j

CIRCULAR No. 113.

Issued November 13, 1909.

United States Department of Agriculture,

BUREAU OF ENTOMOLOGY,

L. O. HOWARD, Entomologist and Chief of Bureau.

THE CHINCH BUG.

(Blissus leucopterus Say.)

By F. M. WEBsTER,

In Charge of Cereal and Forage Insect Investigations.

INTRODUCTION.

Few insects, and certainly no other species of the natural order to
which this one belongs, have caused such enormous pecuniary losses

as has the chinch bug (Blissus leucopterus
Say) (fig. 1). No other insect native to the
Western Hemisphere has spread its devastat-
ing hordes over a wider area of country (see
map, fig. 7) with more fatal effects to the
staple grains of North America than has this
one. But for the extreme susceptibility of
the very young to destruction by drenching
rains and to the less, though not insignificant,
fatal effect during rainy seasons of the para-
sitic fungus Sporotrichum globuliferum Speg.,
on both the adults and young, the practice of
raising grain year after year on the same
areas, as is followed in some parts of the
United States, would become altogether un-

Fie. 1.—Chinch bug (Blissus leu-
copterus): Adult of long-winged
form, muchenlarged. (Author’s
illustration.)

profitable. Some of this insect’s own habits, emphasizing as they do
the effects of meteorological conditions, are among the most potent
influences that serve to hold it within bounds by giving its tendency
to excessive increase a decidedly spasmodic character. .

9917—Cir. 113—09——1

2

DESCRIPTIONS OF THE DIFFERENT STAGES.

The egg (fig. 3, a, b)—The average length of the egg is three
one-hundredths of an inch; in shape it is elongate-oval, the diameter
being scarcely one-fifth the length. The top is squarely docked and
surmounted with four small, rounded tubercles near the center.

Fie. 2.—Chinch bug: Adults of short-winged form, much enlarged. (Author’s illustration.)

When newly deposited the egg is pale or whitish and translucent, but
with age it acquires an amber color, and finally shows the red parts
of the embryo within, and especially the eyes toward the tubercled
end. The size increases somewhat after deposition, and the length
will sometimes reach nearly four one-hundredths of an inch.

Larval stages (fig. 3, ¢, d,
e, f).—The newly hatched
larva, or nymph, is pale yel-
low, with simply an orange
stain on the middle of the
three larger abdominal
joints. The form scarcely
differs from that of the ma-
ture bug, being but slightly
Via.3.—Chinch bug: a, b, Eggs; c, newly hatched larva, more elongate ; but the

oc nmph: 6 stan; larva ale festa f° tarsi have only two joints,
dicated at sides; h, enlarged leg of perfect bug; j, tarsus of and the head is relatively
ae enlarged; 1, Proboscis or beak, enlarged. broader and more rounded,
while the joints of the body
are subequal, the prothoracic joint being but slightly longer than any
of the rest. The red color soon pervades the whole body, except
the first two abdominal joints, which remain yellowish, and the legs
and antenne, which remain pale.

After the first molt the red becomes bright vermilion, contrasting
strongly with the pale band across the middle of the body, the pro-
thoracic joint is relatively longer, and the metathoracic shorter. The

LCinei Si]

3

head and prothorax are dusky and coriaceous, and two broad marks
on mesothorax, two smaller ones on metathorax, two on the fourth
and fifth abdominal sutures, and one at tip of abdomen are generally
visible, but sometimes obsolete; the third and fourth joints of
antenne are dusky, but the legs are still pale. After the second
molt the head and thorax are quite dusky and the abdomen duller
red, but the pale transverse band is still distinct; the wing-pads
become apparent, the members are more dusky, there is a dark-red
shade on the fourth and fifth abdominal joints, and, ventrally, a
distinct circular dusky spot, covering the last three joints.

The last-stage larva (fig. 3, g).—In the last-stage larva, or nymph,
sometimes called the ‘“‘pupa,”’ all the coriaceous parts are brown-
black, the wing-pads extend almost across the two pale abdominal
joints, which are now more dingy, while the general color of the
abdomen is dingy gray; the body above is slightly pubescent, the
members are colored as in the mature bug, the three-jointed tarsus
is foreshadowed, and the dark horny spots at tip of abdomen, both
above and below, are larger.

The adult.—There are two forms of the fully developed insect, but
it is not known that the young of these two forms differ in any respect.
One of these forms is known as the long-winged form and is the only
form that occurs over most of the country between the Rocky
Mountains and the Allegheny Mountains, and is the one originally
described. This form is illustrated in figure 1.

The second form is much like the first, with the exception of the
wings, which are more or less abbreviated, as shown in figure 2.
This form occurs along the seacoasts and in the East extends inland
along the lower lakes to northern Illinois. It is not abundant,
however, west of a line drawn from Toledo, Ohio, to Pittsburg, Pa.
Throughout the territory in which this short-winged form is found
there are also intermingled with them individuals of the long-winged
form. Both of these forms may be described as black, with numerous
hairs also black, and with the under wings white. The upper wings
are whitish, with a black spot on each. They are about one-fifth of
an inch or lessin length and may be easily recognized by the accom-
panying illustrations (figs. 1, 2, 3, h, 7, 7).

SEASONAL HISTORY.

Over the territory covered by the long-winged form, as previously
given, the insect has two generations each year. The young of the
first generation appear in May and June, and those of the second
generation in August and perhaps as late as September. The adult
insects (figs. 1, 2) pass the winter among matted grass, fallen leaves,
and other rubbish, and come forth from their hiding in spring and

[Cir. 113]

4

spread to the grain field, where they deposit their eggs. After the
egos are hatched the old bugs die, and the young hatching from these

Fig. 4.—Corn plant 2 feet tall infested with chinch bugs. (<Author’s illustration.)

egos cluster upon the plants and begin at once to live upon the juices.

Figure 4 illustrates a corn plant with the chinch bugs clustering

upon it. The egg-laying season extends over a considerable period
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4)

and chinch bugs of all ages, sizes, and colors are found intermingled.
By August the majority of the first generation have reached the adult
stage, at which time the eggs are deposited for the second generation,
which hatches and matures like the previous one, nearly all indi-
viduals reaching their full development by late fall or early winter.

In the eastern portion of the country, where the short-winged form
prevails, it is doubtful if there is more than a single generation annu-
ally. This short-winged form differs very much in its habits from the
long-winged form, the first passing the winter in the meadows, which
it usually attacks in preference to grain crops, while with the long-
winged form, during the period known as the Indian summer, the
developed bugs may be observed flying about, evidently searching
for winter quarters. With the short-winged form these migrations
to and from the places of hibernation are impossible, the insects being
totally incapable of flying because of their short wings. <A hint of
this characteristic may be witnessed in the case of the exclusively
long-winged form, for in migrating from one field to another, even
though fully half of the individuals may have fully developed wings,
ample for flight, they often travel on foot with the young, even going
considerable distances from one field to another.

Throughout the Middle West, then, where this insect does its great-
est injury, the crops suffer from two attacks annually, although the
later one is seldom noticed. It must be remembered, however, that,
although attracting little or no attention, this later attack is of the
utmost importance, for, if there are but few of the second generation
developing to adults, there can be no serious outbreak the following
spring. If, on the other hand, there are enormous numbers of adults
developing in the fall and going into winter quarters, there is a proba-
bility that, with weather during April and May favorable for their
development, there will be an excessive abundance the following year.

It must be remembered that each female of the species is capable
of laying from 1 to 500 eggs, and she will scatter them during a period
of from two to three weeks. The time required for the eggs to hatch
is from about ten days to three weeks, and it requires about forty days
for the young to become fully developed after hatching from the egg.

HIBERNATION.

While the matter of winter quarters has been previously mentioned
in a general way, the winter habit of the pest is of such importance
that this phase of its life history is deserving of full explanation.
Again and again serious and destructive outbreaks of the pest in wheat
fields have been traced directly to the influence of shocks of corn
fodder allowed to stand in the fields throughout the winter. The
chinch bugs which flocked to these corn shocks the previous autumn

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6

were protected throughout the winter, migrating from them in the
spring and spreading over the wheat field. In other cases destructive
outbreaks have been traced directly to woodlands bordering upen the
fields, the chinch bugs beginning their destruction along the margins
of the fields nearest to the woodlands, having passed the winter
among the fallen leaves. So, too, have destructive outbreaks in the
Middle West been traced to the matted grass and fallen leaves border-
ing hedges of Osage orange (fig. 5). The farmer must understand
that it is to such places as these that the chinch bugs flock in the fall,
and whatever measures can be effected to prevent their wintering

Fic. 5.—A road between two farms, with neglected hedges on either side affording ample protection for
destructive insects during winter. (Author’s illustration).

about his fields in this manner will be measures of protection to his
crop from attacks of their offspring in the following year.

In the timothy meadows of New England, New York, and northern
Ohio these conditions are of less importance, because there the insects
pass the winter largely in the meadows themselves, and do not
migrate to or from these places, except to travel on foot. Chinch
bugs will stand almost any degree of cold, provided it is continuous
and they are fairly well protected from sudden changes. ‘Thus it is
that the farmer may be able to take advantage of their hibernation
to deal a disastrous blow to their occurrence in his fields during late
spring and early summer.

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7

FOOD PLANTS.

Over the western country the major portion of the damage is that
accomplished in fields of wheat, barley, rye, and corn, the outbreak
generally originating in wheat or barley fields and the bugs migrating
at harvest to the cornfields. In the eastern part of the country,
where the timothy meadows are the most seriously infested, this is
not the case, and here the migrations are as likely to be to the timothy
meadows as to the fields of corn where both are equally within reach.
Rye and oats are less liable to infestation. The chinch bugs attack
sugar cane in Mexico, according to Mr. Albert Koebele. They are
known to attack the following grasses: Forked beard-grass ( Andropo-
gon furcatus), broom beard-grass (A. scoparius), oat-grass (Arrhena-
therum), bur-grass ( Cenchrus tribuloides), millet, witch grass (Panicum
capillare), barnyard grass (Panicum crus-galli), Phragmites sp?, sor-
ghum, kaffir corn, large crab-grass (Syntherisma sanguinalis), timothy,
yellow foxtail (Jzophorus glaucus), green foxtail-grass (I. viridis), Ber-
muda grass ( Capriola dactylon), and what is locally known in Florida
as St. Augustine grass. Prof. Lawrence Bruner has also found it
feeding upon so-called buckwheat (Polygonum dumetorum or P. con-
volvulus).

It will thus be seen that the insect has an ample food supply outside
of the cultivated fields.

LOSSES CAUSED BY CHINCH BUGS.

It would appear that this pest first made its presence known by
its ravages in the wheat fields of the North Carolina farmers, for we
are told that “in 1785 the fields in this State were so overrun with
them as to threaten a total destruction of the grain. And at length —
the crops were so destroyed in some districts that farmers were obliged
to abandon the sowing of wheat. It was four or five years that they
continued so numerous at this time.’’@

In the year 1809, as stated by Mr. J. W. Jefferys,’ the chinch bug
again became destructive in North Carolina to such an extent that in
Orange County farmers were obliged to suspend the sowing of wheat
for two years. In 1839° the pest again became destructive in the
Carolinas and in Virginia, where the bugs migrated from the wheat
fields at harvest to the corn, and in 1840 there was a similar outbreak,
and both wheat and corn were seriously injured. In all of these cases,
however, there is no recorded estimate of the actual financial losses
resulting from the attacks of the chinch bug. According to Le Baron,

a Webster on Pestilence, Vol. I, p. 279. Not seen. Quoted from Fitch.
b Albany Cultivator, first series, Vol. VI, p. 201.
¢The Cultivator, Vol. VI, p. 103.

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8

during the years from 1845 to 1850 the insect ravaged Illinois and
portions of Indiana and Wisconsin, and in 1854 and 1855 it again
worked serious injury in northern Illinois. The writer’s earliest recol-
lection of the chinch bug and its ravages in the grain fields of the
settlers on the prairies dates from this last outbreak. Mr. B. D.
Walsh estimated the loss to the farmers of Illinois in 1850 at
$4,000,000, or $4.70 to every man, woman, and child living in the
State.

In 1863, 1864, and 1865 the insect was again destructive in Illinois
and other Western States, its ravages being especially severe in 1864,
when we have another attempt at computation of the financial loss.
Dr. Henry Shimer, of Mount Carroll, Il., who had carefully studied
the chinch bug, estimated that “three-fourths of the wheat and one-
half of the corn crop were destroyed by the pest throughout many
extensive districts, comprising almost the entire Northwest.” In
criticizing the doctor regarding another point, Walsh and Riley?
admit that the estimate was ‘‘a reasonable one,” and, taking if as a
basis, with the actual cash price per bushel, computed the loss at
about 30,000,000 bushels of wheat and 138,000,000 bushels of corn,
with a total value of both amounting to over $73,000,000. Of course,
all computations of this sort are necessarily only approximately
correct, but there is more likelihood of an underestimate than of an
overestimate in this case.

There was a serious outbreak of the chinch bug in the West in the
year 1868, and again in 1871, but in 1874 the ravages were both wide-
spread and enormous. Le Baron computed the loss in 1871 in seven
States, viz, Iowa, Missouri, Illinois, Kansas, Nebraska, Wisconsin,
and Indiana, at $30,000,000. Riley computed the loss in Missouri
alone in the year 1874 at $19,000,000, and added the statement that
for the area covered by Le Baron’s estimates in 1871 the loss in 1874
might safely be put down as double, or upward of $60,000,000. ¢
Dr. Cyrus Thomas, however, estimates the loss to the whole country
for the same year at upward of $100,000,000. ¢

The next serious outbreak of the chinch bug of which we have an
estimate of the losses occurred in 1887, and covered more or less
territory in the States of Kentucky, Ohio, Indiana, Illinois, Wisconsin,
Minnesota, Iowa, Missouri, and Kansas. In this case the damage
was estimated by the United States statistician, Mr. J. R. Dodge, at
$60,000,000, the heaviest losses occurring in Illmois, Iowa, Missouri,
and Kansas.¢ ‘This gives us as the estimated loss in the thirty-eight

a American Entomologist, Vol. I, p. 197, 1869.

b Second Report State Entomologist of Illinois, p. 144.
¢ Seventh Report State Entomologist of Missouri, pp. 24-25.
@d Bulletin No. 5, U. S. Entomological Commission, p. 7.

¢ Report of U. S. Commissioner of Agriculture for 1887, p. 56.
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3)

years from 1850 to 1887, both inclusive, the enormous sum of
$267,000,000.

There was a serious outbreak in Kansas, Iowa, Minnesota, and
Illinois, having its beginning probably as early as 1892, but reaching
its Maximum severity, as in Ohio, in 1896. The loss in Ohio during
the years 1894, 1895, 1896, and 1897 could not have fallen far short
of $2,000,000. If we could have careful estimates of the loss during
the last fifteen years-it would in all probability swell the amount to
considerably in excess of $350,000,000 for the period from 1850 to
1909. (See map, fig. 6.)

Fic. 6.—Areas in the United States over which the chinch bug occurs in most destructive numbers.
(Author’s illustration.)

NATURAL ENEMIES OF THE CHINCH BUG.

Chinch bugs have few natural enemies, none of which, owing,
perhaps, to their repugnant odor, appears to be of any very great
importance when it comes to suppressing a serious invasion. They
are far more fortunate than most insects in escaping the attacks of
natural enemies that exert a tremendous influence in holding other
species in check.

THE BOBWHITE OR QUAIL.

Inland, the common “‘quail’’ or bobwhite (Colinus virginianus) is
the only bird that can be said to devour the chinch bug in considerable
numbers. It is said that from 300 to 400 chinch bugs have been
found in the crops of bobwhites; 100, however, is the largest number
found so far by the Biological Survey. As the bobwhite is one of

9917—Cir. 113—09 2

10

our most highly prized game birds, it is slaughtered annually in
tremendous numbers, frequently with no other object in view except-
ing for gain. Some also are killed by flying against electric wires,
while during severe winters entire coveys are sometimes smothered
or frozen under the snow. As a result, the helpfulness of the quail
against chinch bugs is greatly diminished. It would seem that as
important an enemy of the chinch bug as this bird is known to be
would receive protective immunity throughout the agricultural
regions and that farmers would see to it that protective laws were
not only enacted but also stringently enforced.

The following list will show the degree of protection offered the
quail by legislative enactment in the States where the chinch bug is
the most destructive (see map, fig. 6). The close seasons for quail
in the several States, during which killing is prohibited by law, are
as follows: .

Maine, all the year.

New York, December 1 to November 1, except in Dutchess, Putnam, Richmond,
Rockland, and Westchester counties, where it is closed until 1910.

Pennsylvania, November 15 to October 15.

Ohio, December 5 to November 15.

Indiana, January | to November 10.

Illinois, December 10 to November 11.

Minnesota, December 1 to October 1.

Iowa, December 15 to November 1.

Missouri, January 1 to November 1.

Nebraska, all the year.

Kansas, December 15 to November 15.

Oklahoma, February 1 to November 15.

Texas, February 1 to November 1.

The breeding season from latitude 38° northward to Canada begins
in May and continues through July and occasionally into September.

OTHER BIRD ENEMIES.

To what extent tne birds of the coast region feed upon the chinch
bug it is impossible to say. However, among the bird enemies
of the pest are the prairie chicken, redwing blackbird, catbird,
brown thrush or thrasher, meadowlark, house wren, tree swallow,
horned lark, Arkansas kingbird, Traill flycatcher, seaside sparrow,
savanna sparrow, song sparrow, tree sparrow, and barn swallow.

THE FROG.

Dr. Cyrus Thomas quotes Ross and others as stating that the
common frog is an enemy of the chinch bug. While this is probably
true, it is nevertheless well known that comparatively few frogs
frequent grain fields, as a rule, and thus the benefit derived from
their attacks is of too little importance to merit further notice.

2 From Farmers’ Bulletin No. 376, pp. 18-29, 1909.
[Cir, 113]

11

INSECT ENEMIES.

Of the invertebrate enemies of the chinch bug the same may be
said as of the frog. The writer has occasionally found a chinch bug
containing a species of Mermis, or “hair snake.” Occasionally,
also, ants may be seen dragging these bugs away, while lady-beetles
have sometimes been found to devour them, as recorded by Walsh
and Forbes. Perhaps the worst insect enemies of the chinch bug
are to be found among its comparatively near relatives—the insidious
flower bug (T'riphleps insidiosus Say), (Anthocoris pseudo-chinche of
Fitch’s Second Report), and Milyas cinctus Fab., the latter being
reported by Thomas as the most efficient of the insect enemies of
this pest, while Riley found that the former also attacked it. Pro-
fessor Forbes ascertained, by examinations of the contents of the
stomach of a ground beetle (Agonoderus pallipes Fab.), that one-
fifth of the total food of this species was composed of chinch bugs.
Shimer and Walsh both claim that lacewing flies (Chrysopa spp.)
destroy chinch bugs, and they are doubtless correct. The writer
has also very often found dead chinch bugs entangled in spider
webs, although whether killed for food or by accident it has been
impossible to determine.

NATURAL CHECKS OTHER THAN ANIMALS.

There are two natural checks to the increase of the chinch bug
other than animal enemies. One of these is vegetable in nature, being
a fungus, the other meteorological, and the interrelation of the two
is so close that the former is almost entirely dependent upon the
latter. It will at once be seen that the chinch bug, occurring, as it
does, from but little north of the equator to nearly a latitude of 50°
north and from an elevation of upward of 200 feet above the sea
level in the Imperial Valley of southern California to an elevation
of upward of 6,000 feet in the mountain regions, must be able to
withstand almost every conceivable variation of climatic conditions.
(See map, fig. 7.) So far as the influence of temperature is con-
cerned, it is only in the most unprotected situations that severe
winter weather appears to have much effect in regulating the abun-
dance of the pest, although frequent freezing and thawing is known
to be fatal to a large percentage of the adults if these occur in exposed
situations. Thus temperature may practically be eliminated from
consideration. It is also true that the nearly developed insect will
withstand not only the humidity of the Tropics, but continuous
drenching rains of more northern latitudes. It is at the time of
hatching that the species is most susceptible to meteorological con-
ditions. Frequent drenching rains during the hatching season are
fatal to the pest almost to the extent of extermination, and it is due

[Cir. 113]

12
to this more than to any other influence that the chinch bug is kept
within the limits of its present abundance and destructiveness.

It matters little how great a number of these insects pass the winter
in safety, provided there are sufficiently prolonged, drenching rains

Fie. 7.—Map of North America showing areas infested by chinch bug. (Author’s illustration.)

during the hatching period. Again, with an excessive abundance

of individuals developing from the first generation, if at the time

of the hatching of the young of the second generation there are

frequent drenching rains, an outbreak the following year is prevented.

Thus it is that although an outbreak may seem inevitable as the
[Cir. 113]

13

season for the ravages of the chinch bug draws near, there is often a
radical reduction instead of an increase in numbers. The forecasting
of chinch-bug outbreaks is therefore based wholly upon the fore-
casting, months in advance, of meteorological conditions that are
likely to occur at certain periods. If the farmer would but watch
the seasons, he need not be taken unawares by chinch-bug outbreaks,
as dry weather during the two breeding seasons is usually sufficient
to precipitate an invasion the following year, provided that, at the
critical period or time of hatching, rains do not destroy the young.
The general statement may be made that throughout the Middle
West a dry June followed by a dry August is favorable for the develop-
ment of chinch bugs. These dates will of course vary, and must not
be applied to the more southern or more northern localities.

PARASITIC FUNGI.

The fact that the abundance and consequent influence of fungous
enemies of the chinch bug are almost entirely dependent upon
meteorological conditions is sufficient to place them in a secondary
position, even though they may, under favorable weather conditions,
act as natural checks.

Dr. Henry Shimer“? long ago made the truthful and important
statement that ‘‘this disease among the chinch bugs was associated
with the long-continued wet, cloudy, cool weather that prevailed
during a greater portion of the period of their development.’’ These
are precisely the conditions under which these fungi have been
observed to prove the most fatal to the chinch bug during recent
years where their introduction among the host insects was accom-
plished by artificial means. Although Shimer probably never
anticipated the artificial cultivation of his ‘‘disease”’ and the results
which have since been obtained from its artificial dissemination in
the fields, yet his careful and painstaking studies must ever be asso-
ciated with the application of fungous diseases in the destruction
of insects in America.

The principal fungus to be artificially employed in destroying
chinch bugs has come to be known as the chinch-bug fungus (Sporo-
trichum globuliferum Speg.), and this is the one used by Doctor Snow
in Kansas for artificial introduction into localities where there is an
overabundance of these bugs.

Doctors Roland Thaxter and S. A. Forbes devised a method of
artificial cultivation, the latter using a basis of sterilized mixture of
beef broth and corn meal. As this fungus has many other host
insects, it is probably present to a greater or less degree throughout
the country every year. There is no doubt that during wet weather

a Proc. Acad. Nat. Sci. Phila., May, 1867.
[Cir. 113]

14

considerable benefit may be derived from the artificial cultivation
and application of this fungus, but its efficiency is very dependent
upon this meterological condition, and, as has already been shown,
chinch bugs develop in the greatest abundance in dry seasons. It
will thus be seen that only during unusual seasons—that is to say,
seasons that have been dry while the chinch bugs were hatching from
the eggs but wet afterwards—can satisfactory results be expected
from this measure.

The effects of this fungus have probably been overestimated,
although there is no doubt whatever that those who have been most
instrumental in popularizing this means of destroying chinch bugs
were thoroughly sincere and honest in their statements. One very
important element of deception to the ordinary farmer, when
assuming the results of the effect of this fungus, lies in the fact that
chinch bugs, when molting for the last time and passing from the
last-stage larva to the adult, hide away under the sheaths of corn
and other grain, and, casting the larval skin, make their escape,
leaving this behind. These cast skins will occur in immense num-
bers in such places and frequently become covered with a white mold.
It is almost impossible for anyone except an expert to distinguish
the difference between chinch bugs that have been actually killed
by this fungus and the mass of cast skins covered with ordinary
mold. The uncertainty as to the effects of this fungus is responsible
for its having fallen largely into disuse during recent years. It will
thus be seen that this whole matter hinges upon meteorological
conditions which are, as has been stated, most powerful factors in
holding the chinch bug continually in check, and it is following a
succession of dry seasons that the pest commences to become destruc-
tive. During seasons of excessive abundance of chinch bugs, this
fungus will almost invariably appear among them in the fields, pro-
vided that at this time there occurs a considerable period of wet

weather.
REMEDIAL AND PREVENTIVE MEASURES.

All remedial and preventive measures that have been found to
possess the merit of reasonable efliciency and practicability are
discussed in the following pages. These may not all prove appli-
cable in all localities or under every variety of circumstance, and the
farmer will often have to adapt his protective measures to weather
conditions, location of field and its surroundings, and to the thou-
sand and one other variations of a similar nature.

DESTRUCTION OF CHINCH BUGS WHILE IN HIBERNATION.

The first effort that may be made with a view to warding off an
attack of chinch bugs is to destroy them in their winter quarters.
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15

This can be accomplished by burning all dried grass, leaves, or other
rubbish during winter or early spring. The burning of all such
grass will destroy thousands of bugs in their winter quarters; but
sometimes the matted bluegrass remains green in winter, or the
weather is not sufficiently dry to enable the farmer to burn over
such places. In such cases a flock of sheep, if given the freedom of
the fields during winter and spring, will eat off all living vegetation
and trample the ground with their small feet, so that not only is all
covering for the bugs removed, but also the bugs are crushed to
death. So it is with the matted grass along roadsides and fences,

Fic. 8.—Poorly kept roadside with rail fence overgrown with brambles, thus affording protection for
large numbers of destructive insects during winter. (Author’s illustration. )

especially the Virginia worm rail fence (fig. 8). The ease with which
the narrow strip of grass land along a post-and-wire fence can be kept
free of matted grass and leaves, as compared with that along a hedge
or rail fence, indicates that there may be an entomological factor
connected with the modern fence that has been overlooked, giving
it, in this respect, an advantage over the more ancient form. <A
ood illustration of the fact that large numbers of chinch bugs may be
in hiding among fallen leaves in woods and other places and escape
detection is shown by the fact that a quantity of dried leaves from
about a vineyard located on a narrow neck of land about a quarter of
a mile from the Bay of Sandusky on the one side, and about 1}
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16

miles from the shore of Lake Erie on the opposite side, was col-
lected late in April. At the time of collecting the leaves only an
occasional chinch bug was to be observed, but under a warm atmos-
phere they began to bestir themselves, and soon demonstrated that
there had been a large number ensconced unseen among the dried
and curled, dead grape leaves.

Shocks of fodder corn, left in the fields over winter, certainly
afford protection for many chinch bugs, as will also coarse stable
manure spread on the fields before the chinch bugs have selected
their place of hibernation in the fall. In short, the first protective
measure to be carried out is a general cleaning up in winter or early
spring either by burning, or pasturing, or both.

SOWING DECOY PLATS OF ATTRACTIVE GRAINS OR GRASSES IN EARLY SPRING.

Judging from the manner in which the overwintered adults are
attracted to hills of young corn, wheat fields, or plats of panic and
foxtail grasses, it has always seemed to the writer practicable to
take advantage of this habit and sow small patches of millet, Hun-
garian grass, spring wheat, or even corn, early in the spring and thus
bait the adults as they come forth from their places of hibernation.
Their instincts will prompt them to seek out the places likely to
afford the most desirable food supply for their progeny, and, if an arti-
ficial supply can be offered them that will be more attractive than
that furnished by nature, the bugs will certainly not overlook the
fact, but will take advantage of it to congregate and deposit their eggs
there, whereupon eggs, young, and adults can, a little later, be
summarily dealt with by plowing both bugs and their food under
and harrowing and rolling the ground to keep the former from
crawling to the surface and escaping. The writer has thoroughly
tested this method in a case where the bugs, young and old, had
taken possession of a plat of neglected ground overrun with panic
grass (Panicum crus-galli), which was mown and promptly removed
and the ground plowed, harrowed, and rolled before the bugs could
escape, thus burying them beneath several inches of soil, out of which
they were unable to make their way. As a consequence they were
almost totally annihilated, hardly 1 per cent making their escape to
an adjoining cornfield.

WATCHFULNESS DURING PROTRACTED PERIODS OF DROUGHT.

It has always appeared to the writer as though a little watchfulness
on the part of farmers during periods of drought might enable them
to determine whether or not chinch bugs were present in any con-
siderable numbers in their fields in time-to interpose a strip of millet
between the wheat and corn, to be utilized later as previously indi-

[Cir. 113]

iW

eated. Instances have come under observation where, in wheat fields
overgrown with panic grass and meadow foxtail, the bugs transferred
their attention to these grasses as soon as the wheat was harvested.
In such cases a prompt plowing of the ground would have placed the
depredators beyond the possibility of doing any serious injury. If
the weather at the time is hot and dry, a mower may be run over the
stubble fields or along the borders of them, cutting off grass, weeds,
and stubble, as the case may be, leaving them to dry in the hot sun,
when, in a few hours, they will burn sufficiently to roast all bugs
among them, and, while not destroying every individual, this will
reduce their numbers to such an extent that they will be unable to
work any serious injury.

DIFFICULTY OF REACHING CHINCH BUGS IN MEADOWS.

There is, however, some doubt in regard to the practicability of
applying these measures in timothy meadows. Meadow lands can be
burned over with perfect safety to either the grass or clover, if done
while the ground is frozen, but there is danger of injury if burned
over in spring, and it is somewhat doubtful if the hibernating chinch
bugs would be killed unless the surface of the ground was heated to a
degree that the grass and clover plants would hardly be able to with-
stand. .

Infested areas of meadow land could be plowed, it is true; but the
work would have to be done very carefully, else the grass and stubble
would be left to protrude above ground along each furrow and con-
stitute so many ladders by which the chinch bugs could easily crawl
out and make their escape. Where the ground will admit of sub-
soiling, or where a “‘jointer” plow can be used, this latter difficulty
can be easily overcome. Usually, however, the chinch bugs work too
irregularly in a field to permit of plowing under infested areas without
disfiguring the field too much for practical purposes, especially in the
case of meadows, unless it be where the bugs have migrated en masse
from an adjoining field, when a narrow strip along the border can
often be sacrificed to good advantage. In many instances the drastic
measure of turning under a few outer rows of corn with the plow would
have saved as many acres from destruction. In the majority of cases it
is the fault of the farmer himself that these measures are not effective,
as he will seldom take the trouble to burn the dead leaves, grass, and
trash about his premises at the proper time, and when there occurs an
invasion of chinch bugs, instead of resorting to heroic and energetic
measures to conquer them on a small area, he usually hesitates and
delays in order to determine whether or not the attack is to be a
serious one, and by the time he has decided which it is to be the
matter has gone too far, and the chinch bugs have taken possession

[Cir. 113]

18

of his field. This is especially true in the West, where the bugs breed
exclusively in the fields of wheat and remain unobserved until harvest,
when they suddenly and without warning precipitate themselves upon
the growing corn in adjacent fields. In fighting the chinch bug
promptness of action is about as necessary as it is in fighting fire.

ELIMINATING CHINCH BUGS FROM TIMOTHY MEADOWS BY CROP ROTATION.

In several instances where chinch bugs have become especially
destructive to timothy meadows over considerable areas of country,
it has been found that these outbreaks were attributable to the fact
that these sections of country were largely given over to dairying.
The dairymen and stockmen found it more desirable to allow timothy
pastures and meadows to remain more or less permanent, with the
result that the chinch bugs gradually became so excessively abundant
as to destroy the grasses on these areas. In a number of instances it
was found that where the prevailing agricultural methods were
changed and the infested grass lands were broken up and devoted to
other crops, the difficulty was eliminated, as the new meadows were
not attacked. This shows that throughout the country where the
short-winged chinch bug attacks timothy meadows a rotation crop
will be found an efficient measure in overcoming the difficulty with a
reasonable degree of permanency.

UTILITY OF KEROSENE IN FIGHTING CHINCH BUGS.

In fighting the chinch bug there is at present no more useful sub-
stance than kerosene, either in the form of an emulsion or undiluted.
From its penetrating nature, prompt action, and fatal effects on the
chinch bug, even when applied as an emulsion, it becomes an inex-
pensive insecticide, while it has the further advantage of being an
article universally found in every farmhouse, and is therefore always
at hand for immediate use. The emulsion has the further advantage
of being capable of sufficient reduction in strength to preclude injury
to the vegetation while still strong enough to be fatal to insect life.
Diluted and ready for use, the emulsion is prepared as follows: Dis-
solve one-half pound of hard soap in 1 gallon of water, preferably
rain water, heated to the boiling point over a brisk fire, and pour this
suds while still hot into 2 gallons of kerosene. Churn or otherwise
agitate this mixture for a few minutes until it becomes of a cream-
like consistency and, on cooling, forms a jellylike mass which adheres
to the surface of glass without oiliness. For each gallon of this emul-
sion use 15 gallons of water, mixing thoroughly. If appled to growing
corn, it will be best to use the emulsion either during the morning or
evening, say before 8 a. m. or after 5 p. m., as at these times it will
be less likely to affect the plants than if applied in the heat of the day.

LCirs ius]

19

Where an invasion of the chinch bug is in progress from a field cf
wheat to an adjoining field of corn, as an illustration, the marginal
rows of corn can be frequently saved, even after the bugs have
massed upon the plants, by spraying or sprinkling them freely with
kerosene emulsion, being careful not to get much of it directly into
the crown of the plants and using a sufficient quantity so that the
emulsion will run down the outside and reach such bugs as are about
the base of the plants. This treatment will kili the bugs clustered
upon the corn, and in case of those on the way to the field, while it
will not keep them out, it will cause a halt in the invasion, and thus
give the farmer an opportunity to put other measures in operation,
one of which will include the use of kerosene in another manner. If
a deep furrow is plowed along the edge of the field, running the land
side of the plow toward the field to be protected, the furrow will form
a temporary barrier to the incoming hordes.

UTILITY OF DEEPLY PLOWED FURROWS SUPPLEMENTED BY THE USE OF KEROSENE
EMULSION.

In dry weather the sides of the furrow can be made so steep and
the soil so finely pulverized that when the chinch bugs attempt to
crawl up out of the furrow they will continually roll back to the bot-
tom, where they can be sprinkled with either kerosene alone or with
the much less expensive emulsion and killed. In case of showery
weather, which prevents the sides of the furrow from remaining loose
and dry, the bottom can be cleared out with a shovel, making it more
smooth and the sides more perpendicular, thus rendering it so much
easier for the bugs to follow along the bottom than to attempt to
climb the sides. If holes are dug across the bottom at distances of,
say, 30 or 40 feet, the bugs will fall into them and can be still more
easily disposed of by the use of kerosene. That both of these meas-
ures are thoroughly practicable the writer can attest by ample per-
sonal experience, and he knows that under most conditions that are
likely to obtain prompt and efficient application is all that is neces-
sary. During a few days this work will demand the closest watching
and application, but fields of grain can be protected thoroughly and
effectually if these measures are faithfully carried out, and the
expense of time and money will be found to be less than in almost
any other plan that has been discovered up to this time. In no case
has a field attacked by a migrating army of chinch bugs come under
the writer’s observation but that might have been saved from very
serious injury by the prompt use of either of these measures, though
under some conditions the farmer might find it advantageous to
apply some of the other methods of protection here given. In all of
the following methods crude petroleum may be substituted for coal
tar if the former is more easily obtainable.

[Cir. 113]

20

THE SURFACE AND COAL-TAR METHOD.

The objections made by farmers to the use of most of these bar-
riers is that the finest pulverized soil soon becomes incrusted by even
the slightest rainfall and the bugs then pass over it without difficulty,
while barriers of boards are expensive. It is feasible to eliminate
both by simply smoothing off a path along the margin of an
infested field where such an one adjoins the one to be protected.
This can be done with a sharp hoe, and as the margins of wheat
fields usually become compacted, it is but little trouble to thus
clear off a path a foot or more in width, smooth as a floor, with
the surface almost as hard. Along this path circular post holes
are sunk, as in the bottom of furrows, and a train of coal tar is run
between them, being so arranged that it will reach the post hole
at the edge farthest from the field from which the bugs are migrat-
ing. The bugs, on reaching the train of coal tar, will follow along
until they reach the post hole, while those meeting with the post
hole will usually divide and, following around it, join with the
flow of bugs moving along the train of coal tar. The result is that
they become congested in the acute angle where the coal-tar train
is intercepted by the post holes. Those in the apex of this angle
ean not turn back, and thus are continually pushed into the post
holes by those behind. As the bugs, varying from the red larvee
of the younger stages to the almost black ones of the last stage,
mass along the line of coal tar, they have much the appearance of
a reddish-brown stream running into the holes. From these holes
there is no escape and here the bugs can readily be killed by sprinkling
with kerosene. The slightest train of coal tar is sufficient to obstruct
the passage of the bugs, and light rains wil! not affect its efficiency.
In dry weather these trains of coal tar soon become covered over with
dust and must be renewed; but in showery weather there is no dust,
and if the coal tar is renewed daily or, at most, twice each day, it will
accomplish its work and nothing further will be needed than to kill
the bugs that have collected in the post holes. This measure is inex-
pensive and can be promptly put into operation if the coal tar is at
hand. The writer has been able in this way to effectively protect a
field of corn bordered on two sides by a wheat field literally overrun
with chinch bugs at harvest and during a time when light showers
were occurring, frequently several times each day.

THE RIDGE AND COAL-TAR METHOD.

Differing quite materially from the preceding are the various com-
binations of coal tar and ridges of earth, smoothed and packed along
the apex, or, instead of the ridge of earth, 6-inch boards, such as are
ordinarily used for fencing, placed on edge and the upper edge coated

[Cir. 113]

21

with tar. Forbes has reported excellent results from the application
of a line of coal tar put directly upon the bare ground where the surface
has been rendered compact by a recent fall of rain. Even in this
series of protective measures kerosene can be used to great advantage.
In the experiment recorded by Professor Forbes the coal tar was put
upon the ground between a wheat field and a cornfield from an ordi-
nary garden sprinkling pot from which the sprinkler had been re-
moved and the orifice of the spout reduced in size with a plug of wood
until the tar came out in a stream about the size of the little finger and
made a line on the surface of the ground about three-fourths of an
inch in width. Post holes were sunk along the line from 10 to 20 feet
apart on the side next to the wheat field, thus practically completing
the barrier, and the chinch bugs, being unable to cross the line of tar,
accumulated in the post holes in vast numbers, where they were
killed, and those bugs that had already entered the cornfield before the
barrier was poe cicred were prevented from spreading farther by
tar lines between the rows of corn, the infested corn itself being
cleared of bugs by the application of kerosene emulsion. The same
writer states* that several farmers in Vermilion County, IIl., pre-
pared for the coal-tar line by hitching a team to a heavy plank and
running this, weighted down with three or four men, over the ground
once or twice until a smooth, hard surface had thus been made to re-
ceive the tar. If the barrier was to be made in sod, a furrow was
plowed and the bottom of this made smooth by dragging the plank
along the bottom. In both cases post holes were annie Hane the tar
lines, and in these were placed cans or jars into which the bugs fell in
myriads and were destroyed.

On one farm of 250 acres a coal-tar line 90 rods in length was re-
newed once each day and killed about 8 gallons of chinch bugs. In
the case of another farmer there were 300 rods of tar lines with post
holes, cans, etc., which resulted in destroying about 10 bushels of
chinch bugs. <A 6-gallon jarful was destroyed in less than half
-day at one point on the line. In this last instance the lines of tar
were renewed three times a day, but even then less than a barrel of
tar was used. Still another farmer, with 120 rods of tar line, used
about a third of a barrel of tar and did not lose a hill of corn; he
caught chinch bugs by the bushel. In some of the cases cited the
tar line was run in a zigzag course, the post holes being situated at
the angles, and in others leader tar lines were run obliquely to the
main tar line, one end terminating at the traphole, but both of these
plans were afterwards regarded as unnecessary, a single straight line
being entirely sufficient and less expensive. The numerous cases
where these methods were put into execution w un entire success aud

a Twentieth Report State Beg oeiolcere: of ifliesaa) D.o9; 1898.
[Cir. 113]

19) »)

at small expense afford the best possible proof of their practical utility.
If a farmer is situated near town, where refuse tin cans are dumped
in anv locality where they can be got out of the way, he can select
the larger of these, set them in the post holes and partly fill them
with kerosene and water. The water, being heavier than the kero-
sene, will sink to the bottom, leaving a stratum of kerosene on the
surface. The chinch bugs falling into this will be forced down by the
weight of those coming after, and thus all will be passed through the
kerosene into the water below. This will obviate the necessity of fre-
quently emptying the cans or treating their contents. It may also
be stated that where the post holes are quite deep and enlarged at
the bottom the bugs falling into them will perish without further
attention.
OTHER BARRIER METHODS.

The late Professor Snow, working in Kansas, followed a somewhat
different method, and one that, under certain conditions, might be
found superior to that used by Professor Forbes, or the furrow and
kerosene method applied by the writer in Ohio. This modification
consists in throwing up a double furrow, known among farmers as
“back furrowing,’ and thus forming a ridge, the top of which is
smoothed and packed with a drag having a concave bottom of the
form of the ridge to be made. If the bottom of this drag is covered
with zine, it will be found to keep bright and polished, and by this
means make a smoother ridge. Along the top of this ridge is run a
train of coal tar as it came from the gas works, or crude petroleum as
taken from the oil wells. The former is more easily obtained, except
in certain localities, and will probably be found the more practical,
as it stands on the surface better and is not so readily washed away
by rains. Both of these substances are, however, offensive to the
bugs, and they will seldom attempt to cross them or even come close
endugh to touch them, but on approaching will turn and run along
the ridge in the evident hope of finding a gap through which they can
pass. Post holes were dug on the outside of the line, but close up to
it, so that the bugs in passing along beside the tar line would crowd
each other into them. Professor Snow suggested that it will be better
to construct this barrier several weeks prior to the time when it will
be needed, as then the tar line has but to be run along the ridge, and
the post holes dug, when the whole system is complete, and the
chinch bugs can be thus shut out from the first.¢

With these barriers of either ridge or furrow and the use of coal
tar or crude petroleum, supplemented by kerosene emulsion, a very
large percentage of the injury from chine +h bugs may be obviated,

a¥ifth Annual Report of the Director of a enone fal Station of the Wnivenity
of Kansas, for the year 1895 (1896), pp. 45-47.

[Cir. 113]

23

and, in fact, with a reasonable degree of watchfulness and prompt
action, all injury from migrating hordes may be prevented. The use
of tarred boards set on edge or slightly reclining might, under some
circumstances, take the place of the ridge or furrow, but these cases
will be exceptional, and the use of kerosene emulsion will probably
be found equally practicable here, as also will the post holes for col-
lecting the chinch bugs. This method is merely cited in order to call
attention to its possible use where the others are found impracticable.

THE USE OF FURROWS WITHOUT PETROLEUM OR COAL TAR.

The plowing of furrows has been in vogue since the first writings
of Le Baron and the second report of Fitch, and may be utilized in
other ways than those previously mentioned. A heavy log dragged
back and forth in this furrow will pulverize the soil in dry weather,
and Doctor Forbes has recorded the fact that where this furrow has
a temperature of 110° to 116° F. it is fatal to the young bugs that
fall into the furrow, even if they are not killed by the log. As 120°
is not uncommon in an exposed furrow on a hot summer day, it will
be observed that there may be cases where this method will be found
very serviceable, and especially is this likely to prove true in a sandy
soil with a southern exposure. In sections of the country where irri-
gation is practiced, these furrows may be flooded and in this way ren-
dered still more effective without the expenditure of either time or
money to keep them in constant repair. Riley long ago laid consid-
erable stress on this measure, believing it of much value, especially
in the arid regions of the far West. The same writer advised the
flooding of infested fields, wherever it could be done, for a day or so
oceasionally during the month of May. It is hardly probable, how-
ever, that this will often be found feasible except in rice fields, where
it is sometimes practiced.

NECESSITY FOR PREVENTING CHINCH BUGS FROM BECOMING ESTABLISHED IN FIELDS
OF WHEAT AND GRASS.

In the foregoing it will be observed that prevention of migration
has been the chief end in view, either by destroying the chinch bugs in
their hibernating quarters, and thus preventing the spring migration
to the breeding places, or by various traps and obstructions to prevent
them from migrating from such places to others not already infested.
The great problem remaining to be solved is to prevent their breeding
in wheat fields at all. As has been shown, it is absolutely impos-
sible, with our present inability to forecast the weather months in
advance, to be able to foretell whether or not an outbreak of chinch
bugs is likely to take place. There may be an abundance of bugs in
the fall—enough to cause an outbreak over a wide section of country—
and these may overwinter in sufficient numbers to cause some injury

[Cir. 113]

24

in spring, vet a few timely, drenching rains will outbalance all of these
factors, and our wisest prognostications fail of proving true. It is
this very factor of uncertainty that renders unlikely the suecessful
sarrving out, over any large area of country, of any protective meas-
ures, where, as in this case, the benefit to be derived will only be real-
ized nearly a year afterwards, if at all. The average farmer, when
smarting under a heavy loss, will often take such long-range precau-
tions as to sow belts of flax, hemp, clover, or buckwheat around his
wheat fields once; but if the chinch bugs do not appear, and he sees
the useless investment of time, labor, and seed, he will be likely to
conclude next year to take the risk and do nothing. For the present,
then, we have no method whereby we cai prevent the chinch bugs
from taking up their abode in wheat fields cr timothy meadows and
raising their enormous families there, except to destroy the adults in
their winter quarters.

The writer once tried to destroy the young in a wheat field by
spraying with kerosene emulsion the small areas of whitening grain
that indicated where the pests were massed in greatest abundance.
The result was unsatisfactory, and it is very doubtful if it is possible
to apply this measure with any degree of success, and we are forced
to the conclusion that, for the present at least, we shall be obliged
to rely upon the measures previously given. It therefore becomes
of the utmost importance to clean up the roadsides, and the ground
along fences and patches of woodland, as well as any other places
likely to afford protection for the hibernating chinch bugs. There
are, of course, obstacles in the way of carrying out this plan generally
over any large area of country, and especially in sections where the
rail fence predominates. But as the country gets older it will be
found that it is not chinch bugs alone that seek these places in which
to pass the winter, but myriads of the other insect foes of the farmer
as well, and that careful attention to the condition of roadsides,
lanes, hedgerows, and waste places about the farms, .during the
season when insects seek out these places wherein to pass the winter,
will pay well for the time expended in that direction. It may come
about that some phase of the street-cleaning reform may invade
the country, and it is certain that if such were to occur it would,
in time, save the country enough to go far toward reducing the
expense of securing good roads. In fact, the term ‘‘good roads”
ought to include the proper care of the roadsides, as well as the
erading and macadamizing of the roadbeds themselves.

There are at present so-called ‘“‘weed laws”? in many States, and,
though more or less of a dead letter in most cases, these laws are
steps in the proper direction. The time when insect pests will be
looked upon in the eye of the law as so many public nuisances, and

[Cir. 113]

; 25

the harboring of them a corresponding crime, may be a long way off,
but as it gradually draws nearer we shall come to learn that after
all it is the rational view to take and will go far toward solving not
only the chinch-bug problem but many others of a similar nature.
So far as the chinch bug is concerned, when we burn over the waste
lands and accumulated rubbish about our farms in autumn or
winter, we are simply applying the same check that the dusky
savage did when he lighted the prairie fires, though unwittingly and
for an entirely different purpose. In the timothy meadows of the
northeastern portion of the country, where, for lack of wings fitting
it for locomotion, the chinch bug does not so largely migrate to the
waste lands in autumn, the problem is somewhat different, and it
will require some careful experiments to determine the exact effects
both on the hibernating chinch bugs and on the grass roots of
burning over the meadow lands in winter. There can be little
doubt, however, that a rapid rotation of crops, so as not to allow
the short-winged form to become thoroughly established in a meadow,
and the burning over of waste places, thus destroying such rubbish
and débris as wil] serve to offer hibernating places for the long-winged
form, will go far toward settling the chinch-bug problem in grass
lands.

As previously stated, the chief drawback in putting preventive
measures in force is the difficulty of foretelling an invasion. In
northeastern Ohio in 1897 hundreds of acres of timothy meadow
were destroyed after the hay crop had been removed, but. so late
that the farmers did not suspect the true condition of their meadows
until the spring of 1898, when the young grass failed to put forth
and an examination revealed the fact that the roots had been killed,
the abundance of chinch bugs pointing unerringly to the cause of the
trouble, though in many cases a heavy crop of hay had been removed
the previous year where now the ground was entirely bare. While
in the case just cited a previous knowledge of the presence of chinch
bugs in these meadows might not have enabled the owners to have

saved them in the fall of 1897, yet the fall plowing of the land, possibly
early enough to have sown the ground to fall wheat, out have
buried the majority of the bugs so deeply in the soil as to have killed
vast numbers of them and thus prevented their migrating to other
lands in the spring of 1898. A rotation of crops that would have
included grass for not to exceed two successive years, followed by
wheat, would have amounted to precisely the same remedial measure
as the one suggested.

A case in fee wearer Ohio has come to the writer’s notice where
an infested timothy meadow was plowed late in the fall of 1897.
Late in April of 1898 this ground was cultivated, rolled, and harrowed

[Cir. 113]

26

several times and most carefully and completely prepared for corn,
which was planted, but with the result that a portion of the field was
attacked and destroyed by chinch bugs, largely of the short-winged
form. An examination about June 10 revealed the bugs in consider-
able numbers about the plants still remaining, but scattered over the
field were more or less numerous clumps of timothy, in some cases
apparently killed by the chinch bugs, while in others the bugs were
literally swarming about the dying but still green clumps of grass,
thus showing that they had either not been buried by the plowing and
cultivation of the ground or else the grass had not been thoroughly
covered, and thus ladders had been left whereby the bugs were enabled
to climb to the surface.

SUMMARY OF REMEDIAL AND PREVENTIVE MEASURES.

In summing up the matter of remedial and preventive measures for
the control of the chinch bug, it may be stated that the insects can be
destroyed in their places of hibernation by the use of fire. They can,
under favorable meteorological conditions, be destroyed in the fields,
if present in sufficient abundance during the breeding season, by the
use of the fungus Sporotrichum globuliferum, if promptly and carefully
applied. They can be destroyed while in the act of migrating from
one field to another by tarred barriers or deep furrows supplemented
by post holes and by burying them under the surface of the ground
with the plow and harrow, or the latter method may be applied after
the bugs have been massed upon plats of some kind of vegetation for
which the bugs are known to have a special fondness, these decoy
plats being so arranged as either to attract the females and induce
them to oviposit therein or to intercept an invasion from wheat fields
into cornfields. When these decoys have been turned under with a
plow and the surface immediately smoothed and packed by harrow
and roller the bugs will be destroyed, while in the cornfields they
can be destroyed on the plants by the application of kerosene emulsion.
Without vigilance and prompt action, however, only indifferent results
are to be expected from any of these measures.

PROSPECTS OF A FUTURE OUTBREAK.

The past history of the chinch bug in America indicates a series of
years of the insects’ abundance and destructiveness, followed by peri-
ods of comparative immunity from its attacks. For a number of
years there have been no serious ravages and, in fact, until within the
past two years the pest has hardly been noticed by farmers; but
within the last year (1908) there have come a number of complaints
of serious injury, and, while these outbreaks have so far been of a
rather localized character, they seem nevertheless to betoken the

[Cir. 113]

27

drawing to an end of the period of immunity and the beginning of a
series of years of abundance and destruction. These somewhat por-
tentous reports have come from the farmers of Ohio, Indiana, Illinois,
Kansas, and Texas. Strangely enough, the city man has not been
allowed to rest unmolested and reports of serious ravages by chinch
bugs on lawns have come from the widely separated points, Brooklyn,
N. Y., and Palm Beach, Fla. It is because of these ominous reports
that this publication has been prepared at this time with the hope
not only of sounding a note of warning, but also, if possible, of impres-
sing upon the farmer the necessity of watchfulness and the prompt
application of preventive measures where the insect is found to occur
in any considerable numbers. The Bureau of Entomology has the
present summer (1909) been carrying out much experimental and
demonstrative work in the West, notably in Kansas.

Approved:

JAMES WILSON,
Secretary of Agriculture.
Wasuineton, D. C., September 16, 1909.
[Cir. 113]

O

wn

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