, where one infested tree had been
previously found, no scale could be detected. This tree had been taken
out and burned, and others near it had been twice sprayed by the owner
with whale-oil soap.
Mr. Lowe’s orchard of five acres at Auburn, in Sangamon county,
1899. |. WORK ON THE SAN JOSE SCALE IN ILLINOIS. 259
was found by Professor Summers very generally infested, together with
a hedge adjoining. This whole orchard and two rows of another
orchard adjacent to it, not infested, were thoroughly sprayed by Pro-
fessor Summers the first week in January, (898. The infested hedge
was not treated, as the owner promised to destroy it. September 17,
1898, it was found by Mr. Green that this orchard was by no means
free from the scale, a considerable number of trees—apple, pear, peach,
and plum—still showing from one to a dozen, twenty, or more, living
scales. A few scales were also found upon apricot trees in an old
orchard near by which was not: treated by Professor Summers. The
situation at this place was on the whole quite unsatisfactory, and the
premises will. doubtless become thoroughly infested again within the
course of two or three years unless additional measures are taken for
_ the destruction of the scale. The infested hedge mentioned above had
been twice cut down, but had not been killed. :
The infested trees on Mr. Henry Archer’s place, two miles from
New City, in Sangamon county, were scattered through the western end
of an orchard of about five acres. These were mostly young, but a few
of them were large peach-trees, and others were of various sizes inter-
mediate. All the very badly infested trees were, however, very small,
and the scale had apparently spread but a short distance from them.
About sixty trees were sprayed in this orchard in January, 1898, includ-
ing, of course, all those visibly infested but going some distance beyond
them. September 18, 1898, about seventy trees were found still infested
with the scale, commonly not more than from ten to twenty specimens
onatree. It was also found in an old orchard adjoining the one prin-
cipally infested and which had not been sprayed by Professor Summers
in January.
At Assumption, in Christian county, the entire small orchard be-
longing to Mr. Tobias on a city lot on which a single infested tree had
been found, was sprayed February 12, 1898, by Mr. Green, and the
pear-tree on which the scale had been brought to these premises was
dug out and burned. This tree was one of six obtained by mail from
a Philadelphia dealer. The remaining five were found in the hands of
other citizens, all free from the scale except one belonging to Mr. Hiram
Hooten,: which bore a few specimens sufficiently like the San Jose scale
to give ground for suspicion. This tree was thoroughly sprayed by
Mr. Green. September 20, 1898, on a single tree (a quince) Mr. Green
found one San Jose scale; otherwise the trees on Mr. Tobias’s lot
seemed free from the scale. |
At Tower Hill early in February, 1898, two trees on Mr. Grisso’s
place were cut out and burned, six were thoroughly sprayed with soap
260 BULLETIN NO. 56. [ July,
solution, and others adjacent were partly sprayed. On Mrs. Connor’s -
place one tree was dug out and seventeen trees were sprayed. Septem-
ber 21, 1898, Grisso’s place was found in rather bad condition. On
three of the trees sprayed in February from three to eight living scales
were detected by Mr. Green; on two adjacent trees not sprayed the
San Jose scale was found, the trunk of one being covered and its upper
branches infested; and on another part of the place, a hundred rods
from the infested trees above mentioned, three trees were found badly
incrusted with the scale, one an apple, one a plum, and one a flowering
quince, <-1t3i8 probable that the scale-is generally distributed on Mr.
Grisso’s place, and that only a thorough insecticide treatment of the
whole of it can check its spread effectively. On the village lot of Mrs.
Connor no scale was found at this time.
At Herrick, in Shelby county, it.was found that the owner had
removed the infested trees in August, 1898, and burned them up. A
very careful examination of eight others, planted near them and sepa-
rate from the main orchard of the owner, was made by Professor Sum-
mers February 12, 1898, but no trace of San Jose scale could be found
upon them.
Spraying at Ernst, January 18 to 24, 1898, was attended by unusual
difficulties and much delay owing to unfavorable weather, frequent rains
probably washing off much of the soap. Work began January 18th and
continued through the forenoon of the rgth, but was then interrupted by
rain which lasted all the afternoon and into the night. The 2oth was too
windy for orchard work, but spraying began again on the 21st and was
followed by rain—in part violent showers—nearly all the 22d. On the
afternoon of the 24th spraying began again, but was followed at night
and in the morning by several hard showers. One hundred and sixty-
four trees were sprayed in all, ranging from yearlings to trees fifteen
feet high; and, besides these, rose-bushes, currants, gooseberries, honey-
suckles, etc. ;
Notwithstanding this unusual exposure to rains, Mr. Green could
find March 24th only nine living scales on these premises, six under a
bit of bark upon a pear-tree and three on a currant bush. A great
part of the premises was, however, sprayed again, seventy-two bushes
and trees being included inthe treatment. Only about four hours’ work
was needed, but it took six days to do it on account of daily rains.
October 12, 1898, Mr. R..W. Braucher carefully inspected everything
on these premises and could not find living San Jose scale upon any
shrub or tree. He also observed that the whale-oil soap had generally
destroyed the Forbes scale (4Aspidiotus forbest), but that the scurfy scale
(Chionaspis furfurus) was but little affected by the winter application of
1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. 261
whale-oil soap. From seventy-five to ninety-five per cent. of the fruit
buds on the peach-trees had been killed by the January treatment, but
buds on the other trees were apparently uninjured. Spray applied dur-
ing the latter part of March had, however, killed many buds on plum-
and pear-trees.
At the farm of Mr. E. L. Howard, in Edgar. county, a short dis-
tance from Sandford, Ind., it was found in January, 1898, that all the
infested currant bushes had been dug out and destroyed by the owner,
and that the woodland brush next the infested field had been partly
cleared off and burned. It was the owner’s intention, in fact, to com-
plete this work the following spring as a safeguard against the possible
perpetuation of the scale in this situation. A plat of quince bushes and
some rows of apple-trees in the vicinity of the infested grounds were
sprayed by Mr. Braucher at this time, although no San Jose scale was
detected on any of these trees or shrubs. Another inspection made by
- Mr. Braucher October 11, 1898, gave a similar negative result, and it
seems likely that the San Jose scale has been exterminated at this point.
At Mr. A. H. Evinger’s place near Vermilion, Edgar county, to
which the scale had been transferred by purchase of currant bushes
from the premises of Mr. Howard, just mentioned, the San Jose scale
was found on only three currant bushes among some four hundred in
the plantation, and on these it was so scarce as to make it little likely
that it had spread to adjacent plants. All the currant bushes in this
plantation, together with eighteen small plum-trees near by, were
thoroughly sprayed January 4, 1898, and October 1ith no San Jose
scale was to be found on this place.
The colony on the place of Mr. Charles Eckert, three miles from
Collinsville, was visited by Mr. Green February 18, 1898, with a view
to its destruction. It had by this time made considerable progress, as
is shown by a comparison of the observer’s notes with the statement
published on page 1o of my last Report. Trees then slightly infested
were found by Mr. Green in the last stages of disease from scale attack;
and where one badly infested pear-tree was reported previously sixty pear-
trees were now badly infested and some of them dead. Work here was
retarded by rain and by the reluctance of the owner to allow his trees to
be sprayed. Five trees were finally dug out and burned, however, and
forty-eight sprayed. The spraying was, unfortunately, followed within
twelve hours by about eight hours’ rain. Twenty-two trees were found
still slightly infested on these premises September 27, 1898, when
revisited by Mr. Green, the number of scales detected varying from one
to twenty on each tree.
At Mascoutah the infested premises described as_ belonging
262 BULLETIN NO. 56. [ July,
originally to John Baisch* were found in the possession of Charles
Clements. The small orchard contained about one hundred trees of
various sizes, and the place was in greatly neglected condition, black-
berries, raspberries, and gooseberries having grown unchecked, to form
a dense and almost impenetrable thicket under the orchard trees. . There
were no fruit trees adjacent to this lot except in one direction, across the ~
street, and no scale could be found anywhere in the vicinity. It was
abundant, however, on a row of peach-trees about the middle of the lot,
and had spread from these to blackberries beneath. The owner declined
to allow any trimming of trees or any removal of shrubbery, but Pro-
fessor Summers made, December 8, 1897, a persistent effort to spray
thoroughly everything on this lot, using nearly six hundred pounds of
soap. The scale was nevertheless found by Mr. Green September 28,
1898, on about thirty of these trees, the number detected ranging from ~
one to twelve per tree, except in a single instance, apparently over-
looked earlier, of a peach-tree thickly infested throughout. _
At West Salem, visited by Mr. Braucher February 4, 1898, all the
trees known to.be infested on Mr. Fishel’s premises were sprayed, to-
gether with adjacent trees for six rows in one direction and four in
another. Sixty-one trees were treated in-all, ranging from six to eigh-
teen feet in height. From Mr. Braucher’s report of a visit made
October 28, 1898, it appears, however, that this spraying was not carried
far enough, as he found at the time a few infested trees outside the area
sprayed, as well as eighteen within the area which still carried a very
few living scales each. |
The infested orchard on the farm of Mr. C. S. Frame, three and a
half miles east of Alhambra, in Madison county, was treated February
25, 1898, twenty-one trees being cut down and destroyed and thirteen
others sprayed after heroic cutting back.. The weather continued steady
for several weeks after spraying, and the soap could still be seen upon
the trees a month after it was applied. Visited September 23d and 24th
by Mr. Green, it was plain not only that the treatment was but partially
effective but also that the scale attack had extended farther than was
supposed at the time the spray was applied. From one to a dozen
scales were found on each of twenty-five trees, apple, peach, pear, and
plum, still standing in various parts of this orchard. The trees had
-made an excellent growth, and the living scales remaining were usually -
found on the trunk beneath a thick crust of the dead or in deep cracks
where young shoots started out from the old wood.
At Walnut Prairie both Mr. Cline’s and Mr. Kreager’s orchards
were sprayed by Mr. Green March 15 to 18, 1898, fifty-six trees and
* See Twentieth Rep. State Ent. Ill., p. to.
1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. | 263
fifty-five bushes on Mr. Cline’s place and sixteen large trees on Mr.
Kreager’s. Operations here were much hindered by rains, and part of
the spraying was repeated on this account. These premises were
inspected by Mr. Braucher, October 13, 1898. Mr. Cline’s orchard
still gave evidence of having been very badly attacked by the scale, and
living scales were found upon it in sufficient number to reproduce the
difficulty within two or three years. On Mr. Kreager’s place, originally
infested from Mr. Cline’s, much the same condition of things was
found. The transplanted plum-tree by which the scale was brought to
these premises had been very severely cut back and very:thoroughly
-treated with whale-oil soap, which was rubbed in by hand and applied
so freely that it formed a pool around the base of the trunk. Neverthe-
less, many living scales were found on this tree by Mr. Braucher in
October, especially on the young growth of the year. Several other
trees on these premises were likewise still infested with living scales,
which were found also on two peach-trees not sprayed by Mr. Green.
The imperfect result of the insecticide treatment of these orchards is
doubtless to be attributed mainly to the accompanying rains.
At Mt. Carmel, five trees were dug out and two hundred and sixty-
~ two were sprayed, belonging to eleven different owners living on five
adjacent blocks. About eighty feet of infested osage-orange hedge was
also cut out and destroyed. Most of the trees were large and full of
branches, necessitating much pruning as a preparation for the spray.
One owner refused my agent admission to his premises, although an
inspection on a previous visit had determined the presence of the scale
on his trees. :
Subsequent inspection showed that the scale was much more widely
distributed at Mt. Carmel than was supposed at the time this spraying
wasdone It was found, indeed, by Mr. Braucher, late in October, on no
less than fifteen blocks, many of which had, of course, not been sprayed,
and even on those which had been treated with the whale-oil soap it had
not been completely eradicated from a single one. The failure of the
insecticide to exterminate the scale is well illustrated by the fact that
_ twenty-five trees and bushes were found infested in October upon a lot
(Mrs. Deischer’s) where forty-eight had been sprayed the preceding
March, and that twenty-three were still infested in an adjoining lot
(belonging to Mr. R. K. Stees) where thirty-two had been sprayed by
Mr. Green. :
The situation at Richview proved on continued inspection to be
much more serious than was at first anticipated, the scale being so wide-
spread as to make it impracticable for us within the time remaining
last spring and with the funds at my disposal, to complete the procedure
264 BULLETIN NO. 56. [ July,
for its extermination at this point. Instructions were consequently
given to my field assistants, Mr. Braucher and Professor Summers, to
spray thoroughly those orchards or parts of orchards in which it was
present in destructive numbers, and to treat also all other infested
vegetation whence it was likely to spread within a year to new territory,
thus arresting the ravages of the insect where it was doing real injury,
and preventing the extension of the area infested by it. These measures
were taken with the expectation of returning to this locality after the -
fall of the leaves in 1898 fora final treatment of these premises. All of
the infested property on the ground of Mr. J. W. Stanton, where the scale
was first discovered at Richview, was thoroughly sprayed with whale-oil
soap in February, 1898,—some sixteen hundred trees in all,—except
certain badly infested trees which were dug out and burned. In addi-
tion to this the premises of Mr. Jasper Wilgus, separated from those of
Mr. Stanton by a country road and a high hedge fence, were very gen-
erally treated, several badly infested trees being destroyed and many ©
others sprayed. About an eighth of a mile of hedge was cut down and
burned, and the stumps remaining were profusely sprayed with kero-
sene. From the orchard of Mr. Chas. Cooper, all trees originally
found infested had been cut out and destroyed, but a few remained
infested February 14, 18908.
One of the places worst infested, a mile south of Richview, on the
estate of Mr. Newcome, contained about twenty-three hundred trees.
The condition of the spring weather and the exhaustion of funds avail-
able for the purpose prevented the thorough treatment of these premises,
but the trees originally infested were all cut out and extensive spraying
was done with the object of exterminating the scale from the orchard
worst infested and of reducing its numbers in other parts of these
grounds sufficiently to render its spread unlikely. Approximately five
hundred trees were sprayed in all upon these premises, leaving only a
few partially infested trees scattered here and there. Later all or nearly
all of these were infected with a fungus parasite of the San Jose scale,
as will be described in another section of this article.
Half a mile north of the Newcome place a single apple-tree, in a
garden belonging to Mr. B. F. Johnson, badly infested with the San
Jose scale, was sprayed, together with two other trees adjacent to it. A
single infested tree which had been detected in an orchard immediately
west of Richview, rented by Mr. Hamilton, was dug out and destroyed
by the owner. Although no scale could be found on any other orchard
tree, eighteen or twenty trees immediately surrounding were thoroughly
sprayed by Professor Summers, and a large osage-orange hedge beside
this orchard was cut out.
1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. 265
A prolonged inspection of one of Mr. Stanton’s orchards at this
place, made by Mr. Braucher early in November, showed substantially
the same results as in those previously described. The great mass of
the scales had been killed, but everywhere enough remained to give
origin to a new attack, which in a short period of years would equal in
destructiveness the one suppressed by our insecticide operations. Fif-
teen hundred and forty-four trees were sprayed in this orchard of dwarf
pears, and of these, fourteen hundred and nine were examined by Mr.
Braucher the first of November. Not less than one hundred and seven
of these trees still showed the living San Jose scale—in a great majority
of the cases in small numbers only, but quite numerous on here and
there a tree. . °
As a general result of the operations above described it appears
that the San Jose scale has been exterminated in seven™ out of twenty-
one places treated, namely, at Dundee, Monroe Center, Sandford, Ver-
milion, Ernst, Herrick, and Paloma, but that more or less conspicuous
traces of its presence are to be found in all the fourteen others.+ On
several of these fourteen premises it was wholly killed on many badly
infested trees, but in none of them onall. Even at Quincy, where a
single small orchard was sprayed, at intervals, three times in a very
thoroughgoing manner, enough of the scales survived to reproduce the
original condition in three or four years at most. The places where the
scale was completely destroyed were those where it had made least
headway and where everything seen to be infested was promptly cut up
and burned, this destruction being reinforced in most of the cases by a
general spraying of everything’in the immediate neighborhood on which
the scale could live. There seems, on the whole, little likelihood that
the spraying method can be depended on even where most thoroughly
and persistently applied, to exterminate the scale on any place where it
has had a few years to establish itself. On such a place the only sure
remedy is the ax and the faggot, applied to every tree and shrub on
which the scale is seen to have made a lodgment, supplemented by lib-
eral spraying of all vegetation which may have become obscurely in-
_fested. It is true that fumigation with hydrocyanic acid gas has occa-
sionally been recommended as efficient for the extermination of the
scale even where the trees are completely and heavily infested, and some
experiments lately published, especially in a Report on the San Jose
*Now nine.
+Inspections made since the preparation of this manuscript show that the San
Jose scale has apparently been exterminated at Villa Ridge alsoand on Mr. Winzeler’s
place near Tremont. At both places, every tree upon which there was any definite
reason to suppose that the scale was finally present, was cut out and destroyed.
266 BULLETIN NO. 56. [ July,
scale in Maryland,* seem to sustain this recommendation. The general
judgment of economic entomologists will, however, doubtless support
the following statement quoted from a letter by Dr. L. O. Howard, writ- _
ten December 14, 1808.
‘‘ While hydrocyanic acid gas furnishes the most effective means
of destroying the San Jose scale and many other scale insects, it is not,
as some seem to suppose, an absolutely perfect remedy, and experience
for many years has fully demonstrated, and also experience in the East,
that here and there an occasional scale will escape this treatment, and,
in the course of two or three years, it will be necessary to go over the
plants again. In California, treatments are found to be necessary about
every three years. Where the work is done with exceptional care, per-
haps a longer period of immunity is sometimes gained.”
In brief, the San Jose scale can clearly be kept in check by thor-
ough spraying with whale-oil soap or by general fumigation with hydro-
cyanic gas once in two to four years, according to the situation and the —
rapidity of its multiplication; but it can be exterminated where it has
once effected a lodgment only by drastic measures of destruction sup-
plemented by careful spraying or fumigation, or by repeated treatment
applied in every case just as soon and just as frequently as a watchful
inspection gives any evidence of the presence of the scale.
DIFFICULTIES OF COOPERATION.
The state legislature, as has already been said, rejected in 1897 a plan
of legal and authoritative control and substituted therefor a mere appro-
priation to the State Entomologist, who ‘was thus provided with funds
for an investigation and destruction of the San Jose scale, but was left
without authority to compel action on the part of reluctant owners, or
to proceed to act in opposition to their wishes. The success of the
work of destruction was consequently dependent upon volunteer co-
operation between the Entomologist’s office and the citizens most im-
mediately concerned. There was commonly no difficulty in securing
such. codperation, at least in the form of permission to enter upon
premises and the contribution of a considerable amount of labor in the
application of insecticides. It was much more difficult, however, to
induce the responsible owner to share in any way the expense of opera-
tion, some refusing absolutely, declining to acknowledge any responsi-
bility to the community; others declining to bear any share of the
expense until satisfied that the insecticide operation was fully successful;
and still others agreeing, but neglecting, either to purchase the insecti-
cides or to pay for them when furnished, as proposed in my office circu-
*Bull. No. 57, Md. Agr. Exper. Station, Aug., 1898.
1899.|.. . WORK ON THE SAN JOSE SCALE IN ILLINOIS. 267
lar. Indeed, three owners out of the thirty or more concerned posi-
tively objected to have their premises entered on. Two of these were
finally prevailed upon by the use of tact and persistence, but the third
successfully resisted the persuasions of the agent of my office, and his
premises were necessarily left without treatment. As illustrations of
the difficulties encountered, the following items from the reports of Pro-
fessor Summers and Mr. Green will be of interest:
‘« Stepping into the yard of Mr. ————_,” writes Mr. Green, ‘‘I met
an angry old gentleman who vehemently ordered me to move on, saying
that his trees did not need any inspection. I tried to tell him about the
scale, and referred him to his neighbors who were having their trees
examined, assuring him that there was no charge for the inspection or
the work. He would listen to nothing, however, but said that he was
old enough to care for his own trees and didn’t ask the state to look
after him. The last legislature, he said, was a band of thieves and rob-
bers, and had started a scale scare to furnish fat salaries for two of its
favorites; then further remarked that a man-had been there some time
before who had gone across his lot without permission, and that now he
would be glad to see the last of me. I finally apologized for troubling
him and left.”
At walked out to the place of Mr. —, three miles
from town. The oldest son, a man of about twenty-five, showed me the
_ infested trees, the mother also coming along. Some Japanese plums in
‘one corner of a large peach and apple orchard were in the last stages of
disease, completely infested by the scale. In another lot were several
pear-trees, all badly infested and some dead. Both mother and son
tried to convince me that the trees did not need treatment, or at any
rate that they could wash off the scales themselves with their own soft
soap. I pointed out the trees which I was sure that it would be abso-
lutely necessary for me to treat with whale-oil soap, but they said noth-
ing. I asked if one of their sons could take me back to town that after-
noon and bring cut the apparatus if it had come. They said the boys
were busy and had no time to spare; but as a friend was to be taken to
the train that afternoon, one of the girls hitched up a horse and I was
allowed to ride with them. I found my spraying apparatus at the depot
and sent back a note by the girl asking that the team be sent for it in the
morning. Starting out to the place on foot, I met the team with a girl
_ driving. She said she was going for a load of brick, and would not
bring out my material without orders from home. I presently found a
neighbor of the family who agreed to bring my apparatus out that day
as he returned from hauling a load of wheat to town, and I sent word to
Mr. — that I would be out to spray his trees, asking him to have
268 BULLETIN NO. 56. [ July,
water hot that we might go to work without delay on my return. He
looked more surprised than pleased when I came back with the appa-
ratus, and there was no hot water. It threatened rain, and was then too
late to begin, so I contented myself with their promise to have hot
water ready in the morning. ‘The next day, while the boys were heat-
ing the water, I pruned the trees. The boys finally helped in spraying
and took the machine back to town, but the owner flatly refused to pay
for the soap. The elder son, who took the apparatus to the station,
became quite friendly before we separated, and told me that when I
came back the second time they talked of getting the shot-gun and
driving me off the place.”
At another town, where the trees and bushes on a village lot were
thoroughly infested by the scale, Professor Summers was met at first by
a refusal to give him admission to the grounds. He ignored the refusal,
however, and continued his preparations, entering upon a good ‘natured
conversation with the owner. Seeing a large soap kettle at hand, he
asked the use of it for boiling up his whale-oil soap. This was refused
on the ground that the kettle belonged to the owner’s father and that it
‘‘might be called for any minute.” By inquiry in the neighborhood
another kettle was found, and this was hired at fifty cents a day. The
owner of the infested trees, on his way to town to consult a lawyer, met
a neighbor who told him not to interfere with his unwelcome visitor who,
if an agent of the state, was probably acting under authority of law.
This very reasonable but mistaken supposition served our purpose, and
no further objection was made, although all assistance was steadily
refused. The work was thoroughly done by Professor Summers, and
no charge was made by us for materials used.
As an example of the cordial spirit in which our propositions were
‘commonly received, Mr. Green’s account of his experience at Manito
may suffice.
‘‘Visited, according to instructions, the farm of P. B. Stem, three
and a half miles north of Manito. Walked out in the morning and
found the owner plowing, He at once put away his horse and showed
me the worst infested section of his orchard, spending the rest of the
day with me in examining trees and hedges. We found that the scale was
scattered through something more than six acres and had also infested
twenty rods of hedge. Learning that the soap necessary to thorough
insecticide treatment would probably cost about $30, he asked me if I
wished the money at once. The next day he hired an additional man
for the work and gave also his own time and that of his son. We all
worked two days in pruning trees to be sprayed, and afterwards one of
us cared for the fire, another worked the pump, and the remaining two
18990. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. 269
applied the spray. Everything I asked was cheerfully done. Trees too
seriously damaged for treatment were cut down and burned over their
stumps, and a row of osage-orange hedge especially valued by the owner
because in a year or two it would yield valuable posts was also cut out
by my advice and thoroughly destroyed. Mr. Stem made five trips to
town On my account, gave five days’ work of three men, sacrificed about
two hundred trees besides the hedge, and put himself to considerable
inconvenience in his farming ‘operations, as his teams were left idle
when his oats should have been planted.”
GENERAL INSECTICIDE PROCEDURE.
The field assistants responsible for the spraying of infested orchards
were Professor H. E. Summers and Messrs. E. C. Green and R. W.
Braucher. Their methods were, of course, substantially the same.
When hand sprayers were used the soap solution (two pounds to the
gallon of water ) was made in large soap kettles, which it was possible
to find in every neighborhood. To diminish the labor and expense,
and likewise to insure a more thorough application of the insecticide,
trees to be sprayed were pruned and cut back as much as the owner
would permit. If the trunks of the trees were rough they were scraped
to remove loose bark, and if the scale was found upon the trunk the
earth was scraped away to the surface of the upper roots. The assistant
always directed the spray himself, depending on the aid of owners for
the rest of the work. In distributing the insecticide, limbs and branches
were followed out one by one with the nozzle in a way to make sure
that the spray reached every portion of the surface. Trees were fre-
quently sprayed from opposite directions, especially if the wind were
blowing considerably. Trees so covered with the scale that the surface
of the bark was generally concealed were commonly cut out and burned.
When the machine sprayer was in use two men from my office traveled
with it, and two lines of hose were commonly used at once, with two
spray nozzles for each. The soap solution was in process of {prepara-
tion in one of the tanks while the spraying was emptying the other,
and the spraying machine was thus kept continuously at work. For this
continuous operation of the apparatus, however, a third;man was re-
quired to attend to the engine and make the soap solution.
The progress of the work was very much delayed and continuously
embarrassed by the unusually wet and open winter. Frequent rains and
sleets hindered orchard work or made a repetition of it necessary, and
the wretched condition of the roads blockaded the machine.sprayer for
“weeks at atime. We also found this large and heavy apparatus incon-
venient for our purpose owing to difficulties of railroad transportation.
270 : BULLETIN NO. 56. [ July,
It could only be moved on a flat car,—not always to be had at call,—
and loading facilities at small stations were sometimes insufficient for
the handling of it. These experiences, together with the partial failure
of the engine, led towards the end of the season to a substitution of
hand equipments entirely for the machine sprayer, three of these being
in the field at once during the latter part of our operations.
AN EFFICIENT FUNGOUS DISEASE.*
Notwithstanding the quantity that has been done and written—
much of it by myself—concerning the use of the bacterial and other
fungus parasites as a means of spreading contagious disease among in-
sects for their destruction, it can scarcely be said that this insecticide
method has been reduced to practice with entire success for so much
as a single insect species. In the nearest approximation to a practical
method yet’ made, the use of Sforotrichum for the chinch-bug, the
results have been from the beginning s9 equivocal and so variable that
this method has never yet been recommended from this office as gener-
ally available or in any way trustworthy. It is with especial satisfaction,
consequently, that I now report a series of experiments with a fungus
parasite of the San Jose scale, first successfully applied by Prof. P. H.
Rolfs, of the Florida Agricultural Experiment Station, which gave in our
hands during the summer of 1898 great promise of usefulness as a strong
and steady check upon the increase of this orchard pest.
The conditions of experimentation with this fungus are fortnieeele
very favorable to tangible and precise results. The scale insects being
motionless, we are able to keep the identical individuals treated under
continuous observation without artificial management; and the fungus
used being one not native to the San Jose scale, the results of experi-
mentation are not liable to be clouded by its spontaneous occurrence
either before or after the experiment is begun. It has been very easy,
consequently, to demonstrate the success or failure in every case, and
the results may be accepted as unequivocal.
The existence of this parasite of the San Jose scale was first
brought to my notice by a letter from Prof. John B. Smith, written
January 5, 1897, informing me that Professor Rolfs, of Florida, seemed
to have found a specific organism which ‘‘had cleaned out some infested
orchards in Florida and promised to control the scale completely.” He
further quoted Professor Rolfs to the effect that the fungus had with-
stood quite a low temperature, and that it was a constant parasite of a
scale on the oak. He was also kind enough to send me a small quantity
* See Plate IV., Fig. 7, for an illustration of the characteristic growth of Sph@- :
rosttlbe coccophila from the edges of a San Jose scale killed by this fungus.
NS
1899.]_ WORK ON THE SAN JOSE SCALE IN ILLINOIS. 271
of a culture received from Professor Rolfs purporting to be that of the
‘scale fungus mentioned.
The condition of this material from Professor Smith was not such
as to encourage attempts at cultivating it, and I obtained instead, direct
from Professor Rolfs, early in February, 1898, some limbs of the water
oak infested by the common scale of that species, Aspidiotus obscurus,
many of which had been killed by the fungus parasite in question—
Spherostilbe coccophila Tul. In the letter accompanying this material
Professor Rolfs informed me that in order to introduce this fungus into
orchards infested by the San Jose scale it was only necessary to tie a
piece of a branch bearing the fungus to some portion of the infested
tree. February 27th he also sent me a small amount of Spherostilbe
on the San Jose scale itself, the product of an infection made by him
the preceding year.
From the dead oak scales (Asfpidiotus obscurus) received from
Florida in February, 1898, cultures of the fungus were. begun March
4th, by my assistant, Ernest B. Forbes, at first on gelatine, then on
boiled potato, and finally on corn meal and milk, and corn meal and
beef broth. Although the inoculations were all made from the insect
itself, all the material proved to be much contaminated, containing
especially Penzcelium, Pestalozzia, and a liquefying bacillus. Careful
separation cultures were thus necessitated, and by transfer from these,
perfectly pure cultures of the Spherostilbe were finally obtained.
The arcuate conidial spores of this fungus may germinate within
four or five hours, and the growing mycelium acquires a characteristic
pinkish color usually within five days. Vigorous growths of the fungus
developed identical arcuate spores within a week from the time of in-
oculation, this fruiting stage being indicated to the naked eye by the
appearance of patches of a deep red color in the lighter pink of the
mature mycelium. In one case a culture begun May 17th on bread
soaked with sweetened milk, developed spores profusely by May 2oth.
It proved extremely difficult to obtain the conidial stage of the fungus,
or fruiting bodies of any kind, on peptonized gelatine, and scarcely less
-so on boiled potato, but cultures on corn-meal batter made up with beef
broth, or on pieces of bread saturated with the same, yielded the spores
very readily and in great abundance, the whole infected surface pres-
ently becoming a bright scarlet color, and being covered with a thick
dense layer of elongate, curved conidia. A considerable amount of
moisture seemed necessary to a full development of the fungus, and
several of our failures in the beginning were apparently due to the fact
that the medium was kept too dry.
By May 2tst we had grown a considerable quantity of this fungus
\
292 BULLETIN NO. 56. . [ July,
on corn meal and beef broth as a preparation for extensive inoculations.
of the San Jose scale in the orchards of southern Illinois. In the
meantime a personal visit to the peach and pear orchards of northern
Florida gave me reason to expect a favorable result in Illinois, and it
likewise put me in possession of a considerable amount of fresh mate-
rial in the form of twigs of trees infested by the oak scale killed by the
Spherostilbe spontaneous on that insect.
My principal observations in Florida were made on the 2oth of
March in the vicinity of De Funiak Springs, when, in company with
Professor Rolfs, of the Florida Agricultural Experiment Station, 1 care-
fully examined three peach orchards. In the first of these, the Rose
Hill orchard, there were but very few of the San Jose scale to be found,
the number having greatly decreased within the last four years. These
trees had been sprayed with rosin, potash, and sulphur during the winter
of 1893 and 1894, but had never been artificially infected with the -
scale fungus. We found, nevertheless, on a single tree a very few speci-
mens of the San Jose scale with a fungus parasite which seemed to be
the Spherostilbe coccophila and was so taken by us at the time. Subse-
quent study on my return showed, however, that the fungus in this
orchard was of a form closely related to S. coccophila, but of a species
apparently new. It is distinguished not only by the smaller and much
more strongly arcuate conidia, but also by strongly marked culture
characters. The color of a mature culture, for example, is not red but
a dusky brown with a slightly reddish tinge, and identical culture pro-
cesses and media with those which yield the arcuate conidia of Spheros-
tilbe coccophila give with this only masses of minute oval spores.”
A second orchard, belonging to Mr. Mellish, had originally been
heavily infested with the San Jose scale, but this had now almost
entirely disappeared. The scale in this orchard had been inoculated in
August, 1897, by tying to branches of the infested trees pieces of twigs
of the oak bearing the scale fungus. At the time of my visit only a very ©
few living scales could be found, and among the dead occasionally
one still remained with an obvious growth of Sphe@rostzlbe projecting
from beneath the edge. This scale fungus was found not only upon
trees to which infested twigs had been tied, but upon others adjacent to
them, indicating a spread from tree to tree. According to the owner’s
statements the surface of many of these trees had been conspicuously
reddened by an abundant development of the fungus on the scale, these
growths having subsequently been removed, with the dead scales them-
* Letters received from Professor Rolfs since my visit to Florida notify me of the
frequent finding of this fungus there on the San Jose scale and other species.
1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. 27
selves, by exposure to the weather. The trees in this orchard were in
very good condition, showing but little effect of the scale attack.
The third orchard visited, that of Mr. Thalimer, was in very much
worse condition, the fungus having been introduced too late to save
many of the trees. The plat contained two hundred and seventy-five
peach-trees, three years old, which had become infested two years
previously by extension of the scale from the premises of a neighbor.
Nine-tenths of the trees in this orchard were dead, according to the
owner's estimate, many of them those to which pieces of oak branches had
been tied in July of the previous year. Where the trees and the scales
upon them were still living, the scale fungus could yet be found
_ From the history and condition of these orchards and from other
observations made upon this visit it seemed clear that the Spherostilbe
could be made useful, especially where for any reason immediate insec-
ticide work could not be done, but that it would at best serve only as a
strong check upon the multiplication of the scale and not as an efficient
means of its complete extermination. I consequently decided to apply
it in Illinois on those premises only which we could not reach with the
insecticide spray owing to the exhaustion of funds available for this field
work. The most important region remaining without insecticide treat-
ment was that at Sparta. Some orchards at Richview likewise had been
only imperfectly sprayed, and others remained heavily infested and in
condition to afford a means of testing the efficiency of this fungus
parasite.
This scale fungus was distributed to orchards at Sparta and Rich-
view by Mr. E. B. Forbes on three separate visits; one from April 30th
to May 5th, the second from May 28th to June 7th, and the third on
June 23d. Thirty trees belonging to Mr. James Newcome, were thus
infected near Richview, and three hundred and fourteen trees, belonging
to twenty owners, in the Sparta district, as follows:
S. A. Blair, 6 trees. H: A, W. Otten;5 trees:
Henry Bodiker, 18 trees. Jefferson Porch, 35 trees
Robert Conch, 1 tree. Lowis«Pritz;\s tree:
James Davison, 8 trees. J. W. Robinson, 85 trees.
Henry Lout, 6 trees. fohne>teel> 7-trees.
George Lyons, 4 trees. Jacob Stahlman, 4 trees.
Fred Marshall, 1 tree. J M. Temple, 76 trees.
John McHenry, 3 trees. Silvenus Wilson, 7 trees.
Riley McKelvey, 11 trees. James Wood, Sr., 8 trees.
Sidney McKelvey, 2 trees. James Wood, Jr., 26 trees.
At the earliest visit only infected scales on pieces of bark or twigs
of oak obtained from Florida were used. The twig or bark with the
fungus on it was tied to the upper side of a limb, as high up on the
274 BULLETIN NO. 56. [ July,
branch as the infestation was severe and in such a position that the
southwest rains would readily strike it. From one to a dozen pieces
were placed on a single tree, according to the size of the tree and the
abundance of the scale, three or four being the commoner number.
On the second visit, beginning May 28th, only artificial cultures of
Spherostilbe were used, mostly those grown on corn meal or on pieces
of bread. About a half inch square of the culture material was softened
for a short time with water, and mixed with fifty centicubes of water,
and the liquid was spread with a sable brush on the spot selected. The
infected spot was then covered by wrapping the branch with a strip of
wet duck four inches wide and forty inches long, the wrapping being
fastened with a string. These strips were wet a second time on the
following morning and were removed in twenty-four hours after appli-
cation, the object of this procedure being to keep the culture material
continuously moist until the spores had time to germinate. That this
was done was shown by the fact that particles of the fungus were
generally whitened by a mycelial growth from the germinating spores by
the time the cloth was removed. The infected spot was then marked by
a white string for convenience in subsequent inspection.
The first such visit of inspection was made at Sparta by Mr. Forbes
May 27th, three weeks after the infected twigs were put in place. At
this time a few dead scales were found in the vicinity of the twigs, but no
certain evidence of the spread of the fungus was obtained. On the next
inspection, June 21st, a scale dead with Spherostilbe, and showing the
fungus in the form of a fruiting growth, was found on a tree to which a
corn-meal culture had been applied May 28th. Thecloth wrapping had
been accidentally left on this tree, and the fungus had grown under its
protection. July 6th, about two months after the first infection of these
trees, the fungus had taken effect upon adjacent scales in practically
every case where they had been originally abundant and the infection
material had been liberally applied, but in no case was the growth on
the tree profuse nor even generally visible even on the scales immediately
adjacent to the infection material. When only a few scattered scales
were present no start had been made. Returning to the same trees
September 1st, we found the fungus was by this time growing vigorously
everywhere, spreading downward in some cases as far as five or six feet
and on lateral branches from the one to which the infection had been
applied, as far as a foot beyond thefork. The upward spread, however,
was not so great, the spores being evidently disseminated mainly by
washing down; and there was nothing to indicate the spread of the fungus
across an air space. On one tree six inches in diameter, for example,
on Mr. Temple’s place, the fungus had spread downward about two feet, —
1899.] . WORK ON THE SAN JOSE SCALE IN ILLINOIS. 275
as far as the scales extended, and upward not at all. From another
piece on the same tree the fungus had spread upward a foot and a half,
downward two and a half feet, and thence an equal distance on a lateral
branch. From still a third piece it had spread downward three and a
half feet and out six inches ona branching twig. Another tree five
inches in diameter, to which six pieces of bark had been tied, was so
generally covered with the fungus infesting the scales that it was difficult
to say whence and how far it had spread. Excepting the smaller and
upper twigs and branches, the entire tree was infected. In some places
on this tree the lateral spread must have been at least six feet. Another
_ tree in this same orchard, to which five twigs had been attached, showed
the scale fungus distributed upward from points of infection to distances
varying from six inches to a foot, downward from sixteen inches to
three feet, and laterally from six to twenty-six inches.
The results of infection by means of artificial cultures were equally
favorable, and on the whole more marked, owing especially to the fact
that pieces of the culture medium remaining on the tree continued to
grow the fungus and to produce the spores for an indefinite time. On
one tree, for example, the scales on which were infected June 17th by
smearing on a thick paste of spores from a culture of broth and corn
meal, the fungus had made a visible start by the 5th of July. A few
scales were then dead with a noticeable growth of the fungus, and by
September rst this growth had become very profuse spreading in various
directions from two to four feet from the point of infection. On an-
other tree, similarly treated at the same time, the fungus growth Septem-
ber 1st (about two and a half months after infection) had become very
profuse, extending downward more than six feet and upward about
sixteen inches and crossing an air space of at least three feet. The
infection material was still growing in good condition and bearing large
numbers of spores.
On the final visit of the season, made by Mr. E. B. Forbes to
Sparta November 2d, it appeared that there had been no great increase
in the growth and abundance of the fungus since the September inspec-
tion, but that in a number of cases it had spread from limb to limb in
such a manner as to suggest that the spores had been conveyed by the
blowing of rain drops in a high wind. An occasional washed-out
appearance and pale color of the fungus suggested the probability that
the recent weather had been too cool and wet for its rapid spread.
The fact should be carefully noted that however generally the fun-
gus was distributed, it was easy to find everywhere in the infected area
scale insects still living and apparently not invaded by it, and even
young scales crawling about in considerable number. It remains to be
276 BULLETIN NO. 56. [ July,
seen, consequently, how completely even thoroughly infected areas may
be cleared of the scale by this fungus, since it is possible that only those
scales which were in some way comparatively deficient in vitality were
actually destroyed by the parasite. Contrary to this supposition we
have only the observations made in Florida, where, again, it is not
impossible that other and inconspicuous causes have conspired with the
Spherostilbe to reduce the number of the scale.
No instance could be found either at Sparta or at Richview of the
appearance of the fungus on trees not immediately infected by Mr.
Forbes, a fact doubtless due to the hard and tenacious character of the
fruiting growth, which is such that the spores of this fungus are little
likely to be carried by the air. Doubtless, however, after a time birds and
insects passing from tree to tree would effect these transfers accidentally.
On the other hand, it is but little work to snip off twigs from an infected
tree and tie them to branches of those adjacent, thus securing and has-
tening the infection process which a single season should suffice to make
general on any badly infested premises. Indeed artificial cultures are
so readily made in quantity and capable of being so rapidly applied
that it would be a matter of little difficulty to treat a large orchard com-
pletely, provided only that the supply of the cultivated fungus could be
had by the orchardist. As the cultivation of this fungus parasite
requires the expert methods of the bacteriological laboratory, it is
beyond the reach of the farmer, who must depend upon the simpler
method of infection except where the state or some private expert can
furnish the fungus cultures to him as required.
Thinking it possible that scales killed by the fungus would be gen-
erally removed from the tree, and the dormant fungus with them, by
exposure to the winter weather, I took measures to prevent a removal
by this means of all the fungus growth upon infected trees by having
selected portions of the infected surfaces on each tree wrapped with
cloth early in November, to be left on all winter. I have thus made
sure that each infected tree will have upon it a considerable area of the
fruiting fungus in the spring in condition to renew the infection in 1899.
Attempts at infection of the San Jose scale with the new fungus
(Microcera sp.) detected in the Rose Hill orchard in northern Florida
were not wholly successtul, owing perhaps in part to the small amount
of the fungus available for experiment. Applications of a culture made
on corn meal and beef broth were so far successful as to infect the
scales to which the spores were applied, but there was no considerable
spread, in the single experiment made, from the infected area to the
adjacent scales. :
As aresult of this field work with the above-mentioned fungous
1899. | WORK ON THE SAN JOSE SCALE IN ILLINOIS. CB
disease of the San Jose scale it is evident that the distribution of S.
coccophila under conditions prevailing in southern Illinois this year is
likely to prove a valuable adjunct to more energetic measures for the
destruction of this insect. Indeed, we may go so far as to say that if
the scale should finally become a permanent resident in this state, it is
quite possible that this and similar enemies will forma permanent check
upon its multiplication such as to reduce its injuries to comparative
insignificance. It must be noted, however, that the summer of 1898
was favorable to the growth and reproduction of this fungus species,
both with respect to temperature and rainfall. An abundance of rain-
fall was, in fact, shown by my laboratory culture experiments to be
indispensable to the profuse fruiting of the fungus, cultures made on a
comparatively dry medium often growing freely but remaining sterile
for weeks, while those made in a saturated atmosphere would fruit with
excessive abundance within four days from the sowing of the spores.
In a dry season, consequently, we cannot expect a rapid spread of this
fungus from scattered infection points.
FIELD NOTES ON FUNGOUS INFECTION.
More definite details with regard to the spread of this fungous
infection in the field are presented in the following items abstracted
from the notes of Mr. E. B. Forbes, the Assistant in charge of the
experiments.
Neighborhood of Sparta.
Orchard of J. M. Temple.—Twigs and bark of oak from Florida
bearing infected scales were tied April 30, 1898, to seventy-six trees in
this orchard. May 27th, a large number of scales were examined
microscopically, but no positive case of death from the fungus was
found. t Papas
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1899. | “WORK ON THE SAN JOSE SCALE IN ILLINOIS. ur 20S
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286 BULLETIN NO. 56. [ July,
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