AGRICULTURAL EXPERIMENT STATION.
TWO PEACH SCALES.
By H. A. GOSSARD.
The Bulletins of this Station will be sent free to any address in Florida, upon
application to the Director of the Experiment Station, Lake City, Fla.
E. O. PAINTER & COMPANY,
BULLETIN NO. 61.
BOARD OF TRUSTEES.
GEO. W. WILSON, President ................. Jacksonville.
F. E. HARRIS, Vice-President..................... Ocala.
J. D. CALLAWAY, Secretary .................. Lake City.
C. A. CARSON, Chairman Executive Committee, Kissimmee.
J. R. PARROTT ............................ Jacksonville.
E. D. BEGGS................................. Pensacola.
L. HARRISON................................Lake City.
T. H. TALIAFERRO, C. E., Ph.D ............... Director.
H. E. STOCKBRIDGE, Ph.D ................. Agriculturist.
H. K. MILLER, M. S .......................... Chemist.
H. A. GOSSARD, M. S ................... Entomologist.
H. HAROLD HuME,B.Agr.,M.S. Botanist and Horticulturist.
CHAS. F. DAWSON, M. D., D. V. S......... Veterinarian.
A. W. BLAIR, M. A ................... Assistant Chemist.
W. P. JERNIGAN ................ Auditor and. Bookkeeper.
C. S. BROCK ............... Stenographer and Librarian.
LUCIA MCCULLOCH .... Asst. Biologist and Asst. Librarian.
JOHN F. MITCHELL ............ Foreman of Station Farm.
JOHN H. JEFFRIES.. Gardener in Horticultural Department.
Louis DEGOTTRAw,Supt. Citrus Experiments at Boca Raton.
Introduction .......... ............. ............ 473
Distribution of San Jose Scale............. ....... 474
The Native Home of San Jose Scale ................ 475
Treatment With Crude Petroleum ................. 476
Experiences of Practical Orchardists ............... 480
Summer Treatment ................... ..... .... 486
Pumps and Nozzles ............. ................ 487
Sphaerostilbe coccophila or Disease of San Jose Scale. 487
Fungous Treatment Combined with Fumigation...... 491
Distribution of White Peach Scale.................. .492
Food Plants of White Peach Scale................. 493
Description of White Peach Scale .................. 495
Life History of White Peach Scale........... ...... 496
Treatment for White Peach Scale .................. 496
Natural Enemies of White Peach Scale............... 497
Summary of Important Facts .................... 497
Two Peach Scales.
Commercial peach growing is certain to become a more
important industry in Florida than it is at present; new areas
are being planted and abandoned orchards are being reclaim-
ed. Our horticulturists are constantly seeking new varieties,
better suited to Florida conditions than those at present
grown, and I am confident that they will eventually cease to
compete with neighboring states on equal terms but instead
will produce distinctive Florida varieties, anticipating all
competitors in the early markets and giving northern sec-
tions a race for the latest shipments.
Probably the fear of San Jose scale has been a greater de-
terrent to extensive planting than any other single drawback
and the White Peach scale, Diaspis pentagon, is not less fear-
ed where it is known.
Practices in treating these and similar dangerous scales
are not at present what they were a few years ago, and the
necessity of reviewing previous recommendations made by
the Experiment Station as well as of giiring a statement of
the most approved of present treatments furnishes the occa-
sion for this bulletin. The conclusions here set forth have not
been reached suddenly or unadvisedly, but sufficient time has
been taken to observe, to experiment, and to collect the ex-
periences of practical orchardists in the field so as to render
the recommendations here made safe, and I am confident that
if they are carefully followed results will be satisfactory.
BULLETIN NO. 61.
San Jose Scale.
This insect is now so widely scattered over Florida that
the problem has become an individual one with every orchard-
is and the only aid that the Entomologist can give is to iden-
tify specimens and recommend methods of treatment. More
than thirty points of infection are known in the state, scatter-
ed through about twenty counties, and since I am dependent
upon incidental reports and discoveries for my information
regarding its distribution, it is safe to say that more unknown
cases of infection exist than are upon record.
The nurseries of the state that have my certificate of in-
spection thoroughly fumigate their stock and if a case of
scaly trees having gone out-under my certificate has ever
occurred I have been unable to discover it, though I have
endeavored to ascertain the source of infection in every case
of which I have learned. The first certificates issued by me
were dated in1899.A list of the, certified nurseries in the state
will soon be published in a separate circular. Those who wish
to buy only of certified nurseries should demand a copy of
the certificate; one firm in the state has used the following
expression in advertising its products: "We have an excel-
lent stock of these peach trees that are grown in nurseries
free from disease and insect pests. This is certified to by the
State Entomologist." This statement, if true at all, is so mis-
leading as to practically amount to an untruth for I have
never inspected the stock of this firm and if it has 'ever had
any stock growing in any of the nurseries that were regularly
inspected it was not so represented to the inspector. The
stock of this firm may be safe enough for anything I know to
the contrary, but I warn them and all others that any future
use of a similar statement without authority will cause the
parties making it to be advertised by name in a way that will
TWO PEACH SCALES.
not help their business. The name of this firm is only withheld
at present because I know nothing against their stock. I have
had some indications that some uncertified nurseries have
sold infested stock during the past two or three years, and
inquiries addressed to the proprietors asking if they possess-
ed fumigatoriums have elicited no answer. The Entomologist
of the Experiment Station is neither a state nor a police of-
ficer and has no more power to investigate cases of this kind
than any other citizen of this state, but should I find that a
nurseryman continues to sell diseased stock without properly
fumigating it after being advised that his nursery is infested,
I shall not hesitate to publicly expose him, because with our
present knowledge of the methods by which dangerous scales
on peach stock can be destroyed, there is no excuse for send-
ing out anything but clean stock.
The Native Home of the San Jose Scale.
One of the most important announcements ever made to
the fruit growers of the United States is that of the Division
of Entomology at Washington, stating that Mr. Marlatt has
determined that China is unquestionably the native habitat
of the San Jose scale, and that in that country as well as in
Japan it is kept in practical subjection by a lady-bug, Chilo-
corus similis, closely related to our well known two-stabbed
lady-bug, Chilocorus bivulnerus. It is hoped that this lady-bug
will find in this country conditions that are as congenial for
its multiplication as they are for the development of the scale,
and that the end of the long warfare against this most noted
pest of all entomolgical history has been reached at last. The
lady-bug feeds upon the white peach scale, Diaspis pentagon,
.and if it proves equal to the task of reducing San Jose and
also of preventing the Diaspis from repeating San Jose's his-
tory, which disaster is not beyond the bounds of possibility,
this achievement by the Department at Washington will out-
BULLETIN NO. 61.
rank in value any single piece of agricultural work ever ac-
complished by any similar bureau in the history of the world.
However, hopes may be too sanguine and it is possible that
many years may yet elapse before we can abandon the meth-
ods of warfare which years of -experience have developed. A
colony of these lady-bugs is promised to Florida whenever
the Department is able to distribute them.
Treatment With Crude Petroleum.
During the winter of 1901, some experiments as follows
were carried on with crude petroleum at Lake City. The oil
used was not tested for specific gravity as the necessity for
such a test had not been discovered at that time, but judging
from its appearance it must have been very nearly of approv-
ed standard composition, 43 to 45 degrees specific gravity.
On the 25th of January some applications of ioo per
cent. crude petroleum were given to pear, plum and peach
trees. The petroleum was applied with a Deming Kero-water
pump with a Vermorel nozzle. The variety of pear was un-
known, but three trees, of which I shall speak as No.'s I, 2
and 3 were badly infested with San Jose scale. Tree No. I
was apparently nearly dead; the trunk was blistered and
crusted with scales, the leaves and branches having been
thickly infested the proceeding season clear to the tips; there
was probably not an inch in length of living twig to be found
in any place upon the tree which was not crusted with scales.
To all appearances the tree could not be expected to. live
whether the scales upon it were killed or not. The bark upon
both trunk and branches was very much hide bound and had
to be split open with a knife in order to give the new wood
a chance to form beneath. This tree was slow in putting out
its leaves in the spring, but eventually leaved out and on the'
first of May seemed to have a fighting chance for life. A11
TWO PEACH SCALES.
scales upon it were apparently killed. I am uncertain whether
it would have been possible for this tree to have recovered
any degree of healthful vigor under any circumstances and
unfortunately for our observations, it was one of our first
pears to succumb to fire-blight. Later two or three sprouts
came up from the roots, healthy and free from scale.
Tree No. 2 was a larger pear of the same variety and not
so badly infested, although many of the branches were com-
pletely crusted and coated with scales and the bark of the
trunk and larger branches had to be split with a knife as in
the first case to give an opportunity for new growth. This
tree leaved out at the usual time and by May Ist was vigor-
ous and thrifty in appearance, apparently not having suffer-
ed at all. This tree also perished by fire-blight. I am unable
to pass judgment as to whether the petroleum affected the
resisting powers of the trees against blight or not. It would
be as reasonable to charge any apparent weakness in this
respect against the scale as against the spray.
A smaller pear tree, No. 3, was also given a treatment of
ioo per cent. petroleum and came through in perfect con-
dition with all scales upon it killed, remaining in health until
it was removed by the gardener more than a year after being
treated. Fire-blight was unusually severe during the season
referred to and many trees died in the same manner as those
under observation, though given no insecticidal treatment at
Upon the same day a number of plums of eight different
varieties, including representatives of the Satsuma, Burbank,
Kelsey, Normand, Yellow Japan, Abundance, Bailey and Bo-
tan varieties were sprayed with 1oo per cent. petroleum. Be-
side each of these trees in an adjoining row another tree of
the same variety was left untreated as a check for compari-
son. Both the treated row and the check row later showed
evidences of unhealthfulness, partly due to crown gall on the
roots and partly to obscure causes probably connected with
BULLETIN NO, 61.
their location. A much larger number of the sprayed trees
died during the next year's interval than of those in the
check row, and from the first they were in much worse shape
than some adjoining rows that were sprayed with a 30 per
cent. mechanical mixture of water and petroleum. Some
smaller plum trees which had been in the ground only one
year at the time of making the Ioo per cent. application
seemed to survive without noticeable injury.
One hundred per cent. petroleum was also applied to nine
bearing Florida Gem peaches on the 26th of January. Of
these trees but two or three ever put forth any signs of life
and these quickly died. Two young trees in the same row and
of the same variety did not seem injured by the same treat-
ment. Bearing trees of the Florida Gem variety will not
stand a heavy dose of crude petroleum in Florida unless the
conditions governing its application are different from those
that surrounded these particular trees. No, special care was
taken in making these applications, as my object was to find
out what would be the effect of crude petroleum if put on lib-
erally, in quantities sufficient to just reach the dripping point,
and without regard to sunshine or the precautions that are
generally observed in making applications of kerosene.
Some hundreds of plum and peach trees of several vari-
eties were sprayed with from, 15 to 30 per cent. mechanical
mixture of petroleum and water during the first three weeks
of February and I was unable to detect the least injury of any
kind following any of these diluted applications, the trees re-
maining under observation for two years after the treatment
was given. The trees in all cases were sprayed until they
reached the dripping point and in no case were they banked,
nor was any attention given to cloudy weather nor to the
hours of evening near to dusk. Some applications were made
upon bright days but most of the time the weather was de-
cidedly hazy, the sun being scarcely if at all visible.
The experiences of others that the oil would remain on
TWO PEACH SCALES.
the trees for some weeks and that it can be plainly seen just
what parts of the trees have been treated, and that the oil
will gradually spread a considerable distance from the spot
where the liquid has fallen I was able to confirm throughout.
As I also made some applications of kerosene, 15 to 20 per
cent. at the same time, I decided that the petroleum seemed
to be the more desirable insecticide, although it might not
come through the pump quite so easily as the kerosene mix-
Very careful comparisons of the sprayed and unsprayed
trees were made to ascertain the effect of the application on
the bloom with the result that I was unable to discover any
injury where the diluted spray was used. The buds were
swelling at the time the applications were made, many of
them being just ready to burst. At this time, when the cur-
rents of life are beginning to flow and assimilative processes
are commencing in the outside leaves of the buds and when
the vital organs of the blossom are not pressed in close con-
tact to the sheathing parts of the perianth, conditions are
most favorable for giving treatment without endangering
Some of the trees were sprayed when a strong wind was
blowing and on such trees the work was not thorough, the
scale again developing after a few months, but where the con-
ditions of application were reasonably suitable complete ex-
termination seemed to be the result with the weakest mater-
ial used. A few months later, natural agents, especially "San
Jose Scale fungus" Sphaerostilbe coccophila, which Prof. Rolfs
had introduced into the orchard about two years previously
developed to such a degree that no further spraying was ne-
cessary, and indeed no conclusions could have been reached
as to the efficacy of such treatment after this time.
My horse was blanketed as a protection against injury
from the spray falling upon him.
BULLETIN NO. 61.
Experiences of Practical Orchardists.
The following record from the journal of Mr. Wm. Mack-
lin, of Dinsmore, Duval county, Fla., is printed with his per-
mission and is commended to the attention of all peach grow-
ers because of the evident care with which the treatment was
given and the close observations he made.
November 23, 1900.
After my return from England, after a four months ab-
sence, my foreman called my attention to a very bad attack
of San Jose scale that had developed in my peach orchard
during the time I was away. On careful inspection, I found
that almost all the trees were affected, some so badly as to
be incrusted with the scale and in a few cases killed; the oth-
ers, though not coated with scale, were all infected more or
less. As I could hear of no treatment that promised such suc-
cess, I decided to try kerosene or crude petroleum, spraying
with a Gould's "Kerowater" spray pump, but did not com-
mence the treatment until-January, since I was informed that
it was better to let the buds become slightly swollen as they
would then be in the best possible condition to withstand the
effect of the oil which might possibly do some injury. Bulle-
tin 146, New Jersey Experiment Station, advised the use of
crude petroleum only when of a specific gravity of 43 degrees
or over, and as the Standard Oil agency in Jacksonville could
not at the time give me any information about the crude oil
they had in stock I began by spraying with kerosene.
January 14, 15 and 16:
Sprayed with kerosene, 25 per cent. per guage on pump,
but according to actual measurement of the kerosene and
water, when allowed to settle after being sprayed into a grad-
uating glass, the mixture showed only 20 per cent. oil. This
strength was adhered to throughout.
January 16: Examined trees sprayed I4th and 15th.
Some of the scales appeared dead but many still alive. Kero-
TWO PEACH SCALES.
sene on trees sprayed 14th beginning to dry off. Weather 14,
15 and 16 warm with bright sun.
January 17, 9.00 A. M.: Raining since 8.30 A. M. Examin-
ed trees again. Kerosene quite apparent as the rain stands
unevenly on the tree in globules. This effect least marked on
trees sprayed 14th. Examined scale; some undoubtedly dead
but a large proportion still alive showing bright yellow when
pierced with the blade of a knife. When squeezing the scale
as above, noticed instances where a thin film of oil ran out
from beneath the scale. A few open blooms on the Jewel va-
riety show damage to the edges of petals from the oil; look
as if they had been touched by a slight frost. Cannot detect
any damage to the interior of the bloom.
January 18: Cut off two twigs from trees sprayed i4th
and dipped them in water; greasy state of the trees very ap-
parent as the water would not lie on them. Can find plenty
of dead scales but also plenty of live ones. Painted two trees
with pure kerosene applied with a brush. Tree No. I, three
years old, Waldo, so badly crusted with scale that bark of
main limbs is completely hidden. Painted thoroughly almost
the -entire tree except very smallest twigs. Tree had been
sprayed with twenty-five per cent kerosene on 14th. Tree No.
2, Jewel, two years old; trunk crusted with scale so as to
hide bark, larger limbs nearly encrusted but not so as to com-
pletely cover the bark. Tree still fairly vigorous and healthy.
Painted trunk and main limbs with pure kerosene. Tree had
been sprayed with 24 per cent mixture of oil and water on
January 19: Sent twigs showing orange colored fungus
growth to State Entomologist to determine whether it was
the fungous disease of the scale. Reply received, saying that
it was the disease referred to (Sphaerostilbe coccophila).
January 20: Continued spraying with crude petroleum
same strength. Having been informed by Standard Oil com-
pany at Jacksonville that the crude oil in stock was between
BULLETIN NO. 61.
43 and 44 degrees specific gravity abandoned kerosene al-
together. Examined trees sprayed I4th and 15th, noticed
many more dead scales. The perfectly healthy scales found
were very few. Effect of treatment more encouraging. Exam-
ined trees painted with pure kerosene on I8th. Encrusted
parts still contain living scale. Scale on other parts all dead.
January 21 and 22: Continued spraying with crude oil.
January 27: Examined trees sprayed 14th and I5th; did
not find a living scale.
January 28: Finished spraying.
February 14: Scales apparently all dead. Trees sprayed
with crude petroleum still quite greasy. No greasy effect no-
ticeable on those sprayed with kerosene.
March 2: Trees sprayed with crude oil still greasy, scales
April 10: Sprayed trees healthy, and no bad results from
the oil treatment, no live scale apparent anywhere. Painted
tree No. I dead but death more probably due to. scale than
to painting with undiluted kerosene. Tree No. 2 alive and
fairly healthy. As far as can be judged at this date a weaker
spray than 25 per cent. would be sufficient to destroy the
August I: No further notes were taken. At present the
trees are healthy and have made a better growth than last
year. Remarkable recoveries were made by many trees which
were so badly injured by the scale as to make their death
seem almost certain.
Unfortunately, a one year old grove in which we did not
notice any scale at the time of spraying was left untreated
and I now find some scale there, and in a very few instances
an isolated specimen or two in the sprayed groves, but the
destruction of the scale was as complete as possibly could be
.expected and I am of the opinion that had we sprayed the
young grove alluded to, that it would have been practically
eradicated. The crude petroleum used was a brown oil and
TWO PEACH SCALES.
the much greater lasting greasy effect made it infinitely su-
perior to the kerosene. The Gould Kerowater pump has one
important defect. The oil tank which is imbedded in the wa-
ter barrel is not sufficiently watertight at the top, the result
being that in hauling to the orchard the water splashes over
the top of the tank, displacing a certain amount of oil which
in turn goes into the water barrel. In this way oil is lost and
in starting to pump, all the water which has passed over into
the tank and sunk to the bottom of the oil has to be pumped
out before a mixture will be obtained. Otherwise the pump
suits the work well 'enough.
The treatment has been a marked success, tho owing to
the fact that one grove was not sprayed it left a breeding
place for the scale. I will repeat it this winter, when I believe
we will completely.eradicate it. In the case of diseased limbs
where the bark was unsound the oil penetrated the bark and
destroyed the limb. This was the only injurious result notic-
ed and there was no oil penetration on sound bark. The trees
bloomed and fruited naturally, though much of the crop on
the earlier varieties was cut off by frost. The later kinds bore
a heavy crop.
Some of the trees were sprayed just before the rain came
on (but none while it was actually raining) and it did not
seem to make any difference in the destructive effect of the
oil on the scale. Great care was taken to cover the trees thor-
oughly with the spray without applying so much as to have
the mixture running down the tree to any great extent. The
oil destroys rubber hose very quickly and after a couple of
weeks use the hose is useless. The horse used for hauling the
pump should be covered with water proof cover as otherwise
he gets wet by the spray which blisters the skin and tempor-
arily removes the hair.
Under date of March 2, 1902, Mr. Macklin writes: "I may
now add to my letter (the one just given) that after two
year's experience with the crude oil treatment, I consider the
BULLETIN NO. 61.
San Jose scale the least to be dreaded and the easiest to, con-
trol of any parasite or disease affecting deciduous trees that
we have hereabouts. No orchard need be seriously injured by
the scale if the above treatment is used. Though I have spray-
ed thousands of trees I have never seen one suffer the slight-
est injury from the oil if sprayed while dormant."
Another correspondent writes: "I have had but one
year's thorough experience with crude petroleum on peach
trees, and even from this experience am unable to give exact
results, except that we apparently killed every San Jose scale
and incidentally some of the trees.
I made two applications of crude petroleum to my peach
orchard the past winter. A few of the trees had considerable
San Jose, but very few of them were affected in this way to
an extent sufficient to weaken their vitality. The vitality of
nearly the whole orchard had, however, been very seriously
affected by too much water around the roots. The ground
upon which the orchard was located did not drain off well
and the excessive rains that we had here during the past
eighteen months had nearly killed some of the trees and
weakened others. The trees had been already weakened and
could not stand the double dose of petroleum and quite a
number of them succumbed. I do not think, however, that
any of the trees that were in first class condition were very
seriously affected by the double dose of petroleum.
From my rather imperfect data I should recommend but
a single application of crude petroleum and this, according
to my experience, should be made after the buds are well
swollen or are just breaking out-of course a little ahead of
the bloom. Contrary to my expectations the trees on which
the buds were well swollen came out better than those on
which the buds had not yet commenced to, swell.
The application was made with a Deming bucket pump
and I think the nozzle was a Bordeaux. I am not sure of this,
however, as we have several different kinds of nozzles. I have
TWO PEACH SCALES.
just purchased a Gould's Kerowater barrel pump, the hose of
which is fitted with Vermorel nozzle. I have not, however,
had occasion to use it yet.
The percentage of crude petroleum used was twenty-five,
I am inclined to believe that for peaches one or more ap-
plications of 15 per cent. kerosene made after fruit has been
picked in the summer-and always on sunny days-is really
less harmful to the tree than crude petroleum, unless the pe-
troleum is applied at just the right stage of bud expansion-
and this is hard to regulate through an orchard of mixed va-
rieties." From another correspondent we quote: "Our spray-
ing with kerosene or crude petroleum in winter has only been
with pear trees. We have used varying strengths from Io to
50 per cent. We made two applications to most of the trees,
Those that were sprayed with from 20 to 50 per cent. showed
the petroleum as long as two years on the trees, making
them a dark chocolate color. We did not think any of the
trees were injured by the mixture. The little summer spray-
ing we did on peaches was with 15 per cent. of kerosene oil,
in Deming kerosene sprayer. It killed whatever scales there
were on the trees and did no damage whatever to the foli-
age or trees. We never knew what kind of scale was 'on the
Mr. W. H. Bliss, of Chipley, Fla., wished to use his Knap-
sack pump without going to the expense of purchasing a
Kerowater machine and was advised to make an emulsion as
follows: Dissolve one-half pound of whale oil soap in one
gallon of water and while still hot pour in two' gallons of
crude petroleum, away from the fire, and after testing a small
quantity of the oil in the heated water to make sure that the
point of ignition has not been passed, then pump the mixture
back into itself until a thick creamy mass is obtained. For use
dilute one gallon of the emulsion with nine gallons of water.
Under date of June 22, 1902, Mr. Bliss writes: "Yours of
BULLETIN NO. 61.
June 14th duly received and would have been answered
sooner but I wanted to inspect a few trees that were very
scaly this spring, before answering your letter. I have look-
ed them over carefully and am very glad to say that I can-
not find a single live scale on any of them. I also requested
one of my men to see if he could find any; he says he has not
been able to find one. I sprayed twice and if I find any scale
this fall I think I shall spray in December and January with
the same mixture. There is no doubt in my mind that this
is the right mixture with which to exterminate the scale.
Before I used this mixture I cut out a number of trees that
were full of scale and which I am now satisfied I might have
Crude petroleum can be ordered from the Standard Oil
company, Jacksonville, Fla. In ordering be explicit in the
statement that the oil is wanted for insecticidal purposes and
that it must be from 43 to 45 degrees specific gravity. The
present quotation on such oil is 14 cents per gallon f. o,. b.
Where correct winter treatment has been employed no
summer treatment will be needed. Crude petroleum will not
do for summer use nor can it be applied to evergreen plants,
as the heavy oils choke the breathing pores of the leaves
causing them to fall. Ten or fifteen per cent mechanical mix-
ture of kerosene and water applied only on bright, sunny
days and when there is not too much humidity in the air at
the time the young scales are hatching and migrating will
be satisfactory. Whale oil soap, one pound in four gallons of
water also timed to catch the young scales is practiced by
many with good results. Good's Potash Whale Oil Soap, No.
3 or Leggett's Whale Oil Soap compound are well adapted
to such use.
rel Nozzle, (sin-
Gould's Double Vermorel Nozzle.
Gould's Kero-water Sprayer.
TWO PEACH SCALES.
Pumps and Nozzles.
The best pumps upon the market and adapted to throw-
ing crude petroleum and kerosene mixtures so far as they
have been tried in Florida are the Kerowater sprayers
made by the Gould Manufacturing Company, Seneca Falls,.
N. Y., or by the Deming Company, Salem, Ohio. The Spra-
motor pump, made by the Spramotor Company, London,
Ontario is said to be fully equal to the very best machines
yet produced but it has not yet been tried in Florida so far
as I have learned. The Vermorel nozzles are better adapted
to Kerowater use than any others known to me. The cut of
Kerowater machine was furnished by the Gould company,
the cut of single nozzle by the Deming company.
Sphaerostilbe Coccophila or Disease of San Jose Scale.
In August, 1897, Prof. P. H. Rolfs, then Biologist of this
Experiment Station, now in charge of the U.S. Semi-tropical
Laboratory at Miami, Florida, announced the discovery of
this fungus growing indigenously upon San Jose and other
scales in Florida. Prof. Rolfs instituted some interesting ex-
periments to test the practicability of fighting the scale in or-
chards with this fungus and I quote as follows from his rec-
ords (Bulletin 41, Florida Experiment Station). The experi-
ments given were located in the orchard of Mr. John Astle-
ford, of DeFuniak Springs:
"Experiment No. I.-A plum tree sprayed twice with
spores of this fungus prepared by placing some of the infect-
ed bread in a quart of water. The first application was in the
afternoon and the second just before dark, July 29, 1896. A
portion of the tree was then wrapped with a moist gunny
"Result.-February 20, 1897. Scales thoroughly inocu-
lated. The disease having spread to many branches.
488 BULLETIN NO. 61.
"Remark.-The idea of wrapping moistened burlap or
other cloth loosely about the treated limbs is well worth fol-
lowing out. It is a question of only a few hours whether
the spores are to produce the disease or whether they will
die. If a moist atmosphere prevails all is well and good, if
drouth, the spores will die. The reason for this is brought
out strongly in the study of the biology of this fungus, so it
will not be stated here.
"Experiment No. 2.-A peach tree in good condition,
except severely infested with San Jose Scale, which seemed
perfectly healthy, was sprinkled late in the afternoon of July
29, 1896 with material similar to that used in experiment
"Result.-February 20, 1897. Insects not affected. No
trace of disease.
Experiment No. 3.-A peach tree like the one in experi-
ment No. 2, sprinkled July 29, 1896, with material similar to
that used in experiment No. I.
"Result.-February 27, 1897. Insects all dead.
"Experim'ent No. 4.-A peach tree like the one in Ex-
periment No. 2, sprinkled, July 29, 1896, with material simi-
lar to that used in Experiment No. I.
"Result.-February 27, 1897. Insects not affected. No
trace of disease.
"Experiment No. 5.-A peach tree a considerable dis-
tance from No. 2, but conditions very similar to the one in
Experiment No. 2, sprinkled later in the evening, July 29,
1896, with material similar to that used in Experiment No.
"Result.-February 20, 1897. A large proportion of the
insects dead and peeling off. The disease well disseminated
throughout the tree."
An examination of Mr. Astleford's orchard at the pres-
ent time discloses a most interesting monument of Prof.
Rolf's discovery. It consists of about forty acres of peach
Viewain Mr. Astleford's Orchard.-"This orchard is carrying a good crop of fruit."
Viewli r.AterdsOhad.-"hsocadi arigago rpo ri.
Peach Orchard Destroyed by San Jose Scale.-The fungus was not established in this orchard, neither was
any treatment given.
TWO PEACH SCALES.
trees, now about twelve years old or reaching well up toward
the extreme natural limit of life of a Florida peach orchard
and has had San Jose scale in it for six or seven years. Be-
fore the introduction of the fungus it was sprayed repeatedly
with resin wash but with only temporary relief. Since the in-
troduction of the Sphaerostilbe no insecticidal treatment of
any kind has been given to this orchard. Every tree has been
scaly at one time or another, yet but few trees are missing,
perhaps not more than would be wanting if the scale had
never visited it, and but little scale can now be found. It occa-
sionally becomes conspicuous on some trees or on certain
limbs, but disappears as if by magic whenever a brief rainy
season enables the fungus to thrive.
This orchard is carrying a good crop of fruit this year,
and has done so for several years. Except when damaged by
storms, a fair estimate places the yield per tree at about one
bushel, nearly half of which is rendered worthless by the
In striking contrast with Mr. Astleford's orchard another
of 80 acres is shown in Plate III, not over one-fourth of a mile
distant, the two orchards having become infested at about
the same time. The fungus was established in the dead or-
chard too late to be of service and the abandoned buildings
and packing houses on the premises complete the scene of
desolation, emphasizing as nothing else could the value of ap-
plied scientific knowledge as made known by the Experiment
In 1898 Prof. Rolfs planted in an enclosure at Lake City
twenty-five or thirty trees of peach, plum and Keiffer pear
with branches interlocking, and infected a few (I think two
of them) with San Jose scale, at the same time introducing
the fungus. When I first saw the two originally infected trees,
at the beginning of 1899, the trunks had died back to the
base, but clean, healthy limbs had sprung out below the
point of death and *ere making a strong, vigorous growth.
BULLETIN NO. 6n.
A few of the adjacent trees were just beginning to show the
scale. During the summer the insects spread to nearly all
the peach and plum trees in 'the plot, passing the pears, and
threatened to destroy them the second season. However,
spreading more slowly but just as certainly as the scale was
the 'fungus and a minute lady-bug-a species of Scymnus,
the two together finally striking a balance with the scale,
which has since been successfully maintained, and I have no
doubt the trees will remain in first class condition indefinitely
without any need of treatment. During warm, rainy weather
the fungus easily outstrips the scale. Observations upon an
orchard of several hundred trees, also at Lake City, were
commenced at about the same time. How long it had been
infested when I first saw it, I cannot say, but most of the
pears were so nearly dead by 19oo that they were all dug up
and destroyed. Adjoining the pears were several hundred
peach and plum trees just beginning to show signs of the
scale in particular areas. With the exception of a single
treatment with varying strengths of crude petroleum and
kerosene already referred to, these trees were allowed to take
their own course. A very few died outright, but their death
might be charged to several other causes as readily as to the
scale. The limbs of some trees died, undoubtedly from scale
attack, and everything suffered, but a balance was finally
reached which was practically maintained until the entire or-
chard was destroyed to make room for other crops better
suited to the land upon which it was set. Prof. Rolfs had
established the fungus at several different points in the or-
chard in 1898 and this was doubtless the chief natural agent
checking the increase of the scale, though it was assisted by
the minute lady-bug previously mentioned. Mr. Astleford
reports that his trees at DeFuniak became black with these
lady-bugs previous to his introduction of the fungus but they
did not perceptibly decrease the scale.
Mr. Astleford's method of "planting" 'the fungus is to tie a
TWO PEACH SCALES.
piece of cardboard against a scaly spot upon a tree so as to
form a "wall pocket." Infected scales, scraped from diseased
patches of scale or scaly twigs upqn which the fungus is es-
tablished are dropped into the bottomnof the pocket and a
wad of wet cotton or of damp sphagnum moss is then put
in the top. Within twenty-four hours the disease will gen-
erally have established itself. The fungus is usually found
without difficulty on the "obscure" scale, infesting nearly
every live oak tree in the state. It is most conspicuous just
after a rain, appearing as small orange-red tufts from beneath
and among the scales.
Fungous Treatment Combined With Fumigation.
Spraying with kerosene, petroleum, whale oil soap, resin
wash and similar preparations destroys fungous growths as
well as scales,but fumigation with hydrocyanic acid gas,while
deadly to insect life, does little or no injury to fungi or plant
life and is therefore the proper auxiliary treatment to em-
ploy where the main reliance is upon Sphaerostilbe coccophila.
By introducing and disseminating the fungus and fumigating
during the winter season such trees as have not been reach-
ed or cleaned by the disease, an orchard can in all probability
be kept in satisfactory shape at a minimum of expense. The
box tents used in Maryland or the hexagonal tents used by
Prof. Sirrine in New York are the best patterns for work
with peaches. Descriptions of these tents can be found in
Prof. Johnson's Fumigation Methods published by the Or-
ange Judd Co., New York.
White Peach Scale.
Besides San Jose scale this is the most dangerous peach
enemy in Florida, equalling San Jose in destructiveness
where it has become established. Fortunately it has never ob-
tained a foothold in any large nursery in the United States
and our present system of nursery inspection with the like-
lihood that its natural enemy, the Chinese lady-bug will fol-
low it up from its incipiency, renders it unlikely that it will
ever become so generally scattered as San Jose. The original
home of this scale seems to be China or Japan as Mr. Mar-
latt's recent explorations revealed it sparsely scattered over
much of the territory of both countries, its numbers being
limited by the lady-bug, Chilocorus similis, previously men-
tioned as feeding upon San Jose scale, and indicating that it
is indigenous to those countries. Recently some peach wood
collected by the U. S. Department of Agriculture in China
and mailed to one of our Florida fruit growers for propaga-
tion was sent to me for examination and proved to be slightly
infested with this scale. It also occurs in Ceylon, Australia,
Fiji, Jamaica, Trinidad, Martinique, Grand Cayman, Bar-
bados, San Domingo, Grenada, and Antigua. In the Unit-
ed States, outside of Florida, it is found in the District of Co-
lumbia, in California, in Ohio and in Georgia,. Prof. Scott re-
ports that it has utterly destroyed some large orchards in
Georgia, one of Io,ooo trees located at Irby.
In Florida it was first observed at Quintette in 1889, by
Mr. S. F. Harvey whose postoffice at that time was Molino.
The original source of infection seems to have been trees
brought from California or from a nursery then existing in
TWO PEACH SCALES.
Thomasville, Georgia. The present territory.infested around
Quintette is comprised in a radius of about three miles and
includes perhaps not more than a dozen orchards. The old
Harvey orchard was long ago killed by the insect. In Janu-
ary, 1901, Mr. Geo. Veloudois, of Nesbitt, Duval county re-
ported this scale as destroying his peach orchard. He had
first noticed the insect about two years earlier on the limb of
a large mulberry tree, suggesting that it had been introduced
by birds, but from what place the bird could have come is
The list of known food plants is lengthy but important
for Florida since the scale is evidently a very polyphagous
feeder on tropical and semi-tropical plants. It attacks the
peach, mulberry, plum, apricot, cherry, pear, grape, persim-
mon, Guaguma ulmifolia (Bastard cedar), Cycas media, Cycas
circinalis, Capsicum (pepper), Argyreia speciosa, Bryophillum
calycinum, Pelargonium, Jasmimum, Zizyphus, Tylophora asth-
matica, heliotrope, stems of cotton, Calotropis procera (French
Cotton), Hibiscus esculentus (okra), Carica papaya
(melon pawpaw), Acanthus, Sedum, Zamia mexicana,
Callacarpa lanata, Ricinus communis (Palma Christi or castor-
oil plant), and some unnamed garden plants. Leconte and
Keiffer pears are not attacked by it in Florida nor does it
seem to thrive on weeds and garden plants in this state, part
of which are named in the above list. .
BULLETIN NO. 1.
Explanation of Plate IV.
Fig. I. Piece of geranium stem with colony of insects.
Fig. 2. Male puparium, from above, uncarinated form.
Fig. 3. Male puparium, from above, with median cari-
Fig. 4. Male puparium from below.
Fig. 5. Female puparium, upper side, from smooth part
Fig. 6. Female puparium, upper side, from hairy part
Fig. 7. Female puparium from below.
Fig. 8. Female puparium, from above, with pellicles
Fig. 9. Adult male, dorsal view.
Fig. Io. Adult female, dorsal view.
Fig. II. Adult female, ventral view, before oviposition.
Fig. 12. Adult female, ventral view, after oviposition.
Fig. 13. Female puparium, from Tylophora (Chionaspi-
form variety). (Photographed from E. Ernest Green's Coc-
cidae of Ceylon, by H. H. Hume.)
-4. .,2 4 W
TWO PEACH SCALES.
The female scale is 2 to 2.5 mm. or .08 to .10 inches in dia-
meter, quite convex and usually grayish white in color. The
scales are often inconspicuous from being covered with a thin
layer of the skin of the outer bark. Again they stand out
conspicuously white against the natural color of the plant they
infest, naked, glossy and smooth. Where they rest upon a
hairy surface, the hairs are elevated and united with the sur-
face texture of the scale, standing erect in their original po-
sition. Scale irregularly circular, and in the younger speci-
mens oblong. Exuvia orange yellow, inclining to brown or
reddish-brown in lines and spots, sometimes approximately
central, again approaching the margin. Ventral scale very
thin, whitish, remaining adherent to the plant. Removing the
dorsal scale exposes the female insect, usually 'of a bright or-
ange color, but again varying from pale creamy white to
rosy pink according to the food plant. The posterior extrem-
ity or anal plate.is always brownish.. Shape broadly oval,
widest and rounded in front, narrowing to two closely ap-
proximated serrated or scalloped points behind. Segments
of abdomen very distinct.
The male scale is pure white, exuvia pale straw color.
Uncarinated or median keel feebly developed. Length i to
1.5 mm. or .04 to .06 inches. The male scales cluster together
in dense chaffy patches, preferably on the lower parts of the
branches of young trees, and on the trunk near the ground
giving the impression of a coat of whitewash at a distance
from the tree. A scattering male scale can generally be found
here and there among the females. The adult male is a mi-
nute, two-winged insect, bright red in color, with darker
head and pale legs.
BULLETIN NO. 61.
At Washington there are three broods per year, egg-lay-
ing commencing the first week in May and hatching of the
spring brood occurring about a week later. The scales reach
maturity during June, oviposition for the second brood be-
ginning during the last week in June. The winged males is-
sue.from one to two weeks before egg-laying begins. By the
middle of August the second brood has matured, the eggs
of this brood being laid near to the end of the month. A
third brood develops at the end of October.
Prof. Scott states that in Georgia there are three or four
broods, the first appearing about the middle of March if the
season is favorable. Mr. G. F. Mills, a correspondent at Quin-
tette, Florida, writes that there are four broods per year in
his section and he believes there are sometimes five. Prof.
Sasaka of the Tokio Agricultural College states that in Ja-
pan the insect breeds only twice per year.
Professor Scott of Georgia recommends that about the
same winter treatment be given for this insect as for San
Jose scale. Twenty per cent. mixture of kerosene and water
or whale-oil soap at the rate of one pound in one gallon of
water is specifically approved. For spring treatment he rec-
ommends that ten per cent. mixture of kerosene or whale-oil
soap, one pound to four gallons of water, be applied while the
young of the first brood are migrating which is usually dur-
ing the latter part of March. Prof. Scott has observed that
February freezes greatly reduce the scale in numbers. Mr. H.
Maxwell Lefroy, Entomologist of the Imperial Department
of Agriculture for the West Indies recommends resin wash,
several times repeated at intervals of about a week.
The California State Board of Horticulture gets more
TWO PEACH SCALES.
satisfactory results from fumigation under tents than by oth-
Mr. J. A. Anderson, of Quintette, obtained quite satis-
factory results by spraying with machine oil, one of the by-
products of crude petroleum, being unable to procure the
latter material. For winter spraying crude petroleum used
as for San Jose scale is recommended.
The two-stabbed lady-bug, Chilocorus bivulnerus, feeds
upon this scale and when carefully encouraged is apparent-
ly able to subdue it. The lady-bug larvae may sometimes be
counted by dozens upon single limbs, and trees that are
plastered with the scale are often cleaned up perfectly in a
few weeks. Mr. Anderson reports that an orange red fungus
attacked the insect on some trees two years ago, but has not
since been observed. The description suggests Sphaerostilbe
Summary of Important Facts.
I. Florida is well able to compete with other states of the
South in growing peaches for the market.
2. Two among the most important insect enemies of the
peach tree are San Jose scale and the White Peach scale.
3. Crude petroleum of 43 to 45 degrees specific gravity
applied in 20 per cent. mechanical mixture with water is an
efficient winter remedy for both of the above named scales.
4. The trees should be banked with earth about the roots
to catch the surplus spray and the application should be
made on a bright sunny day. The spray-soaked earth about
the roots should be removed within a half hour after the
work is completed.
5. A Kerowater machine with Vermorel nozzles should
BULLETIN NO. 61.
be used or if an ordinary pump is employed an emulsion must
6. Blanket the horse attached to the spraying wagon.
7. One thorough application while the buds are swelling
or ready to burst is sufficient and is recommended.
8. The pump should be tested periodically by allowing
the spray to settle in a graduated vessel to learn if actual
percentage of oil being used tallies with the setting of the
9. The surface of the tree should be thoroughly covered
with spray but there should be but little running of the liquid
down the trunk to collect at the roots.
o1. Trees in leaf in spring and summer should be spray-
ed with a Io to 15 per cent mixture of refined kerosene and
water when the young are migrating; or instead of kerosene
use whale oil soap, one pound of soap to four gallons of wa-
I I. The fungus, Sphaerostilbe coccocphila, has proven itself
a practical success in some orchards through several years of
trial. It is a cheap and seemingly reliable remedy if used in
conjunction with tent fumigation.
12. The fungus should be collected from the live oak
scale or other known source of supply and planted in a card-
board "wall pocket" against a scaly tree, the top of the pock-
et being filled with moistened cotton or sphagnum moss.
The fungus must be established soon after the scale for se-
curing satisfactory results.
13. Peach trees should not be fumigated except during
the winter season.
14. The two-stabbed lady-bug is a very efficient enemy
of the White Peach scale and when well established is able
to subdue it without help.