Group Title: Bulletin / University of Florida. Agricultural Experiment Station ;
Title: Insects injurious to stored grain and cereal products
Full Citation
Permanent Link:
 Material Information
Title: Insects injurious to stored grain and cereal products
Physical Description: p. 355-385 : ill. ; 22 cm.
Language: English
Creator: Quaintance, A. L ( Altus Lacy ), 1870-1958
Publisher: Florida Agricultural Experiment Station
Place of Publication: Lake City, Fla
Manufacturer: Dacosta Printing and Publishing House
Publication Date: 1896
Copyright Date: 1896
Subject: Grain -- Storage -- Diseases and injuries -- Florida   ( lcsh )
Food storage pests   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
General Note: Cover title.
Statement of Responsibility: by A.L. Quaintance.
 Record Information
Bibliographic ID: UF00024528
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 - AAB6185
notis - AEN1405
alephbibnum - 000920967
oclc - 18154743

Full Text

Bulletin No. 3Q. October, ia00.







The Bulletins of this Station will be sent free to any address in
Florida upon application to the Director of the Experi-
ment Station, Lake City, Fla.



Hox. WALTER GwYNN, President Sanford
HON. W D. CHIPLEY, Vice-President Pensacola
HON. F. E. HARRIS, Chl'n Executive Committee Ocala
HON. A. B. HAU CN, Secretary Lake City
HON. S. STRINGE Brooksville


0. CLUTE, M. S., LL. D. Director
P H. ROLFS, M. S. Horticulturist and Biologist
A. A. PERSONS, M. S. Chemist
A. L. QUAINTANCE, M. S. Assistant in Biology
J. P. DAVIES, B. S. Assistant in Chemistry
JOHN F. MITCHELL Foreman of Lake City Farm
J. T. STUBBS Supt. Sub-Station, DeFuniak Springs
W. A. MARSH Supt. Sub-Station, Fort Myers

General remarks 358
The Angumois grain moth 359
The meal snout-moth 362
The Mediterranean flour moth 363
The Indian-meal moth 364
The granary weevil 366
The rice weevil 367
The bean weevil 369
The Chinese cow-pea weevil 370
The four-spotted bean weevil 371
The pea weevil 372
The slender-horned flour beetle 374
The confused flour beetle 375
The rust-red flour beetle 376
The red grain beetle 377
The corn Silvanus 378
The grain-eating Brachytarsus 380
The Catorama flour beetle 381
Treatment 382
Acknowledgments . . . . . . . 385

The ravages of insects in stored grain and cereal
products in Florida are particularly severe. That this is
true, is at once understood from the fact that our climate
allows of a very long, and doubtless with many species,
an uninterrupted breeding season. Grain stored away in
the fall may become so badly infested by spring that its
value as feed is greatly reduced, and for seed purposes it is
quite worthless. The weight of grain infested with insects
soon becomes greatly reduced from the fact that the nutri-
tious substance has been eaten out, leaving the empty hulls.
Observations thathave been made, on grain infested by the
Angumois grain moth for six months, show that it sustain-
ed a loss of fifty per cent in weight, and seventy-five percent
in its farinaceous matter. The example of the work of
this one insect alone, will serve to give some idea of the
great loss sustained by farmers and dealers, from grainin-
festing insects.
According to Hon. L. B. Wombwell, Commissioner
of Agriculture, the corn crop in Florida for 1893 was
3,403,728 bushels, valued at $2,462,890.75. From ex-
tended observations we believe that fully twenty per cent
of all the corn stored in granaries is destroyed by insects.
If the above figures on the yield and value of the corn
crop of Florida be entirely correct, it is seen that our an-
nual loss becomes exceedingly great. Twenty per cent of
$2,462,890.75 is $492,598.15. This will indicate approxi-
mately the yearly loss sustained by the farmers.and grain
dealers of this State. Corn, however, is not the only crop
that is attacked. Rice, cow-peas, oats, beans, peas, peanuts,
cotton-seed, flour, corn-meal, grocery produce, and many
other substances are quite as subject to the attack of in-
sects, as corn. It is thus seen that the total annual loss
from these insects becomes very great.

The question at once arises, is there no remedy against
these insect pests? Fortunately, there is. The carbon bi-
sulphide remedy has been used with the best of success
against all kinds of insects infesting stored grain and ce-
real products. This is a cheap and efficient remedy, and
when properly used will give perfect satisfaction. Under
the head of TREATMENT, on page 382, will be found
complete directions for its purchase and use.
In the following pages it is desired to give brief de-
scriptions, with the life-history of the more important grain
insects to be found in this State. In most cases figures
are given illustrating the different stages in their life-his-
tory, which is hoped will greatly facilitate their recogni-


Fig. 1.-Gelechia cerealella; Oliv.: a, larva; b, pupa;
c, female moth; e, egg; f, kernel of corn showing larva
within-all enlarged except f.
This insect is very abundant in this State, and is one
of the most serious pests to stored grain that we have.
Several granaries which were visited during the month of
August of this year were found to be most badly infested,
and corn stored the previous fall was almost worthless
from the ravages of this insect and the rice weevil. The
Angumois grain moth is thought to be indigenous to the
region of the Mediterranean sea. It derives its name from
the French Province Angumois, where it was at one time

particularly injurious. The earliest notice we have of this
insect is in 1736, when it was noted by Reaumur as in-
juring stored barley in France. In the United States it
occurred in North Carolina as early as 1728. Since this
early date of its occurrence in North Carolina it has
spread quite generally over the Southern States, where its
ravages are most severe. The food of the Angumois moth
in America is quite varied, but corn and wheat suffer most
from its ravages. In this State the injuries are confined
chiefly to corn and cow-peas.
The adult is a small moth, having a wing expanse of
about one-half of an inch. Its body and fore-wings have
a soft, shiny, light gray color, while the hind-wings are
darker and bordered with a long, delicate fringe. The
ventral surface of the body and the wings are darker than
the dorsal surface, while the logs are somewhat darker
than the body, the caudal pair being hairy, and provided
with spurs. For an illustration of the moth enlarged, see
fig. 1, c. The hair lines below indicate the natural length
and wing expanse.
The larva, illustrated in fig. 1, a, is, when full grown,
nearly one-fourth of an inch in length, of a light color,
provided with numerous hairs, which on the first and
last segments are somewhat longer than elsewhere. In
general form the body is cylindrical, gradually tapering
caudad from the second segment; the head is brown.
Fig. 1, f, shows the larva at work in a kernel of corn,
natural size.
The egg is illustrated at e, greatly enlarged; it is
somewhat oval in form, and of a pale red color.
The pupa shown at b, is about one-fourth of an inch
long, brownish in color, with the abdominal region of a
somewhat lighter shade.
The eggs are deposited on the grain, either in the
field or in the granary. They are placed in the ears of
corn, between the rows of seed, or at their bases under the
thin membranes. They may be found either singly or

in clusters of twenty to thirty. In
the course of a few days the eggs de-
velop into small, active larvae, which
at once eat into the grain, devouring
the starchy matter, eventually leaving
,but a thin empty shell. Two, three,
i l or more larvae may be found within a
*- single kernel of corn, but the smaller
cereals usually afford food for but
one. The length of time of the larval
stage is usually four or five weeks,
-* although this varies somewhat with
1-,=' 0 the temperature.
c$ \yWhen the caterpillar has attained
its growth it bores a small hole to
the exterior of the kernel to allow of
its escape as a moth, and then passes
into the pupa state within the seed.
The pupa state lasts from a few days
3 to weeks. depending upon the tem-
perature. The entire life cycle from
' --*,-.^ egg to adult is, in this climate, about
;; ? five weeks. The moths mate soon
after emerging from the crysalis, and
deposit a laying of eggs. There
-1* -- fi appears to be no regular time for the
appearance of the adults, as all stages
0smay be found at almost any time in
the infested grain. This rapid fecund-
ity soon enables them to bring about
the destruction of the grain. In the
(*'9 Gulf States doubtless as many as
a gsg eight broods are raised each year.
led*^ Corn that has not been husked is
T*, much freer from the attack of this
S* B *insect than corn that has been husked
S1,- or shelled.
Fig. 2 represents an ear of pop-
corn showing the work of this in-
Fig 2.-An ear of pop- sect G badly
orn illustrating the wosect Grain may be badly infested
ot the Angumois grain with larvae and appear to be sound,

as the excrement from the larve may fill up the small
holes through which they entered; but it may be easily
detected when grain is infested from its lighter weight. If
a few seeds are thrown into water, the infested ones will
not sink as will the sound ones.
For the treatment of this and the other insects attack-
ing stored grain considered, see the directions for treat-
ment at the close of this bulletin. Since the treatment
for the various grain infesting insects is the same in all
cases, it is useless to repeat it for each species.


Fig. 3.-Pyralis farinalis, Linn.: a, moth; b, larva; c,
chrysalis; all natural size.
The meal snout-moth is well known in Europe where
it is a great nuisance. In this country it is gaining quite
a foothold, and may ultimately become a serious pest.
Like the Indian-meal moth and flour moth the lar-
vwe of this insect make long tubes, by fastening together
small particles of food with silken threads which they
secrete. In these tubes they live, feed and go through
their transformation. The meal moth feeds upon various
cereals, and their products. It is said to even attack straw
and hay. I am not aware of the occurrence of this in-
sect in Florida. It is liable to be introduced at any time,
and become of considerable trouble.
In fig. 3, a, the moth is shown natural size. The
general color is light brown. The fore-wings are marked

on their basal and distal parts with patches of dark brown.
Across each fore-wing are two wavy, whitish lines.
The larva and pupa may be seen in fig. 3, b, and c;
d, illustrates the head of the larva enlarged.


Fig. 4.-Ephestia keuhniella, Zell.: a, moth; b, same
from the side; c, larva; d, pupa, all enlarged.
This insect first became noted as a pest in 1877, when
it was found to be doing much damage in a flour mill in
Germany. From Germany it spread into Holland and
Belgium and later appeared in England. In 1889 it
appeared in the Dominion of Canada. It has recently
been reported from North Carolina, New Mexico, Alaba-
ma, Colorado, Chile, and Mexico. From this it is evident
that it is becoming quite generally distributed. Although
it has probably not yet appeared in this State, it may
be expected any time.
The adult is a grayish colored moth having a wing
expanse of about one inch. The fore-wings are marked
with transverse black lines, as shown in fig. 4, a. The
hind-wings are of a dirty white color with a darker border.
At b, fig. 4, the moth is seen from the side.
The larva is worm-like, about one-half inch long. The
head is dark brown, and the body provided with bristle-
like hairs as shown in fig. 4, at c. The chrysalis is repre-

sented at d fig. 4; e, shows an abdominal joint of the
larva, showing arrangement of spines.
About five weeks are required for this insect to pass
through all its stages from; the egg to the adult. In the
latitude of Washington there may be six or more gener-
ations a year. In the Southern States, doubtless more
than this may be raised, and it is quite probable that
breeding may continue uninterrupted throughout the year.
In some places where this insect is known, it has created
such havoc that it has been called the scourge of the flour
mill. The larvae live in silken tubes which they spin
through the grain or flour, and it is this habit that ren-
ders them so injurious. These webs cause a felting
together of the flour which clogs the machinery, causing
frequent and protracted delays. This caterpillar seems
to prefer flour or meal, but it will also attack other cereal


Fig. 5.--Plodia interpunctella, Huebn.: a, moth; b, chrys-
alis; c, larva; d, head of larva, all enlarged.
The Indian-meal moth is another serious pest to
stored grain and cereal products in this State.
The moths were found to be very abundant in the
granaries visited the present summer. They were ob-
served among the ears of corn in considerable numbers.
Twenty-six moths were counted on the inside of a barrel

that contained a few inches of shelled corn on the bottom.
So far as my experience goes, its ravages in this State are
almost equal to those of the grain moth and granary wee-
vil. I have bred it from flour, dried apples, dried peaches,
sweet-corn, field-corn, grits and corn-meal. In the latter it
was particularly abundant. Corn-meal set aside for a few
weeks becomes badly infested. Besides the above mentioned
products which it infests, it is recorded as infesting nuts,
condiments, sugars, jellies, yeast-cakes, herbs, roots, millet,
all kinds of dried fruits, raisins, prunes, and pea-nuts. In
fact it may be said that almost any kind of edible is sub-
ject to its attack.
The adult is a small moth of the family Phycitida,
to which family also belongs the Mediterranean flour moth
just referred to.
The indian-meal moth has a wing expanse of about
five-eighths of an inch. The basal one-third of the fore-
wing is of a dirty white, while the distal portion is reddish
brown. The body is -rather stout for moths of this group.
See fig. 5. a, enlarged.
The larva, or worm, is a small whitish insect, with
brownish yellow head, living within the silken tubes
which it spins through the meal, dried fruit, or other ma-
terial which it may infest. In fig. 5, c, the larva is illus-
trated much enlarged. At d, the head is shown, while e,
represents the enlarged first abdominal segment, showing
the arrangement of the spines, which is of great import-
ance in recognizing this species from others nearly allied.
The pupa is illustrated at b; it is seen to be a capsule
shaped body about three-eighths of an inch in length.
The wing-pads and antennae are distinctly visible on the
ventral surface.
The eggs are laid by the moth in the material on
which the larvae feed. The larvae spin silken tubes
through the food, and in these they live and finally un-
dergo their transformation. Infested meal becomes clot-
ted and lumpy from these silken threads binding the

grain together. The life cycle from egg to adult is com-
pleted in about one month, which being so short, allows
of many generations during the year. This insect prob-
ably breeds continuously throughout the year in the
greater portion of our State.




/ ' /
Y r A. ,' <

Fig. 6.-Calandra granaria, Linn.: a, adult; b, larva; c,
pupa; d, Calandra oryza, adult. Hair lines represent
natural length.
This insect is doubtless native to the Mediterranean
region where it probably was known before the Christian
era. Having been domesticated for so long a time, it
has now lost the use of its wings, which are present only
as rudiments, and cannot function for flight. In Florida
the granary weevil is not sufficiently abundant to be the
cause of much damage. It has been found infesting corn,
cow-peas, flour, corn-meal and rice.
The granary weevil is one of the true grain weevils

6'ri I-



of the family Calandridse. It is a short, stout-bodied bee-
tle, being about one-seventh of an inch long. The thorax
is marked with punctures arranged longitudinally as
shown in fig. 6, a. From the head there projects, in front,
a long snout-like proboscis, bearing the mandibles, and a
pair of elbowed antenna. The body is hard, and of a uni-
form chestnut-brown color. See fig. 6, a, enlarged.
The larva of this beetle is illustrated at b, fig. 6. The
pupa is shown at fig. 6, c.
The eggs are deposited singly in the grain. The fe-
male punctures the grain with her snout, and in this cav-
ity places an egg. The egg hatches into a very small,
white, footless grub, which eats further into the grain, and
in which it attains its growth and completes its transfor-
mation, emerging as an adult. In the smaller cereals but
one larva occupies a single grain. In a grain of corn
however, food is found for several. In the Southern States
six or more broods are probably raised annually. Ac-
cording to Mr. Chittenden, Assistant Entomologist, United
States Department of Agriculture, the time required for
the completion of the life cycle from egg to adult in the
lalitude of Washington is forty-one days. The length of
time of the life cycle varies much according to the season
and climate. The granary weevil is injurious, both in the
larval and adult stages.
Flour made from badly infested wheat, according to
Dr. Riley, has been the occasion of much suffering, and
even death.

(Calandra oryza, Linn.)
The loss caused by the work of this insect in Florida
equals, if it does not exceed that caused by the Angumois
grain moth. Together they are responsible for the greater
part of the injury done to stored grain.
The rice weevil takes this name from the fact that it
was first found in rice, but the name is rather misleading,

in that it feeds upon many kinds of grain and cereal prod-
ucts. It is doubtless indigenous to India, from where it
has becomewell distributed through commercial relations,
to many grain-growing parts of the globe. It was brought
to America from Europe, and it now enjoys quite a gen-
eral distribution in this country, where it is to be found in
every State and Territory, including Alaska. Its ravages
in the North, however, are not so severe as in the South.
The rice weevil bears a close resemblance to the gra-
nary weevil, both in size and appearance. It is somewhat
smaller, however, and differs from it, in that it is of a dull
brown color, and in having the wing-covers marked with
a reddish colored spot on each corner as shown in fig. 6,
d. The thorax of this species is densely marked with pits.
On the wing-covers the pits are arranged longitudinally.
As with the granary weevil the head bears a snout, on
which are born elbowed antennae.
The larva, when full grown, is about one-eighth of an
inch long, footless and fleshy, being quite similar to the
larva of the granary weevil.
The pupa is whitish, about an eighth of an inch in
length, very much resembling that of the preceding spe-
In this State this insect does more damage to corn
than to other cereals. It is to be found in the field early
in August. But it is when the corn has been gathered and
housed, however, that the rice weevil does its greatest dam-
age; here in the warm atmosphere it breeds rapidly, both
larvse and adults sharing in the work of destruction. Eggs
are deposited by the female in punctures made in the ker-
nels with their long snouts. But a few days are required
for them to hatch into grubs. From three weeks to two
months are required for this insect to pass through its life
cycle, depending upon the season. Corn infested with this
weevil has been reported as injurious to stock when fed,
and it is not improbable that meal made from infested
corn would be seriously injurious to man.


Fig. 7.-Bruchlus obtectus, Say. a, adult beetle; b, in-
fested bean. Natural size indicated by small figure.
This bean weevil and the four-spotted weevil are both
quite abundant in this State, and are frequently thought
to represent but one species. The bean weevil is proba-
bly an imported enemy, and has now become quite well
distributed over the greater part of the United States. As
early as 1860 it was noticed that it was attacking the
bean. It is a serious pest to this crop in the field and
when harvested.
The adult is a small beetle about one-tenth of an inch
in length, ashy black, with a slight brownish tinge. The
body is quite hard and somewhat flattened. See fig. 7, a.
The larva is a small, soft-bodied, grub-like insect,
passing its entire life in the bean. An infested bean is
illustrated at fig. 7, b.
Recent observations by Prof. Slingerland correct the
heretofore accepted statement that the eggs of this species
are deposited on the outside of the pod. His observations
show that the eggs are placed inside of the pod, the adults
gnawing a narrow slit along the ventral suture, through
which the ovipositor is thrust and the eggs deposited. No
doubt the eggs are sometimes deposited on the outside of
the pod, but it is probable that such cases are accidental,
and that the eggs are frequently destroyed before hatch-
ing. Several eggs may be deposited at one place. In
about two weeks these hatch, and the larva eat into the

beans. Several may occupy one seed, but each having
its separate cavity. The germ is rarely injured, it being
avoided as if it were distasteful. The larvae reach maturity
in the latter part of the summer, and transform into pupae
in the fall. Some of the beetles emerge in the fall while
others do not appear until the following spring, when
they deposit eggs again in the young and tender pods.
In stored beans the eggs are laid on the outside of
the beans, loosely attached. Many successive generations
may be raised in stored beans.

(Bruchus chinensis, L.)
This pest has been reported as doing much damage
to cow-peas in this State. During the late spring of the
present year some "wormy'" cow-peas were received from
a correspondent, which proved to be infested with the
Chinese cow-pea weevil. These were set aside to await
development. On August eleventh it was found that
sixty-one beetles had been bred from seventeen small
cow-peas. This indicates their fecundity and rapidity of
development. The peas were quite badly eaten, as
many as six and seven weevils having been bred from a
single pea.
The adult is about one-eighth of an inch in length,
and quite robust; the wing covers are reddish brown,
mottled, more or less, with a lighter shade, with the pro-
thorax and head darker. It bears a general resemblance
to the pea and bean weevils, but the body is stouter.



Fig. 9.-Bruchus quadrinmaculatas, Fabr.: a, adult; b and
c, egg from above and below e, head of mature
larva. front view. All enlarged.
The four-spotted bean weevil is a common and
abundant pest in many parts of the Southern States,
where it does much damage. It is an abundant pest in
Florida in many different localities. See fig. 9.
The eggs, when deposited on dried cow-peas, are
placed on the outside, being firmly glued on by a thin
cementing substance, which extends around them some-
what. The small oval eggs may be detected by the
unaided eye. Larva', after hatching, bore into the peas,
and begin to feed and grow. The pupal state is passed
within the pea, and from which the adult emerges and
deposits eggs for the next brood.


Fig. 10.-Bruchus pisi, Linn.: b, adult; c, full grown lar-
va; d, pupa; g, pea showing exit hole.
All enlarged except g.
This small beetle is quite familiar to all as the "pea-
bug," and will be recognized as the pea weevil, from the
accompanying figure. Originally confined to America, it
has now become quite well distributed to most parts of
the world.
The garden pea, which fortunately has not many
insect enemies, probably suffers more from this insect than
from any other. Its ravages on peas gathered for seed or
other purposes however, may fortunately be prevented.
The adult, shown in fig. 10, is a small beetle, about
one-fifth of an inch long, rusty black in color, marked
with more or less white on the elytra, or wing-covers, and
with a whitish spot on the caudal margin of the protho-
The larva is a short fleshy grub of a yellowish color,
with the head black. See fig. 10, c.
The eggs are very small, of a deep yellow color,
pointed on one end, and quite blunt on the other.
The pupa is shown at fig. 10, d. Fig. 11, a, illus-
trates the egg in its natural position on the pod and the
outline of tunnel to b; c, is a young larva entering the
interior of a pea; e, first larva, greatly enlarged.

/ / 1 \ -
Fig. 11.-Bruchus pisi: a, egg in natural position on pod;
c, young larva entering pea; d, points where eggs
have been laid on pod; e, first larva.
The eggs are deposited by the adult female, indis-
criminately on the young pods, soon after they have
begun to form. The larvae, hatching eat to the interior
and enter the soft peas within, only one grub occupying
one pea. The embryo of the pea is rarely destroyed by the
grub, but the plant resulting from its germination will be
feeble, and dwarfed.
When the larvae attain their growth and are ready
for transformation, they eat a round hole outward to the
shell of the pea, to allow for their exit as adults, and then
pass into the pupa state. Adults may emerge in the fall,
or in the spring.
The result of using weevily peas for seed should be
noted. Weevily peas as before stated are not able to pro-
duce strong, healthy vines from the fact that the stored up
nourishment for the plantlet in its early growth has been

destroyed, and it is hence unable to get a strong vigorous
start in the soil. It is quite important therefore, that
peas selected for seed should be free from weevils.


Fig. 12.-IEchocerus ma.cillosus, Fab.: a, larva ; b, pupa; c,
adult; length indicated by hair lines.
The slender-horned flour beetle is quite generally dis-
tributed over the Southern States where it is destructive,
feeding upon grain, both in field and when gathered. It
is also destructive to cereal products. This insect is doubt-
less indigenous to tropical America. Its northern limit is
probably in the region of the Ohio River.
The beetle is a small insect, a little more than one-
eighth of a inch in length, bearing much resemblance to
the species of Tribolium (fig. 13, a,) except that it is
somewhat smaller, and lighter in color. On the head are
two pointed protuberences. See fig. 12, c.
The larva is also much like the larva of Tribolium.
The habits are essentially the same. It is illustrated en-
larged at fig. 12, a. Fig. 12, b, is an enlarged drawing of
the pupa.

The habits and life history of this insect is for all
practical purposes the same as those of the confused flour


Fig. 13.-Tribolium confusum, Duv.: a, adult; b, larva; c,
pupa; enlarged.
The confused flour beetle probably does not occur to
great extent in this State. It is probable, however, that
before long it will be found among us in injurious num-
bers and hence is here considered.
By a study of fig. 13, a, an idea of the adult may be
obtained. It is a minute, elongated, reddish colored beetle
of the length shown by the hair line at the right of the
The larva and pupa are illustrated at fig. 13, b, and
c, respectively.
Eggs are laid in flour or other material infested,
which hatch into small inconspicuous larvae. In the due

course of time the adults appear and eggs for another
brood are laid. These insects increase with considerable
rapidity, and soon bring about a loss to the infested sub-
stances. They impart to the infested material a persistent
and disagreeable odor.

(Tribolium ferrugineum, Fabr.)
This insect is well known in Europe as a grain and
flour pest. Dr. Hagen records it as also quite injurious to
the collection of insects in the Museum at Cambridge. In
the United States it seems not to have attracted much at-
tention by entomological writers until the last few years.
It seems now to be on the increase, and has already be-
come a pest of no little significance. In Florida this
insect is quite abundant, doing much damage to all forms
of cereal produce, corn, cotton-seed, peanuts, dried fruits,
and like substances. It is by far the worst museum pest
with which we have to deal here at the Station. It at-
tacks the herbarium specimens, bird-skins, and insect col-
lection. To the latter it does most damage ; presence in
the specimens is indicated by the accumulation of dust
beneath, on the bottom of the box. If an infested speci-
men be examined it will be found to be perforated with
small holes which these pests have made. They feed
upon the dried tissues within where their larval and
pupal stages are passed.
Unless an insect case is exceedingly tight they find
their way inside, their flat bodies enabling them to pass
through very small cracks. Frequent inspections of the
collections, and fumigation with carbon bi-sulphide is the
means employed in keeping them in check.
The adult is a small beetle of a rust-red color, being a
little more than an eighth of an inch in length. The
body is greatly flattened, and is elongated. The insect
bears a close resemblance to Tribolium confusum, but it
differs from it in that in this species the antennae end in a

distinct club composed of three segments-(see fig. 13, e,
and f.)
The larva is about one-fourth of an inch in length, and
is quite active. It is of a whitish color, provided with
three pairs of legs, and with numerous hair-like bristles
distributed over the body.
Eggs are deposited by the adult females, in the food
upon which they feed. These hatch into minute, pale
colored larvaw which when in flour, meal, and similar
products, are rarely detected on account of their small
size. These grow into full-sized larve which pupate and
give origin to the adult beetles. The entire life cycle re-
quires probably from thirty-five to forty days. In this
climate it is quite probable that they breed throughout
the year. This insect will attack corn while yet in the
field, doing damage before the corn becomes hard.


a 6

Fig. 15.-Cathartus gemellatus, Duv.: a, larva; b, pupa;
c, adult; all enlarged.
This small red beetle is a pest of considerable impor-
tance in the Southern States. It attacks corn, peas, and

the cotton-bolls of the cotton-plant in the field, and will
continue breeding in corn after it has been gathered.
Specimens of this insect were also found infesting bird-
skins in the college collection.
The adult is a small, flat, reddish beetle, measuring
one-tenth of an inch in length. In figure 15, c, it is illus-
trated much enlarged. The hair-line to the right indi-
cates the natural length.
The larva when full grown is about the same length as
the adult. It has a somewhat flattened body, of a whitish
yellow color, with the head brownish. See fig. 15, a.
The eggs, which are laid at the base of the grains of
corn, soon hatch into small larvae which at once eat into
the grain. In the course of three weeks tile larvae be-
come full grown, and transform into pupte. This state
last about two weeks, when the adults appear. These
insects are very prolific and in infested corn stored away
in the fall, they soon become quite numerous. It is prob-
able that eight or ten generations are reared annually,
and in some portions of Florida breeding probably


Fig. 16.-Silvanus surinamensis, Linn.: a, adult; b, pupa;
c, larva.

The saw-toothed grain beetle is a small insect of the
family Oucujidae. The majority of the insects of this
family live under bark and are carnivorous, both in the
larval and adult stages. The corn Silvanus, and some
others of this family, however, feed upon grain. The
corn silvanus is to be found over almost the entire globe,
infesting granaries, barns, dwelling houses, grocery
stores, and in fact almost any place where it may find
food. In Florida it is very common in flour, meal, corn,
dried fruits, rice, and bread. It is a common pest in the
museum specimens here at the Station, and with the
rust-red flour beetle is responsible for much of the dam-
age done to the entomological collection.
The adult Silvanus is only about one-tenth of an
inch in length, with a slender, much flattened body of a
chocolate brown color. The thorax on each side is pro-
vided with six teeth-like projections, while the upper sur-
face has two shallow longitudinal grooves. Fig. 16, a.,
represents the beetle greatly enlarged. The hair lines to
the right represent the natural length.
The larva, represented in fig. 16, c, is a yellowish
white, worm-like insect about one-fourth of an inch in
length, provided with three pairs of well developed legs.
It is exceedingly active, readily passing from one seed to
another for food.
The pupa is illustrated in fig. 16, b, much enlarged.
It is a little shorter than the beetle, of a yellowish white
color, and has spinous processes on both sides of the thorax
and abdomen.
The life cycle in this climate requires about four
weeks; it is thus readily seen that there may be many
generations during the year. The eggs deposited among
the grain soon hatch and the active larvae begin to feed.
When ready to pupate the larva constructs a protecting
case by jointing together bits of trash and food material
with a silken secretion. In this case the pupal state is
passed, and from which the adult beetle emerges later on.

Unlike the Angumois grain moth the adult of this
insect feeds upon the grain with the larva.

(Brachytarsus alternates, Say.)
This is an insect that has not heretofore been re-
corded as injurious to stored grain. The larve of the
genus Brachytarsus have been supposed to be parasitic on
scale insects, or Coccids, but this species has been found
feeding, both in the larval and adult condition, on stored
corn, cow-peas and English peas, and doing serious dam-
age. The English name of grain-eating Brachytarsus has,
therefore, been given to this species, indicating its grain-
eating habits.
Many of the species of the family Anthribidw, to
which this insect belongs, infest seeds, and the stems of
plants, in their larval state; it is not the cause of much
surprise, therefore, to find this species of snout beetle feed-
ing upon various seeds.
The adult is quite a thick bodied insect of an ashy
brown color, and densely hairy. The wing-covers are
marked with punctured lines, and a series of gray and
black spots. These spots are due to the presence or ab-
sence of the light colored hairs. It is about one-fifth of
an inch long.
The pupa is about five thirty-seconds of an inch in
length, whitish, and densely covered with short spine like
protuberances. Rather long hairs are sparsely distributed
over the body. The head is bent down on the ventral
surface of the prothorax. Each wing-cover is marked with
two pairs of rather prominent lines, the lines of each pair
curving in and meeting each other at the distal extremity
of the wing-cover.
The larva measures about three-sixteenths of an inch
in length, is whitish in color, and footless. The body is
quite robust, sub-cylindrical in shape, somewhat flattened

on the ventral surface. The caudal end is rather bluntly
rounded, the cephalic end tapering slightly from about
the third segment. Labrum and mandibles yellow, the
tips of the mandibles being almost black. The body
is quite thickly covered with hairs.
A single larva only occupies the interior of a kernel
of corn, eating out a broad cavity from the base to the
opposite end of the kernel, where it is usually enlarged,
and a small portion eaten out to the hull before pupating.
It would seem that the larva enters the kernel at its base
where it may be more easily penetrated. An infested
grain usually appears quite sound exteriorly until the
pupal stage is reached when the cavity may be detected
through the thin hull. The adult escapes by gnawing
through the thin membrane to the exterior. Immediately
after coming from the pupa state the adults are reddish
brown, not acquiring their final color and activity for two
or three days. Older specimens liberated from their cav-
ities immediately took flight; they are surprisingly quick
in the use of their wings, and thus frequently escape.
Adults kept in confinement fed readily on cow-peas
and corn, showing no preference to any part of the seed.
Eggs have not as yet been discovered, nor has the
manner of ovoposition been observed. Experiments in-
dicate that under favorable conditions the life cycle may
be completed in five or six weeks. Breeding continues
as late as November and probably throughout the winter.

(Catorama punctulata, Lee.)
This small beetle, which may be called the Catorama
flour beetle, is an insect of considerable abundance in
corn, corn-meal, and flour. It is also quite destructive to
museum specimens, particularly bird-skins and insects.
It belongs to the Ptinids, a family of small beetles, which
feed mostly upon vegetable matter in an incipient stage
of decay.

The beetle is about one-eighth of an inch long, body
rather elongate, the head being strongly deflexed, and
when in repose bent up on the under surface of the pro-
thorax. The beetle is of a dark brown color, quite densely
and uniformly covered with light yellowish colored hairs.

Many different substances have been recommended
at various times for the destruction of insects injurious to
stored grain. Some of these are of value in a greater or
less degree. Others are quite worthless. Certain pre-
ventive measures that are in practice in the South seem
to be of some value. Most farmers in Florida do not
husk their corn when harvested as the husks offer consid-
erable protection against lepidopterous insects, and weevils.
It is also a common practice to gather the corn and leave
it in heaps in the field for a few days to allow the ants to
destroy the larve that infest it. Others leave an open
space in the roof of the crib so that rain may enter and
thoroughly wet the corn, bringing about a period of heat
that is said to destroy the infesting weevils and larvae,
doing no harm to the corn. It is a rather prevalent idea
that certain varieties of grain are weevil proof, and in-
quiry is sometimes made for definite information on this
subject. It should be known that there is no variety of
grain that is weevil proof. However, the condition in
which the grain is kept is of some importance. In general,
unhusked grain is much freer from attack than grain that
has been husked. Corn is much more subject to attack
when shelled than when left on the cob. Those varieties
of corn that have hard, flinty kernels and close fitting
husks are not so subject to attack as other varieties. But
it is hardly profitable to discuss these various preventive
measures as we have in carbon bi-sulphide, a remedy that
is effective, cheap, and simple in its application. Carbon-
bi-sulphide was first recommended for use against insects,
on a large scale, by Dr. Riley in 1879. Its use is yearly

becoming much more general. Carbon bi-sulphide is a
chemical compound of the formula C S.; as the name
and symbol indicate, it is a bisulphide of carbon. It is
a colorless liquid, having a very strong, disagreeable odor,
and is quite volatile, vaporizing at an ordinary temperature.
It is also highly inflamable, and hence in its use care
should always be taken that no fire of any kind be brought
near it. A lighted match, lighted pipe or lighted cigar
should not, under any circumstances, be brought near a
building that is being fumigated. The fumes of this
compound are very poisonous. Therein lies its value as
a destructive agent against insects. The deadly fumes of
this compound enters their breathing tubes with the air
which they breathe and quickly brings about their death.
The fumes are also poisonous to other animals, but there
is little danger to man from inhaling a small quantity.
The application of carbon bi-sulphide is but a process
of fumigation, and in order that the fumes may be kept
within the bin or crib they should be as tight as possible.
If they are not tight much more of the compound will be
required. Bins may be made much tighter by covering
them as much as possible with cloths and blankets.
Oil cloth and heavy canvas are excellent. In a moderate-
ly tight bin one pound of the sulphide should effectually
fumigate one hundred bushels of grain. Several meth-
ods are in use for the application of the sulphide. A ball
of cotton tied to a stick may be saturated with the com-
pound and pushed down to near the center of the grain.
By doing this, it is believed that the air becomes more
evenly saturated with the sulphide. Another method
consists in pushing a long pipe, in which is a tight fitting
rod, down into the grain. The rod is withdrawn and
the carbon bi-sulphide poured into the tube, and after
which, it may be withdrawn. But the most effective way
of applying the compound, when the bins are moderately
tight, is to pour the reagent in shallow dishes or pans
which may be placed here and there on the top of the
grain. The compound being volatile rapidly vaporizes,
and being heavier than air, sinks and becomes thor-

oughly diffused throughout the bin. Balls of cotton or
waste may be saturated with the sulphide and distributed
over the surface of the grain. In case all the insects are
not destroyed by one application, another should be
made. Grain treated with the sulphide is not injured
for food purposes, or for seed. To secure the very best
results from the use of carbon bi-sulphide a tight quaran-
tine bin should be made, somewhat separated from the
other buildings, where the grain may be subjected to a
thorough fumigation before being stored away. Here the
insects that have gotten into the grain while in the field
will all be destroyed, thus removing a serious source of in-
fection to the stored grain. Before a crib is to receive
the harvested and fumigated grain, it should be thor-
oughly fumigated and cleaned. All cracks, loose fittings,
and holes should be stopped up as well as possible.
Grain having been fumigated and placed in a tight
crib or bin that has been cleaned will suffer but very little
from the ravages of insects during the year. Should they
become troublesome at any time another application of
the sulphide should be made.
Peas, rice, shelled-corn and other seeds are frequent-
ly stored in barrels or boxes. These may be easily fumi-
gated by saturating a piece of cotton with four or five
ounces of carbon bi-sulphide and placing it on top of the
seed, throwing a heavy cloth over the top of the barrel
to keep the fumes within. It should be noted that the
treatment given above, is for grain that has been husked
or hulled. Where the grain is not husked a somewhat
larger quantity of the bi-sulphide will be needed.
It is the prevailing custom in this State to harvest
corn unhusked, on account of the protection afforded by
the husks against weevils and moths. The husks, how-
ever, interfere with the best results that may be obtained
from the use of carbon bi-sulphide, as the fumes do not so
readily reach the insects.
The protection afforded by the husks against grain
insects is far less than the advantages gained by having
it husked so that it may be the more thoroughly sub-
jected to the fumes of the insecticide. It is therefore re-

commended that corn be husked when harvested, and
carbon bi-sulphide be used to keep it free from weevils and
other insects.
Carbon bi-sulphide may be purchased at drug-stores
for twenty to thirty cents per pound. It may be pur-
chased at wholesale rates in fifty pound cans of Mr. Ed-
ward R. Taylor, Chemist, Cleveland, Ohio, at about ten
cents per pound. Arrangements might be made with
local druggists, who would order carbon bi-sulphide in
fifty pound cans, or larger lots, and who could then afford
to sell it much cheaper than the usual retail price.

I desire to express my thanks to the United States
Department of Agriculture, through Mr. L. 0. Howard,
United States Entomologist for the use of figures 1-7, 10-
13, and 16; to Prof. Slingerland, of Cornell University,
for the use of figure 9; to Prof. H. E. Weed, of the Mis-
sissippi Station for figure 15.
Dr. E. A. Swartz, and Mr. F. H. Chittenden, of the
Division of Entomology at Washington, have kindly de-
termined some of the beetles herein considered for me.
Prof. Rolfs has kindly looked over my manuscript.

University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs