Group Title: Bulletin University of Florida. Agricultural Experiment Station
Title: The cottony cushion scale
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Permanent Link: http://ufdc.ufl.edu/UF00005168/00001
 Material Information
Title: The cottony cushion scale
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: p. 309-356 : ill. ; 23 cm.
Language: English
Creator: Gossard, H. A ( Harry Arthur ), 1868-1925
Publisher: Florida Agricultural Experiment Station
Place of Publication: Lake City Fla
Publication Date: 1901
 Subjects
Subject: Cottony-cushion scale   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: by H.A. Gossard.
General Note: Cover title.
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Bibliographic ID: UF00005168
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: ltqf - AAA6486
ltuf - AEN1438
oclc - 18155411
alephbibnum - 000920998

Full Text






BULLETIN NO. 56.


FLORIDA
AGRICULTURAL EXPERIMENT STATION




The Cottony Cushion Scale


By H. A. GOSSARD.


The Bulletins of this Station will be sent free to any
address in Florida upon application to the Direct-
or of the Experiment Station, Lake City, Fla.


DELAND. PLA.:
E. O. PAINTER & COMPANY.
1901.


MAY, 1901.








310


BOARD OF TRUSTEES.


Hox. GEO. W. WILSON, President ...... .Jacksonville
Hox. F.-E. HARRIS, Vice-President ........... Ocala
Hox. J. D. CALLAWAY, Secretary .......... Lake City
Hox. C. A. CARSON, Chairman Executive Committee,
............................. Kissimmee
Hox. E. D. BEGGS ...................... Pensacola
Hox. L. HARRISON ......................Lake City
HoN. J. R. PARROTT ................... .Jacksonville


STATION STAFF.


'W. F. YOCUM, A. M., D. 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. Botanist and Horticulturist
A. W. BLAIR, A. M ............... Assistant Chemist
\\. P. JERNIGAN ............ Auditor and Bookkeeper
JOHN F. 1\ITCHELL ........ Foreman of Station Farm
JOHN H. JEFFRIES ..... Gardener in Horticultural Dept
VIRGINIA M. WIGFIELD.. Librarian and Mailing Clerk
MINNIE HELVENSTON ................ Stenographer
















CONTENTS.


The Cottony Cushion Scale (Icerva purchase) in
Australia ........ ............. .. 311
The Germs Icerya ............. . ......... 312
Icerya purchase in other countries .......... 313
History in California .... .......... .... 313
Icerva purchase in Florida ................ 317
The Infested Area and Measures of Suppression.. 320
The Food Plants .................... 325
Characters and Life History .............. 326
Habits .............................. 336
Methods of Dissemination .......... ...... 337
Natural Enemies .................. .. 339
Sprays and Washes ................... 353
Acknowledgements .................... 354
Summary of Important Conclusions .......... 354






ERRATA.
"Germs," page 3II, should read Genus.
"fungus," page 327, should read fungous.
"Coccide," page 338, should read Coccidae.
"those," page 354, should read these.











THE COTTONY CUSHION SCALE,
Icerya Purchasi Maskell.
IN AUSTRALIA,

The Cottony Cushion Scale is a native of Austra-
lia. In its original home it attracts comparative-
ly little notice, seldom multiplying to such an
excessive degree that it threat-
ens important agricultural interests. -
The names Fluted Scale and Austral-
'11' >'.
ian Scale are also applied to the in- _
sect. In Australia and South Africa
it is sometimes alluded to as the Aus-
tralian Bug. '
It seems that in the Australian '
fauna this scale occupies about the ,
same economic position that the ..
Cottony Maple Scale, Pulvinaria in-
-mmerabilis, an insect belonging to
the same family, the Coccidae, holds
among the insects of this country. .,i'i1
Local outbreaks of either at timesi"
may be observed in their respective ',
home countries, but natural checks.
serve to keep them from inflicting se- bilsrho. (fer Miss
C. M. King in Bulletin
vere damage upon more than re- No. 43 Iowa Station, by
stricted areas. In Australia, various Wilma. N...)
species of lady-bugs, flies, and hymenopterous parasites
contribute to deplete the numbers of Icerya, and
in America the lady-bugs, lace-wings, carniv-
orous caterpillars, and hymenopterous parasites
dispose of the Pulvinaria in the same obliging
way. To further pursue the parallel both Icerva and











Pulvinaria excrete a white cottony mass, which covers
and protects unusually well a mass of hundreds and
sometimes of thousands of eggs. The scales are at
least comparable in size and the sets of changes in the
two insects are very similar throughout the course of
their development. Both are highly polyphagous, or
very indiscriminate in the selection of their food plants.
An American lady-bird, Hyperaspis signata, feeds in its
larval stages in the egg-nests of Pulvinaria in precisely
the same manner that the celebrated Australian lady-
bird, Novius cardinalis, does in the nests of Icerya,
though it is perhaps more rare than the Novius. Also
the methods by which the two insects distribute them-
selves are very much the same.
There are other insects in Florida even more nearly
related to the Fluted Scale than Pulvinaria, but we have
preferred to compare these two because Pulvinaria is
more widely distributed and better known to the ma-
jority of observers than the nearer relatives of Icerya,
and because some of the natural enemies of this native
species seem to have taken a liking to the imported one.

THE GENUS ICERYA.

This genus includes a number of important insects
besides Icerya purchase, the most noteworthy being
Icerya sacchari (Signoret), native to the islands of Mau-
ritius and Bourbon, and exceedingly destructive to
sugar-cane; Icerya Egyptiacum (Douglas), to be found
at Cairo, Egypt, feeding upon Banyan and figs; Icerya
montserratensis (Riley and Howard), Montserrat, West
Indies, destructive to Cocoa, Palms and Bananas. Oth-
er species are Icerya rose (Riley and Howard), de-
scribed from specimens found at Key West, Fla.; and











Icerya Palmeri (Riley and Howard), collected on grape
at Sonora, Mexico.
ICERYA PURCHASE IN OTHER COUNTRIES.
From Australia this pest has been shipped either
directly or indirectly into Tasmania, the Sandwich Is-
lands, Mauritius, St. Helena, New Zealand, South Afri-
ca, California, Mexico, Portugal, and Florida. It was
also observed in green-houses at Cambridge, Massachu-
setts, several years ago by Dr. Hagen, but it did not
establish itself there, and it seems questionable if it
would be able to maintain a foothold in a very cold
climate.
It has practically repeated the same story in every
land where it has been newly introduced, and is always
expected to carry certain destruction among many
classes of plants, particularly among those of the Citrus
family. It has always practically defied the efforts of
the fruit-grower to combat it by artificial means. Im-
portations of the Australian lady-bird have always been
singularly successful in reducing this scale to unimpor-
tant numbers, and it also appears that certain other
agencies may play no insignificant part, during some
seasons at least, in keeping it in subjection in Florida.
HISTORY IN CALIFORNIA.
It is believed that the Icerya was first introduced
into California directly from Australia upon Acacia lati-
folia by Mr. George Gordon, of Menlo Park, about 1868
or 1869. At all events the insects seemed to originate
on these plants.
They attracted Mr. Gordon's attention two or three
years later and the first printed reference to them was
published in the proceedings of the California Academy











of Science in 1872. Some reports received by this soci-
ety during this same year indicate a possible spread by
this time of several miles from Menlo Park.
By 1886 the pest was in eight different counties of
the state, some of them widely separated from each
other. The areas of infection seemed to increase even
more rapidly during the next three years and many of
the Citrus growers of California had already abandoned
or were preparing to abandon their business, when the
advent of the lady-bird happily restored the confidence
of the fruit-growers and the Fluted Scale has not been
a very important factor in California orange culture
since.
The suggestion that the enemies of the Fluted Scale
might be studied with advantage in their native home
and be profitably imported into this country was due
to Prof. Riley, who urged upon Congress that either
an appropriation should be made for this purpose, or
that part of the appropriation given to the Division of
Entomology should be made available for paying an
agent to travel outside of this country. He found it
impossible to secure any action on the part of the Na-
tional Legislature, although his efforts in this direction
were supported by the representatives from California
and by officials of the California Horticultural Society.
The opportunity was finally afforded by the Melbourne
Exposition. Upon request of Prof. Riley, supported
by other friends of the enterprise, Secretary Blaine ar-
ranged that Mr. A. Koebele, an Entomologist in the
employ of the Department of Agriculture, should go to
the Exposition under the auspices of the State Depart-
ment, and was given leave to employ his spare time in
making the desired investigations. During the sum-
mer of 1888 large consignments of parasitic flies, hym-











enoptera, and predaceous insects were sent by Mr. Koe-
bele to Prof. D. W. Coquillett, another agent of the
Department, stationed in California. These were care-
fully colonized upon infested trees under closed tents,
but no striking success was attained until the Austra-
lian lady-bird was received, which at once proved its
valuable qualities. Something like one hundred and
twenty-seven specimens were received and from the
progeny of these bugs alone California was completely
stocked and practically cleared of the scale in about
eighteen months.
The following letter from Mr. A. Chapman, of Cali-
fornia, to the United States Department of Agriculture
gives some idea of the rapidity with which the lady-bird
does its work after it gets a good start: "The Vedalias
that you brought to my place about the 20th of last
March and which we colonized on four large orange
trees that were covered with Fluted Scale have spread
in all directions, although, to begin with they followed
the directions of the wind most readily. From those
four trees they have multiplied so rapidly that in my
orchard of three thousand trees it is seldom that we
can now find a Fluted Scale. I find a few of them on
weeds in spots, but I can also find the beetles there.
The trees have put on a new growth and look alto-
gether different; even the black fungus on the old
leaves has loosened its hold and begins to fall to the
ground. Besides having cleaned my orchard they spread
also to the orchard of my cousin and to my father's
orchard; the latter was re-enforced by colonies from
Mr. J. W. Wolfskill and from Col. J. R. Dobbins. As
my father has some ten thousand trees, and most all
were more or less infested, the Vedalias had a grand
feast ahead of them, and they have done their work










most wonderfully. What I have said of my orchard ap-
plies to my father's also, and really to all our neighbors'.
When the Vedalias first began to multiply we took col-
onies of fifty or more in the pupa state and placed them
in different portions of the orchard, and even had we
not done so the Vedalias, unaided, would have reached
there in almost the same time.
"On the Chapman place the Vedalias have cleaned
the Fluted Scale off of the one hundred and fifty acres
of land. They have taken more than an oppressive
burden off of the orchard grower's hands, and I for
one, very much thank the Division of Entomology for
the Vedalia cardinalis, the insect that has worked a mir-
acle."
Very soon after the lady-bird had done its work
Prof. W. A. Henry, Director of the Wisconsin Agricul-
tural Experiment Station, visited California and writes
thus in regard to his observations upon the result of
this importation of the Vedalias:
"A word in relation to the grand work of the De-
partment in the introduction of this one predaceous
insect. Without doubt it is the best stroke ever made
by the Agricultural Department of Washington. Doubt-
less other efforts have been productive of greater good,
but they were of such character that the people could
not clearly see and appreciate the benefits, so that the
Department did not receive the credit it deserved.
Here is the finest illustration possible of the value of
the Department to give people aid in time of distress.
And the distress was very great indeed. Of all scale
pests the White Scale seems the most difficult to cope
with, and had no remedy been found it would probably
have destroyed the Citrus industry of the State, for its
spreading to every grove would probably be only a








318


matter of time. It was the Department of Agriculture
at Washington which introduced the Washington Na-
vel orange into South California, and the Department
has now given an effective remedy for the worst scale
insect. The people will not soon forget these bene-
ficial acts."

ICERYA PURCHASE IN FLORIDA.

This pest seems to have found its way into Florida
through a curious accident. In 1893 Duncan Bros., a
firm of nurserymen at Keene, Florida, addressed an in-
quiry to a California party regarding the merits of the
lady-bug and as to the possibilities of its proving useful
against some of our common Florida scales. These
nurserymen affirm that they did not request that any
lady-bugs be sent, but merely inquired about them.
However, their correspondent packed up a number of
lady-bugs and also enclosed some of the scales for the
purpose of supplying food to the lady-bugs on their
journey. The Duncans say further that they were not
notified that the scales had been enclosed, and having
no knowledge of the fact that the lady-birds would
feed upon no other material than this scale, were en-
tirely unsuspicious of danger, so after turning the lady-
bugs loose they innocently left the box in which they
were received in the neighborhood of one of their
grape-fruit trees; as a consequence they found this and
some of the adjacent trees infested with the scale a few
months later. This consignment of lady-bugs was not
sent by the California State Board of Horticulture, nor
by any officials connected therewith, according to the
statements of Mr. Craw, chief inspector of the Califor-
nia State Board, but he writes to Mr. J. A. Duncan









319


(not a member of the Duncan nursery firm) that he has
the impression that one of the County Boards of Horti-
culture in that State sent some lady-bugs to Florida
some years ago. However, we have only been able to
learn that the scales were sent by some horticultural
official in California, and are unable to say definitely
with what Board he was connected, though Mr. Craw
gives the name of the Board which is believed to have
sent them. Dr. Howard, writing from memory of the
oral report made by Mr. H. G. Hubbard to. the U. S.
Department of Agriculture, gives the name of an of-
ficial belonging to the same Board mentioned by Mr.
Craw as the responsible party.
Mr. Duncan's house was consumed by fire a few
years since and all the correspondence relating to the
matter was destroyed.
We suppose it is more charitable to say that the
California individual who bequeathed this ungracious
legacy of his official service to the orange growers of
Florida was stupidly thoughtless rather than selfishly
thoughtful, or perhaps that the very success of the lady-
bird in California had so far removed his fears concern-
ing the scale that he believed it a very immaterial cir-
cumstance that it should gain a foothold elsewhere,
since it could be controlled, according to his belief, as
readily as he had seen it done in his own State; but the
best that can be said of the proceeding is that it was
inexcusably careless, giving it the most charitable con-
struction possible; for climate or other conditions some-
times render futile in one country, the measures that
are strikingly successful in another part of the world,
and the expense that attaches to even successful meas-
ures is not an agreeable burden when the outlay might
have been avoided. Nor would it help matters to plead











that the lady-birds were asked for, a supposition the
truth of which is denied by the Duncan firm, because
were it granted to be true, from any moral standpoint
it would still be a criminal abuse of privilege for an
official, or any one else acquainted with the nature of
this pest, to send it anywhere under such circumstances,
even if it were requested and although full warning was
sent with it. It would be more agreeable to confine
oneself to stating facts without comment, and we would
gladly forego writing these words of censure except that
we have seen some and have heard of more people in
Florida to whom the remarks apply equally well. To
be careless regarding the infection of a grove within the
natural area of infestation is bad enough, but no pa-
tience whatever can be exercised with those who deliber-
ately and knowingly take a first-class risk of infecting
districts many miles distant.
When specimens of the scale were sent by the Dun-
can Bros. to the United States Department of Agricul-
ture for identification, Mr. H. G. Hubbard was sent to
Keene to investigate and advise with the owners of the
infested grove. The infested trees were cut down and
burned and all suspicious stock was treated in the same
manner. However, the scale was present in large num-
bers a few months later and Prof. Rolfs, then of the
Florida Station, paid a visit to the locality and repeated
the processes of burning and destruction. All ground
on which the insect was suspected to be present was
covered with straw, chips, and litter, which was then
saturated with kerosene and set on fire. Nothing fur-
ther was heard of the scale in Florida until November,
1898, when Dr. Howard received a letter from Mr. J.
A. Duncan informing him that it was in evidence again
at Clearwater Harbor, about two miles from the place











where it originally appeared. Mr. Hubbard, residing
at Crescent City, Fla., received the same information
through Mr. D. S. Starr. These letters were referred
to the Florida Station and the writer made a visit to the
infested districts during the last week of February, 1899.
We learned that a tramp peddler of nursery stock
had brought some stuff to Clearwater about two years
after the first introduction of the scale in 1893, and had
heeled it in in the grove which was found to be most
badly'infested. This was believed by some to have been
the source of a second introduction, though it seems
uncertain that he brought any material from California.
We are inclined to think from the local surroundings
and such evidence as could be found, that there was but
a single sending. A second introduction, made in such
a way, within two years after the first was thought to
have been exterminated, and within two miles of the
original site, would be a circumstance even more strange
than the original infection.

THE INFESTED AREA AND MEASURES OF SUPPRESSION.

Upon our arrival at Clearwater Mr. J. A. Duncan
courteously conducted us over the infested ground so
far as it was known to him. We found the insect in
small numbers upon rose bushes in about half a dozen
yards in the town of Clearwater. We could find signs
of its presence in but one orange grove at this time,
namely, that of Mrs. Pierce. We found it in greatest
numbers upon an undergrowth of myrtles near the rail-
road track. They were swarming over these bushes in
great numbers and in all stages of development. We
were unable to find any living scales at all upon Citrus,
though the frayed cushiony sacs of dead scales could be











seen here and there. We also found adult specimens
with filled egg sacs upon two or three different species
of Solidago. During this season of the year the myrtle
seemed to be the favorite food plant and in May we also
found them upon it in great numbers, but in very small
numbers later in the season. As this plant is widely
scattered over the whole State, especially over those
areas upon which cattle pasture, it has proved to be an
important factor in the dissemination of the scale. We












4--.


Icerya furchasi; adult females on branch of myrtle,
Myrcia cerifeta; from photograph by the author.

estimated that about twenty acres of land might be
considered infested at this time, though we could find
the insect only here and there within this area. We in-
vestigated all suspicious territory and made examina-
tions of all suspected orange groves for some five miles
out of town, but were unable to find any trace of it ex-
cept within the corporation limits.
When we revisited the place about the 12th of May
we found that Mrs. Pierce's orange grove was alive with











the insect and that the myrtle trees and bushes were so
covered with it that we were able to saw out limbs cov-
ered with great white patches of adult scales for photo-
graphing purposes. Some of the myrtles showed evi-
dence of weakening and a few afterwards died. The
orange grove before mentioned also showed the effects


"V, I i-- t


Orange tree infested with Cottony-Cushion Scale.
Photograph by the author.
of the intense drain upon it, and at this time we doubted
if the trees would survive the season.
Through the influence of Mr. Jno. Thompson and
some of his interested neighbors the Town Council of
Clearwater Harbor appropriated the sum of $50.00 to
be expended under Mr. Thompson's direction for sup-
pressing and exterminating the insect. Mr. Thompson
had cut and burned a large quantity of myrtle bushes be-











fore our arrival. When we again investigated this
cleared area in July we could find but very few scales
where there had been millions of them, and as most of
the town cattle ranged freely over this land, we believe
the dissemination of the scale during the summer was
much reduced by this measure, though of course it


Nearer view of orange trunk covered with Iceryas.
Photograph by the author.

would have been too much to hope that it would not
eventually replenish its numbers over the same ground.
We also found that the scale was known at this time
in groves some five miles from town and had also been
observed upon myrtle bushes from two to three miles
from the section where we first saw it. We judge, there-
fore, that part of this additional area had been infested
the preceding year, but that the numbers of the insect









325


had been so. small that we were unable to find it during
our winter's visit. Some of the groves, however, were
known to have become infested within the five or six
preceding months.
While upon this visit we had a meeting with Mr. M.
E. Gillette, of Tampa, who had seen something of the
scale in California. Mr. Thompson had approached the
Board of Commissioners of Hillsboro county for the
purpose of securing an appropriation for carrying on
the work of suppressing and exterminating the scale
and the Board had appointed Mr. Gillette as their ad-
viser and to confer with the Entomologist regarding the
most advisable steps to take. As a result of our con-
ference Mr. Gillette recommended that the Board ap-
propriate the sum of $500.00, or so much thereof as nec-
essary, to be expended under the direction of the Ento-
mologist upon warrants signed by Mr. Thompson. Mr.
Gillette's recommendation was acted upon favorably by
the Board and the amount appropriated.
We visited Clearwater a third time June 29th and
remained on the field until August 23d. At this time
we found Mrs. Pierce's orange grove very thickly in-
fested, though perhaps not worse than when we saw it
in May, and many other groves had been discovered to
contain the scale in small numbers. Probably 12 or 15
different groves were known to have one or more trees
slightly infested by this date. Some of these groves
were located outside the city limits, and three or four of
them at a distance of six or seven miles.
We found that the scales had practically left the
myrtles by the first of July, very few specimens now be-
ing found upon this plant. The trees, on which great
patches of them had existed two months before, were
almost clean and beginning to put forth a new and vig-












orous growth. We could find but little indication of the
reasons for their departure, but later discoveries enabled
us to surmise that they had been swept off by disease.
During the latter part of the summer of 1899 the scales
steadily decreased in numbers, though the area of in-
festation.was somewhat extended. The numbers began
to replenish about the first of the year 19oo and reached
a maximum about the first of July. By this date every
grove in Clearwater seemed to be infested and the num-
ber of infested outlying groves had been, perhaps, more
than doubled. The pest commenced to succumb at this
date to various enemies, including the Australian lady-
bird, and by the end of the year was practically extermi-
nated. A few insects yet remain, but are accompanied
by the lady-birds.

THE FOOD PLANTS.

The list of food plants of this insect is very long for
the insect is capable of living for a time upon almost
anything in the shape of tree, plant, or shrub, but it
multiplies most rapidly upon a few favorite plants. The
more important plants listed for California are as fol-
lows: Pomegranate, Quince, Apple, Peach, Apricot,
Fig, Walnut, Locust, Willow, Pepper, Grape, Rose, Cas-
tor Bean, Spearmint, Rose-geranium, Purslane, Ambro-
sia, Polygonum, Nettle, Sweet-gum, Verbena, Veronica,
the Acacias, Magnolia, White Oak, Dwarf Flowering
Almond, Pecan, Grape, Potato, Nightshade. Amaran-
tus, Chenopodium, and others. We have seen it upon
many plants, such as Purslane, Coffee Weed, Bermuda
Grass, etc., under the trees, but this sort of infestation
must be regarded as accidental rather than normal and
the insect in such abnormal situations is itself very sus-












c'eptible to the attacks of fungus disease. There are but
iew plants in this list upon which it would thrive to such
:a degree as to become uncontrollable by ordinary meth-
ods if it could gain no access to others. Dr. Riley ex-
pressed the opinion in 1886 that besides the Acacias and
the Citrus family it would probably be unable to thrive
.on many other trees than the Quince and Pomegranate
in California. We can certainly add Myrtle and possibly
Mulberry in Florida. After Citrus, Myrtle, and Mul-
berry, we have observed it in greatest abundance upor
Rose and Solidago. The Pear, the Peach, the Apricot,.
and the Apple are but little affected by this scale. We
have found it difficult to find even a wandering young;
scale upon a Peach tree standing in an orange grove
which was over-run with the insect. The Pine is quite
immune from attack, though it is recorded in New Zea-
land as a food plant, and one or two thickly infested
trees are reported to have been observed in Florida. We
have personally observed the insect upon Pine, but not
in large numbers. We find no record of its having been
observed to feed upon Pineapple, but it is not improb-
able that it would injure this plant, since the mealy-bug,
a not distant relative, sometimes infests it in considera-
ble numbers. The Fig, Quince, and Pomegranate are
said to be among its favorite food plants.

CHARACTERS AND LIFE HISTORY.

The following descriptions have been abbreviated
from the writings of Riley and Howard with a few per-
sonal observations added:
THE EGG.-The egg is quite smooth and elongate-
ovate in form, and is of a deep orange-yellow color. It











is about 0.7 mm. in length. The number of eggs varies
according to the condition of the plant upon which the
female dwells, the season of the year, and perhaps from
other causes also. The greater the number of insects
upon a plant the fewer will be the eggs produced by
the'insect. Mr. Koebele has counted over I,000 eggs
from the sac of a single female, and we have found spe-
cimens containing from 600 to 800. The time required
for the eggs to hatch after leaving the body of the fe-
male varies with the temperature. In the winter season
the sacs are usually large and filled with eggs, while in
the hottest part of the summer the number varies from
one or two dozen to several hundred. Some eggs col-
lected by Mr. Koebele on March 18 did not hatch until
May io, but in midsummer hatching is only a matter of
a few days. A female with the Fluted cushion only par-
tially developed, and, therefore, possessing a sac con-
taining eggs, the last of which must have been newly
laid, Was killed and confined in a glass jar and the young
scales were killed as fast as they hatched, our supposi-
tion being that the last eggs hatched would very nearly
represent the time required in July for incubation after
the eggs left the ovary. The last insects were killed
about o1 days after the mother-scale was placed in the
jar.
THE FEMALE LARVA.-First Stage. The newly
hatched female larva is red in color with a somewhat
yellowish tinge, inclining towards brown. The outline
of the body is ovoid, and is convex above and flat be-
neath. To the unaided eye it looks like a mite or small
spider. The antennae are oblong and six-jointed. The
last joint forms a club which broadens out at its tip.
The joints are sparsely hairy and the club, in addition
to several short hairs, bears near its tip four very long











ones which are longer than the whole antennae. The
legs are thin and brown in color. The eyes are com-
paratively large and are each mounted on a short tu-
bercle. At the tip of the rounded abdomen are six small
tubercles, three each side of the tip, each of which car-
ries a long stout hair which is as long as the whole body.
The body above shows six rows of poies, four along the
middle, and one on each side. More or less regular
rows of hairs alternate with these pores. In a few days
after hatching the exudations from the pores along the
back appear as two distinct rows of yellowish or whitish
wax, the two rows approaching each other and nearly
coalescing before the first moult. The male larva is
seemingly identical with the female at this stage of
growth, since they have never been separated, though
we as well as the agents of the U. S. Department of
Agriculture have carefully studied numbers of larvae
with this purpose in view.
THE FEMALE LARVA.-Second Stage. It is more
rounded and appears less stout than in the first stage.
The antennae have the same number of joints, 6, but
the relative proportions of the corresponding joints are
quite different. As a whole they are relatively much
shorter. The eyes do not appear on the margin of the
body, and are only seen on a ventral view. The legs are
proportionately much shorter. The trochanters are
much shorter and consequently form a broader triangle
in shape. The six tubercles and the end of the tip are
still present, but the hairs which they bear are much
shorter. The secretary pores are no longer arranged in
rows, but are scattered sparsely over the back and under
the sides. The back is more hairy and the short black
hairs occur in irregular tufts. The waxy secretion on
the back is more abundant, but is no longer in lines,


























EXPLANATION TO PLATE.

THE COTTONY CUSHION-SCALE.

Fig. I.-Outline of the egg-greatly enlarged.
Fig. 2.-Dorsal view of newly-hatched larva-greatly enlarged.
Fig- 3.-A female larva, second stage, ventral view-greatly en-
larged; b, antenna of same-still more enlarged.
Fig. 4.-Female larva, third stage, ventral view-greatly enlarged.
Fig. 5.-Adult female, fourth stage, dorsal view-greatly enlarged;
a, antenna-still more enlarged.
Fig. 6--Greatly magnified portion of lateral border of adult,
showing base of glassy filaments.
Fig. 7.-Male larva, second stage, ventral view-greatly enlarged.
Fig. 8.-Male pupa, ventral view, greatly enlarged.















Fig. 7.


Fig 2.

/' L c
Fig. 1


F'ig. 3.











Fig. 4.






Fig. 6. Fig. 5.
Jceiya purchase, (Riley, Division of Entomology, U. S. Dept. of Agr.,
Ann. Report, 1886.)











conforming instead to the change in the distribution of
the pores.

THE FEMALE LARVA.-Third Stage. The body is
broadly oval in shape, reddish brown in color, but is ob-
scured more or less by the thick, curly, cottony excre-
tion. The antennae are now 9-jointed instead of 6 and
are sub-cylindrical, narrowing somewhat from base to
tip. The insect as a whole is much more hairy than in
either of the previous stages. The hairs are short and
black and grow together in tufts. They are thickly
scattered over the thorax, but less so over the abdomen,
and may be seen in tufts above the edge of the body.
The secretary pores are irregularly scattered all over the
back and are more numerous than in the previous
stages. They also occur on the lower edges of the body.
Around the edge of the body is a row of larger pores,
brown in color, each with a circular crown or lip at the
tip, from which proceeds a long, fragile, glassy tube.
The legs and feet are a little stouter than before. The
six anal hairs are still present though hardly noticeable
as they protrude from the mass of shorter hairs.

THE ADULT FEMALE.-Fourth Stage. Immediately
after the moult by which the insect passes into this stage
it is free from the waxy execretion and presents a broad-
ly oval form with two prominent raised surfaces on the
second and third thoracic segments. Its color is still
reddish brown, with several dark spots along the front
sides, and along the sides of the posterior part of the
body, while the antennae and legs are black. Just after
the insect in any stage has withdrawn from its old shell
in moulting the legs are perhaps the most transparent
and whitish parts of the body; but they begin to darken
in about a half hour and within two hours are black in








333


this stage, and as dark as they become in the preceding
stages. The antennae are II-jointed, the club being one
and one-half times as long as joint number o1. The
whole body is furnished with tufts of short black hairs
which are gathered into a parallel row around the edge
of the body. The secretary pores are very numerous,
occurring in enormous numbers beneath the sides of the
body and scattered more sparsely over the back. The in-
ner row of tufts on the back is broken at its anal point by
a depression, in which is situated ,a very large pore from
which the insect occasionally ejects a globule of semi-
liquid honey-dew. This depression is surrounded by an
irregular ring of hairs, which are yellowish in color in-
stead of black. The glassy filaments described in the
last stage are now very long and radiate from the body
in almost every direction. They break off very easily,
yet they often reach a length double that of the insect
and her egg-sac together.

THE EGG SAC.-Just as the body of the fe-
male begins to swell from the eggs forming
inside, the beginning ,of the egg sac is made.
The insect lies flat on the bark. The edges.
of the body turn slightly upward, and the waxy mate-
rial of which the sac is composed begins to issue from
numberless pores on the under side of the body, but
more especially along the sides below. As the secretion
advances the body is raised, the head end still being
attached, until the insect is apparently standing on its
head, nearly at right angles to the surface to which it is
attached. The egg-laying commences as soon as the
thin layer of secretion has begun on the inner side of the
abdomen and it continues during the formation of the
sac. Around the edge of the abdomen there soon ap-










pears a narrow ring of white felt-like wax, which is di-
vided into a number of flutings. These flutings grow in
length and a mass of eggs and wax under them increases,
forcing the female upwards until the sac is completed.
When complete it is from two to two and one-half times
the length of the female's body. It is of a snow-white
color. The outside is covered with fifteen of these longi-
tudinal ridgings or flutings of about equal size, except
that the middle one is smaller than the others. The
upper part of the sac is firm in texture, but the lower is
looser and thinner and from the inner side the young
make their escape after hatching. The size of the sac
and length of time required for its growth depend, leav-
ing the weather and the health of the food plant out ot
consideration, upon the number of eggs which the fe-
male deposits. The excretion of the egg-sac continues
as long as oviposition lasts.
It probably requires from 60 to 90 days to complete
the egg-sac from the time of its beginning. The length
of time depends largely upon the health of the tree on
which the insect is located and also upon the number of
insects infesting it. Development is much more rapid
upon vigorous than upon sickly trees.
THE MALE LARVA.-Second Stage. This stage of
the male larva differs from the corresponding stage of
the female in its more slender form, longer and stouter
legs, and -longer and stouter antennae. The legs and
antennae are not only relatively longer and stouter, but
are absolutely so. The body is more hairy than that of
the corresponding female stage. The antennae are six-
jointed and the joints have the same relative propor-
tions as in the female. The secretary pores are not quite
so numerous as in the female.
THE MALE LARVA.-Third Stage. In this last larval







335


stage the male is readily recognized from any other
stage with the naked eye. Its body is narrower, more
elongate, more flattened, and the insect is more active
than the female. The general color is also more dull
than that of the female. The body is almost naked, be-
ing very sparsely covered with short, white, cottony
matter, and is destitute of the short black hairs seen on
the female during the third and fourth stages. The
antennae are 9-jointed. The average length when full
grown is about 3 mm. and width about I mm.
THE MALE PUPA AND CocooN.-When the male
larva is grown and is ready to transform, it seeks a place
of concealment, finally secreting itself under a bit of
projecting bark, under leaves in the crotch of a tree, or
under some mass of females. It often descends to the
ground and hides under clods of earth, beneath fallen
leaves, or under boards, and in cracks in the ground.
When its movements are interfered with by prolonged
and violent rain, it pupates wherever it may happen to
be upon the trunk or branches of the tree. It exudes a
delicate, flossy substance to form the cocoon. This ma-
terial is waxy in character, but lighter, more flossy, and
less adhesive than that of which the egg-sac of the fe-
male is composed. When the cocoon has reached the
proper length the larva casts its skin which remains in
the posterior end of the cavity, and pushes itself forward
into the middle of the cocoon. The pupa is of the same
general color as the larva and also of the same general
form and size. The pupa stage apparently lasts about
three weeks.
THE ADULT MALE.-The adult male is a winged in-
sect with dark red body, grayish wings, and of very
slender, fragile structure. The antennae are dark col-
ored and have two whorls of light hairs extending from












each joint, except joint I.
the wings lie flat upon the
situations where the male


When the insect is at rest
back. It is readily found in
larvae have pupated, under


Irerya furchasi (Riley, Div. of Ent., U. S. Dept. of Agr., Ann. Report, 1886.) a,
adult male-enlarged; b, hind tarsus of same; c, wing and poiser of same, showing
hooks and pocket-still more enlarged.

boards, beneath cracks, and in the general litter of the
grove.
THE NUMBER OF BROODS.

There are supposed to be about three generations
per year in California, and the length of life of any par-
ticular individual, commencing with the egg, probably
extends anywhere from three or four to six months.
Mr. Koebele observed some individuals hatched from
eggs on the 4th of March that cast their last moult on
the 23d of May. This would make about 94 days, allow-
ing io days for the eggs to hatch; this added to an esti-
mate of 60 to 90 days for the formation and completion











of the egg-sac would give a life time of about six
months; but under some circumstances we are confi-
dent that they mature in much shorter time, possibly in
4 months.
HABITS.
The larvae, in the first and second stages, settle upon
the leaves and twigs, generally arranging themselves in
rows beside the mid-ribs and along the veins of the
leaves. In the third stage they prefer to settle upon the
smaller twigs, though some remain upon the leaves and
a few travel to the larger branches and trunk. The
adults always prefer the trunk and larger branches,
though they sometimes develop upon the leaves. They
are very rarely found upon the fruit. In any stage the
scale is quite active, and during all the larval stages or
throughout the greater part of its life it travels freely,
but can move in a very limited way after reaching the
adult stage. The tendency of the insects is to crawl
upwards, and when they are washed from the trees in
large numbers by rain, or are shaken off by the wind,
they will collect in great numbers upon the top of bar-
rels, posts, or any standing object beneath the trees,
and some of them at least will starve to death rather
than descend. Both sexes, in their larval stages, are
most active during the hotter parts of the day, and re-
main stationary at night, but the winged male is rather
sluggish during the day, becoming active during the
latter part of the afternoon just before dusk, at which
time copulation occurs.
One of the most characteristic accompaniments of
the scale is the black or smutty appearance of the leaves
and trunks of the trees which they infest. This appear-
ance is due to the growth of a black mold, Meliola, in the












honey-dew which is excreted by the females in large
quantities. Plant-lice and other Coccide also excrete
honey-dew in large quantities, so the appearance is a
very common one where any of these insects occur.
Sometimes the excretion is so plentiful that it falls in
drops, reminding one of a sprinkle of rain, and again,
especially in the early morning, the drops are sometimes
suspended by slender glassy threads of syrup, remind-
ing one of glass bulbs blown on the end of fine capillary
stems.

METHODS OF DISSEMINATION.

The modes of spread are various and depend upon a
number of different agencies. The insects, when very
numerous, cling with a light hold to the branches of the
trees so that many of them probably let go, and they are
so light of body that they may be carried a considerable
distance by the wind. The wind is also apt to carry
them upon the webs of gossamer spiders which are often
present upon the same trees with the Icerya. They are
also transported upon the feet of birds, lady-birds, the
feet of predaceous or honey-loving insects, in the hair of
animals, and upon the clothes of men. Perhaps the most
important mode of dissemination is by the shipment of
nursery stock. Mr. Koebele gives the following inter-
esting observation regarding the agency of the wind:
"In the infested part of Los Angeles is a large vineyard,
on both the north and south sides of it is an orange
orchard ififested by these insects, but while the recently
hatched insects occur on vines as far out as the loth row
of grape-vines, on the south side of the vineyard, they
are not found upon the vines beyond the third row on
the north side, the wind as stated above blowing from











the southwest. No adult females are to be found on
any part of this vineyard, and the young insects must
have been carried by the wind from the infested orange
trees on either side of the vineyard.
Although other agencies may perhaps have had as
much or more to do with the distribution of the Icerya
in Hillsboro county, the general effect of the wind may
be observed from the fact that the insect is scattered
more generally to the eastward than in any other direc-
tion, except in a few cases to the northward and south-
ward, where domestic animals are known to have been
the source of infection. Mr. Hollis believes that his
grove, situated about one mile from the centre of the
infection, became infested through the agency of birds.
He observed that the worst infested tree contained a
nest, and that the branches near the nest were infested
worse than any other part of the tree. Mr. W. McMul-
len, living in the neighborhood of Largo, about six miles
south of Clearwater, purchased some cattle about Christ-
mas time, 1898, that had been wandering over the in-
fested prairie near Clearwater Harbor and turned them
into his grove, wishing to fertilize the land in this way.
This prairie was not known to be infested at the time of
the purchase. In April following he found a few of his
trees infested by the scale in small numbers.
Another grove is believed to have become infested
through the agency of a couple of vagabond dogs that
were in the habit of wandering among the bushes and
myrtles about Clearwater, and which came to the grove
and amused themselves by digging out a Florida "sal-
amander." Sometime afterwards some trees near the
place where the dogs had been digging were observed
to be infested.
It must be remembered that the myrtle, Myrica cerif-











era, is one of the favorite food-plants of the Icerya and
that it is widely scattered over the entire State, espe-
cially over those areas upon which cattle pasture and,
therefore, must be a most important factor in scattering
'the insect in Florida.

NATURAL ENEMIES.

We have already noticed that the Icerya is kept ir
effectual check in Australia by Novius cardinalis and
other enemies. This lady-bird, as we have seen, became
famous for the work that it did in California. It has
been equally successful in every land into which it has
been introduced. Mr. R. Allan Wight, of Auckland and
New Zealand, gives the following account of its work
in the columns of the Garden and Field, published at
Adelaide, South Australia: "It may interest some of
your readers to hear news of your native lady-bird, Ve-
dalia cardinalis, which has done such good service of late
years, both in New Zealand and California, against
Icerya purchase. It will be remembered that the beetle,
although native to Australia, has never been any other
than an inconspicuous and rare insect in its own country,
and that it was in New Zealand that it first shone out
in all the glory of a conqueror of one of the greatest of
known pests. Some two years ago everything seemed
white around Auckland with the clustering Icerya, a
great many orange and lemon trees (including one en-
tire lemon orchard) were dead, and the prospect was as
gloomy as could be, till Vedalia (which had been acci-
dentally imported from Australia) appeared on the
scene. Astonishing as it may seem to be, and incredi-
ble, within one year hardly any of the scales were left,
and the lady-birds had also disappeared. The little











beetles are rank cannibals when pressed by hunger, and
as no one was able to discover any other food but Icerya
upon which they will feed, it was feared that, in the
absence of Icerya, they would become extinct. There-
fore considerable uneasiness was felt when, some time
ago, the scale again began to increase rapidly, and
spread everywhere, and, as yet, no Vedalia were to be
seen.
"On the 8th of April last I arrived in Auckland to
see whether it would not be possible to procure a few,
when I found that in the meantime they had again ap-
peared and cleared off the accumulated Icerya with an
incredible celerity, and then vanished for a second time.
Even in a distance of 30 miles from the city, where only
at the end of last December I had seen many thousands
of Icerya females, with full ovisacs and larvae without
number, only nine ovisacs of eggs and about 50 scales
could be obtained wherewith to feed any Vedalia that
might be procured on .a voyage. On all the Acacia
hedges around Auckland in every direction for miles
and miles where formerly buckets full of ovisacs could
have been gathered in a few chains there was not a scrap
of even a torn one to be seen, and in all the nurseries,
whose owners had formerly been in despair, not one sin-
gle specimen of either insect was to be procured. Only
after many days of fruitless search an Acacia hedge was
come upon where 79 Vedalia were procured and sent to
Nelson, an intended shipment to the Cape of Good Hope
having been abandoned. From observation, which it is
needless to particularize, the following conclusions were
arrived at: (i) The Vedalia has unquestionably some
other food resources besides Icerya and its cannibal prac-
tices, although it could not be determined at the time;
(2) that in its first attack upon Icerya it runs over the








342


enemy and leaves a few eggs (two or three) in some 5 or
6 per cent. of the ovisacs, and it is these and the few
larvae which escape that found the second Icerya inva-
sion; (3) that the beetles keep on the hedges all through
the winter months, although so hidden as not to be easily
captured, without a net; (4) that the Vedalia larvae soon
perish for want of food, but in the imago state they will
live for a very long time, probably nearly throughout
their natural life, feeding upon their own eggs, which
they devour as soon as laid; (5) that this exhausting
system of warfare will very soon cause both insects to
become exceedingly rare, but that Icerya will always
have a great advantage in its food being abundant and
always at hand, whereas that of Vedalia is at best un-
certain and doubtful."
From the Report for the year 1896, by Mr. C. P.
Lounsbury, Government Entomologist of the Cape of
Good Hope, we quote as follows: "The insect (Icerya)
was reported in South Africa by Roland Trimen in 1877;
it has been known by him since 1873, and was first ob-
served in the Botanical Gardens at Cape Town. Grad-
ually it extended its range through all parts of the col-
ony and neighboring states, everywhere proving de-
structive, especially to all kinds of Citrus trees. As in
other countries, all sorts of remedial measures were
adopted, but none proved of much value. The cultiva-
tion of Citrus fruits and some of the other favorite food
plants of the insect was rapidly becoming impossible in
the country, when natural checks appeared and stayed
the invasion in a manner unparalleled in the annals of
Entomology. These natural checks, which are preda-
ceous lady-birds, are now prevalent in every locality fre-
quented by the scale and suffice to keep it reduced to
small numbers. There still remain many isolated farms








343


in different parts of the colony not yet reached by the
scale, and, consequently, neither by the enemies of the
scale. These places have most to fear from an out-
break."
h e predaceous lady-birds referred to by Mr. Louns-
bury are the Vedalia, which were obtained and intro-
duce from California, and another lady-bird known as
R.. .'.. ,, iceryae, probably a native of South Africa, and
whici also seems to have quite a liking for the scale.
We further quote from Mr. Lounsbury's Report: "Upon
isola ed farms, and perhaps even in small towns where
their is little for the scale to infest, it may occasionally
happen that both the scale and its lady-bird enemy be-
come extinct, the former from the attack of the latter,
which in turn dies for want of food. In such a case the
scale may spread and cause much damage if again in-
trod ced, but, fortunately, the lady-bird seldom extermi-
nates the scale, simply keeping it reduced to uninjurious
num ers. These numbers, of course, are subject .o con-
sider ble variation. Sometimes a plant or two become
consi erably infested before the lady-bird puts in its ap-
pearance, but given a little time it will almost invariably
come Therefore, the appearance of the scale on a few
plant is no cause for anxiety, except on isolated farms,
or in small towns where it has hitherto never been
known, or has been entirely absent for a long period.
The Vedalia is not known to attack any other scale in-
sect than the Australian bug in South Africa; and it is
undoubtedly this lady-bird, not the Rodolia, that now
holds the scale in check in most parts of the colony.
"When the Australian bug anywhere in this colony
increases to an alarming degree a few specimens of
either Vedalia or Rodolia should be procured and liber-
ated on one of the infested trees. The procurement of











the lady-birds may be attended with some difficulty. As
has been explained they are constantly present about
the large towns, but so well do they keep their prey in
subjection, that they are never long to be found at any
one place, and several hours or even days may be spent
in searching for them before the requisite number is ob-
tained."
THE LADY-BUG IN FLORIDA.
One lot of lady-bug larvae was sent us by Mr. Craw,
of the California State Board of Horticulture, in Feb-




'iI. r d1






A ovius card inM-i (Riley and Howard, Div. of Ent., U. S. Dept. of Agr. Insect
Life, August, 1891.) a. Larva, dorsal view; b. larva, from side; c. pupa; d. adult-
enlarged.
ruary, 1899, but were delayed on the road by snow-
storms, reaching Lake City on the date of our last big
freeze, February I3th. They were all dead upon ar-
rival. Other consignments of both adults and larvae were
sent directly to Clearwater in May and June. Adults
were invariably dead upon arrival, and their eggs in the
shipping-cases were too dry to hatch. Larvae and pu-
pae came through in good condition and from them
somewhere between two dozen and thirty adult bugs
were hatched, kept under close observation until they
were observed to have copulated, after which they were
confined for a short time in a large sack upon thickly








345


infested limbs, so as to insure the deposition of their
eggs before they flew to other trees. As we were not
expecting a sudden onslaught from a fungus disease,
we naturally put our lady-bugs upon the worst infested
trees to be found in the worst infested grove. It was
but two or three weeks from the time the lady-bugs were
liberated until a fungus struck the scales, and we sup-
pose that the lady-bug larvae must have perished from
want of scales to feed upon, unless they, like the scales,
withered before Florida rain and heat. We hoped that
some of the bugs had gone to other trees than the ones
upon which they were turned loose, since they were con-
fined in the sack not more than 12 or 15 hours, or over
night, and that many lady-bugs would appear in the
grove later, but nothing was ever known to develop.
The trees upon which the bugs were liberated were al-
most wholly free from scales in April, but later support-
ed them in numbers. We attribute the temporary dis-
appearance of the scales, however, to fungus disease and
native predaceous insects, and not to a probability that
any lady-bugs had anything to do with it. We instruct-
ed our correspondents to keep a careful watch on the
field and report to us later in the season if circumstances
seemed to favor a new introduction.
In December letters from two Clearwater corre-
spondents indicated that the scales were sufficiently nu-
merous in some groves to warrant the belief that the in-
troduction of the lady-bug would prove successful. We
therefore wrote to the California Board on the 2d of
January, informing them of the situation and our desires,
but learned that their colonies were low and they could
not supply us with bugs until the latter part of May.
However, Mr. Kimball, a gentleman stopping in Clear-
water, succeeded, through the request of the Fruit











World, in getting a consignment from one of the Coun-
ty Boards of Horticulture, at San Diego, California,
about the middle of April, and the bugs were turned
loose upon an infested tree in accordance with instruc-
tions received along with the insects. While no obvious
explanation for their failure to propagate can be given,
no subsequent trace of them could ever be found. It is
possible that they were not wasted, but that their prog-
eny became mixed with that of later importations of
bugs, colonized at no great distance from them, though
we have no evidence to suggest such a probability.
Three colonies of insects were sent to Clearwater by
Mr. Craw, under date of May 28: one of them was sent
to Mr. Thompson, at our request, the two others being
sent tb Mr. H. C. Markley by request of his brother, a
resident of California. We instructed Mr. Thomson to
have an infested tree tented with cheese cloth for the
reception of the insects upon their arrival, as previous
experience in putting bugs upon open trees had failed to
give satisfactory results. Mr. Markley, after conference
with Mr. Thomson, adopted the same plan, using can-
vas instead of cheese cloth. One of his colonies was
placed upon a tree standing in his yard in Clearwater,
and the other by Mr. Thomson's advice was sent to the
grove of Mr. Wm. McMullen, about seven miles from
town. The rainy season setting in at about this time,
and fearing another onslaught of fungus, we wrote Mr.
Thomson about ten days after he received the lady-bugs
to remove the tent and give them the freedom of the
grove. This suggestion was at once put into practice
by Mr. J. H. Brown, who had been placed in immediate
charge of the insects, and who advised Mr. Markley to
pursue a similar course. The heavy covering upon the
colony at Mr. McMullen's grove was not removed so











soon, and, as a consequence, the insects did not do nearly
so well. We made an examination about one month
after the insects were loosed and found larvae well scat-
tered over perhaps twenty different trees, adjacent to
the one upon which they were liberated, and, while they
were not so widely scattered at Mr. Markley's place, they
were much more readily found in numbers.
Since some caution must be exercised in choosing.
trees upon which to plant colonies, if embarrassment
from fungus was to be wholly avoided, we spent a day
with Mr. Brown in going over the infested territory and
arranged to have him take charge of the work of dis-
tributing bugs over all the infested district as soon as
sufficient material could be procured.
During August and September the bugs got under
such headway that to use the language of Mr. Brown,
"It was as if a fire had gone through the scales," the
whole country being practically cleaned up by October
I. An inspection made about the last of January, 1901,
discovered only a few scales in a single grove in Clear-
water. Mr. Brown reported that both scales and lady-
bugs were present in a grove about six miles from town,
but he knew of their being present nowhere else. Let-
ters dated since April I report that lady-bug larvae are
present in both groves referred to, from which it seems
that the South African experience is to be repeated in
Florida, and that we can depend upon the lady-bug re-
maining with us as a fixture. We doubt if it would be
practicable to maintain an artificial propagating estab-
lishment for lady-bugs with our present resources and
conditions. The area of infestation appears to us to have
become sufficiently large to warrant the belief that the
lady-bug will remain permanently upon the field despite
the slender food supply available in autumn, and that








348


the chances for its permanent retention have been great-
ly increased by the failure to get it successfully estab-
lished in 1899. Some means should be provided by
Hillsboro county or by the State, by which a record can
be kept of where it shall have been last seen, and col-
onies can, therefore, be secured for infested spots from
which it is absent. Under ordinary circumstances much
less than $Ioo per annum will be sufficient for this pur-
pose. Localities, likely to become infested; are apt to
be at some distance from Clearwater rather than in its
vicinity.
LIFE-HISTORY AND HABITS OF THE LADY-BIRD.-
Each female lays from 150 to upwards of 200 orange-
:ed eggs, depositing from one to three or more beneath
the Icerya or on the side of the cottony egg-nests. The
eggs hatch in less than a week, usually in 5 or 6 days,
when the young larvae burrow into the egg-masses from
below and consume the eggs; later they attack all stages
of the Icerya, the adults agreeing with the larvae in habit.
The larva completes its growth in about 3 weeks, when
it attaches itself, head downward, to bark or leaf, and
pupates. In two or three days the skin splits open along
the back exposing the pupa to view. The pupa stage
lasts about a week when the adult beetle emerges with
general reddish color and black markings. Two black
crescents with convex sides turned toward each other
are conspicuous on each wing cover. Egg-laying begins
in a day or two after the adults emerge. The insects are
known to feed only upon the Icerya and their own kind.
The females often devour their own eggs and the strong-
er larvae the weaker ones when food is scarce. The
adults live for several weeks.
NATIVE ENEMIES OF THE SCALE.-At the beginning
of our investigations, July, 1899, we were able to find











some trees thickly infested with scales, which were be-
ing rapidly consumed by a small caterpillar which we
were soon able to identify as Loetilia coccidivora, an in-
sect hitherto recorded as feeding upon the Lecanium
scales, Pulvinaria, mealy bug, the wax scales, the cochi-
neal insect, and at times upon the armored scales. Mr.
H. G. Hubbard, in speaking of this insect; writes as fol-
lows:
"Underneath the covering of web the caterpillars of
Dakruma (Loetilia) move back and forth actively en-
gaged in removing the bark-lice from the bark and sus-
pending them in the investing web. Nothing could be
more thorough than their work. Branches incrusted
with Lecanium scales are very quickly cleared of the lice,
and the Dakruma larvae do not cease to extend their
operations until every individual coccid in the colony
has been lifted from its place and securely fastened in
the web above.
"While constructing their galleries the caterpillars
stop occasionally to feed upon the coccids. At such
times they seldom finish their repast, but, like busy
workmen as they are, hastily snatch a bite or two by way
of lunch, and suspend the half-devoured fragments in
their web. When the entire scale colony has been se-
cured within its net the Dakruma larva rests from its
labors and feeds at leisure upon the coccids suspended
in the larder. It devours not only the eggs and the
young and the softer parts of the bark lice, but even to
some extent the harder skin or scale. The result of its
operations upon Lecanium and Ceroplastes scales is to
utterly annihilate the colonies of these insects which
they attack."
What Mr. Hubbard observes of this insect in connec-
tion with the Lecaniums and Ceroplastes we also affirm











of it in regard to the Cottony Cushion Scale. We were
curious for a long time to learn if the Loetilia would be
able to catch up with the scale in the course of a season,
since the young scales fasten upon the leaves of the trees
and only upon reaching maturity go to the trunk and
limbs where the caterpillars make their webs. We,
therefore, had these trees upon which the caterpillars
were in greatest numbers carefully inspected at inter-
vals, and under date of September 22 our correspond-
ent, Mr. Duncan, wrote that these trees, which had at-
tracted our special interest, were "pretty well rid of the
old bugs, but there were a good many young ones on
the leaves."
An inspection of these trees made by the writer,
April, 1900, disclosed a scale here and there, but they
were practically free. The trees were not greatly in-
jured, and although white with Icerya last summer, they
appeared at this date to have suffered more and to be
in greater danger of injury from the long scale, Mytilas-
pis gloverii, than from Icerya purchase. Observations
upon the same trees in July, 1900, showed considerable
Icerya upon them, and the caterpillars just beginning to
put in their appearance. One of the trees became in-
fested just badly enough to attract notice in 1899, but
it seemed impossible for any of the scales upon it to
reach maturity before they were attacked, and only a
few larvae could then be found upon the leaves. At the
time of the last examination referred to, this tree was
thickly infested, while its near neighbor, which was coat-
ed with the pest the preceding summer, was in much
better shape and not suffering a great deal, though still
threatened. In 1899, we found the same caterpillar scat-
tered everywhere over the infested district and multiply-
ing rapidly. Among the myrtles and even in places











where would be found an isolated infested tree, half a
mile or more away from others, we found this little cat-
erpillar at work, and often in numbers. We do not recall
an instance of finding an infested locality, whether con-
taining one or many trees, where, by diligent search, we
did not find the Loetilia also. In the forks of the trees
just now discussed, where the scales had gathered in
great white patches, covering in total several square feet
in area upon a single tree, it was almost impossible to
find an adult that had not been eaten out and the egg-
mass completely destroyed. The caterpillar seemed to
be not present with the first brood of scales, which ap-
parently hatched in January or February, nor with the
second brood, which in very general terms may be said
to appear about the first of May, but the moths must
issue some time during June, for the caterpillars are to
be found during the first week in July and are abundant
by August. We, therefore, consider it probable that
these insects feed only upon the third and subsequent
straggling broods of scales that appear in the fall. The
broods of Icerya so overlap each other and appear so
irregularly that their separation is not very readily
made.
We found a number of other predaceous insects, har.
vest mites, forficulas, lace Wings, etc., feeding upon this
scale, some of them possessing a considerable degree of
efficiency. The work of none of these insects can be
considered equal to that of the Australian lady-bug, for
the reason that their modes of attack are different, and
the caterpillars, which alone agree in habit with the lady-
bugs in eating the nests, will not go out upon the leaves
hunting for their dinners. However, it must be said in
their favor that they are natives of Florida. that they
feed upon other insects than the Cottony Cushion Scale,
and that they will never be absent, nor become lost, nor-











need artificial propagation in order to secure their per-
petuity.
FUNGOUS DISEASE.-During the season of 1899 a
fungous disease which, as yet, had received no biological
study, but determined by Mr. Ernest Bessey to belong
in the family Phymatasporae, destroyed more scales than
any other agency. The first diseased specimens were
found on the 12th of July upon certain badly infested
orange trees, and a few days later we noticed that the
weeds and undergrowth of this, the worst infested grove
in Florida, especially in damp situations, were covered
with the remains of slaughtered scales. We, therefore,
impatiently awaited a shower of rain, and from the 23d
to the 26th of July were favored with a continuous
downpour, accompanied with heat, as much as 14 or
16 inches of water, at the very least, coming down in
72 hours. We examined the trees upon which the fun-
gous was discovered, at the conclusion of the storm,
while it was still raining, and found them enveloped in
a white winding sheet of dead scales from the trunks
to the tips of the leaves. We estimated that not less
than ninety-five per cent. of the scales in all stages had
perished. About a month later we estimated that
not more than one scale in a thousand was living upon
what had been the worst infested trees in the grove,
and the few living ones that could be found were new-
ly hatched larvae, a few of the eggs in the egg-sacs ap-
parently not having been completely destroyed by
the fungus. During the month following the heavy
rain mentioned we had but one or two light showers,
so the condit-ins for the rapid growth and spread
of the fungus were not so favorable as they might
have been. Notwithstanding the drought at the time
of our departure from Clearwater on the 23d of Au-
gust there was hardly an infested tree upon which











the fungus was not established, and trees that gave no
evidence of it two weeks before now had many diseased
specimens. It seems certain that the air was at this
time full of the floating spores of the disease, and that
in our naturally moist atmosphere, with the help of the
dews, the disease is enabled to gradually progress, even
when comparatively dry. After the disease is established
upon a few specimens located in different quarters of a
tree a driving rain will drench the remainder with spores,
and in a short time afterwards the tree is largely cleared
of the scale. The egg-sac, when wholly or partially
formed, furnishes sufficient protection to the eggs and
newly hatched insects beneath to render improbable the
complete annihilation of the bugs for several weeks, but
trees inhabited by scales in the various larval stages are
practically freed of them in a few days.
Mr. Duncan, writing under date of September 22,
reported that the bugs in the grove before mentioned
were decreasing; that the fungus was affecting them
very badly; he could scarcely find one that was not af-
fected, and that while some trees in the grove still har-
bored young scales, the fungus was to be found upon all.
He further reported that about 95 per cent. of the insects
in some other groves that were just beginning to show
the presence of the fungus at the time of our departure
were dead, and the owners stated that where ten scales
existed three weeks earlier not more than one could be
found at the date of writing. The fungus was found
present in a number of groves in the latter part of April,
1900, and by the I5th of July following the scales in the
myrtle thickets were nearly all dead through its agency,
and from 25 to 75 per cent. of those in infested groves
were dead. with the disease rapidly spreading and daily
increasing in virility. That this disease and the native











insects mentioned, possess capabilities of immense value
for subduing the insect during some, and perhaps we
may say all seasons, we do not doubt, but it should still
be remembered that without the lady-bug present the
scale multiplies vigorously during certain periods of the
year and that it is capable of inflicting great damage
during this time. The third brood of scales is well on
the way to maturity before any of those native destroy-
ing agencies appear.
SPRAYS AND WASHES.
The experience of several growers at Clearwater has
shown that the scale may be almost exterminated by the
free and persistent use of resin-wash or kerosene appli-
cations. When the Novius is slow about putting in its
appearance two or three applications about a month
apart will do much to reduce injury. Not more than
three treatments per season should be given if it can be
avoided, and more than one or at most two per year are
apt to weaken the trees if continued through a series of
years. The standard kerosene emulsion may be used, or
15 per cent. of kerosene in mechanical mixture with
water may be applied with a Gould or Deming pump.
Such applications should not be given during the bloom-
ing period, nor until the fruit is a quarter grown, unless
the destruction of the scales is a greater consideration
than the saving of the crop.

FUMIGATION.

Fumigation of infested trees with hydrocyanic acid
gas is the most efficient of artificial remedies, and is ac-
complished with little danger to the tree. It is but little
used on account of its comparative cost. It destroys
lady-bugs as well as scales.











ACKNOWLEDGEMENTS.

In conducting this investigation we are indebted to
Dr. W. F. Yocum, Director of the Experiment Station,
for a generous allotment of time in which to do the
work, and all other favors possible; to the Hillsboro
Board of County Commissioners for financial aid; to
Mr. Alexander Craw, of the California State Board of
Horticulture, and Dr. L. O. Howard, of the United
States Department of Agriculture; to the Plant System
of Railways for transportation; to Messrs. John 'Ihom-
son, M. E. Gillett, H. C. Markley, and many others for
co-operation and favors of various kinds; and to Messrs.
J. A. Duncan and J. H. Brown, who have acted as local
inspectors in the employ of the County Board, and have
kept us accurately informed as to the history of the scale
and its enemies. The reports and investigations of the
last two gentlemen have furnished the basis for some
very important conclusions set forth in this bulletin, and
visits to'the field have always confirmed the correctness
of their observations.

SUMMARY OF IMPORTANT CONCLUSIONS.

I. Icerya purchase is in Florida to stay. It is not
known to exist elsewhere than within a radius of seven
or eight miles of Clearwater.
2. If uncontrolled, it would imperil and perhaps de-
stroy the Citrus industry of the State in a very few
years.
3. It is scattered by wind, birds, animals, men and
nursery stock.
4. Its most successful enemy is the Australian lady-
bug, Novius cardinalis.











5. Novius is established in Florida and will in all like-
lihood remain with us permanently.
6. The scale is in perfect control at the present time.
7. Dangerous outbreaks of the scale are apt to occur
outside of the infested district rather than in it.
8. The scale will at times become somewhat threat-
ening, but will be found by the lady-bug if only a few
months' time be given.
9. A local inspector in the infested district can be
profitably employed by County or State to keep himself
informed as to the development of both scale and lady-
bug and to collect and distribute the latter when neces-
sary.
io. Native enemies and diseases of the scale are great
helps in suppressing it, but cannot be relied upon alone.
They confine their work mostly to the third brood of
scales.
II. While waiting temporarily for lady-bugs an ap-
plication of resin-wash, kerosene emulsion, or mechani-
cal mixture of kerosene and water is useful.




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