Title: Florida Entomologist
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Title: Florida Entomologist
Physical Description: Serial
Creator: Florida Entomological Society
Publisher: Florida Entomological Society
Place of Publication: Winter Haven, Fla.
Publication Date: 1932
Copyright Date: 1917
 Subjects
Subject: Florida Entomological Society
Entomology -- Periodicals
Insects -- Florida
Insects -- Florida -- Periodicals
Insects -- Periodicals
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Volume ID: VID00292
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Florida Entomologist
Official Organ of the Florida Entomological Society

VOL. XVI NOVEMBER, 1932 No. 3

NOTES ON THE BIOLOGY OF
LAPHYGMA EXIGUA HUEBNER*
J. W. WILSON
Several species of Noctuidae occur in the ferneries of Florida
and are responsible for more or less injury. Laphygma exigua
is the most abundant species north of Auburndale. This insect
is commonly known in the western states as the sugar-beet
army worm, which is the common name recognized by the Ameri-
can Association of Economic Entomologist. In Florida this
army worm does not usually betray its relationship to the fall
army worm by marches such as are characteristic of the latter
species. The plant of economic importance attacked by L. exigua
in Florida is Asparagus plumosus var. nanus, ("asparagus
fern"). Thus it is known to the growers of A. plumosus as the
fern caterpillar and the bud worm. The latter name is applied
to the first and second instar larva because of its habit of climb-
ing to the bud and chewing a hole at the base of the tender tip.
The first record of L. exigua in the United States is that given
by Harvey (1876) in the Canadian Entomologist. Harvey col-
lected specimens of this insect in Oregon. Larvae were collected
in California by Coquillett (Chittenden 1902) in 1882 and 1886.
In 1899 Gillette (1899) reported the larvae feeding on sugar-
beets in Colorado. Sanderson (1905) reported the larvae dam-
aging cotton in Texas in 1904. Marsh (Campbell and Duran
1929) reported a serious outbreak on sugar-beet in Kansas in
1911, and observed a few larvae on turnips at Phoenix, Arizona
in 1916. In a letter Dr. Foster H. Benjamin states that this
insect is often confused with Laphygma frugiperda and prob-
ably for this reason escapes detection. According to Dr. Benja-
min L. exigua is abundant as far east as Brownville, Texas, and
was collected at Quincy, Illinois in 1899, and at Altemont
Springs, Florida in 1924. Mr. J. M. Langston of the State Plant
*Contribution from the Department of Entomology, Florida Agricul-
tural Experiment Stations.









THE FLORIDA ENTOMOLOGIST


Board of Mississippi writes me that he has specimens of L.
exigua in the collection which were taken at A. & M. College
and Starkville, Mississippi in August 1920. Larvae were also
collected feeding on corn at Natchez, Mississippi on May 14,
1931.
Specimens sent to the United States National Museum during
the summer of 1932 were identified by Dr. Foster H. Benjamin
as Laphygma exigua Hbn. Although we have no accurate rec-
ord of its first appearance in the ferneries of the State, it is cer-
tain that this insect has been present for a number of years. At
the present time the fern caterpillar occurs at Pierson, DeLand,
Leesburg, Groveland, Yalaha, Auburndale, Altemont Springs,
and Fern Park. It has not been found south of Auburndale,
although these ferneries are infested with other species which
are as destructive as L. exigua.
It is difficult to estimate the amount of damage inflicted by
the fern caterpillar because of the fluctuations of the market
value of A. plumosus during the summer, and because of the
variable thoroughness with which control measures are applied.
The greatest injury occurs during the rainy season which usu-
ally lasts from eight to twelve weeks from mid June or July to
September. During much of this period some rain falls almost
every day and frequently the amount is large; as much as one
inch in an hour is often recorded. These frequent and heavy
rains make it difficult to keep the plants covered with an insecti-
cide. Thus the damage multiplies with increased rainfall. The
first and second instar larvae, as previously mentioned, have
the habit of climbing to the tip of the asparagus shoot and feed-
ing on the tender bud. This feeding on one side of the bud
causes it to curl over and eventually to wither. Such tipless
sprays are valueless under present market conditions. The older
larvae feed on any part of the plant, preferring the soft succu-
lent sprays which have just finished expanding.
Campbell and Duran (1929) give a list of eighteen plants
which are attacked by the sugar-beet army worm or fern cater-
pillar. This list includes, in addition to sugar-beets, table beets,
corn, cotton, peas, pepper, a number of wild plants and grasses.
Taylor (1931) reports that in South Africa tobacco, grapes,
young eucalyptus trees, and lawns, as well as cotton, maize, and
peas are attacked by this insect. I have not observed L. exigua
feeding on any other plant than Asparagus plumosus except
upon two occasions. Recently larvae were collected feeding on
Gladiolus sp. which were about twelve inches high. The gladi-









VOL. XVI-No. 3


olus field was surrounded by uncultivated grass land, and the
field itself had not been cultivated during the summer months.
The larvae had probably been feeding on the grasses when the
field was plowed and planted to gladiolus. On the other occa-
sion the larvae had become very abundant in a neglected fernery.
After consuming the asparagus they devoured the grass grow-
ing between the asparagus plants.
The adult moths resemble rather closely Laphygma frugi-
perda S. & A., especially the plain gray form. The wing expanse
of L. exigua ranges from twenty-five to thirty millimeters; the
fore wings are broader and paler than in L. frugiperda; the reni-
form and other spots as well as the mottlings are more distinct,
but the posterior pair of wings differ very slightly from those
of L. frugiperda.
Emergence of the adult moths occurs during the night and
copulation may take place soon after arriving at the surface
of the soil, as is shown by the fact that fertile eggs have been
deposited in the laboratory cages the evening following that of
emergence. Practically all of the activities are conducted at
night, although the moths may be observed flying ahead of one
walking through the fernery in the daytime when the moths are
present.
In the ferneries the eggs are laid on the underside of the
asparagus sprays in masses covered with scales from the abdo-
men of the female. These masses have been collected from both
very young sprays and mature sprays. Egg masses collected in
the fernery were composed -of 50 to 150 eggs while masses de-
posited in the laboratory cages ranged from 5 to 145 eggs. Rec-
ords of forty-five pairs of moths were kept, beginning on June
15 and ending September 23. The average number of eggs de-
posited by these forty-five females was 516.55 eggs per female.
The largest number of eggs laid by a single female was 1171 and
the smallest number was 18. Campbell and Duran (1929) re-
port that eleven females laid an average of 330 eggs. The ovi-
position period usually lasts only 4 or 5 days, the average being
4.80 days. The preoviposition period for these moths was 2 to 3
days, averaging 2.88 days. The moths were fed honey diluted
with water. Of the 45 pairs on record the females lived for an
average of 8.26 days while the males averaged 8.14 days. This
figure may represent a longer life for the males than is the case
in nature as they are protected and undisturbed in the cages
whereas they would be exposed to a number of dangers in the
field. Many of the males died within two or three days after








THE FLORIDA ENTOMOLOGIST


emerging while some of them lived longer than the females.
One male lived twenty-one days and one female lived twenty
days.
On July 6 five pint ice cream cartons were placed in the re-
frigerator each containing a newly emerged male and female
L. exigua with a spray of asparagus for support and honey
water for food. The first carton was removed twenty-four hours
later and one carton was removed each succeeding twenty-four
hours for four days. The temperature of the refrigerator was
maintained at 350 to 400 F. The first female after a preovipo-
sition period of four days, which included the time spent in the
refrigerator, laid 413 eggs in four days. The second female
after a preoviposition period of five days laid 401 eggs in four
days. The third female escaped. The fourth female remained
in the refrigerator four days and deposited eggs a day following
her removal from the refrigerator. This female laid 496 eggs
in six days. The fifth female remained in the refrigerator five
days and also deposited eggs the day after her removal. The
oviposition period lasted four days during which time 311 eggs
were laid. This experiment showed that it was possible for the
moths to withstand a temperature of 350 to 400 F. for at least
five days and still oviposit normally when the temperature again
reached the optimum. Ten egg masses kept in the same refrig-
erator for four days hatched two days after their removal.
The eggs, like those of other Noctuidae are ribbed, oblate-
spheroid in shape, and circular in cross section. The upper third
of the egg has the appearance of a cap surmounting the lower
two-thirds and separated from the lower portion by a white
ring. The eggs are greenish gray in color when freshly laid,
becoming cream colored a few hours later, finally becoming
dark just before the eggs hatch due to the black color of the
larval head. From June 15 to September 19 incubation records
were obtained on 470 egg masses deposited on 45 different days,
the average incubation period being 2.06 days. During this time
the average daily temperature ranged between 790 and 860 F.
Taylor (1931) working in South Africa found the incubation
period to be from 3 to 7 days during the summer and up to 12
days during the winter.
Eggs observed in the process of hatching were first cut open at
the apex by the young larva. The larva continued to feed, gradu-
ally enlarging the original opening. After crawling from the egg
the larva remained feeding on the shell until it was almost com-
pletely devoured, a period from six to eight minutes long. When









VOL. XVI-No. 3 37

this first meal was completed the larva rested near the egg mass
a short time before beginning the search for other food. DeOng
(1918) reports observing the young larvae feeding gregariously
on castor bean beneath a web, during the first and second in-
stars. I have not observed them feeding in such a manner on
A. plumosus during the three years of constant observations in
the fernery. However the first and second instar larvae do spin
a web about themselves just before molting and remain inside
this web a variable length of time after ecdysis. The newly
hatched larva is one millimeter in length, a light green color, with
numerous small tufts of hairs scattered about over the body. If
disturbed or buffeted about by the wind the first or second in-
star larva immediately releases its hold on the plant except for
a thread of web by which it slowly lowers itself to the ground. If
a strong wind is blowing this web acts as a kite string and the
small larva may be carried a considerable distance. If the older
larva is disturbed, it immediately curls up and falls to the
ground. During the hottest portion of the day large numbers
of the larvae may be found on the surface of the soil beneath
the dense shade provided by the fern plant.
From June 14 to October 10 six complete generations of larvae
were reared. There are five instars, each instar consisting of an
active and inactive period. Before the occurrence of each molt
the larva spends some time resting. During this time the old
head capsule is gradually forced off, and when this part of the
molt is completed the exuvia is much more rapidly removed.
Exact records of the length of time consumed by these activities
were not obtained. The total time required for the development
of the larva from the time it hatches to the beginning of the
prepupal stage averaged 11.45 days for the six generations. The
following table is a summary of the data collected for the six
generations, ten larvae of each generation.

TABLE I.-A SUMMARY OF THE TIME REQUIRED BY EACH INSTAR FOR ITS
DEVELOPMENT. THE MEASUREMENTS WERE MADE JUST BEFORE MOLTING
BEGAN.
Ave. Time Ave. Length
In Hours In
Required Millimeters
First Instar ........................................ 56.24 2.49
Second Instar ................................... 51.78 5.77
Third Instar ....................-----................ 44.00 8.88
Fourth Instar .................................... 48.75 13.78
Fifth Instar ...................................... 74.13 22.85








THE FLORIDA ENTOMOLOGIST


The two days usually required for the fifth instar larva to
make its way into the ground and construct the pupal cell is
here considered as being the prepupal stage. The average length
of this period was 1.76 days. After forming the pupal cell the
prepupa becomes shortened, and takes on a mottled gray color.
The skin is shed for the last time and the light green colored
pupa appears.
Within a few hours the pupa gradually turns a light brown
in color. This color slowly darkens as the pupa grows older
until it becomes a deep wine color. The average length of the
pupal stage for the six generations reared by October 20 was
5.94 days. The pupa averaged 10.4 millimeters in length, the
female pupae being slightly larger than the male pupae. No
appreciable difference was observed in the length of time re-
quired for the development of males and females.
The first generation of larvae which was abundant enough to
cause noticeable damage appeared between April 23 and 28 of
this year. A second generation occurred between June 2 and 8.
The third generation began to appear July 1. Thereafter the
generations became so mixed in the ferneries that it was im-
possible to distinguish between them. All stages of the insect
occurred in the ferneries during the winter of 1931-32. This
condition would indicate that the winter is passed by a continua-
tion of development although retarded. The lower temperatures
of the winter months tend to materially increase the length of
the various stages. The number of generations to be expected
in such a case is not known, as the life history studies have not
been carried through a winter. The length of the life cycle
obtained by adding the averages for the various stages of the
six generations reared is twenty-four days. This already gives
the insect one more generation in this State than in California,
as Campbell and Duran (1929) report five generations for the
whole year in California.
During the past summer some of the growers near the labora-
tory did not attempt to control the fern caterpillar because of
market conditions. In these ferneries the larvae frequently be-
came very abundant. This offered an excellent opportunity to
collect and study the parasites which attack this insect. Of the
eight parasites collected and observed Chelonus texanus Cress.
was by far the most abundant. Next in importance to Chelonus
texanus were Meteorus autographae Mues. and Apanteles mar-
giniventris (Cress.) found in equal abundance. Euplectrus pla-
tyhypenae How. has been observed from time to time in the









VOL. XVI-No. 3


ferneries at Leesburg, but it was never abundant. It was ob-
served to be very abundant in the ferneries at Boynton however.
Single specimens of the following parasites were collected:
Hyposoter interjectus Gahan, Zele melleus (Cress.), Gonia
crassicornis Reinh., and Eucelatoria rubentris Coq. Spilochalcis
hirtifemora (Ash.), Spilochalcis albifrons Walsh, Catolaccus
aeneoviridis (Gir.) and Mesochorus sp. were bred from cocoons
of Apanteles marginiventris. Two predators very abundant in
the ferneries were active in destroying larvae of L. exigua.
These were Polistes fuscatus var. rubiginosus Lep. and Podisus
maculiventris Say. There is also a fungus disease Spicaria
prasina which was very active in destroying larvae of L. exigua
during the rainy periods. Chickens and guinea hens have been
used by some of the growers to help keep down the infestations
of worms.
All of the insects listed above were identified by systematists
of the United States National Museum: the Chalcidoidea and
Brachonidae by Dr. C. F. W. Muesebeck; the Ichneumonidae by
Dr. R. A. Cushman; Polistes fuscatus var. rubiginosus Lep. by
Dr. Grace Sandhouse; Podisus maculiventris Say by Dr. H. G.
Barber; the Diptera by Dr. J. M. Aldrich; Laphygma exigua
Hbn. by Dr. F. H. Benjamin; and Spicaria prasina by Mr. Erd-
man West of the Florida Experiment Station. Several of the
fern growers have helped to advance the work by generously
allowing the author free access to their ferneries at all times.

BIBLIOGRAPHY
1929 CAMPBELL, R.E. and V. DURAN. Notes on the sugar-beet army worm
in California. Mo. Bul. Dept. Agr. Calif. vol. 17 no. 4, p. 267-275.
1902 CHITTENDEN, F. H. Some insects injurious to vegetable crops.
U.S.D.A. Div. Ent. Bul. (N. S.) 33, p. 37-46.
1918 DEONG, E. R. Insect Pests of the castor bean. Jour. Econ. Ent.
vol. 11, p. 480.
1900 GILLETTE, C. P. The beet army worm (Laphygma exigua). Colo-
rado Agr. Exp. Station Ann. Rept. 12, p. 39.
1876 HARVEY, L. F. Canadian Ent. vol. 8, p. 54.
1905 SANDERSON, E. D. U.S.D.A. Farmers Bul. 223, pp. 14 and 15.
1931 TAYLOR, J. S. Notes on the biology of Laphygma exempta Walk.
and L. exigua Hbn. (Lep. Noctuidae). Bull. Ent. Res. (London)
vol. 22, no. 2, p. 209-210.









Uhe
FLORIDA ENTOMOLOGIST
Official Organ of The Florida Entomological Society, Gainesville,
Florida.

Vol. XVI SEPTEMBER, 1932 No. 3

J. R. WATSON ---...--..... ..--. ....--------------..----- .-------Editor
E. W. BERGER --..------...... -----...................Associate Editor
H. E. BRATLEY. -----------..------.-------.Business Manager
Issued once every three months. Free to all members of the
Society.
Subscription price to non-members is $1.00 per year in ad-
vance; 35 cents per copy.

UNE LETTRE DU V CONGRESS INTERNATIONAL
D'ENTOMOLOGIE, PARIS, FRANCE 16 AU 23
JUILLET 1932
J. HAROLD MATTESON'
Dear Fellow Entomologists:
Ecrirai les impressions de ce congr6s en francais ou anglais ?
I presume that for the benefit of all it will be best to write in
English, yet if you were here with me at this Congress you
would wish more than ever that you had spent the extra half
hour (after the smart French student went to bed) in perfect-
ing your French. Everyone is speaking French. The English
seem to be having the easiest time due to the fact that they speak
softly and we Americans talk in our throats, more guttural and
harsh than they, and consequently they are more easily under-
stood. I have had quite a time for the first couple of days trying
to speak softly with my lips, (Try it) but after that it was not
so difficult, and just about the time that the shores of England
called me I found that my French was much improved, and
that speaking was becoming a delicious pleasure instead of the
superb effort which it proved originally. If someone has told
you that you do not need French in Paris, you tell them that
as a matter of insurance you are going to carry your French
with you, and in the latest approved package for instant use,
for you will need it, and no joking. It is my impression that
the French are not so much inclined to cheat an American who
can make them believe that he understands what they are say-
ing, and can make himself understood to them.
'Official Representative of the Florida Entomological Society at the
International Entomological Congress.









VOL. XVI-No. 3


Possibly you would like a word about the Agronomique (In-
stitut National) the headquarters, for it is here that the scene
is laid, and it was here that we spent so many interesting hours.
The building is of red brick and is situated on a corner of one
of Paris' busiest streets. Entering, on our right is a long hall
which we find leads to a larger number of class rooms and
laboratories devoted to agriculture. Turning to the right on
entering, we have in front of us the tea garden, and on our
right the hall which leads to the headquarters of the excursions
and the "rogues" gallery of pictures of entomologists conducted
by our friend Mr. Scott. Above us is a large room for the con-
venience of the entomologists, and directly opposite is the audi-
torium in which were held the general sessions of the congress.
My first impression of Paris was that of many streets, nar-
row and wide, circling every which way; and here, and there,
the strains of music and dancing, for it is the day after Bastile
Day. The sidewalks are very wide to provide for the many cafes
and restaurants that are everywhere, and which serve in the
open air on the various artistic tables and chairs placed on the
walk. The little automobiles all blowing their horns will amuse
you. The Louvre and Tuileries which extends to the place de la
Concorde will make their everlasting impression.
Glancing over the programme of the Congress of Entomology
you note that two tours of Paris are provided, a tour of
Versailles, excursion to Chantilly, Fountainbleau, and two ban-
quets in addition to the reception at the Hotel de Ville by the
Municipality de Paris and the Seance solennelle du Centenaire
de la Soci6t6 entomologique de France, dans le grand amphi-
theatre du Museum national d'Histoire naturelle en presence de
M. A. Lebrun, President de la Republique; all this in addition to
the regular meeting of the sections.
On the sixteenth of July I attended two receptions and at
8 P.M. took dinner at the Hotel Claridge offered to the official
delegates by the Entomological Society of France on the cele-
bration of the one hundredth anniversary of the founding of this
celebrated society in 1832. We Americans and English joked
about the wines offered-Chateau respide, Pontet Canet, Pom-
mard 1923, G. H. Mumm Double Cordon et Cordon Vert,
Liqueurs de Marque-served to you whether you liked it or not.
Mrs. A. Hartzell and her husband who sat next to me on my
right wanted me to drink theirs as well as my own, but Mr.
J. J. Davis of Lafayette, Indiana insisted that if I handled what









THE FLORIDA ENTOMOLOGIST


I had of my own I would be doing well. He was seconded by B.
Wahl of Vienne, and J. W. Edwards of London.
Dr. Jeannel welcomed the delegates in the name of the En-
tomological Society of France. Glancing around I saw M. Bou-
vier, Dr. L. O. Howard, Dr. W. Horn, Dr. Karl Jordon, M.
Alquier, H. F. Johannsen, M. Marchal, E. B. Poulton of Ox-
ford and many others. Following the dinner a reception was
held where the delegates had another opportunity to meet each
other.
On Sunday at ten in the morning the delegates visited the
Tomb of Latreille in the cemetery of Pere-Lachaise, followed
by the excursion to Chantilly and the visit to the chateau and
the forest.
Monday at nine-thirty the Congress itself began in earnest
with a general session in the Agronomique under the chair-
manship of M. A. Gardey, Minister of Agriculture, followed at
two by the meetings of the sections of Entomologie general;
Morphologie, Physiologie, Developpment; Ecologie, Biogeogra-
phie; Entomologie appliquee; Apiculture; Nomenclature. This
program was carried out daily including tea in the garden of the
Agronomique at four in the afternoon especially for our English
friends.
A day that I will remember for a long while was Mer-
credi 20 juillet when we left by big auto busses for the forest
of Fountainebleau and the chateau where every emperor of
France strode through its stately halls and where Napoleon him-
self bid adeau to his troops. But better still, the forest was full
of butterflies, and I took thirty specimens in about forty min-
utes that we had to spend in the leafy jungle, much to the en-
joyment of M. Le Charles, M. Corti, my most excellent com-
panion of the day, and Mr. F. M. Jones of the Philadelphia
Academy of Natural Sciences. After an entire day of marvels
for both the traveller and the scientist we returned to Paris at
eight in the evening, tired, but not too tired for Sir B. N. Blood,
J. W. Edwards and myself to classify the specimens I had cap-
tured and make such interesting notes as, "Taken in the path
which was so often trod by Napoleon from the Chateau of
Fountainebleau to the Carp Pond", or "Beside the field where
Millet painted the 'Angelus'."
The outstanding feature of Friday was the banquet au Jardin
de Vincennes. Here I had the interesting experience of being
told by a French waiter that a tip of ten francs was not suffi-
cient due to the fact that all Americans were rich and could well









VOL. XVI-No. 3


afford more. It seemed that the tips were not included in the
service for some unknown reason. It was another delightful
banquet and while eating we were entertained by some attend-
ants riding by the entrance to the pavilion on camels. Here
also the method by which the animals were caged was inter-
esting. To the eye the lions were free to come and go as they
pleased but upon closer examination it appeared that a huge
moat arranged so that it was impossible for the animals to
cross separated them from us.
Saturday was the last regular day of the Congress and the
sessions of the sections were held and a final general assembly
in which motion pictures of German experiments with color as
an essential element in attracting bees to a preparation of sugar
and water were shown. The attractiveness of 20 per cent solu-
tion of sugar and water was shown and then reduction of the
solution produced a reduction of the bees attracted. Dr. L. O.
Howard moved to thank the committee in charge of the Congress
for its efficiency and the motion carried unanimously. A heated
debate on the location of the next congress was held and it was
decided that the next congress would be in Madrid, Spain. The
International Committee on exchange was abolished and A.
Avinoff announced that the dream of Entomologists for such a
committee has been fulfilled with the completion of an organi-
zation sponsored under the League of Nations. So closed the
Fifth International Congress of Entomology.
Just what would be of value to the many entomologists of
Florida it is difficult for me to know without knowing the spe-
cialty of each entomologist, however, I will give you a few of
the notes that I made in the hopes that they may be of value.
Yin-Chi Hsu gave some new morphological findings in Ephe-
meroptera and said, "On the ventral side of the eighth and
ninth abdominal segment above the sternum there are two small
oval shaped chitinous bodies, which lie along the median line
at the middle of the segment." "A distinct valve was found in
between the ileum and the colon. It is very similar to the oesoph-
ageal valve." This organ (Johnston's Organ) has been so far
recorded in many orders of insects. A similar organ was found
in the pedicel of the antennae of Stanonema." There are uni-
cellar mating glands on the inner surfaces of the male forceps.
The ventral surface of the egg valve is armed with many min-
ute conical spines beset with numerous small spines."
B. P. Uvarov spoke on Conditioned Reflexes in Insect Be-
havior, and said, "The best example of a conditioned reflex is









THE FLORIDA ENTOMOLOGIST


offered by the flower-visiting habit of insects feeding on nectar.
The attraction of females to their larval feeding food for ovi-
position is a case of conditioned reflex which remains inhibited
until the sexual maturity. The usual explanations of insects'
actions either by instincts, or by forced movements are one-
sided, and the problem of insect behavior must be studied with
an open mind, by physiological methods."
S. Metalnikov, speaking on Immunite Naturelle et Acquise
chez les Insects, named the factors of natural immunity as 1-
Phagocytose, 2-Formation of plasmodes ou cellules geantes,
3-Formation des capsules autour des plasmodes, 4-Formation
des abc6s, 5-Des anticorps: bacteriolysines et antitoxines."
G. Haeussler summarized the general information concerning
the oriental fruit moth and its parasites accumulated during the
course of investigations conducted by the Bureau of Entomology
in France and Italy.
B. P. Uvarov, in speaking of the Physiological basis of ap-
plied entomology, said that Ecological point of view which is
now firmly established in applied entomology, tends to stress
the study of the environment, while the insect as a living or-
ganism is often neglected. The importance of the environment
is in the responses on the part of the insect towards various ex-
ternal factors and these responses can be studied only from the
physiological point of view.
I had the pleasure of presenting a list of the butterflies of
Florida and urging the establishment of international bureau
where the entomological works of the world could be tabulated
and duplication of efforts checked. In line with this was the
announcement of Dr. Avinoff on the last day of the Congress
and the announcement of Dr. W. Horn that the Deutsches En-
tomologisches Institut under his direction had commenced the
cataloguing of entomological works from about 1864 to 1925
and further urged that all entomological publications be sent
to him.
Dr. Poulton of Oxford discussed Mackatee on protective col-
oration, pointed out that the eye is attractive on the butterfly
to the birds and so accounts for the eye like spots on Hemiargus
and Leptotes and certain other families of butterflies as being
an imitation of the eye which is first attracted by the birds and
which results in freedom for the insect. He cites examples to
prove this theory.
Other subjects discussed which at a later date for the cost of
preparation and mailing may be secured from me are: "La res-









VOL. XVI-No. 3


piration pendant le vol chez les LUpidopteres, Recent advances
in applied entomology in Canada, Sur les populations hybrid6es
des L6pidodteres dan la zone de contact entire races genetiques,
Les Larves primaries des M6loides, Erlauterungen zu meinem
System der Lepidoptera, Notice entomologique sur le Var et
quelques points de la C6te d'Azur, Sense ecology and numbers
of insects, Un Trechus cavernicole du Maroc, The axillary vena-
tion of the Insects, Organs odoriferants chez les Insectes, Sur
les ailles d'insectes, Some fundamental aspects of parasitism
in Insects, Apergu sur la biologie de l'Urania rephaeus, Les In-
sectes parasites des plants cultiv6es en Nouvelle-Cal6donie,
Notes sur la Mouche des fruits, Sur une invasion de la cochenille,
Das Auftreten der San Jos6 Laus in Europe, Natural control
of some tropical insects, and many others, a complete list of
which may be had at a later date.
To completely cover this Congress would be to write a book
and as the space is limited I close with the wish that you may
be able to attend the next Congress and to assure you that
if there is anything of particular interest on which you wish
more information to assure you of my willingness to cooperate.



THE BEAN LEAFHOPPER SITUATION
The bean leafhopper situation in Florida at this time is just
the reverse of that of a year ago. In the fall of 1931 Empoasca
fabae (Harris) was less abundant than usual in the northern
and central portions of the state. Some growers found it nec-
essary to employ control measures but many fields of beans pro-
duced good crops without any control measures being used. In
the Everglades, on the other hand, the leafhoppers were ex-
tremely abundant and it was practically impossible to produce
a crop of beans even with frequent spraying with contact insecti-
cides. The infestation continued throughout the mild winter
and large acreages of the early spring crop were completely de-
stroyed. The insects were found everywhere in the region and
the young beans became infested almost as soon as they came
through the ground. Professor R. N. Lobdell of the Everglades
Experiment Station reported that in one instance young beans
having only the first two leaves and located in the middle of a
forty acre field had an average infestation of seven adult leaf-
hoppers per plant.
The writer has recently investigated the leafhopper situation








THE FLORIDA ENTOMOLOGIST


in the region surrounding the southern end of Lake Okeechobee
where thousands of acres of beans are now growing. The leaf-
hoppers were present in all fields visited but in every case they
occurred in relatively small numbers. In no instance was the
infestation sufficiently severe to cause any appreciable damage
and artificial control measures seemed entirely unnecessary at
that time.
A very different condition exists in the central portion of the
state in the region extending southward from Gainesville for
a distance of one hundred-fifty miles. Here practically every
field shows injury resulting from the feeding of the leafhoppers.
In some fields where no control measures were used the plants
are almost all dead. In others the plants have not been killed
but are so severely injured that they will yield little or no fruit.
In a few isolated fields and in others where the land was pre-
pared well in advance of planting time the injury from leafhop-
pers is much less severe though even here the yield will doubt-
less be affected.
The bean leafhopper is known to be practically free from pre-
daceous and parasitic enemies and it seems probable that its
abundance or scarcity in a region may largely be determined by
weather conditions. There are not sufficient weather data from
the two regions of Florida above discussed to enable one to de-
duce just what factors may have been responsible for the abund-
ance of leafhoppers in one region and the comparative scarcity
of the insects in the other. A. N. TISSOT.




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