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Bulletin No. 15, New Series.

U. S. DEPARTMENT OF AGRICULTURE.

DIVISION OF ENTOMOLOGY.

rp

THE CHINCH BUG:

] PROBABLE ORIGIN" AND DIFFUSION, ITS HABITS AND
DEVELOPMENT, NATURAL CHECKS AND REMEDIAL
AND PREVENTIVE MEASURES,

WITH

MENTION OF THE HABITS OF AN ALLIED EUROPEAN SPECIES.

PREPARED UNDER THE DIRECTION OF THE ENTOMOLOGIST,

By F. M. WEBSTER,
Entomologist of the Ohio Agricultural Experiment station.

WASHINGTON:

GOVERNMENT PRINTING OFFICE.

18(J8.

DIVISION OF ENTOMOLOGY.

Entomologist: L. O. Howard.

Assist. Entomologists : C. L. Marlatt, Th. Pergande, F. H. Chittenden, Frank Benton.

Investigators : E. A. Sclnvarz, H. G. Hubbard, D. W. Coquillett.

Assistants: E. S. Clifton, Nathan Banks, F. C. Pratt, Aug. Busck, Otto Heideraann.

Artist : Miss L. Sullivan.

Bulletin No. 15, New Series.

U. S. DEPARTMENT OF AGRICULTURE.

DIVISION OF ENTOMOLOGY.

THE CHINCH BUG:

ITS PROBABLE ORIGIN AND DIFFUSION, ITS HABITS AND

DEVELOPMENT, NATURAL CHECKS AND REMEDIAL

AND PREVENTIVE MEASURES,

WITH

MENTION OF THE HABITS OF AN ALLIED EUROPEAN SPECIES.

PREPARED UNDER THE DIRECTION OF THE ENTOMOLOGIST,

By F. M. AVEBSTER,
Entomologist of the Ohio Agricultural Experiment station.

WASHINGTON:

GOVERNMENT PRINTING OFFICE.

1 8 9 8 .

LETTER OF TRANSMITTAL

U. S. Department of Agriculture,

Division of Entomology,
Washington, I). C, August 25, 1898.
Sir : I have the honor to transmit, for publication as Bulletin No. 15,
new series, of this office, a manuscript upon the chinch bug, which lias
been prepared at your direction and under my supervision by F. M.
Webster, the entomologist of the Ohio Agricultural Experiment Sta-
tion. This insect was the subject of a bulletin prepared by myself and
published as No. 17 of the old series of this Division in 1885. Since
that time, however, many new facts have been learned concerning the
life history and distribution of the species, and the whole subject of
the practical handling of its diseases has been elaborated. The chinch
bug is one of the half dozen most destructive insects with which the
American farmer has to contend, and requests for information about it
are constantly received by the Department. It is therefore necessary
that the Department should have for distribution a full and up-to-date
bulletin such as this aims to be. Professor Webster, by virtue of his
familiarity with this insect, gained through long and careful study in
advantageous localities, was admirably fitted for the work, which, it
seems to the writer, has been well done.

Eespectfully, L. O. Howard,

Entomologist
Hon. James Wilson,

Secretary of Agriculture.

8

CONTEXTS

Page.

Distribution 9

Hibernation 10

Spring, summer, and autumn migrations 17

Oviposition 18

Egg period and number of eggs deposited by each female 19

Descriptions of the different stages of development 19

Development and habits of the young 21

Number of annual generations 23

Gregarious habits of the chinch bug 26

Food plants 27

Losses caused ])y chinch bugs 2!t

Natural checks 31

Influence of precipitation on the chinch bug 31

Influence of temperature on the chinch bug 38

Natural enemies 39

Parasitic fungi 39

Fungous enemies of the chinch bug determined 41

Field and laboratory experiments in Indiana 42

First field applications of fungous enemies of the chinch bug 45

The work of Professor Snow in Kansas Ifi

Other insects attacked by SporotricMum globuliferum 17

First artificial cultivations of Sporotrichium globuliferum 48

Results of field applications in Ohio 48

Meteorological influences favoring development of fungous enemies of

the chinch bug

A bacterial enemy of the chinch bug 51

The practical utility of fungous and bacterial enemies in fighting the

chinch bug 51

The quail :»2

Other bird enemies of the chinch bug 53

The frog ;.:;

Invertebrate enemies of the chinch bug 53

Remedial and preventive measures 51

Destruction of chinch bugs while in hibernation 54

Sowing decoy plots of attractive grains or grasses in early spring 55

1 difficulty of reaching chinch bugs in meadows .~>t>

Watchfulness necessary during protracted periods of drouth T>7

Utility of kerosene in fighting chinch bugs 57

Utility of deeply plowed furrows supplemented by the use o( kerosene

emulsion :>;<

The ridge and coal tar method ;,;i

Other barrier methods ft)

Necessity for preventing chinch bugs from becoming established in fields

of wheat and grass 81

Summary of remedial and preventive measures 63

5

6 CONTENTS.

Page.

Insects that are mistaken for chinch bugs 64

Probable origin and diffusion of the chinch bug 66

Indications of a probable distant origin and later diffusion 67

Unique appearance and gregarious habit 68

Occurrence of the long-and short winged forms and their distribution 69

Relation of the inland and seacoast short-winged forms 71

Probable course of diffusion 71

Habits of the European species, Blissus dorm Ferr 75

Previous ideas on the diffusion of the chinch bug 78

Reasons for the present theory of diffusion 80

ILLUSTRATIONS

Page.

Fig. 1. — Map of North America showing areas infested by chinch bug 11

2. — Immature stages of chinch bug 19

3. — Blissus leucopterus — adults of long and short winged forms 20

4. — Blissus leucopterus — adults of short-winged seashore form 20

5. — Corn plant infested with chinch bugs 28

6. — Map showing areas in the United States over which the chinch bug

occurs in most destructive numbers 31

7. — Map showing distribution of chinch bug in Ohio in 1896 32

8. — Map showing distribution of chinch bug in Ohio in 1897 33

9. — Map showing distribution of chinch bug in Ohio in 1894 34

10. — Map showing distribution of chinch bug in Ohio in 1895 and amount

of precipitation over the State during May, 1895 35

11. — Triphleps insidiosus Say ":;

12. — Milyas cinctus Fab 54

13. — Xysius (uigustatus 64

14. — Piesma cinerea 65

15. — Corimclana pulicaria 65

16. — Braehyrhynchus yranulatus — larva, pupa, and adults 65

17. — Map showing probable course of diffusion of chinch bug over North

America 72

18. — Blissus doria'— immature stages 76

19. — Blissus doriw — adults 76

7

THE CHINCH BUG.

Few insects, and certainly no other species of the natural order to
which it belongs, have caused such enormous pecuniary losses as has
the chinch bug, BUssus leucoptcrus Say. Xo other insect, native to the
Western Hemisphere, has spread its devastating hordes over a wider
area of country with more fatal effects to the staple grains of Xorth
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 destructiveuess during rainy seasons of the parasitic
fungus, Sporotrichium globuliferum Speg..on both the adults and young,
the practice of raising grain year after year on the same areas, as fol-
lowed in the United States, would be altogether unprofitable. Some
of this insect's own habits, also emphasizing as they do the effects of
meteorological conditions, are the most potent influences that serve to
hold it within bounds, by giving its tendency to excessive increase a
decidedly spasmodic character.

DISTRIBUTION.

The genus Blissus is widely distributed over the world, occurring in
South Africa, Abyssinia, southern Europe, northward at least to the
sand dunes of central and northern Hungary, and in the Western
Hemisphere from Panama and the Island of St. Vincent northward to
middle California on the Pacific coast and Cape Breton on the Atlantic.
When we come to understand that the hemiptera of the world are far
from being well known, and the faunas of South America and central
Africa have as yet hardly been studied at all. we may well presume
that future studies of the heniipterous insects of these countries may
fill in some of the wide stretches of country separating the different
areas now known to be inhabited by the several species of this genus.

At present in the Old World it may be said to occur in the Ethiopian,
Oriental. Sonoran. and Holarctic life /ones, while in the New World
it ranges from the Neotropical at Panama and St. Vincent, through the
Sonoran and past the borders of the Holarctic in British America.

Our American species, Blissus leucopterus Say. the only one at present
known in the Western Hemisphere, has been recorded from St. Vincent
and Grenada, West Indies, by CThler; Cuba, by Stal; Volcan deChiriqui,
Bngaba, and San Feliz, Panama, by Champion: San Geronimo. Paso
Antonio. Pauzos. Chainperico. and Rio Xaranjo. Guatemala, by Cham
pionj Lower Pnrissima, Lower California, by CThler; Alameda, CaL,

9

10 THE CHINCH BUG.

by Koebele; and in the vicinity of San Francisco, Cal., by both Uhler
and Koebele; Orizaba, Mexico, by H. H. Smith; Tainaulipas, Mexico,
by Uhler; Mesilla Park, N. Mex., by Cockerell; Florida, by Schwarz
and Dr. J. G. JSTeal; Sydney, Gape Breton, by W. H. Harrington; Mus-
koka, Ontario, Canada, by E. P. Van Dnzee; and Winnipeg, Manitoba,
where a single specimen was collected by Dr. James Fletcher and
given by him to Mr. Harrington, to whom I am indebted for informa-
tion regarding its occurrence. Inland, in the United States, it may be
said to be generally distributed from Texas to Manitoba and eastward
to the Atlantic coast, along which it is known to occur almost con-
tinuously from Cape Breton to Cape Florida. It is also very probable
that its occurrence along the Pacific coast is much more extended
than is at present known, as it has not been searched for to any extent
in that region. (See map, fig. 1.)

HIBERNATION.

The chinch bug hibernates in the adult stage, and though there may
be occasional exceptions, especially in the South, it has yet to be
observed in very early spring in any other than the adult stage, at least
in any locality north of Mexico. I have observed pupa? in central
Illinois apparently in hibernation in company with adults on November
11, but there is no proof that these survived the winter. In Tensas
Parish, La., adults were abroad in considerable numbers during March,
1887, yet there was no indication of any young having wintered over.
The adults were pairing and seemingly engaged in oviposition, pre-
cisely as is to be observed in the Northern States during May and June.
I did not observe any young, as I most certainly should have done had
they occurred, as my observations were made in fields of young corn,
where, had the young bugs been present even in very limited numbers,
they would certainly not have escaped my rigid searching under and
about the bases of the leaves of the young corn plants.

Dr. Howard* quotes Prof. G. F. Atkinson, at that time of Chapel
Hill, N. C, as having observed half grown chinch bugs on crab grass,
about the 1st of October. The same authority also quotes Dr. Eiley
to the effect that many of the chinch bugs pair in the fall preparatory
to seeking winter quarters, and also cites the fact that Mr. James O.
Alwood observed them pairing in a field of uncut pearl millet, October
27, 1887, on the grounds of the Ohio Agricultural Experiment Station,
then at Columbus, Ohio. Dr. Cyrus Thomas.f in speaking of the pos-
sibilities of an occasional third brood in southern Illinois and Ken-
tucky, states that there were some evidences of this, but not sufficient
to justify him in asserting it as a fact or to satisfy him of its correct-
ness.

*The Chinch Bug, by L. O. Howard; Eeport of the Commissioner of Agriculture
for the year 1887, pp. 51-88.

t Bulletin No. 5, IT. S. Entomological Commission, p. 13.

HIBERNATION.

11

Pio. l. — Map of Nortb America showing areas Infested by chinch bng (original).

12 THE CHINCH BUG.

It therefore seems probable that no young are ^produced as a result
of the late pairing, at least until spring, and it has yet to be shown
that the late appearing larvae do not mature before the hibernating
season sets in, or else die during the winter. When we come to con-
sider the extreme susceptibility of the newly hatched chinch bug to
wet weather, it will be apparent that, as we approach the tropics, the
wet and dry seasons would exert a powerful influence in regulating
the breeding seasons, as those individuals that hatched before the
close of the rainy season would be, largely, at least, continually elimi-
nated, while those that hatched so late as to be caught in the com-
mencement of the rainy season would also be to an equally great
extent destroyed, and thus, by continually restricting the breeding
period to certain months, establish a fixed law that would be adhered
to even under the somewhat different conditions which occur farther to
the northward. Unfortunately, I do not have the date or dates on
which the young were observed by Mr. Champion, on Yolcan de Chiri-
qui, in Panama, but it seems very probable that they were found during
or near the dry season.

In an article on the hibernation of the chinch bug, Mr. C. L. Marlatt*
calls particular attention to the met that in Kansas the chinch bug in
autumn seeks the dense stools of some of the wild grasses in which to
hibernate, and to such an extent did this occur that it was suggested
as probably the normal hibernating habit of the species.

Before entering into a discussion of this matter, it will be well to
preseut two communications received from the late Dr. J. 0. Neal, at that
time of Stillwater, Okla. As he was located in a section of the country
where, in many cases, civilization had not influenced to such a marked
degree the natural insect fauna, I applied to him to secure some exact
information in regard to the chinch bug under such conditions. Our
correspondence, however, was terminated suddenly by his death. The
two letters here given are among the last he ever penned. They are
of a somewhat general nature, and I shall refer to them later in this
discussion.

Oklahoma Agricultural and Mechanical College,

Stillwater, Okla., October 31, 1895.

My Dear Sir: Yours of the 28tli just received. Last year was the first wheat
year in most of the new additions to this Territory, and from all sections the cry was
for infection, as "the hugs are ruining us." I received letters from every county in
the strip and in the western sections. The most damage was done in the extreme
southern range of the counties, and near Okarche (see map, fig. 6) the damage
was excessive. I do not think there is a single acre in this, or Indian Territory that
is not saturated, so to speak, with the chinch hug. You may put this whole area down
as within the infested boundary line. My helief is that the increase of country roads,
the decrease of March fires, the shiftless habits of the vast majority of our farmers
in allowing volunteer wheat and oats to grow, and wheat lands to remain fallow,
and the planting of new and better grass crops than the tough blue-stem, are direct
causes of what I believe a decided increase of this insect in Oklahoma during the

* Insect Life, Vol. VII, pp. 232-234, 1894.

HIBERNATION. 13

last five years. It would be amusing if it were not so pathetic, to read the many
letters I get, something in thiswise: ul planted wheat on sod land, the chinch bnga
destroyed it so badly that in February I plowed it up and sowed oats, this, too
went the same way; I then planted corn, and when it was a foot high the little
bugs came by the millions and destroyed that : I then planted the land to Kafir corn,
and that will be ruined if you can not help me." What could I do for such a man?
Had the bugs laid out a programme for their daily sustenance, no better commissary-
general could have been obtained for them than he was, and 1 had to write him that
his plan was the worst one possible for him, and the best for the bugs, and that the
only suggestion I could make, from the bugs standpoint and for their benefit, would
be to plant wheat again so that they could have something for the coming winter's
food. In his case it was a series of fatal mistakes from ignorance of the habits of
the bugs.

Another thing which I believe adds materially to the increase of these pests is the
complete destruction of the prairie chickens, the decimation of partridges, and the
thinning out of all kinds of smaller birds, such as the cow blackbirds, bank spar-
rows, martins, larks, and other prairie birds. This section is full of reckless boys
and men who kill everything that flies, good, bad and indifferent, •• for fun.''

Some years ago I was out on the Cherokee Strip, miles away from human habita-
tion, and sawsome of the small birds — larks and killdees — busily picking in the young
grass, in early spring, and upon examination found these places swarming with
chinch bugs sucking the juices of the blue-stem grass.

Almost any time in the winter when the weather is warm one can find chinch bugs,
and I have witnessed two "nights" of these insects and determined them. I should
be glad to answer any more specific questions at any time.

AVith regards. I remain. J. C. Neal.

The second letter is a short note in reply to my question regarding

the grasses fed upon by the chinch bug, their hibernating habits and

developments.

Stillwater, Ok la., November 20, 1895.

Deab Professor Webster: In reply to your postal, I would say that I do not
know, but will at once make observations and report at my earliest chance.

My belief is that the bugs attack all the grass family except the Cenchrus. and
that only is exempt on account of its bitter taste, which effectually shields it from
insects, as far as I have seen, both in this section and in Florida.

I will take the matter in hand at as early a date as possible and write you progress
and results.

Very respectfully, J. C. Nkal.

It is reasonable to infer from these letters that the chinch bug win-
tered over about the stools of grass, and that the birds were observed
to attack them there in early spring, as the statement is made that
later, when the young corn was a foot high, the little bugs came by the
million. This condition of affairs may be considered in connection with
the statements of Dr. Asa Fitch,* regarding his observations in Illinois
in the autumn of 1854, when in passing over the northern part of the
State he found the ground in some places, in the midst of extensive
prairies, eovered and swarming with chinch bugs, reminding him. as
he says, "of the appearance presented on parting the hair on a call'
that has been poorly wintered, where the skin is found literally alive
with vermin." Farther along in his report (p. 290 he stares that

Se< "nd Report on Noxious, Beneficial, and Other Insects .»t New York, p 28

14 THE CHINCH BUG.

late as the forepart of October I met several of these insects in the
pupa state, and some of these I do not doubt would pass the winter in
that state, and therefore would not deposit their eggs until the follow-
ing spring." That he did not find these pupre in New York is shown
by his statement on page 287, of the same report, to the effect that he
had " met with but three specimens in New York, occurring on willows
in the spring of 1847 and May 12, 1851." As shown farther on in this
bulletin, there is no proof that these pupie did not develop to adults
before winter, or die before spring, and the conditions indicated would
almost presuppose that hibernation would take place on the prairies
where the insects were observed by Dr. Fitch. From personal recol-
lection I know that that section of the country was, at the time men-
tioned, but thinly populated, and there were still very extensive tracts
of the original prairie grasses miles distant from woodlands.

In an interesting note by Mr. E. A. Schwarz * on the hibernation of
the chinch bug, in discussing Mr. Marlatt's paper, previously mentioned,
attention is called to the fact that the hibernation of the chinch bug
had been observed by him, in its maritime home, in the vicinity of
Fortress Monroe, Ya., which locality he had been in the habit of
visiting for a number of years, during the first warm days of spring.
The maritime flora and fauna are here late to awake, and most insects
peculiar to the seacoast can still be found in their winter quarters by
the end of April. By pulling up any good-sized stool of grass and
beating it out on the smooth surface of the sand or over a cloth a
multitude of various insects are sure to be found, and among them
always plenty of chinch bugs. These stools of grass not only serve as
winter quarters, but in summer the chinch bugs crawl into them to
protect themselves during the daytime from the fierce rays of the sun.

In the timothy meadows of northeastern Ohio a similar phenomenon
may be observed, and I have witnessed cases where the chinch bugs
had commenced their operations along one side and worked part way
across the field, killing the timothy as they advanced, and continuing
their depredations the following year precisely where they suspended
work the autumn before, the long- winged individuals only migrating
in the intervening time. Thus the forms infesting this region have
deteriorated from their maritime progenitors, and the short- winged
individuals at least are more primitive than the more highly developed
and specialized long-winged form inhabiting the country to the west.
I believe that a careful survey of the timothy meadows of New York
and New England, and perhaps a more laborious study of those of
Ontario, Canada, and of Michigan, would reveal a similar condition,
though possibly to a less degree than at present exists in northeastern
Ohio. Also if these same timothy meadows were to be burned over
regularly each autumn the short-winged form would within half a
century become nearly or quite eliminated, though the total amount of

Insect Life, Vol, VII. pp. 420-422, 1895.

HIBERNATION. 1 5

injury to farm crops might be thereby increased instead of diminished.
It seems to me that the wings of the chinch bug were in early days in
the Mississippi Valley kept up to a high standard of development by
the necessity of escape from prairie fires and not by the presence of
Sporotrichium globuUfenim, as suggested by Professor Sajo in his
paper, a translation of which is included herein under the heading.
"Habits of the European species, Blistsus dorice Ferr."

As mentioned further on, the advance of civilization having revolu-
tionized the face of the country, with this change there has come a
corresponding one in the hibernating habits of the chinch bug, which
must now seek shelter in the limited patches of timber that are left in
the sections that were once entirely wooded and in the matted grass
along fences and roadsides, but especially among the fallen leaves and
rubbish that usually accumulate along Osage orange hedges. Brush
piles, old haycocks, strawstacks, and, in Ohio at any rate, shocks of
corn fodder left standing in the fields through the winter, all harbor
chinch bugs during the hibernating season.

The fact of the insect hibernating in matted blue grass along road-
sides and fences has been called in question by Professor Forbes and
by Mr. Marlatt, the former in his first report as State entomologist of
Illinois (p. 37) and the latter in Insect Life (Vol. VII, p. 232), but not-
withstanding this, in some parts of Ohio, in Indiana and Illinois, they
do hibernate in just such places and can be found there, especially
during the winter and early spring following a season of abundance,
but the investigator must know how to search for them. 1 have found
them late in the fall collected under rails, half buried in soil and dead
grass, and in northern Illinois while searching for other insects in
early spring I was sure to find them in varying numbers with small
Carabida*, Staphylinida^, and other early-appearing insects, on the
under side of boards laid down in grassy places, though no amount of
searching the grass itself would haye revealed their presence.

In the timothy meadows of northeastern Ohio the percentage of long-
winged individuals is always much greater in fall than in June, show-
ing that some, at least, hibernate there and migrate to the cultivated
fields in spring. In Kansas, where Mr. Marlatt made his observations,
there was still too much prairie, and the species was doubtless still
adhering to its ancient habits of hibernation. In southern Ohio 1
have found them attacking the wheat in May. in small isolated spots
over the fields, while there was nothing in the least to imply an inva-
sion from outside, but the wheat had been sown in the fall among corn.
and later the corn stalks cut off and shocked, remaining in this condi-
tion until the following spring. This occurred so frequently that there
seemed no room to doubt that the attacks had been caused by adults
wintering over in the corn fodder, and that these left their winter
quarters in spring to feed and breed on the grain growing nearest at
hand.

16 THE CHINCH BUG.

Prof. Herbert Osborn,* in giving a summary of his observations on
the chinch bug in Iowa in 1894, states that "In a great majority of
cases, 90 per cent or more, the infested fields were directly adjacent to
hedges or thickets or belts of timber, and iu 75 per cent Osage orange
hedges were the most available shelter. In about 13 per cent of the
cases the evidence showed hibernation in grass and weeds, and in some
of these cases there could scarcely be a doubt that the hibernating bugs
were protected by a heavy growth of grass or weeds and that they
moved from these directly into the adjacent grain fields." Prof. Law-
rence Bruner had previously called attention to the fact that the
chinch bug hibernated in great numbers about Osage orange hedges in
Nebraska. Dr. Lugger, in Minnesota, gives the following as offering
shelter to the bugs during winter: "Rubbish, of all kinds, but chiefly
that of hedges, wind-breaks, and along the edges of woods, as well as
corn fodder, logs, and even loose bark and stones."

Just why an insect that is apparently so unaffected by cold, even
under the most adverse circumstances, should seek shelter at all from
the elements is somewhat of a problem. While drenching rains are
beyond all possible doubt fatal to the newly hatched young, the adult
bugs seem to be almost proof against either wet or cold weather. It is
doubtless true that very many individuals die in their winter quarters,
and in fact I have found these dead in considerable numbers in some
instances during early spring, but it seems at least doubtful if either
cold or wet would entirely account for this fatality. I can but feel
that, somewhere and at some period in the past, this hibernation has
been more for protection from natural enemies than against the ele-
ments, though of course there might have been other reasons not dis-
cernible under its changed environment. The pupa hides away to molt,
though it does not appear that this course is followed in the earlier
stages, and the reasons for this are not at all clear. That the adult is
able to withstand combined cold and wet weather is amply proved by
the observations of several people. Dr. Hy. Shinier, in Illinois, found
that those which were in corn husks filled with ice, even inclosing the
chinch bugs themselves in the crystallized element, when they were
thawed out were able to run about, apparently unaffected by a tem-
perature that had varied from 15° to 20° below zero Fah. It seemed that
when exposed to the sweeping prairie winds at that temperature, with
no protecting cover, they perished. A Mr. G. A. Waters, in the Farm-
ers' Review for October 19, 1887, relates that a bunch of fodder having
fallen into a ditch, washed out near a corn shock by heavy rains, became
overflowed with water that stood over the fodder long enough for a
sheet of ice to form over it. When the water had subsided the corn
was husked and a number of chinch bugs were found among the ears,
where they had been immersed for a week or more; yet on being
exposed to the warm sun they began to crawl about in a lively manner.

* Chinch Bug Observations in Iowa in 1894, Insect Life, Vol. VII, pp. 230-231.

SPRING. SUMMER, AND AUTUMN MIGRATIONS. IT

Some very similar instances of the tenacity of life among chinch b
have been related to me by farmers in Ohio, so that I have no reason

for doubting these statements. It is more than likely that the ine
seeks to protect itself from its enemies during a period when it will be
helpless, and also from sudden and radical changes in temperature.

SPRING, ST7MMEB, AND AUTUMN MIGRATIONS.

If there is an ample supply of proper food close at hand the chinch
bug simply crawls from its hibernating place, but if it is in the timo-
thy meadows of northeastern Ohio it does nothing but continue its
ravages where it left off the autumu before, except a portion of the
long- winged form, which very evidently fly to the wheat and corn fields.
Iu wheat fields, unless the migration has been from an adjoining field,
in which case the attack is made along the edge nearest thereto, the
females do not seem to entirely forsake their gregarious habits, as
they do not scatter out evenly over the entire field, but appear to
locate in colonies, and when the young hatch and begin to attack the
growing grain their presence is first disclosed by small whitening
patches, which increase in dimensions as the young become older and
more numerous. In low-lying fields these whitening patches more
commonly appear on the back furrows or on any slight elevations that
occur in the field. But on higher and level ground the whitening areas
are observed scattered over the entire field, and constantly widening
until the whole field appears to ripen prematurely and crinkle clown.
When the migration is accomplished by crawling, the females seem to
spread only enough to afford food for the young until the latter are
able to make their own way from place to place. The young remain
clustered on the plant about which they were hatched until this has
been drained of sap. when they make their way, almost in a body, to a
second plant, and in this way an attack will be pushed forward day
after day.

In the spring the chinch bug probably lingers about its winter quar-
ters until a favorable day occurs during which to migrate. Transfer a
typical Indian summer day to early May. and perhaps raise the tem-
perature a few degrees, and yon have a day during which chinch bags
may be seen on the wing, crawling along on fences, or at rest on the
tops of fence posts as if taking observations, and in reality, as 1 have
come to believe, to catch the scent of wheat or corn fields. It is on
just such a day as this that Aphoditis senoal will be observed posted in
precisely the same way. opening and closing the leaves of its antenna',
evidently to catch the scent ot' the fresh droppings of animals. The
same movements characterize Aphodius inquinatut during the Indian
Bummer days of autumn. I have also observed the plum curculio. (
tracheitis nenuphar, acting in precisely the same way in late autumn.

While discussing the subject of chinch-bug migrations, it may be best
to state here that there i^ a second flight of chinch bugs in summer
5968— No. 15 2

18 THE CHINCH BUG.

after the majority have become fully developed, and not as they reach
the adult stage, as Professor Sajo has found to be the case with the
European species, Blissus dorice. A migration by flight takes place in
the fall, usually, I believe, during the period of Indian summer. The
magnitude of such migrations depends in the spring on the number of
individuals that have been in hibernation and in the summer and fall
entirely on the abundance of the species during the current year. If
there has been no great abundance during the spring the summer
flight will not be likely to attract attention. During the invasion of
1896 in Ohio an individual alighted on my hand while I was riding on
a street car in the heart of the city of Columbus. A heavy storm of
rain has much influence in scattering the bugs in midsummer, and just
preceding a heavy rain I have noted the fully developed adults very
abundant on Indian corn plants, while immediately after the storm
there would be very few to be found. As these storms were not always
accompanied by high winds, I am led to believe that it is the rainfall
that scatters the insects.

In timothy meadows where the original attack has begun along one
side and gradually extended inward, the line of separation between
the entirely dead grass and the uninjured is frequently not over a yard
in width, and within this narrow, irregular strip we may have the dead
and brown, the yellowing indicating more or less serious injury and
the perfectly healthy green of unattacked plants. This many-colored
border may change but little in the space of a week or ten days, except
to advance very materially, leaving the grass completely dead or dried
up, while the clover plants were uninjured. This indicates that the
females, after leaving their places of hibernation, do not spread out
over any large area, but to a certain degree maintain their gregarious
habits. I can but believe that these habits have been shaped by some
past environment in which the species has been placed for a long period
of time, as, for illustration, the inhabiting of bunches or tufts of grass
more or less isolated from each other.

To what extent pairing takes place in these places of hibernation
before the insects make their way to the cultivated crops is a matter
of considerable uncertainty. From my own observations I am not
inclined to believe that more than a very insignificant minority follow
this course.

OVIPOSITION.

According to most writers the eggs are deposited either about or
below the surface of the ground, among the roots of the grass or grain.
It is more than likely that this varies with the conditions, as the eggs
are not infrequently found above ground about the bases of the plants,
and even upon the leaves, though I have never found them there,
but have often found them under the sheath of grasses. It would
seem, then, that the eggs require a cool, damp, but not a wet locality.

DESCRIPTION OF DIFFERENT STAGES OF DEVELOPMENT. 19

EGG PERIOD AND NUMBER OF EGGS DEPOSITED BY RACE FEMALE.

Dr. Shinier states that each female deposits 500 eggs, scattering

them over a period of from ten days to three weeks, and as the adult
develops in fifty-seven to sixty days after the eggs are deposited, or

about forty-two days after hatching, it will be seen that some of the
earliest hatched young are well along toward fall development by the
time the last eggs are being deposited. According to Dr. Riley
the eggs hatch, on the average, in two weeks.

In a series of breeding-cage experiments Prof. W. G. Johnson found
that each female deposited from 98 to 237 eggs, the egg period lasting
from eighteen to twenty-one days, the period of oviposition covering
from thirty-eight to forty-two days. Forbes also records in his Fifth
Keport (p. ±±) experiments showing that the period of incubation may
extend from twelve to twenty-two days. (See Forbes's l!»th Report,
pp. 177-183.) It must be remembered, however, that Professor John-
son had but six females employed in his experiments and that these
were necessarilv under an artificial environment.

DESCRIPTIONS OF THE DIFFERENT STAGES OF DEVELOPMENT.

The following descriptions of the egg and various stages of the
young bugs are taken from Piley's Seventh Missouri Report, while that

of the adult is from the origi-
nal by Thomas Say, as pub-
lished in his American En-
tomology Vol. I. p. 329,
LeConte, Ed.).

The efjg. — Average length. 0.08
hull, elongate-oval, the diameter
scarcely one-lit'th the length. The
top squarely docked and sur-
rounded with four small, rounded
tubercles near the center. Color
when newly laid, paleand whitish
and translucent, acquiring with
age an amber color, and finally
showing the red parts of the em-
bryo, and especially the
toward the tubernaeled end. The size increases somewhat after deposition, and will
sometimes reach near 0.04 inch in length. Fig. 2, n. b.

Larval stage*. — The newly hatched larva is pale yellow, with simply an or
(colored) stain on the middle of the three larger abdominal joints. The form scarcely
dit't'ers from that of the mature bug. being but slightly more elongate; but the tarsi
have bur two joints and the head is relatively broader and more rounded, while the
joints of the body are Bnbequal, the prothoracic joint being but slightly longer than
any of the rest. The red color soon pervades the whole body, except the tiist two
abdominal joints, which remain yellowish, and the members, which remain pale.
After the first molt the red is quite bright vermilion, contrasting strongly with the
pale band across the middle of the bod} : tin- prothoracic joint i^ relatively longer
and the metathoracic relatively shorter the head and prothorax are dusky and

Fig. 2.— RH8SVS leueoptenu: a. b. eggs: <\ newly hatched

larva; d. its tarsus : '>. larva after first molt ; /. same after

<>nd molt: g, pupa — the natural sizes indicated at

sides: /■. enlarged leg of perfect bug; ./'. tarsus of same
>till more enlarged; ?'. proboscis or beak, enlarged (from
Rile-.

20

THE CHINCH BUG.

coriaceous, and two broad marks on the mesothorax, two smaller ones on the meta-
thorax, 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 antenme
are dusky, but the legs 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. (Fig. 2, c, d, e,f.)

The pupa. — In the pupa 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.
(Fig. 2, sr.)

The adult. — Blackish, hemelytra white, with a black
spot.
Inhabits Virginia.

Body long, blackish, with numerous hairs. Antenme,
rather short hairs ; second joint yellowish, longer than
the third ; ultimate j oint rather longer than the second,
thickest; thorax tinged with cinereous before, with
the basal edge piceous ; hemelytra white, with a blackish oval spot on the lateral
middle; rostrum and feet honey yellow ; thighs a little dilated.
Length less than three-twentieths of an inch.
Took a single specimen on the eastern shore of Virginia.

The whiteness of the hemelytra in which is a blackish spot strongly contrasted
distinguishes this species readily.

Fig. 3.— Blissus leucopterus:
adult of long-winged form —
much enlarged (original).

Fig. 4.— Blissus leucopterus: adults of short- winged form — much enlarged (original).

To the foregoing description of the adult Dr. Asa Fitch, in his
second report on the Insects of New York, adds brief descriptions of
nine varieties, all, with but one exception, being based upon slight
variations in color, some, perhaps, being due to immaturity, the single
exception being the short- winged inland form, of which variations from
the nearly wingless to fully winged are shown in tigs. 3 and 4.

DEVELOPMENT AND HABITS OF THE fOUNG. 1\

Leaving, then, out of consideration the color varieties as arrang

by Dr. Fitch, we have a long-winged form, in which individuals from
the eastern portion of the country differ from those found in the West
by being more hairy and robust, as pointed out by Mr. Van Duzee; a

short-winged form, found along the seacoast, and a similar inland form
differing from this last chiefly in its more robust body, broader and
usually much more abbreviated wings.

DEVELOPMENT AND HABITS OF THE YOUNG.

The newly hatched young are very active, and the first to appear
may be observed with their progenitors about the bases of wheat, corn,
or grass plants, and later all stages are seen mingling together, having
little appearance of belonging to the same species, so greatly do they
vary in size and color in their several stages of development.

As a rule the bugs confine themselves to the lower portion of the
plants attacked, but may later push their way upward, especially if
the lower portion becomes tough and woody, finally covering it in
patches, as seen in fig. 5. where they are shown on a stalk of young-
corn. Mr. E. A. Schwarz relates a curious exception to this habit in
Florida upon sand oats, Uniola paniculata, where the entire develop-
ment of the insect is undergone upon the highest part of this tall
plant and not close to the bottom. Mr. Schwarz has given as a proba-
ble reason for this the fact that strong winds are continually blowing
the tine, sharp sand through among the lower parts of the plants,
rendering it nearly or quite impossible for the bugs to remain in that
situation, thus forcing them to seek their sustenance farther up the
plants. While the figure just referred to gives a good representation
of the appearance of a corn plant when the chinch bugs are present in
excessive numbers, yet the writer has invariably found that they much
prefer a stalk that has been blown down by the wiud or partly broken
off by the plow and left lying nearly flat upon the ground.

In timothy meadows the very young are to be found only by pulling
away the soil from about the bulbous roots and drawing down the dead
sheaths that usually envelop them. An observer may even pull up a
tuft of grass entire, and yet. unless he examines in this way closely.
may overlook them, so snugly are they thus ensconced among the roots.
If driven to forsake a tuft of grass the young bugs move t<> another
and crawl downward, and are soon to be found as snugly settled as
before. It is only when they are older and well advanced toward
maturity that they work to any extent above ground, ami even then
only in cases where they are present in great numbers. Singularly
enough, where infested meadows are plowed up and planted with corn
the females seem to forsake the young corn plants and select the occa
sional stray clumps of timothy that cultivation has failed to destroy
and deposit their eggs about these, so that later the young may be
swarming about these last, while hardly one is to be found about the

22 THE CHINCH BUG.

young corn. This is precisely the opposite of what is observed farther
west.

Although living externally on their food plants, and notwithstanding
the young may attack the bases or even the roots of some of these,
yet the species is essentially an external feeder, and appears while thus
engaged almost totally indiffereut to possible attacks of natural ene-
mies. When not feeding, however, there is at times a tendency to
hide away under the sheaths of young corn or beneath clods of earth
or bunches of coarse stable manure, where this has been recently
applied and left more or less exposed on the surface of the ground. I
have noted this in cases where neither an uncomfortable temperature
nor wet weather necessitated protection.

As has been shown in the description of the larval stages, there are
four molts between the egg and the adult state. Just how the molting
larvae act I have never been able to determine; neither have I wit-
nessed pupation, but a fully developed pupa that is ready to molt is
easily distinguished by its larger size and more tightly fitting skin, which
is almost shining white on the median ventral surface of the abdomen.
It now hides itself away, seemingly preferring to get under the sheaths
of grasses or grains; but if these are not convenient it will crawl under
loose clods, or even into crevices in the ground. While thus hidden
away the pupa skin splits along the back and the fully developed adult
makes its way out, leaving the empty skins behind, which last are very
frequently mistaken for dead chinch bugs, and, when moldy, the
farmer is very likely to suppose that they are bugs which have been
killed by the fungus Sporotrichum glob iilifer 'urn, if this has been
applied in the fields.

On first emerging from the pupa the adult is generally of a dull pink
color, except the wings, which are white, exclusive of the veins, these
being of the same pinkish hue as the body. In a short time these col-
ors change to the normal ones of the species, but during the breeding
season these newly developed adults may be observed crawling about
with the young of all stages as well as the maturely colored adults.

If this development has been taking place in a wheat field and the
grain is harvested at this time, or if from any other cause the food sup-
ply becomes suddenly exhausted, all sizes of larvae with pupae and
adults will start off on foot to hunt for a fresh supply. Though many
individuals may now have become fully developed, and, so far as can be
determined, possess wings entirely fitted for active service, neverthe-
less they will crawl along a dusty road or across freshly plowed fields
in company with their less fortunate fellows, seemingly never for a
moment supposing that they can span the intervening space by flight.
The writer is totally unable to account for this phenomenon in the
species at this time, the disinclination to use the wings being so wholly
unlike the habits of B. dorice, as shown by the careful and painstaking
observations of Professor Sajo in Hungary. Again, the seeming desire

NUMBER OF ANNUAL GENERATIONS. 23

on the part of the pupa- to secrete themselves while transforming to
adults does not at all coincide with the idea of a supposed immunity
from attacks of uatural enemies. Surely our species of Blissus has not
always lived where natural enemies were as few as they are with us at
the present time. Even where we have both the long-winged and
short- winged forms occurring together in timothy meadows, then- is
no such haste exhibited on the part of the former to escape from the
companionship of the latter, as observed by Professor Sajd. We know.
however, that our species certainly does enjoy a considerable immunity
from natural enemies, though its conspicuous colors in both the larval and
adult stages contrast very strongly with those of its usual food plants
and its presence is still further advertised by its strangely persistent
gregarious habits. We have come to suppose the species to be. in part
at least, protected from attack by its vile odor, and so, indeed, it may
be in the United States, but I fully believe that somewhere in its south-
ern habitat it will be found to have one or more enemies, like the ant,
Eciton hamata, of Central America, for illustration. Our native ants,
however, will seldom attack even the young.

NUMBER OF ANNUAL GENERATIONS.

Over the most of its area of habitation in North America, at least, the
chinch bug is two brooded, though in northeastern Ohio I have totally
failed to detect the second brood, or, in fact, to perceive any indica-
tions that a second brood occurs ; but to this I shall refer later. As
previously shown, there is not sufficient proof at hand to warrant the
statement that there is even in the far South a partial third brood.
I believe that the number of annual broods of this species has been
primarily decided in its home in the tropical regions by the wet and
dry seasons occurring there, and that we have in the North these same
broods occurring at slightly different periods under the influence of a
change from wet and dry to hot and cold seasons.

Belt, in his Naturalist in Nicaragua, has the following to say with
regard to the seasons on the northeastern side of that country: -*The
rains set in in May and continue with occasional intermissions until
the following January, when the dry season of a little more than three
months begins" (p. 103). "The heaviest rains tall in July and August.
and at those times the brooks are greatly swollen." " In September.
October, and November there are breaks of tine weather, sometimes
lasting for a fortnight, but December is generally a very wet month,
the rains extending far into January, so that it is not until February
that the roads begin to dry up" (p. 104 . It seems that we here have
the possible key to the secret of the number of annual broods of the
chinch bug. That it may be able to adapt itself still further to changed
latitude and environments and become single brooded is not at all
impossible. As illustrating the ease with which insects, at least some
of them, can change their habits to correspond with their environment.

24 THE CHINCH BUG.

we have in South Australia the following facts regarding the codling
moth, Carpocapsa pomonella, of which, though being still double brooded,
" the winter caterpillars hatch into moths irregularly from the begin-
ning of October until the middle of November and deposit their eggs
accordingly, giving rise to a succession of young caterpillars until the
beginning of December. About the third week in December the first
moths of the second brood begin to appear and deposit eggs, and mem-
bers of this second generation of moths continue hatching and egg lay-
ing until the end of February." *

My notes on the chinch bug in northeastern Ohio are as follows:
Very young larvae, with what appeared to be their progenitors, were
observed at Jefferson, Ashtabula County, within 11 miles of the shores
of Lake Erie, on June 16, 1893, no advanced larva? being observed
among them. On August 27, 1896, a few miles south, at West Andover,
in the same county, I could find only adults in two days' search, though
some of these showed by their color that they had but recently passed
the pupal stage. In this latter locality, on May 7, 1897, the sexes were
pairing, but no young were present, so far as could be observed, while
to the south and west of this locality, on June 8 and 9, precisely the
same conditions obtained as to the bugs, no young appearing at this
time. Quite copious rains might have destroyed the young, but within
15 miles of these localities, on July 14 of this year also, I found larva?
after first molt and stages intervening between these and the adults.
Near Youngstown, on October 3, 1897, 1 could find only adults and pair-
ing was not in progress, and the insect was not pairing in Ashtabula
County on August 27, 1896. June 9, 1898, only two very young larva?
could be found at Salem, about 15 miles southwest of Youngstown. In
the light of the information that has been gained by these observations
I am led to doubt the occurrence of a second brood of young in north-
eastern Ohio. Hatching is not fully in progress here before the 25th
of June, only an occasional individual having passed the first molt
before the 10th of July, t

The late Dr. J. A. Lintner, in his studies of the outbreak of this
insect in New York State in 1882 and 1883, seems to have relied much
on the published habits of the species farther west (as indeed I have
until receutly done myself), and made no exact studies of the species at
that time; and in his annual report, where the outbreak is discussed, I

* George Quinn, in Journal of Agriculture and Industry, S. A., Vol. I, p. 112.

tUp to date of revision of proof sheets of this bulletin, October 17, 1898, no
young of a second brood have been observed though careful search has been made
from time to time in the fields and meadows of northeastern Ohio, and a large
number of adults which developed in July and August, and since kept in confine-
ment, have not only not reproduced but have shown no disposition whatever to
pair. On the other hand, in southwestern Ohio, in the vicinity of Cincinnati, on
September 24, where the species occurred in abundance, fully seventy-five per cent
were pupye, the remainder being made up of larvae, some of them quite young, and
adults in about equal proportions, some of the latter showing by their immature
colors that they had but just passed the pupal stage.

NUMBER OF ANNUAL GENERATIONS. 25

can find no absolute proof of the existence of a second brood in New
York.* The occurrence of a second brood of young in northern Illinois,
as indicated by Dr. Fitch, has always been considered as settled, and
in a more northern latitude than northeastern Ohio, so that there must
be some other influences besides latitude to account for the phenomenon.
That the species has occupied this territory for many years is indicated
by the observations of Mr. E. P. Van Duzee, of Buffalo, X. Y., who
wrote me that the insect was as abundant twenty-three years ago as
at the present time, so that whatever effect on the insect the recent
occupation of the country might have had that effect has passed away,
and a condition of what we might call equilibrium now exists here.

On July 7, 1889, in the extreme northern part of Indiana, the writer
found an abundance of young which had not yet molted for the first
time. Dr. A. S. Packard records adults as pairing at Salem, Mass.,
June 17, 1871, as quoted by Dr. Lintner, while the latter gentleman
records the young as occurring in Lawrence County, New York, about
July 5, 1883.t

Hardly has the latest hatched young of the first brood developed to
the adult before the young of the second brood begin to appear. In
southern Ohio this is about the first week in August. Generally these
young do little injury, because the wheat has long since been harvested
and the corn is usually too far advanced and tough to offer a desirable
source of food supply, except in cases where fields have been planted
very late, and here the writer has known them to work considerable
injury, especially in seasons of severe drought that prevented the rapid
growth of the plants. Fall attacks of wheat are rare, and the injury is
never of a serious nature, as it is usually the case that by the time the
young wheat is large enough to invite attack the chinch bugs are
searching for winter quarters.

In the timothy meadows of northeastern Ohio, however, the principal
injury is done during August and September, and in favorable weather
on into October. Now if we allow sixty days for development from the
egg, it would be September before the appearance of the adults of the
brood to which these various young belonged. If all eggs were depos-
ited immediately, it would be November before the adults of the second
brood would begin to occur, a condition of affairs that lias never been
observed. As previously shown in this bulletin, the first brood is fally
developed in northeastern Ohio by the first of September, but there
certainly is no indication that a secoud brood of young is developed
during September and October. It would seem then that from eastern
Ohio through New York, New England, and probably to Nova Scotia,
the adults from the first brood of larva1 winter over, and that there is
here but one annual brood.

* Second Report of the State entomologist, pp. L48-164, vx
t Loo. cit., pp. 158, L59, 104.

26 THE CHINCH BUG.

GREGARIOUS HABITS OF THE CHINCH BUG.

I Lave previously called attention to the gregarious habits of the
chinch bug, and only refer to the phenomenon again because it is to
this that its destructiveness is largely due. It is not because of the
excessive numbers, but the persistency with which they will congregate
en masse on limited areas, that renders their attacks so fruitful of
injury. With an ample supply of food the young develop and leisurely
diffuse themselves over the adjacent fields, and there are neither
swarming flights nor migrations. In 1884, in northern Indiana, a small
field of wheat was severely attacked by chinch bugs. At harvest
there was every prospect of a migration from the field of wheat to an
adjacent one of corn, and the bugs were present in sufficient numbers
to have worked serious injury to the latter; but the wheat had grown
up thinly on the ground, and there had sprung up among the grain a
great deal of meadow foxtail grass, ISetaria glauca Beauv., and panic
grass, Panicum crus-galli L., and to these grasses the bugs transferred
their attention, finishing their development thereon, and later, so far as
I could determine, they scattered by flight out over the adjacent fields,
working no further injury. Pedestrian migrations may continue for a
fourth of a mile or even more, but on reaching a suitable food supply
the tendency is to congregate upon their food plants until these are
literally covered with chinch bugs, varying in color from the black and
white adults to those of the more advanced larvte. (See Fig. 5). What-
ever tendency there is exhibited toward a wider diffusion is confined to
the adults, the others remaining and leaving in a body only when the
plant on which they have congregated has been drained of its juices and
has begun to wither, when they simply crawl to the nearest plants and
again congregate upon them as before. In case the migration has been
to a field of corn, and if this is badly overgrown with either of the two
grasses previously named, the bugs will collect upon the latter, and
unless the corn plants are very small they will not as a rule attack them
until the grass has been killed. Some farmers have gone so far as to
claim a benefit to be derived from a certain abundance of chinch bugs,
the statement being made that they will kill out these grasses to an
extent that nothing else will. It is clear that the acquisition of wings is
not the signal for the adults to abandon the companionship of the larvae
and pupae, yet they do gradually disappear from among them. It is
possible that the disposition to pair does not exist until the individual
has reached a certain age beyond seeming maturity, and that it is not
until the passion for mating has overcome their gregarious inclination
that they are disposed to migrate. Or it may be that the phenomenon
may be explained on the supposition that when the pairing season
approaches the males scatter out in order to find females with which
they are not akin, thus following out natural selection and preventing
a continual interbreeding. Over the northern United States, at least,

FOOD PLANTS. 27

tbe injury in cultivated fields is done almost entirely by tbe young

bugs, but in the timothy meadows the damage is due as much, if not
more, to the depredations of the adults.

FOOD PLANTS.

As to food plants there can be no doubt but that these consisted
originally of the native grasses. This is amply proven by the observa-
tions of Fitch and Le Baron, in Illinois; Dr. J. C. Xeal, in Florida and
Oklahoma; Marlatt, in Kansas; Schwarz. in Florida; and, recently, by
those of Mr. Henry G. Hubbard, in the midst of the Colorado desert
in California. Kegarding this last statement, Mr. E. A. Schwarz lias
written to me as follows :

You may be interested to learn that chinch l>n<>8 were collected this year (1897)
on March 28 by Mr. H. G. Hubbard, at Salton, in the midst of the Colorado desert
of California. This locality is considerably below the ocean level, and represent-
an ancient extension of the Gulf of California. Even at the present time the Salton
Basin is occasionally flooded, the water entering through Xew River, which runs
from the mouth of the Colorado River into the Salton Basin. The specimens were
taken on a species of coarse grass which is incrusted with a saline deposit.

No wonder that the chinch bug is accused of being- a seashore
species!

Of cultivated grasses, or such as occur in cultivated fields, probably
Setaria glauca and Panicum crus-galli are the favorites, though millet
and Hungarian grass are apparently nearly as attractive. As early as
1845, iu Illinois, Dr. William Le Baron, afterwards State entomologist,
gave the food plants of the chinch bug as follows: * * * " all kinds
of grain, corn, and herd's-grass " (timothy).* But to this day in Illi-
nois, as shown by the observations of Professor Forbes and myself, the
species will attack timothy only in cases where it is compelled to do so
by reason of alack of other food. In addition to the preceding. Dr. How-
ard gives broom corn, sorghum, chicken corn, Bermuda grass (Cynodon
dactylum), blue grass (Poa pratensis), crab grass (Panicum 8anguinale)}
and bottle grass (Setaria ciridis), and also states that in the rice fields
near Savannah, Ga., in August, 1881, he observed the winged adults
upon the heads. Prof. H. A. Morgan writes me that in 1897 it had
become a serious enemy to "Providence"' rice in Louisiana, where for
two years it had seriously injured corn, and I am otherwise informed
that it is proving injurious to corn again in 1898. 1 have often found
the adults collected in the silk of belated ears of corn in the fields in
September, when all other parts of the plant had either become too old
and tough to afford nourishment or else had been killed by the frosts of
autumn. Prof. Lawrence Brunei* has recorded the insect as feeding
npon so-called wild buckwheat (Polygonum dumetorum or P. convolve
The writer has never seen chinch bugs attack blue grass ( Poa pratt K

Prairie Fanner. December, 1845.
t Report Commissioner of Agriculture. L887, pp

28

THE CHINCH BUG.

and has seldom witnessed an injury to oats. Over the western country
the major portion of the damage done is to fields of wheat, barley, rye,
and corn, the outbreak generally originating in wheat or barley fields

Fig. 5.— Corn plant two feet tall infested with chinch bugs (original).

and the bugs migrating at harvest to the cornfields. (See fig. 5.)
In Ohio this has been the case except in the eastern part of the State,
where the timothy meadows are the most seriously infested, and

LOSSES CAUSED BY CHINCH HUGS. 21)

here the migrations are as likely to be to the timothy meadows as to
the fields of com, where both are equally within reach. Besides,
everything indicates that a very large proportion of the adults may
hibernate in these meadows, even making their way thereto in the
autumn.

LOSSES CAUSED BY CHINCH BUGS.

It would appear that this pest first made its presence known by its
ravages in tbe wheat fields of the Xorth 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,t the chinch bug
again became destructive in Xorth Carolina to such an extent that in
Orange County farmers were obliged to suspend the sowing of wheat
for two years. In 1839 f the pest again became destructive in the
Caroliuas 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,
during the years from 1815 to 1850 the insect ravaged over Illinois and
portions of Indiana and Wisconsin, and in 1854 and 1855 it again
worked serious injury in northern Illinois. The writers 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. W alsh
estimated the loss to the farmers of Illinois in 1850 at -94.000,000, or
$4.70 to every man, woman, and child living in the State. The earlier
outbreaks, though the occasion of smaller money loss, were even more
disastrous; for the destruction of the grain crops in those pioneer days
not only took away all cash profits, but also deprived the early settlers
of their very living, and in some cases reduced them to starvation.

In 1863, 1864, and 1865 the insect was again destructive in Illinois
and other Western States, its ravages being especially severe m 1864,
when we have another attempt at computation of the financial l<>s^.
Dr. Henry Shimer, of Mount Carroll, 111., who had carefully studied
the chinch bug, estimated that k- three fourths of the wheat ami one
half of the corn crop were destroyed by the pest throughout many
extensive districts, comprising almost the entire northwest." In criti-
cising the doctor regarding another point, Messrs. Walsh and Riley, in
The American Entomologist (Vol. 1, p. 107. L869 . admit that the

Webster on Pestilence, Vol. I,p.279. Not seen. Quoted from Pitch.
t Albany Cultivator, first series. Vol. VI, p. 201.
. The Cultivator, Vol. VI, i>. LOS.

30 THE CHINCH BUG.

estimate was "a reasonable one," and, taking it 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 under than an over estimate in this case.

There was a serious outbreak of the chinch bug in the West again in
the year 1868, and again in 1871, but in 1874 the ravages were both
widespread and enormous. Dr. LeBaron computed the loss in 1871
in seven States, viz, Iowa, Missouri, Illinois, Kansas, Nebraska, Wis-
consin, and Indiana, at $30,000,000.* Dr. C. V. Eiley computed the
loss in Missouri alone in the year 1874 at ^19,000,000, and added the
statement that for the area covered by Dr. LeBaron's estimates in 1871
the loss in 1874 might safely be put down as double, or upward of
$60,000,000. t 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 chinch bug of which we have the
losses resulting therefrom computed, 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 Illinois, Iowa,
Missouri, and Kansas. § This gives us as the estimated loss in the
thirty-eight years, 1850 to 1887, both inclusive, the enormous sum of
$267,000,000.

There was a serious outbreak in Kansas, Iowa, Minnesota, and Illi-
nois, 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. The farmers of this State in many cases were entirely
unfamiliar with the chinch bug and its ravages, and therefore were
unable to account for the damage that it worked in their fields until
some time after. This was especially true of the timothy meadows in
the northeastern part of the State; so that there were probably many
fields, both of grass and of grain, that suffered seriously, and, in fact,
in some cases were ruined by the chinch bug without the owners being
aware of the cause. For this reason, while the computed loss appears
large, it seems to me to be entirely reasonable. Of the losses occasioned
in other States during the years above indicated I have no definite
computations, but they were severe, and must have amounted to mil-
lions of dollars. If we could have careful estimates of the loss during
the last seven years, it would in all probability swell the amount to

* Second Report State Entomologist of Illinois, p. 144.
t Seventh Report State Entomologist of Missouri, pp. 24-25.
t Bulletin No. 5, U. S. Entomological Commission, p. 7.
§ Report of U. S. Commissioner of Agriculture, 1887, p. 56.

NATURAL THECKS.

31

fully $330,000,000 for the period from 1850 to 1898. If the indirect
losses were to be added the amount would indeed be enormous. Dur-
ing the outbreak in Ohio at least two farmers became discouraged, and,
thinking that the loss of their crops by the attack of chinch bugs would
result in their financial ruin, in their despondency sought relief in
suicide.

When we take into consideration that the financial losses as above
estimated have not fallen upon the entire nation, but almost without
exception upon the nine States previously named (see Fig. 6) it will be
seen that this diminutive insect constitutes a formidable enemy to the
agriculturist of these States. In fact, small as it is, this pest has cost
the people of these nine States a sum of money sufficient to defray the
entire expense of the National Government for a whole year. Fire

3?X

#•• y

"-""■ 4i *. ■ ■ ' '.*•' '*^£i * A )

• *•*.'•* * X***' »* ~'\* **««** *j»''*»*,-t*

*Jf,

«•».•,»••; •"•,»'«;V .'<»*• J;/;"vij

\\\ ^^^V ) ':'^—\]lSZ

Fig. 6.— Map showing areas in the United States over which the chinch hug occurs in most
destructive numbers (authors illustration).

excepted, there is probably no other element that has caused such an
enormous financial loss within the same period over the same area of
country.

NATURAL (HECKS.

All adverse natural influences affecting the chinch bug will be treated

under this head with the exception of animal and vegetable foes, which
are considered here as natural enemies.

INFI.ll \< B OF PRECIPITATION ON nil' CHINCH BIT..

There is probably no more potent factor in restraining the Increase
in numbers of this species than is to be found in meteorological influ-
ences consequent upon ram. The fact has long been known that the

32

THE CHINCH BUG.

years of greatest abundance of the chinch bug were preceded by a
series of years during which there had been a deficiency in the rainfall
over the area of country devastated by this species. In fact, it has in
a general way come to be understood that dry seasons are favorable
and wet seasons unfavorable for the development of the chinch bug,
though the details of the phenomenon have never been very carefully

Fig. 7. — Ma|> showing distribution of chinch bug in Ohio in 1896 (from Bull. No. 6, n. s.).

and elaborately worked out. The entomological and meteorological
records of the past have, however, clearly shown that the amount of
the annual rainfall is not a safe guide in this problem. Chinch bugs
have occurred in excessive numbers during years of heavy precipitation.
The term uwet season," so frequently used in this connection, is an
indefinite one, but if the term "season" be restricted to the period of
time intervening between the verual and autumnal equinoxes we shall

INFLUENCE OF PRECIPITATION. 66

have more definite grounds upon which to base our studies of meteoro-
logical influences. Thus applied, the terms wet or dry seasons would
include within them the two breeding periods of the chinch bug, at least
largely so, north of latitude 30° N. Hut the history of this species has
shown that there may be an excess of rainfall during this critical period
and that still a sufficient number of insects may develop to work serious
injury over considerable areas of country. This is due to two, and

Fiq. 8.— Map showing distribution of chinch bag in Ohio In l Si>7.

perhaps more, causes. In the first place, an unusually heavy rainfall
at long intervals, while bringing up the total for a given period, may
have but little effect in reducing the number of chinch bugs, while even
a less amount of precipitation coming at short intervals and in the midst
of the hatching season would cause a far greater mortality among the
young. And, in the second place, the precipitation may come at the
beginning or even before the commencement of this breeding season or
0008— No. 15 3

34

THE CHINCH BUG.

just at the close thereof, thus enabling the major portion of the young
to reach a period in their development wherein they are little, if at all,
susceptible to the effects of drenching rains. This was clearly illus-
trated in southern Ohio during the spring of 1896, and again in 1897.
Throughout southern Ohio, in 1896, between latitude 38° 30' and 39° 40',
as the reports of the United States Weather Bureau show, there had

Fig. 9.— Map showing distribution of chinch bug in Ohio in 1894 (from Bull. Ko. 6, n. s.).

been but very little rain up to May 11, and no general rain until May 25.
The effect upon the young bugs, judging from the destruction which
they caused, would seem to have been to destroy only the latest to
hatch, leaving the earlier developing young sufficiently advanced to
withstand the effects of the later and heavier rains. The accompany-
ing map (fig. 7) will show the areas over which chinch bugs were
reported marked thus M, while the area seriously ravaged is indicated

IXFIXENCE OF PRECIPITATION.

;r

tlius =.. showing that the rain came too late in such a section to ward
oft' an outbreak of the pest.

According to the Weather Bureau reports also, the distribution of
rain in May, 1807, differed materially from that of the same month of
LS90, in that in 18(.)7 the major portion of the rain fell prior to the L5th,
the remainder of the month being rather dry. the only general precipi-
tation occurring on the 23d and 24th, with a much lighter rain on the

Chinch Bug

g^Areas infested §§§f Greatly infeste

l'l'.. 1".— Map showing distribution of chinch bug in Ohio in 1895, and amount of precipitation over
the State during May of the same year (author's illustration. |

28th. But here again the amount was insufficient to ward off serious

injury, as is indicated by map fig. 8), the same symbols being used here
as before. In this case it was probably the latter portion of the brood
that survived, as a personal inspection of the country early in the
month failed to reveal the presence of young bugs, though they were
certainly present in abundance at a corresponding period of the pre-
ceding year.

36 THE CHINCH BUG.

That the amount and frequency of rain during the month of May-
has very much to do with the ravages of chinch bugs where sufficient
numbers have wintered over to produce the requisite number of young,
is further shown by the fact that in 1894 the only locality where serious
ravages were committed was in Wyandot County, as shown on map
(fig. 9), and this was one of the few areas in Ohio where the precipita-
tion during that month was less than 3 inches. Except over a circular
area covering less than one half of the county the amount of precipita-
tion was 3 to 5 inches, and this area includes that ravaged by the chinch
bugs during the following month.

Still more striking, however, is the relation between the two phenomena
during the following year. The last of this series of maps (fig. 10) shows
the area over which chinch bugs were reported and the area where their
injuries were the most severe; also, by horizontal lines, the areas over
which the amount of precipitation was the least. From this it will be
observed that in all of the seriously affected area, and in nearly all of the
area over which the pest was reported at all, the precipitation during
the mouth of May, 1895, was from 1 to 2 inches, the extension of the
point westward into Shelby County being especially interesting. It
may be said with regard to the occurrences outside of this area of light
precipitation that the exact localities were probably not indicated, as
the information was secured from farmers, and their locations as indi-
cated on the map were their post-office addresses, which might have
been several miles away in any direction, and the isolated points of
attack were often based upon one or two reports. If exact localities
could have been obtained, and the precise area of precipitation indi-
cated, the connection between the two phenomena would have been
shown more correctly, and would probably have revealed even a greater
uniformity than is now apparent. It must be understood, however, that
in these calculations extreme northeastern Ohio is excluded, and I
believe that what is true of the balauce of the State will be found to be
equally correct as regarding territory occupying the same latitude west-
ward to the limit of this area of distribution. While it is probable that
the effect of precipitation during August would have a similar influence
on the second brood of young, and, consequently, upon the number of
adults which would go into winter quarters, yet a careful study of the
two factors shows that meteorological conditions in August have a far
less influence upou the following brood than do those of May.

Owing to causes which are as yet unknown to me the same laws do
not apply to the northeastern part of Ohio and to what I have termed
the westbound tide of migration. Here and as against the more or
less short-winged form of chinch bug, meteorological conditions appear
to exert a far less potent influence. What is true of meteorological
conditions during May elsewhere in Ohio, seem to be partly true of
June in the northeastern portion of the State, though there is not the
evidence of the effect of precipitation here that we have elsewhere.

INFLUENCE OF PRECIPITATION. ' ?>1

Dr. Lintner, in his second report, while discussing the outbreak of
chinch bug in New York during 1882-83, calls attention to the fact
that both in 1881 and 1882 there was an excess of precipitation. On
page 158 of his report Dr. Lintner says that spring, summer, and autumn
were exceptionally wet. In spring heavy and continued rains flooded
meadows which, later, showed the effect of chinch-bug attack. Even at
haying time while the bugs were young and, according to all accounts.
easily killed by heavy rains, they persisted in multiplying and tiring
despite the fact that rains were so frequent and severe that only a
portion of the hay could be gathered in a proper condition. This was
the state of affairs on July 5 when the hay was cut, and on October 10
Dr. Lintner stated that owing to continued rains grass was still lying
in the fields and could not be gathered, while fields of oats remained
unharvested. In ail of the reports given of this outbreak it was stated
that the damage was first observed in August or September, and I
believe that this will hold good as applied to northeastern Ohio.

As has been stated the females oviposit as a rule at or just below the
surface of the ground, and the young make their way upward in order
to secure food. In case of cultivated grains this mode of procedure is
absolutely imperative, as the bases of the plants are at that time too
tough and woody to offer sufficient food. But in the case of timothy
the conditions are entirely different, as the bulb of this plant, situated
just below the surface of the ground and convenient to the place of
oviposition, furnishes an ample supply of food without making it nec-
essary for the young to crawl upward in order to secure it. Then, too,
the surface of the ground in cultivated fields is nearly or quite free of
dead leaves and stems, there being little but the vertical-growing plants
to afford protection from the weather. In timothy meadows the sur-
face of the ground is usually covered to the depth of an inch or more
with dead and decaying stubble and leaves, and the top of the ground
itself is often more or less loose and mellow in the immediate proximity
to the bulbs of the plants. It would appear that we might here have
a partial solution of the problem of the vital effects of precipitation on
the young bugs. Besides, for aught we know the progeny of this quite
short-winged form may be better able to withstand naturally the effect
of drenching rains than that of the east-bound long-winged form. We
must recollect that in the one case the progenitors have worked their
way over hot, arid plains as well as cool, damp prairies, while in the
other case the tide of migration lay between the more elevated lands
and the sandy beaches of the seashore where there was always a more
or less near proximity to the ocean, until the tide o\ migration left the
seashore and drifted westward over New York and onward into north-
eastern Ohio. (See map, tig. 17.)

This influence of precipitation on the young chinch bugs while in the
act of hatching, and that of temperature upon the adults in winter, are
the only cases where meteorological conditions appear to have a direct

38 THE CHINCH BUG.

effect on this species. As previously shown, the temperature effects
are, largely at least, unfavorable for such adults as may happen to be
more or less unprotected during the hibernatiug season. Upon this
point it might be well to suggest that this protection, which may be
composed of leaves and dried grass, may be burned away in early
winter and thus leave the insects without the expected protective cov-
ering, or this covering may be still further augmented by a mantle of
snow, which, remaining for a more or less protracted period of time,
counteracts the influences of temi)erature, and the latter then becomes
a factor of secondary importance in the problem of life among chinch
ougs. It is very doubtful if temperature is as vital in its effects as are
the indirect influences of precipitation during the breeding season.

It has long been understood that the two species of entomogenous
fungi, Sporotrichium globuliferum Speg. and Untomophthora aphidis
Hoffm., both of which attack the chinch bug, require for their rapid
development an atmosphere heavily charged with moisture, and that
without this neither of these become sufficiently abundant to cause any
serious mortality among the insect host, but this matter will receive
attention in the discussion of these parasitic foes further on.

INFLUENCE OF TEMPERATURE ON THE CHINCH BUG.

I would like to call attention here to what seems to me a possible
influence of temperature upon what I have termed the west-bound tide
of migration. When the time arrives for the hibernating adults to
leave their winter quarters and disperse over the fields prior to oviposi-
tion, if the weather should prove too severe they have but to remain in
these quarters a while longer until more favorable weather. Thus along
the northern Atlantic coast the season is generally much later near the
shore than it is a few miles inland, and Mr. Schwarz* has called atten-
tion to the influence which this phenomenon exerts upon the chinch
bug. Now, this retardation amounts to about a month in spring, I
believe, which would have a tendency to delay oviposition, especially
among the short-winged females. If this were continued through a
long period of time, consequent upon the slow movement of tbis tide
of migration northward along the coast, it would hardly be surprising
to find that this retarded activity in spring had become so characteristic
as to be retained after this tide had swept to the westward, and resulted
in the species being thus single brooded in the East, while it is double
brooded in the east-bound tide of migration in the West. This effect of
a long habitation along the shores of the northern Atlantic would be to
some extent encouraged by the prolonged northern winter and the
correspondingly shorter period during which the species could breed,
and thus instead of the effects of the old environment becoming oblit-
erated they might be continued, or, as in case of the fore-shortening
of the wings, still further intensified. If the effect of this prolonged

* Insect Life, Vol. VII, p. 422.

NATURAL ENEMIES. 39

period of hibernation has been to reduce the number of broods, then it
will have to be considered as a natural check, in that to a certain extent
it prevents excessive abundance by reducing the number of offspring.
This would also account for the rather surprising immunity that has
heretofore been enjoyed by the northeastern portion of the country
from the ravages of this destructive species.

NATURAL ENEMIES.

It is possible that there are some reasons which might appear to
justify the placing of fungous enemies of the chinch bug among the
natural checks, as they no doubt do exert a more or less powerful
influence in that direction, but it seems more convenient to include
them among natural enemies, especially as one at least has come to be
applied artificially to overcome the insect. The fact that the abundance.
and consequent influence, of these fungous enemies is almost entirely
dependent upon meteorological conditions is sufficient to place them in
a secondary position, even though they may under favorable meteor-
ological conditions act as natural checks. All. doubtless, have other
host insects, and the two most important have been known to break
out again and again spontaneously and destroy myriads of chinch
bugs when the latter were present in excessive numbers. But this has
taken place only in connection with the necessary precipitation; hence
these fungi become natural enemies only under certain favorable weather
conditions; and while their season of most potent effect is during the
time when the chinch bug is developing from the egg to the adult, yet as
shown by observation they may exert powerful and fatal effects among
the adults, where these last have congregated together in masses.

PARASITIC FUNGI.

The two species of entomogenous fungi to which reference has just
been made are Entomophthora aphidis Hoffman * and Sporotriehium
globuliferum Speg,f both having probably been associated in destroy-
ing the chinch bug spontaneously m the fields, and doubtless were
distributed to correspondents by Professor Snow and others to be
artificially established in fields where there was an overabundance of
chinch bugs. For this reason it is impossible to separate the two. even
the first observations of Dr. Henry Shinier f probably applying to their
joint effect.

Dr. Shinier, however, was the first to call attention to the widespread
and fatal effects of fungous diseases among chinch bugs, and while his
explanations therefor seem now crude and illogical, his observations
were made with such care and accuracy that we have not yet had occa-
sion to materially revise them, though his conclusions have been shown

"Hoffman, in Fresenius's "EntomophthoresB," p. 208, tigs. 59-67.
* Spegazzini, " Fungi Axgentini," II. p. L2.
fProo. Acad. Nat. Sci. Phila.. May, 1867.

40 THE CHINCH BUG.

to have been incorrect. Under date of July 16, 1865, he makes this
observation. * * * "I found many dying on the low creek-bottom
land from the effects of some disease, while they are yet in the larvse
state — a remarkable and rare phenomenon for insects thus in such a
wholesale manner to be dying without attaining their maturity, and no
insect enemy or other efficient cause to be observed capable of pro-
ducing this important result." Again, under date of July 22: "On
low grounds the chinch bugs are dead from the disease above alluded
to, and the same disease is spreading to the hills and high prairies."

Under this date also he speaks of the very wet weather, and states
that in a barley field the chinch bugs began to die at about the same
time that they did on the low creek-bottom, and that they rapidly met
the same fate, so that few of them lived to find their way to a neigh-
boring cornfield, while under date of August 8 he states that of those
that migrated to the cornfields "very few are to be found remaining
alive; but the ground around the base of the cornhills is almost literally
covered with their mouldering, decomposing dead bodies. They are
dead everywhere, not lying on the ground alone, but sticking to the
blades aud stalks of corn in great numbers, in all stages of develop-
ment, larva, pupa, and imago."

"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. While Dr. Shimer probably never antici-
pated 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 associated with
the application of fungous diseases in the destruction of insects in
America. It is certainly to be regretted that such practical entomol-
ogists as Mr. B. D. Walsh aud Dr. C. V. Eiley should have expressed
themselves so discouragingly regarding Dr. Shimer's observations and
conclusions, Dr. Riley, so late as 1870, even going so far as to ridicule
the theory of disease being in anyway responsible for the death of the
chinch bugs observed by Dr. Shimer.*

It was not until 1879 that an entomologist came to the rescue of Dr.
Shimer's theory of disease among chinch bugs. Dr. Cyrus Thomas, in
his Bulletin No. 5, of the United States Entomological Commission,
1879, page 24, stated that while Dr. Shimer's plague among chinch
bugs was somewhat extraordinary, yet it was in accordance with facts
that he had himself ascertained in reference to other insects, and, in
proof, cited a similar wholesale destruction of flies in southwestern
Virginia and eastern Tennessee in the year 1849, and also a similar

* Second Report State Entomologist of Missouri, pp. 24-25, 1870.

PUNGODS ENEMIES. 41

epidemic amon^ grasshoppers in western Minnesota, Dakota, and north-
ern Iowa in 1872. This position of Dr. Thomas in support of Dr.
Shinier may he regarded as a second step in our advance in a knowl-
edge of the influence of meteorological conditions on the chinch bug.
It paved the way for further research in this direction.

Fungous enemies of the chinch bug determined. — While the subject of
epidemic and contagious diseases of insects was discussed to a greater
or less extent among scientific men, there was a decided lack of actual
experimentation, and none at all with the fungous parasites of the
chinch bug until 1882 and 1883, when Prof. S. A. Forbes began what
ultimately proved to be a long series of studies of the chinch bug and its
natural enemies. At this time, 1882. Professor Forbes was more espe-
cially interested in the bacterial diseases of the chinch bug, and though
he found, at Jacksonville, 111., many specimens of dead chinch bugs
embedded in a dense mat of white fungous threads, which sometimes
almost hid the bod}7 and reminded him of the fatal disease previously
reported by Dr. Shimer, yet except to secure from Prof. T. J. Burrill a
determination of this fungus as belonging to the Fntomophthora no
progress was made in the study of this particular phase of the chinch-
bug problem.*

In July, 1887. Professor Forbes found a second fungus attacking the
chinch bng in Clinton County. 111., and which he determined as belonging
to the genus Botrytus, but this conclusion has since been revised and
the species is now known as SporotHchium globuliferum Speg. This
discovery of a second species of entomogenous fungi and its separation
from the Entomophthora, comprises what maybe justly termed a third
step in the advancement of our knowledge of this problem. Professor
Forbes, however, seems to have still been too deeply interested in his
bacterial studies to pay any special attention to the other phases of
his problem, further than to record the occurrence of his new P>otrytus
in various localities in Illinois, and in one instance on a beetle. Parandra
brunnea (observed by Mr. John Marten, at Champaign), and. similarly,
to note the occurrence of the still specifically undetermined Bntomoph-
thora.T

The scene of action now changes from Illinois to Kansas, and to Prof.
F. II. Snow belongs the credit of first applying the knowledge that
had been gained up to that time (1889) by confining supposed healthy
chinch bugs with others affected by either one or the other of the
fungi, or possibly both Entomophthora and Sporotrichiuiu, and using
the bugs thus infected for the propagation, in the field, o[' the disease
from which they had died.

As early as 1887-88 Professor Snow expressed, in the Sixth Biennial
Report of the Kansas State Board of Agriculture, the opinion that ••in
the warfare of man against his insect toes a most valuable ally will be

Twelfth report of tin- State Entomologist of Illinois, pp. 17 51, L882,
t Sixteenth Report of state Entomologist of Illinois, pp, 16-49, ;vvv

42 THE CHINCH BUG.

found in the bacterial and fungoid diseases which may be artificially
introduced when nature fails to come to our aid," an opinion at that
time largely based upon the investigations of Professor Forbes and
his own observations of the chinch bug in Kansas, thus paving the
way for the experiments of 1889. Professor Snow had now obtained a
specific determination of the fungous disease as (Empusa) Entomoph-
thora aphidis Hoffman, although there is some ground for the suspi-
cion that Sporotrichnim globuliferum was also present.

Entomophthora aphidis was already known to affect hemiptera in
Germany and the United States. Dr. Eoland Thaxter states that, as
early as 1886, his attention had been called to the attacks of this fun-
gus on aphides in the greenhouses at Cambridge, Mass., where it acted
as a decided check, and later, in 1887, Dr. L. O. Howard had called his
attention to great quantities of aphides dying with the same disease
on clover near the Agricultural Department buildings in Washington,
D. C*

Field and laboratory experiments in Indiana. — On July 20, 1889, the
writer, at that time a special agent of the Division of Entomology of
the United States Department of Agriculture, stationed at Lafayette,
Ind., received, through the kindness of Professor Snow, enough mate-
rial with which to make some experiments, the chinch bug being at
that time very abundant at Lafayette, and an exceptionally good
opportunity thus being offered for experimentation. The results of
these experiments were published in detail in Bulletin 22, United
States Department of Agriculture, Division of Entomology (pp. 55-63),
but as this was the first series of experiments carried out with a view
of testing with exactness the precise effects of varying degrees of tem:
perature and atmospheric moisture on the growth of the Entomoph-
thora, and carefully following out the progress of the disease under
varying meteorological conditions, the matter is here republished in
full, the bulletin in which it was originally included being now out of
print.

These diseased bugs were placed under glass with living ones from the fields, the
latter being provided with food and kept thus confined for fifty-three hours, when
the major portion of them were placed on several hills of corn seriously infested by
bugs, the remainder with the dried remains received from Professor Snow being
scattered about over a small area of young wheat sown for experiment and also
swarming witb young chinch bugs. The hills of corn on which the bugs had been
placed were isolated from others, equally badly infested, by narrow frames of boards
placed on the ground and the upper edges covered with tar. This last precaution
was taken in order to prevent communication with other hills, intended as checks on
those used directly in the experiment. The area of young wheat over which infested
bugs had been placed was not inclosed, but its limits carefully marked. Five days
after, July 27, a single bug was found on one of the isolated hills of corn which had
very evidently died from the effects of Entoinophthora, and by the 30th enough
others were found to show that the fungus had fully established itself and the bar-
riers about the isolated hills were removed. On August 2, dead bugs covered with

* Memoirs of the Boston Society of Natural History, Vol. IV, p. 176.

FIELD AND LABORATORY EXPERIMENTS IX INDIA.

43

Entomophthora were found in considerable numbers about hills of corn 2~> feet from
■where the original colonies had been placed and also throughout and even 55 feet
beyond the area of young wheat over which dead and affected bugs bad been dis-
tributed. Daily observations were now made, bur the progress of th< -med
t me to a standstill. From the ."th of August up to the Oth it was almost Impos-
sible to get sufficient material, outside, to enable me to carry on laboratory experi-
ments. August 13 the spread of Entomophthora appeared to have taken on new
life, and diseased bugs were becoming much more numerous. August 15 found
diseased bugs L72 feet from anyplace where they had been previously observed.
August 20, diseased bugs were very abundant over all of the area where disease had
been distributed, and two days later examples were found a quarter of a mile from
the starting point of the disease. Immediately after this, however, another halt,
both in the intensity of attack and rapidity with which it spread, due either to the
dry weather or to the fact that the bugs had now all reached the adult stage and
had become diffused over the country, no longer congregating together. From either
one or the other, or both of these causes, I lost track of the Entomophthora and was
not able to again rind it in the fields. It seems proper to state here that chinch bugs
were not at any time excessively abundant. The greatest numbers were in the exact
localities where the disease was first distributed, the congregating at these places
being brought about by the close proximity to a large number of small experimental
plats of wheat, and when this was harvested the bugs collected • >n the corn
and young wheat. In connection with these facts, it is also interesting to note that
from July 15 to August 31 there were ten days on which rain fell. The dates of these
rains and the amount of precipitation is given below:

Date.

Precipi-
tation.

Date.

Precipi-
tation.

JulvlT

Inches.

0.u2

1.25

.20

.13

July 29

Inches.

19

22

30

Aug. 9

.50

3. 36

-

26

^"13

14

.15

.SB

With a view of learning whether or not there was any difference as regard- - --
ceptibility to the attack of Entomophthora. befween bugs in different stages of
development, a series of experiments was begun, as follows:

Young plants of Setaria glauca were transplanted to a box. and upon each plant
was placed a dead bug covered with the fungus, and al-o healthy Larvae : larva- just
on the point of pupation : pupa' just prior to reaching the adult stage, and fully
developed adults, each stage being placed on separate plants, and each covered with
a small inverted glass vial designated by lettering. As checks, another series
prepared, like the first in every particular. The soil in the box was kept well
moistened, and the plants remained fresh. This experiment was made on Aug
about the time when the attack outside began to diminish in intensity. The follow-
ing are the results of examinations on the dates indicated, the original experiments
being indicated by capitals and the checks by small letters, thus — A-a. adult: B-b,
young larva- : C-c, older larvas j D-d, pup®.

Date.

A.

a.

B.

b.

c.

*

d.

Aug. 5
Aug. G
Aug. 7

Healthy .

1 dead . . .
All dead .
All dead .

Healthy ..

1 dead '. . . .

3 dead

All dead..

Iloalthv .
Healthv .
3 dead *. . .
All dead.

Healthy .
Healthy
1 dead . .
All dead.

1 dead . . .
1 dead ...
3 deed ...
All dead.

Healtliv .
Healthv .

1 dead . . .

1 dead . . .
1 dead . . .

1 dead.

1 (lead.

Aim. 16

All dead.

\

All.:

On the same day this experiment was begun a second was also commenced, like

the first in every particular, except that the healthy bugs used in experimentation

44 THE CHINCH BUG.

were exposed to fungus-infected individuals for only five liours and then placed
under tlieir respective glasses. As a result, on August 15, thirteen days after, none
had died, thus strongly indicating that the Entomophthora did not exist generally
in the fields, and that it could not he communicated during a period of five hours'
exposure.

On August 7 a large number of healthy hugs were placed under glass, with a
number which had recently died from Entomophthora, the moisture in the vessel
being absorbed by calcium chloride. A check experiment was also commenced,
where the material and the conditions were the same, except the humidity of the
atmosphere, care being taken to have the latter as nearly saturated with moisture
as possible. August 10, the original experimeut was divided and a portion of the
healthy bugs removed and placed in a damp environment, the remainder being kept
under the original dry conditions. The results on August 22 were as follows: In
the original experiment, where the healthy bugs had been continually in dry
quarters, not a single bug had died from Entomophthora. Not only this, but none
of those which had been removed after three days and placed in dry quarters had
died, showing that the disease was not contracted and did not develop in healthy
bugs, though kept exposed iu a dry atmosphere for fifteen days, nor could it be
originated by placing, in a damp atmosphere, for twelve days, bugs which had been
exposed to contagion for three days in dry quarters. The results with the check
experiment were quite different. Within five days after being confined with
the Entomophthora, the healthy bugs began to die from effects of the disease, and
in three days more every one had died from the same cause, their bodies being
covered with spores.

Still another experiment was tried which consisted in confining a large number
of healthy bugs with others diseased in a damp environment, and when the fungus
had destroyed a portion the remainder were divided and a part removed to dry
quarters. The result was that while those left in damp confinement continued to
die, none of those inclosed in dry environment were destroyed. As the fungus had
by this time become distributed over the experiment farm so that I could not tell
with certainty whether material from the fields was in a perfectly healthy condition
or not, no further experiments were made in this direction.

From the foregoing it will be observed that the essential element in all of these
experiments was an abundance of moisture, without which the Entomophthora
could neither become established nor flourish after it had gained a footing. Again,
the extent to which the disease will prove contagious will depend upon the number
of bugs. Without great numbers massed together comparatively few would con-
tract the disease. To sum up the matter, there is little hope for relief to the farmer
from the influence of Entomophthora, except when chinch bugs are abundant and
massed together in great numbers, and during a period of wet weather. I have suc-
ceeded in getting the fungus established at two widely located points in Indiana,
and do not consider it at all difficult to introduce in localities where chinch bugs
are abundant, provided the weather is favorable. But if it is ever utilized by the
farmer, which seems to me to be at present a matter of considerable doubt, it will
only be after the pest has become very abundant, during the time between the first
larval and adult stages and in a wet time. After the Entomophthora has been intro-
duced into a certain field it will become diffused only in proportion as the bugs
travel about and healthy bugs come in contact with spores from those which have
died from the disease. This will not be very great until the pupal stage is reached.

The larvae of chinch bugs seem to in some way understand that while molting
they will be well nigh helpless, and hence hide themselves away in vast numbers in
secluded places. Under such conditions the spores thrown from diseased bugs would
reach a larger number of their fellows. I have found adults but recently molted
affected by the Entomophthora. After the bugs acquire wings and scatter them-
selves over the country, the liability to contagion will be again reduced, unless in
case of very severe invasions, where, from force of numbers, congregating on or about
food plants becomes a necessity. Hence, the introduction of the fungus among

FIRST FIELD APPLICATIONS OF FUNGOUS ENEMIES. 45

larvae will at first proceed but slowly, and only in extreme cases and ondei favor-
able conditions can it be expected to proceed much more rapidly among adult
In short, the only way that this fungoid disease seems capable of being employed in
agriculture is by the establishment of some central propagating -ration to which

farmers can apply and receive an abundant supply of infected bugs on short notice.
15y this means they could take advantage of a rainy period of a week or ten days,
and. if they can contrive by sowing plats of millet and Hungarian to mass the bugs
in certain localities about their fields, they might accomplish something toward
warding off an invasion. But the possibility of overcoming an invasion after it is
fully under "way, as is almost sure to be the case during a dry season, it must be
confessed is not very encouraging. My failure after repeated experiments to pro-
duce this Entomophthora in the vicinity of Lafayette without the importation of
germs is decidedly against the theory that might be advanced that the northeastern
portion of the State was kept free of destructive invasions by reason of this die
brought about by wet weather. There is as yet no reason to believe that the die
has ever existed in that section of the State.

The fungus with which I had been experimenting was determined for
me as an Entomopthora by Dr. J. C. Arthur, and the probability is that
it was E. aphid is, though it is possible that Sporotrichium was also
present and remained unobserved by me.

First field applications of fungous enemies of the chinch bug. — 1 have
stated that the credit of first confining- healthy chinch bugs with those
diseased and utilizing the thus infected individuals by transporting
them to sections of the country supposedly free from the disease in
order to create new areas of infection, belonged to Prof. F. H. Snow.
During October, 1888, the year prior to that during which Professor
Snow began his experiments, Prof. Otto Lugger, of Minnesota, collected
a quantity of diseased chinch bugs at the experiment station at St.
Anthony Park and distributed them to eighteen different localities in
the southern part of the State where the pest was known to occur in
destructive abundance. The diseased material was sent out in tin
boxes by mail, and the contents of the boxes, on arrival at their desti-
nation, were simply thrown in any Held where there was an abundance
of chinch bugs. Later in the season the condition of affairs where
these distributions had been made was such that "careful search in
the majority of places failed to produce a single living specimen, while
the traces of the disease were found everywhere." With a spirit ot
caution and exactness in every way most commendable on the part of
Professor Lugger, he says: " The disease spread so rapidly that even
corn growing near wheal fields crowded with chinch bugs was entirely
protected, and no bugs had entered it in all the places visited by myself.
But I am by no means satisfied that the disease was really introduced
in this manner. Is it not possible that the disease was already there,
unknown to anyone, and that I had simply reintroduced its germs.1
The reason for this belief is based upon the fact that too large an area
was infested by the disease — too large to be readily accounted for by
the short time in which the atmospheric conditions were apparently
in its favor.*' '

University of Minnesota Experiment Sta., Bull. t. Oct., 1888, pp. 10-41.

46 THE CHINCH BUG.

In this case Professor Lugger states that both Entornophthora and
Sporotrichium were present and the latter was sent byhini to Professor
Forbes, so there is the same confusion of the two fungi in this case that
existed in my own experiments in Indiana, except that in the one case
it was certain that Entomophthora was present, while in the other it
was the Sporotrichium.

The work of Professor Snow in Kansas. — While Professor Snow had
the experience and observations of Shinier, Forbes, and Lugger to aid
him in his first efforts to apply the knowledge gained by these gentle-
men, yet it must be said that it has been largely due to his untiring
energy and perseverance that the use of these fungi has reached the
present state of importance. It will hardly be saying too much if we
state that his persistent undaunted labors, in the face of much skepti-
cism and opposition, has won for him the admiration of his fellow-
Ayorkers, even among those who were long in extreme doubt as to the
success of his labor. He has done more than any other one person to
call attention to the possibilities of practical benefits to be derived by
farmers themselves; has done more to advertise the merits of these
fungous diseases among the masses than any one else, and, in fact, has
made the " chinch-bug fungus n almost a household word over the entire
United States.

It is therefore all the more to be lamented that he should have
accepted and published in his several reports the unsubstantiated
statements of farmers whose testimony on a matter of this nature is,
as every entomologist knows, absolutely worthless unless accompanied
by specimens. From my own personal experience in this direction and
in several States I have long ago disregarded all reports relating to
the efficiency or inefficiency of these fungous diseases among chinch
bugs, when such came from the ordinary farmer without being accom-
panied by specimens for examination. The cast pupal skins of the
chinch bug pass with nonentomologists very well for dead bugs, and if
the former have been attacked by the ordinary white molds the decep-
tion, except to the eye of an expert, is complete.

It is with extreme reluctance and with anything but ill will toward
Professor Snow that his voluminous reports on the " Contagious dis-
eases of the chinch bug" have been cast aside as quite worthless and
only his laboratory experiments accepted. He has, no doubt, accom-
plished much in his State toward assisting the agriculturist in fighting
the chinch bug, but much is left for others to prove by the care and
caution that should have characterized his own work and conclusions.
There is probably not an entomologist who has used these fungous dis-
eases to distribute among farmers who has not found just such condi-
tions as did Professor Lugger, in Minnesota, where it was impossible
to determine whether these diseases had been introduced artificially
or whether they were already present and had been overlooked. In
my own experience, while receiving chinch bugs from different parts of

USE OF SPOKOTRICHIUM GLOBULIFERUM. 47

Ohio to be infected with the disease, consignments have come to me
with the insects dying and others dead and covered with Sporotrichium,
showing that this was already present and that the very utmost that
we could expect to accomplish would be to aid in locally spreading the
contagion. Besides this, I have sent material to farmers sufficient to
start the fungus in their fields, knowing perfectly well that it would be
a considerable time before actual benefits could by any possibility be
expected to materialize, and within a week received the astonish in g
information that the fungus was so perfectly successful that the bugs
all disappeared within a few days after the application of the disease.
I have no doubt but that the distribution of upward of 7,000 boxes of
these fungi to the farmers of Kansas has accomplished a vast amount
of good, but beyond this it is impossible to go. Of Professor Snow's
laboratory work or the labors of himself and assistants in the fields no
criticisms can be made, and I shall have occasion to quote from these
in future pages of this bulletin.

Sporotrichium globuliferum, or at any rate the fungus which is now
passing under that name, was first found by Professor Forbes to infest
the chinch bug in Illinois in 1887, and its destructive effects observed
in the fields in the autumn of 1888.

Since the last-mentioned date I have distributed upward of 3,000
packages of this fungus to the farmers of Ohio during the outbreak of
chinch bug in the State in 1895, 189G, and 1897, and know from per-
sonal observation and study that it is under certain favorable condi-
tions a deadly foe of this species, that its use under these conditions is
practical, and that if its application can be made simultaneously with
the commencement of the breeding season it will prove effectual. This
statement is made for the reason that so late as 1895 Dr. M. C. Cook,
in his popular work on entomogenous fungi, " Vegetable Wasps and
Plant Worms" (p. 120), states that "no species of this genus is known
to have occurred on living matter as they are saprophytes pure and
simple, and then, probably, only as the stroma or conidiaof some fungus
of higher organization, possibly the Splueriacei.'' This statement was
made in discussing JS. densum, but on the following page (121), after
dealing with S. glob ulifer inn, he appends the following paragraph:
"The remarks made under the previous species are applicable to this,
which is not entitled to rank as a parasite, but rather as an accidental
development upon one out of many forms of decaying animal matter/'

Other insects attacked by Sporotrichium globuliferum. — Spegazzini*
described the species from Argentina as occurring on the dead bodies
of beetles, notably Monocrepidius and Naupactus xylanthographus.
Besides Parandra brunnea, Professor Forbes has recorded this fungus on
Lachnosterna, while 1 have infected, artificially, Epicauta pennsylvanica
and witnessed an instance of accidental infection oi' MegiUa maeulata.
In both cases these beetles were almost entirely covered by the fungus

Spegazzini, Fungi Axgentini, ii, p. 12.

48 THE CHINCH BUG.

after having to all appearances died from its effects. With respect to
this matter one point is clear, either the determination of this fungus
is incorrect or else Dr. Cook has made a very serious misstatement
which ought to be corrected. It is but just to state, however, that
Professor Forbes, in his eighth report (p. 23), calls attention to the fact
that it is closely allied to Botrytus, and would be placed by some botan-
ists under that genus now.*

First artificial cultivations of Sporotrichium globuliferum — In April,
1891, Dr. Eoland Thaxter succeeded in cultivating S. globuliferum arti-
ficially on agar-agar, and a month later Professor Forbes made similar
cultures on the mixture of corn meal and beef broth, this last being an
exceedingly valuable discovery, as it revolutionized our method of dis-
tributing the fungus by securing chinch bugs to be kept for a time
with those diseased, and then sent out to be scattered over the fields —
a cumbersome method which was never satisfactory. My own work in
Ohio was based on material obtained from Professor Forbes, and the
first year we distributed infected chinch bugs, but after that we used
the artificial base of beef broth and corn meal, finding the latter far
more satisfactory to handle, and, so far as I could determine, equally
effective.

RESULTS OF FIELD APPLICATIONS IN OHIO.

In regard to my own experience, it is unnecessary to go into details,
except to state that, under the most favorable laboratory conditions, I
was able to kill apparently perfectly healthy chinch bugs within three
days after bringing them in contact with the Sporotrichium. In the
fields, during the season of 1895, though upward of 750 packages of dis-
eased bugs were sent out to farmers, and I received some astonishing
reports of the results therefrom, yet my own observations led me to
believe that in many cases these were rather more imaginary than real.
Over the areas where local showers occurred during the season of
development of the first brood of young the effect was much more
satisfactory. But in many cases the request for help came late, and
soon after the fungus was applied the bugs scattered out over the fields,
disappearing to the eyes of the ordinary farmer, who, of course, attrib-
uted all to the effect of the Sporotrichium. In 1890, however, meteoro-
logical conditions changed, and at last I had the good fortune to secure
the very opportunity for which I had been waiting for years. All
through April and up to the 10th of May in southern Ohio there was
little rain, and even during the remainder of the latter month. the light
rains hardly sufficed to break the drought, so that there was a perfect

* Forbes has recorded, in his 19th and 20th reports, the occurrence of Sporotrichium
globuliferum on a number of additional species of Coleoptera, and also upon lepidop-
terous larvae, as well as the young of other insects, and it is probable that under
favorable conditions it will be found to attack almost any species more or less readily,
though the present autumn we have failed utterly to infect Murgantia histrionica
even when it was placed among dying chinch bugs in our breeding cages.

RESULTS OF FIELD APPLICATIONS IX OHIO. 4!)

breeding season for the chinch bug during the forepart of the breeding
period. The result was that over some sections (see fig. 7) there were
myriads of young bugs. Then the rains came on, and there were pre-
sented the two essential requisites for success with the fungus, viz,
chinch bugs and wet weather.

Soon the demands for supplies of Sporotrichium began to pour in, and
1,200 packages were distributed within a few weeks, instructions being
given to place the contents of the boxes where the chinch bugs were
massed in greatest abundance, giving preference to the lower and
damper localities in the fields.

After the distribution had been finished I visited the sections where
the outbreak of chinch bugs had been the most severe and where the
larger portion of the Sporotrichium had been distributed. There was
certainly no mistaking the effect of the fungus. Going to the place in
a field (generally a wheat field) where the fungus had been introduced,
the track of the chinch bugs as they moved in any direction was in
many cases almost literally paved with the dead bugs more or less
enveloped in their winding sheets of white. Along ravines, dead-fur-
rows, or other depressions, the ground would be nearly white, the dead
diminishing in numbers as the higher grounds were reached, though
these were by no means free from corpses. In one instance the bugs had
left a field of wheat at harvest, the Sporotrichium having been applied
there before the movement began, and entered an adjoining cornfield.
The way was marked with white, not only the surface of the ground, but
on stirring up the mellow soil of the edge of the cornfield it was found
to be literally full of dead chinch bugs to the depth of 2 or 3 inches,
the white fungus-covered bodies strongly contrasting with the black
color of the rich loam. Not only this, but under the sheaths of the
leaves and on the leaves themselves hundreds of dead were to be found
on the outer rows of corn, on the grass and weeds, and, indeed, almost
everywhere. Millions of chinch bugs were certainly destroyed in this
one field.

In other fields, where the number of bugs had been less, the dead
were less numerous, and then they were more apt to be scattered over
the leaves of corn, as in such cases a diseased bug seems to be animated
with a desire to crawl upward on any object which presents itself, just
as a larva of the clover-leaf weevil, Phytonomus punctatus, when
attacked by Entomophthora sphuerottperma (Fres.) will climb to the tip
of a vertical blade of grass and coil itself around it, and, holding it in
the grasp of death, remain in that position so strongly attached that
the winds and rains fail to dislodge it until it has become disintegrated.
In other localities, where no Sporotrichium had been distributed, the
ravages had certainly been greater, and I failed to find any indication
of the presence of the fungus. So far as my observation extended,
unless there were a sufficient number of chinch bugs massed to become
injurious, the fungus had but little effect upon them. In other wouls,
5908— No. 15 1

50 THE CHINCH BUG.

the massing appeared to be an essential requisite. Whether this was
sufficient of itself, or whether the effect of massing was to reduce the
vitality of the individual bug, and thus render it more susceptible to
the spores of the fungus, it is impossible for me to decide; but I have
long suspected that the latter was the true solution of the problem.
We know that most domestic animals or fowls thrive best and are
the most vigorous when kept in small flocks, while among humans the
maximum of health and minimum of disease is obtained where
the individuals are scattered over a moderate area per capita and the
atmosphere is dry and pure; low, damp, and ill- ventilated quarters,
when overcrowded, being especially fatal, particularly to the young. The
individual in perfect health and vigor may be said to be above and out
of reach of disease, and before the two can be brought together there
must be some interacting element that will bring the individual down
to a point where it can be reached by the disease; that is, the disease
can rise only to a certain plane and the victim must be first attacked
by some element not necessarily fatal in itself, but sufficiently depres-
sing to bring the individual down to where it can be grasped by the
disease.

Meteorological influences favoring development of fungous enemies of
chinch bug. — When human beings are overcrowded and some disease
like yellow fever is introduced among them, every one knows the effect
of a low, damp locality under a high temperature and with both air
and water more or less stagnaut. Even the once healthy and vigorous
are more or less reduced and enervated by their environment, and thus
brought within the influence of the deadly disease. Again, if an indi-
vidual is stricken and forsakes his miasmatic surroundings for those
more salubrious, the disease may still overcome him, but seldom spreads
to others, except such as come in actual contact with either himself or
his belongings, while if not too much reduced before changing his
habitation the chances are much more favorable for his recovery.

It seems to me that in this matter of meteorological conditions and
their relation to the effect of entomogenous fungi ou the chinch bug
we are really dealing with the same problem in a different field. The
young chinch bug, which has not yet come into possession of its full
measure of strength, and the spent females, which have lost theirs, fall
easiest as the prey to these fungi, while the fully developed bugs,
endowed with health and vigor, appear to be to some extent immune
to the attacks of these enemies, and if not massed in large bodies they
seem still more likely to escape destruction. In the timothy meadows of
northeastern Ohio I have found an occasional dead adult in late autumn,
but the fungus had certainly not claimed many victims, though both
the long and the short winged forms were present in considerable abun-
dance, clustered about the roots of grass. With Forbes I believe that
after becoming fully matured the chinch bug is, largely at least, beyond
the reach of Sporotrichium. What is the element that serves to ener-

A BACTERIAL ENEMY. 51

vate and reduce the older larvae and pupae, as well as many recently
developed adults among them? Is there nothing that, not of itself
fatal, so acts upon the system of the bugs that they are brought into
a condition of susceptibility — a sort of "go-between," so to speak, bat
which demands atmospheric moisture before it will rise to an aggressive
state ?

A BACTERIAL ENEMY OF THE CHINCH BUG.

Forbes finds that the bacterium, Bacillus insectorum Burrill, is normal
to the chinch bug and occurs always in the intestinal coeca, and I have
often wondered if this were not the very reducing element. In a
paper contributed to the "American Practitioner,'- September, 1801, he
describes the effect of this bacteria on the coeca as completely destroy-
ing the secreting epithelium, the cells of which break down and disap-
pear, leaving the delicate tubes filled with a vast mass of microbes with
some small intermixture of droplets of fat and a little nondescript
debris, the result of cellular decomposition. Xow it certainly seems to
me that we may here have the very enervating element necessary and
which, in order to become sufficiently aggressive to perform its func
tions perfectly, requires the very conditions afforded by frequent show-
ers, without which it is comparatively helpless. We know very well
that human beings are far more susceptible to disease when weakened
by fatigue, dissipation, or other forms of exhaustion, and under such
conditions succumb to disease when they would otherwise enjoy immu-
nity therefrom. I will not, however, follow this farther, but submit it
as a problem well worthy of careful consideration and study. In my
own experiments with Sporotrichium globuliferum I have found that
under the most favorable conditions the fungus will attack even the
youngest larva», while Forbes states that it will also attack the eggs,
but in the fields 1 believe it is generally most prevalent among the
more advanced larvae, pupa1, and newly developed adults, though much
depends upon meteorological conditions and the abundance of chinch
bags, as well as the time during the breeding season when the fungus
is doing its work. That is to say, there is a time at the beginning of
the breeding season when there are only adults and young larva': later
there will be larva* of various ages, and, toward the last, tew if any
of these, but all will be either pupae or adults. 1 have for some reason
found it more difficult to get the Sporotrichium to work satisfactorily
when the chinch bugs were beginning to breed than later vi\, the last
of June and the early part of duly. These tacts are mentioned here
to show that judging by their effects these fungi hold a secondary
place.

INK PRACTICAL l ri 111 V i>l- FUNGOUS AND BACTERIAL ENEMIES IN FIGHTING I1IK

CHINCH BUG.

Regarding the practicability of utilizing these entomogenous fungi.
in agriculture, 1 see no reason to revise my statement made ten years

52 THE CHINCH BUG.

ago. viz, that this can be done only in cases of excessive abundance
and during* wet weather, the basis for infection being provided by some
central propagating station from which farmers can receive promptly
an abundant supply. I believe that for myself I could manage to get
considerable benefit from their use in destroying chinch bugs provided
I was located within the area of the frequent occurrence. This could
be done only by watching the seasons carefully, and in case there should
occur two years in succession wherein the breeding periods were covered
by drought, then every preventive measure known should be adopted,
notably the burning of leaves, dead grass, and other rubbish during
winter or early spring followed up by sowing small plats of early millet,
Hungarian grass, or, better yet perhaps, spring wheat, in low damp
places in the fields, with a view of attracting the females or in fact
massing the bugs, and then freely applying the fungi in their midst.
Whether the ordinary farmer, with his present crude ideas of entomology,
can do this successfully or not is very uncertain. It is almost impos-
sible to determine even a few weeks in advance whether a season is to
be favorable or unfavorable to the development of the chinch bug,
which would of itself cause occasional false alarm, and the precautionary
measures rendered entirely unnecessary by a few timely and drenching
rains just at the critical time. Before we can expect to be eminently
successful in this matter, the farmer will have to be more thoroughly
educated, while both the entomologist and meteorologist have each
much to learn in order to properly enlighten him.

THE QUAIL.

The chinch bug has few important enemies among the birds of the
northern United States. To what extent the coast birds feed upon
them I am unable to say, but inland the common quail, Colinus vir-
ginianusj is the only species that can be said to devour any consider-
able number. As this is one of our most highly prized game birds, it is
slaughtered annually in tremendous numbers. Dr. L. O. Howard* some
years ago published a table showing the season during which quails
were protected by law in the States where chinch bugs are known to
commit their most serious depredations. At that time (1888) some of
the Northern States had no laws whatever for protection of quails,
while some protected them only during the breeding season. In the
majority of States the open season extended from October or Novem-
ber until January or February, in some instances until April. In
Dakota quails were protected absolutely until 1890, since which time I
am unable to state what the laws are in regard to the matter. Colorado
protects them all the time.f

*Bull. 17, U. S. Dep. Agr., Div. Ent., pp. 24-25.

tThe last general assembly of Ohio, 1897-98, restricted the open season for quail
to within the dates November 10 to December 15, and prohibited at all times the
catching or killing of these birds for the purpose of conveying the same beyond the

BIRD AND OTHER ENEMIES. Od

The breeding season from latitude 38° northward to Canada begins
in May, and during some years continues into September, a young bird
just from the nest having been taken in Wayne County, Ohio, Septem-
ber 5, 1887.* There are probably two, and southward three, broods
each season, and while rather prolific, they are kept well reduced in
numbers, at times to the verge of extermination over considerable sec-
tions of country. They are hunted incessantly and slaughtered with-
out consideration, except for gain. Also considerable numbers are
killed by flying against electric wires, while entire coveys sometimes
are smothered or frozen under the snow. As a result their helpfulness
against chinch bugs is greatly diminished.

OTHER BIRD ENEMIES OF THE CHINCH BUG.

Among the other bird enemies of the chinch bug are the prairie
chicken, red-winged blackbird, catbird, brown thrush, meadow lark,
and house wren, but there is little doubt that the few chinch bugs
eaten by all of these birds is insufficient to reduce the numbers of the
pest to any extent, and for all practical purposes they might have
been omitted from a list of natural enemies.

THE FROG.

Dr. Cyrus Thomas quotes Professor Eoss and others as stating that
the common frog is an enemy of the chinch bug. While this is prob-
ably true, it is nevertheless well known that com-
paratively 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.

INVERTEBRATE ENEMIES OF THE CHINCH BUG.

Of the invertebrate enemies the same may be
said as of the frog. The writer has occasionally
found a chinch bug containing a species of Mer-
mis, "hair snake." Also occasionally ants may
be seen dragging these bugs away, while lady-
beetles have sometimes been found to devour ^^/XnR^T^
them, as recorded by Walsh and Forbes. Per-
haps the worst insect enemies of the chinch bug are to be found among
its comparatively near relatives, the insidious flower bug, Triphleps
insidiosus Say (Authocoris pseudo-chinche of Fitch's Second Report
(fig. 11), and Milyas ductus Fab., (fig. 12) the latter being reported by
Dr. Thomas as the most efficient of the insect enemies of this pest, while
Dr. Riley found that the former also attacked it. Professor Forbes

limits of the State or for sale within the state tor market purposes. The fish and
game commission can, however. Issue permits to colleges and educational institu-
tions to collect hoth birds and eggs lor strictly scientific purposes

*A Preliminary List of the Birds of Wayne County. Ohio, by Harry C. Oberholser,
Bull. Ohio A.gl. Exp. Sto., Tech. Ser., Vol. 1. No. l. p. 270.

54

THE CHINCH BUG.

Fig. 12. — Milyas ductus Fab. (from
Riley).

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 bags. Drs. Sbimer and Walsh both
claim that lace-wing flies (Chrysopa) destroy chinch bugs, and they
are doubtless correct. I have also very often found chinch bugs entan-
gled in spider webs, dead, though whether killed for food or by acci-
dent I have not been able to determine. It will be seen, however, that
the combined influences of all of the natural enemies of the chinch
bug, parasitic fungi excepted, is far too weak to offer any material pro-
tection to the agriculturist against this pernicious enemy of his crops,
with nothing to promise an improved condition of affairs in this direc-
tion in the future. There may sometime ap-
pear hymenopterous parasites of the eggs,
but we have as yet no proof of the existence
of such in this country, and only suspect the
possibility of such a phenomenon because
other allied species have similar enemies,
which destroy their eggs. In short, the im-
munity of the chinch bug from attacks of
other organisms is so striking that it has at-
tracted the attention of all entomologists who
have made a study of the species, and all
accept this as indicating that it is an exotic, not originally belonging
to our insect fauna.

REMEDIAL AND PREVENTIVE jMEASURES.

The list will include all that have been found to possess the merit of
reasonable efficiency and practicability. These measures may not all
prove applicable in all localities or under every variety of circum-
stances, the farmer often having to fit his protective measure to meet
weather conditions, location of field and its surroundings, as well as
the thousand 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 of warding off an
attack of chinch bug is to destroy them in their winter quarters. This
can be accomplished by burning all dried grass, leaves, or other rub-
bish during winter or early spring. Forbes (First Report, p. 37) and
Marlatt (Insect Life, VII, p. 232) have cast some doubt upon the state-
ments to the effect that the chinch bug hibernates to any great extent
among dried grass, leaves, and rubbish, but the evidence is so over-
whelmingly in favor of the assertions of nearly every entomologist
who has studied the insect in its hibernation to the effect that it does
select such places in which to pass the winter that there is hardly any
use of raising the question at all. A good illustration of the fact that
large numbers of chinch bugs may be in hiding in such places and
escape detection is shown by the fact that a quantity of dried leaves

REMEDIAL AND PREVENTIVE MEA8UBES. 55

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 l.\ miles
from the shores of Lake Erie on the opposite side, were collected late
in April and brought to our insectary and placed in a breeding cage.
At the time of collecting the leaves only an occasional chinch bug
was to be observed, but under the warm atmosphere of the insectary
they began to stir themselves, and soon demonstrated that there had
been a large number ensconced unseen among the dried and curled
dead grape leaves. So it is with the matted grass along roadsides and
fences, especially the Virginia worm rail-fence.

While it is not possible to find them by searching, if pieces of boards
are laid down on the grass in early spring chinch bugs will collect on the
under side and may be found there, or they may be discovered by the
method of collecting known to entomologists as sifting. By burning
all such grass thousands of bugs will be destroyed in their winter
quarters 5 but sometimes the matted blue grass 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 they are trampled to
death besides. 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. Shocks of fodder corn left in the fields over
winter certainly afford protection for many chinch bugs, as also will
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 PLOTS OF ATTRACTIVE GRAINS OR GRASSES IN EARLY SPRING.

Judging from the manner in which the wintered-over adults are
attracted to hills of young corn, wheat fields, or plats of panic grass
and foxtail, it has always seemed to me practical to take advantage o(
this habit and sow small patches of millet, Hungarian 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 artificial 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 ot it
to collect together and deposit their eggs there, whereupon eggs.
young, and adults can, a little later, be summarily dealt with by plow

56 THE CHINCH BUG.

ing both bugs and food under and harrowing and rolling the ground
to keep the former from crawling to the surface and escapiug. I have
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-palli), 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, and as a consequence they
were almost totally annihilated, hardly 1 per cent making their escape
to an adjoining cornfield.

DIFFICULTY OF REACHING CHINCH BUGS IN MEADOWS.

There is, however, some doubt in regard to the practicability of
applying these measures in 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
withstand.

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 consti-
tute so many ladders by which the chinch bugs could easily crawl out
and make their escape. Where the ground will admit of subsoiling, or
a " jointer" plow can be used, this latter difficulty can easily be over-
come. Usually, however, the chinch bug works too irregularly in a
field to permit of plowing under infested areas without disfiguring it
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. I have witnessed many instances where the heroic
use of the plow in turning under a few outer rows of corn 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 seri-
ous 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 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 grow-
ing corn in adjacent fields. In fighting the chinch bug promptness of
action is about as necessary as it is in fighting fire.

REMEDIAL AND PREVENTIVE MEASURES. 51

WATCHFULNESS NECESSARY DURING PROTRACTED PERIODS OF DROUGHT.

It lias always appeared to me as though a little watchfulness on the
part of farmers during periods of drought might enable them to deter-
mine whether or not chinch bugs were present in any considerable num-
bers in their fields in time to interpose a strip of millet between the
wheat and corn, to be utilized later as previously indicated. Instances
have come under my observation where, the wheat fields being over-
grown with panic grass and meadow foxtail, the bugs transferred their
attention to these as soon as the wheat was harvested, and 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 it to dry in the hot sun, when, in a few hours, it will burn
sufficiently to roast all bugs among it, 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.

In case the weather at the time should, on the contrary, be wet and
rainy, so that it is impossible to mow and burn, the prompt distribution
of the fungus Sporotrichium will prove of immense value; for in this
case the more the bugs are massed over a limited area, the more fatal
will be the effects of the fungus, and especially will this prove true if
the land is low and inclined to be damp. This statement will also hold
good with reference to meadow lands during the breeding season,
though later the adults do not appear to succumb to the effects of the
fungus nearly as readily, and I have found it present in spring among
masses of hibernating individuals, with little indications of its conta-
gious nature, only an occasional individual being attacked.

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 of universal use 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 prove fatal to insect
life and yet not injure the vegetation upon which such may be depre-
dating. Diluted and ready for use, the emulsion is prepared as fol-
lows: Dissolve 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 oi' a
cream-like consistency, which, on cooling, will form a jelly-like mass
which adheres to the surface of glass without oiliness. For each gallon

58 THE CHINCH BUG.

of this emulsion use 15 gallons of water, mixing thoroughly, and if
applied to growing corn it will be best to use it either during the
morning or evening, say before 8 a. m. or after 5 p. m., as it will be less
likely to affect the plants than if applied in the heat of the day.

Where an invasion of the chinch bug is in progress from a field of
wheat to an adjoining field of corn, as an illustration, the marginal
rows of corn can frequently be saved, even after the bugs have massed
upon the plants, by spraying or sprinkling them freely with kerosene
emulsion, using a sufficient quantity so that the emulsion will run
down and reach such bugs as are about the bases of the plants. This
treatment will kill 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, and one of these measures 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 this farrow 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 bottom,
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 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 measures are thoroughly practical I
have ample personal experience in evidence, and know that under most
conditions that are likely to obtain, prompt and efficient application is
all that is necessary. 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 up to this time discovered. I have
never seen a field attacked by a migrating army of chinch bugs but
that it might have been saved from very serious injury by the prompt
use of either of these measures, though I can imagine conditions where
the farmer might find it advantageous to use some other method of
protection.

REMEDIAL AND PREVENTIVE MEASURES. 59

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 with tar. Forbes has reported excellent results from the appli-
cation 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 corn field
from an ordinary garden sprinkling pot from which the sprinkler had
been removed 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 com-
pleting 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 constructed were prevented from spreading further 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, 111., prepared for the
coaltar 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 receive 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 sunk along the tar lines, and in these
were placed cans or ws into which the bugs fell in myriads and were
destroyed.

On one farm of 250 acres a coal-tar line 00 rods in length was renewed
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 a 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

* Twentieth Report oi' State Entomologist of Illinois, i>. 39, 1898.

60 THE CHINCH BUG.

at the trapnole, 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 with entire success and at small expense is the best possi-
ble proof of their practical utility. If a farmer is situated near town,
where refuse tin cans are dumped in any 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 kerosene 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 frequently 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.

Professor Snow, working in Kansas, followed a somewhat different
method and one that, under certain conditions, might be found supe-
rior to that used by Professor Forbes, or the furrow and kerosene
method applied by myself in Ohio. This modification consists in
throwing up a double furrow, known among farmers as "back furrow-
ing," 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 zinc it will be
found to keep bright and polished and by this means make a more
smooth ridge. The substances used were coal tar as it came from the
gas works and crude petroleum as taken from the oil wells. The
former is the more easily obtained, except in certain localities, and
will probably be found the more practicable, as it stands on the surface
better and is not so readily washed away by rains. Both of these sub-
stances are, however, offensive to the bugs, and they will seldom
attempt to cross them or even come close enough 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 pass-
ing along beside the tar line would crowd each other into them. Pro-
fessor Snow suggests that it will be better to construct this barrier
several weeks prior to its being 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

* Fifth annual Report of the Director of the Experimental Station of the Uni-
versity of Kansas, pp. 45-47.

REMEDIAL AND PREVENTIVE MEASURES. 61

per cent of the injury from chinch bugs may be prevented, 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 prac-
tical here, as also will the post holes for collecting the chinch bugs. I
merely cite this method in order to call attention to its possible use
where the others are found impractical. The plowing of furrows has
been in vogue since the first writings of Le Baron and the second report
of Dr. 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 Forbes has recorded the fact that
where this 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
irrigation is practiced these furrows may be flooded and in this way
rendered still more effective without the expenditure of either time or
money to keep them in constant repair. Dr. Riley long ago laid con-
siderable stress on this measure, believing it of much value, especially
in the arid regions of the far West. The same writer advised the flood-
ing of infested fields, wherever it could be done, for a day or so occa-
sionally during the month of May. It is hardly likely, however, that
this will often be found feasible, though such occasions might arise.

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 I have shown, it is absolutely impossible, with
our present inability to forecast the weather months in advance, to be
able to foretell whether or not an outbreak of chinch bug 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 winter over
in sufficient numbers to cause some injury in spring, yet 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 uncer-
tainty that renders the carrying out, over any large area of country.
any protective measures where, as in this case, the benefit to be derived

62 THE CHINCH BUG.

will only be realized nearly a year afterwards, if at all. The average
farmer, when smarting under a heavy loss, will often take such long-
range precautions as to sow belts of flax, hemp, clover, or buckwheat
around his wheat field once, but if the chinch bugs do not appear, and
he sees the useless investment of time, labor, and seed, he will likely
conclude the next year to take the risk and do nothing. For the pres-
ent, then, we have no method whereby we can prevent the chinch bugs
from taking up their abode in wheat fields or timothy meadows and
raising their enormous families there, except to destroy the adults in
their winter quarters.

I 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
uu satisfactory, 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 impor-
tance to clean up the roadsides, and along fences and patches of wood-
land, as well as any other places likely to afford protection for the
hibernating chinch bugs. I fully understand the 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 con-
dition 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 grading and
macadamizing of the roadbed itself.

There are at present so-called weed laws in many States, and though
more or less of a dead letter in most cases, yet 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 the harboring
of them a corresponding crime, may be a long way off, but as it grad-
ually draws nearer to us 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 differ-

I

SUMMARY OF REMEDIAL AND PREVENTIVE MEASURES. fi3

ent purpose. In the timothy meadows of the northeastern portion of
the country, where, for lack of wings fitted 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 experi-
ments to determine the exact effects of burning over the meadow lands
in winter, both on the hibernating chinch bugs and on the grass roots.
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 burning over the waste places and such rubbish and
debris as will 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 difficulty in putting preventive meas-
ures in force is in the difficulty of foretelling an invasion. In north-
eastern 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 exam-
ination 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, would 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 crop 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.

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 may
be destroyed in their places of hibernation by the use of fire. They
can, under favorable meteorological conditions, be destroyed in the

* A case in northeastern Ohio has come to my notice where an infested timothy
meadow was plowed late in the fall of 1897. Late in April of 18!>S this ground was
cultivated, rolled, and harrowed several times, and most carefully and completely
prepared for corn, which was planted, but with the result that a portion of the field
\\;is attacked and destroyed by chinch bugs, largely of the braohypterous form. An
examination about June 10 revealed the bugs in considerable numbers about the
still remaining plants, but scattered over the field were more or less numerous
clumps of timothy, in some cases apparently having been killed by the chinch hugs.
while in others these were literally swarming about the dying but still green clumps
of grass, thus showing that the former 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 whereh\ the\ were enabled to climb to the surface.

64 THE CHINCH BUG.

fields, if present in sufficient abundance during the breeding- season,
by the use of the fungus Sporotrichium 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 supple-
mented by post holes, and by being buried under the surface of the
ground with the plow and harrow ; or the latter method can be applied
after the bugs have been massed upon plots of some kind of vegetation
for which the bugs are known to have a special fondness, which decoys
should be so arranged as to either attract the females and induce them
to oviposit therein, or they should be arranged with the idea of inter-
cepting an invasion from wheatnelds into cornfields, and, by turning
these decoys under with a plow and immediately smoothing and pack-
ing the surface by harrow and roller, thus destroying them. While in
the cornfields they can be destroyed on the plants by applications of
kerosene emulsion. Without vigilance and prompt action, however,
only indifferent results are to be expected from any of these measures.

INSECTS THAT ARE MISTAKEN FOR CHINCH BUGS.

Messrs. Osborn and Mally* have given a list of twelve species of
Heniiptera which have been mistaken with more or less frequency for
the chinch bug, the list being as follows:

Nysius angustatus TJhl., the false chinch bug (fig. 13), is probably the
most frequently mistaken for the true chinch bug, as it often breeds in

considerable numbers under purslane, ama-
ranth, etc., and more than any other insect
resembles the chinch bug. It is, however,
of a light-gray color, which will always dis-
tinguish it from its more destructive fellow.
Ischnodemus f aliens Say, or the long chinch
bug, as it is sometimes called, is much larger
and longer than the true chinch bug.
Ischnorhynchus didymus Zett. is more

Fig. 13.— Nystius angustatus : b, pu-

pa; c, mature bug (from Eiiey). robust, ol a light-tawny color, with promi-
nent, glassy wings.

Peliopelta abbreviata TJhl. is, next to the false chinch bug, probably
the most often mistaken for the true insect, and especially is this true
in localities where the brachypterous form of Blissus leiicopterus
abounds. In timothy meadows I have more than once been misled.
Its broader head and body, however, quickly enabled me to distin-
guish it.

Geocoris fuliginosus Say, G. borealis Dallas, G. bullatus Say, and G.
Umbatus Stal., according to Osborn and Mally, have all been confused
with the chinch bug in Iowa. These are all broader and flatter than
the true chinch bug, the head being nearly as wide as the thorax.

* Bulletin No. 32, Iowa Agricultural College Experiment Station, pp. 363-385.

INSECTS MISTAKEN FOR CHINCH BUfJS.

05

Ligyrocoris sylvestris Linn, is larger than the true chinch bug. and
its wings are quite dark instead of white.

Trapezonotus nebulosus Fall, is a trifle larger and its body is not so
black as in the chinch bug.

Cymodema tabida Spin., is longer than the true chinch bug, of alight
brown color, and the ends of the wings are glassy.

Triphleps insidiosus Say, or the insidious flower bug
(fig. 11), as it is more commonly called, is another bo-
gus chinch bug, though an enemy of the true pest, as
previously stated.

Piesma cinerea Say, the ash-gray leaf bug (fig. 11) is

often mistaken for the true chinch bug, though its

form differs greatly from that of the latter. It is often

quite abundant, but not in grain fields or meadows.

Corimehcna pulicaria Germ., the

Fig. 14. — Piesma cine-
rea (from Riley).

flea like negro bug (fig. 15), has
been confused with the chinch bug -,
though it does not in the least re-

Fig. 15.— Corimelcena pu-
licaria (from Riley).

burning over
stroying the
came several

semble the latter, either in form or color, and its
confusion is probably to be accounted for by the
fact of its being occasionally found in wheat fields
in considerable numbers.

Brachyrliynclius g rani flat us Say (fig. 1G), has been
mistaken for the chinch bug in Ohio, and in a way that was somewhat
amusing. Farmers in southern Ohio, during the winter of 1S96-97, were

the woodlands with a view of de-
hibernating insects, when there
discouraging reports to the effect
that such a course would be in-
effective, as the bugs were winter-
ing in the tops of trees, especially
where the tops were
dead, under the bark
and often from 50 to
75 feet from the
ground. This was a
piece of astounding
information, to me
at least, and it was
only after securing
specimens that 1 was
able to solve the
ill stages of development except the ogg.

Fig. 16. — Brachyrhynehus grantUattu: a, early nymph

c, late nymph— all enlarged (from Hart).

mystery. This insect, in

b. adult;

hibernates under loose bark. It is broader and much flatter than the
true chinch bug, but the wings are white and the body black.
The object in calling attention to these bogus chinch bugs is to pre-
59G8— No. 15 5

66 THE CHINCH BUG.

vent their confusion with the true Blissus leucopterus, as in some cases
people finding them and supposing them to be the true pest, are likely
to become panic stricken and often destroy property unnecessarily, so
notorious has the name "chinch bug" become in the United States.

PROBABLE ORIGIN AND DIFFUSION OF THE CHINCH BUG.

For the farmer engaged in attempts to check the ravages of the
insect in his fields the question of origin, or how it came to reach him,
will at the time have little interest for him. It will suffice that it is
present in overwhelming numbers, and what he will most desire will be
to learn how to rid his premises of its most unwelcome presence in the
most summary manner possible.

If, however, the farmer happens to be a thoughtful and observing man
he will sometimes wonder how it is that, except in Virginia and the
Carolinas, a person need not be very aged in order to remember a time
when the chinch bug was an unknown factor in his profession, with a
possible value far too small to merit consideration. If he happens to
reside in northeastern Ohio or in some portions of New York, and has
spent some time in Illinois, Iowa, Kansas, or Minnesota, he will prob-
ably marvel at the striking difference in appearance between many of
the chinch bugs of his own locality and those found in any of the last-
mentioned States, and will probably be able to satisfy himself of their
identity only by the similarity of their vile odor. Again, he will prob-
ably be equally at a loss to understand why it is that his own timothy
meadows are overrun by these pestiferous insects and destroyed,
while in other localities, perhaps less than 100 miles away, similar
meadows are left untouched, the injury there being confined to the
wheat and corn fields.

If wondering leads to questioning, as it often does among the con-
stantly increasing number of educated and up-to-date farmers, it will
not satisfy him to receive an evasive or obscure reply to his query as to
why such differences exist, for if he can not get a clear explanation he
will want ideas, theories, or possibilities. He wants the best explana-
tion possible to give until some one finds out a better one, realizing
that had mankind been perfectly satisfied with the knowledge that a
stroke of lightning would split a tree or destroy human life, and had
stubbornly refused to listen to possibilities or to anything but facts,
we would not now be able to understand and utilize electricity in the
many ways that we do at the present time. Such men understand,
perfectly, that the solution of most problems in natural science must
of necessity commence with theories which must be patiently tested
and adopted or rejected as the results demand, while the scientific man
knows that the solution of one problem* often opens up the way for the
solution of another, the last not infrequently having an entirely differ-
ent application from the first.

The science of applied entomology is growing rapidly and becoming

PROBABLE ORIGIN AND DIFFUSION. 67

both broader and deeper, and it is not enough to simply tell the hus-
bandman what an insect is and how to kill it. He must have some-
thing along with that information to set his own mind to thinking, to
work out problems or improve upon the solutions already given him,
otherwise it is much like giving money to a professional beggar. If we
can not give facts based upon demonstrations, then give the best expla-
nation possible, even though it be a theory which is only expected to
stand until some one does better. It is for the thoughtful, progressive
farmer, as well as the student of geographical distribution, that this
possible solution of the problem of the chinch bug has been prepared,
and while the full practical value of the ideas advanced has yet to be
demonstrated, this of itself can not be urged as sufficient grounds for
not sending it forth for study and consideration.

Thanks to the careful observations of Professor Sajo, on the Euro-
pean species of chinch bug, Blissus dorice, it is now for the first time
possible to compare the habits of this species with our own.

INDICATIONS OF A PROBABLE DISTANT ORIGIN AND LATER DIFFUSION.

In the United States our chinch bug, Blissus leucopterus, has a num-
ber of peculiar characteristics, which, while having an economic inter-
est, also points to a probable previous condition differing somewhat
from the present, and not in all cases tending toward its present nu-
merical strength. On the other hand, we find that it is now following
some probably ancient habits which do not appear to be of any special
benefit, but rather the reverse.

In the first place, over its area of greatest destruction, it appears to
prefer level tracts of country where the damp conditions consequent
upon frequent rainfalls remain the longest, and in the second place,
the period of spring ovipositiou is for the most part included within
that during which the spring rains of the United States usually occur —
that is to say, throughout the great grain belt, east of the Rocky
Mountains, April and May are not normally months of severe drought,
and it is during these two months that the larger portion of the eggs
are deposited. As in the reverse of this, however, the period of fall
ovipositiou, August and September, is far more likely to be favored by
a lack of precipitation. These conditions do not always obtain, and it
is because of the fluctuations that the insect is able to reach its maxi-
mum in poiut of numbers.

Another factor which plays quite an important part in reducing the
number of adults maturing during unfavorable seasons may be found
in the almost universally gregarious habits of the young, thereby ren-
dering the ravages of the fungous disease the more universal ami fatal.
In all of these peculiar characteristics as well as in some anatomical
features, it seems to me we have a series of guide posts, so to speak,
which indicate more or less clearly the ancient home of the species.
and at least throw some light on i{s origin and d illusion.

68 THE CHINCH BUG.

UNIQUE APPEARANCE AND GREGARIOUS HABIT.

Mr. E. A. Schwarz* sometime ago called attention to "the unique
appearance of the full-grown chinch bug, with its white wings and
chalky- white pubescence," which, he declared, "forcibly indicates that
the insect is either a psammophilous or a maritime species," and
expressed the opinion that its geographical distribution fully bears
out the theory that it belongs to the latter class. The same author
states that the species has the habit of clustering about the roots of
tufts of grass along the Atlantic coast, from Florida to Atlantic City,
N. J., and Mr. W. H. Harrington t observed it to have the same habit
along the seashore at Sydney, Cape Breton, in 1884. The late Dr. J. C.
Neal, while at Stillwater, Okla., wrote me that he had observed the
species to have the same habit in that Territory, miles from any human
habitation. Dr. Asa Fitch f found them swarming amidst extensive
prairies in Illinois, in 1854, while more recently Mr. C. L. Marlatt has
witnessed the same phenomenon in Kansas. § In short, this gregarious
habit seems to be most tenaciously adhered to wherever these insects
are found in any numbers. Wheu migrating from one field to another,
after crossing a roadway or plowed field they will at once flock together
on a few plants along the margin of the, to them, new field instead of
scattering about, two or three to a plant. It may also be added that
Mr. Koebele found the species in large numbers along the seashore not
far from San Francisco, Cal., in the" first, second, and third stages of
development, on a species of grass growing along the coast.

It has not, so far as is known to the writer, been observed in similar
places along the shores of the Great Lakes, though I have searched for
it there, but it occurs in destructive abundance in timothy meadows
inland in northeastern Ohio for fully 75 miles, and most generally
clustering about the roots of grass, which, by the way, is about the
only vegetation attacked as the species is described as doing along the
seacoasts. I may say also, that it seems to hibernate there precisely
as observed by Mr. Marlatt in Kansas ; Dr. Neal in Oklahoma ; Mr.
Schwarz in Virginia in the vicinity of Fortress Monroe, and as the
earlier observations of Dr. Fitch in Illinois would imply. Thus we
find this habit of clustering upon the plants attacked to be a constant
one, and where the natural grass vegetation has not been displaced by
farm crops, thus leaving the ground more or less bare during winter,
they continue to hibernate there. With these two characteristic habits
generally followed over the great area inhabited by the species in
North America, we may add a third possible factor in the problem
of origin and diffusion of the species which, though an anatomical
diinorpnioin, may be discussed as likely to throw considerable light
upon the probable ancient habitat of the insect.

* Insect Life, Vol. VII, p. 420.

t Can. Ent. Vol. XXVI, p. 218.

X Second Keport, Insects of New York, p. 283.

§ Insect Life, Vol. VII, pp. 232-234.

PROBABLE ORIGIN AND DIFFUSION. $2

OCCURRENCE OF THE LONG AND SHORT WINGED FORMS AND THEIH DISTRIBUTION.

The occurrence of both the long and short-winged forms, intermixed
along our seacoasts and in the northeastern section of the country,
but not elsewhere, shows very plainly that this dimorphism is not due
to the temperature of any particular locality, but must be regarded as
having been brought about by disuse of the wings for a considerable
period of time, thus indicating a seashore habit on the one side, while
the total lack of the short-winged form elsewhere indicated otherwise.

In a paper presented before the Entomological Society of Washing-
ton,* "On the insects found on Uniolapanieula in southeastern Florida."
by Mr. E. A. Schwarz, the author stated that Blisxus leucoptcrus occurred
in large numbers on the upper part of the plant, the imagos and larger
young among the ears and the smaller individuals between the upper
blades. Mr. Schwarz attributes this habit to the tough woody nature
of the storm-beaten plant nearer the ground, thereby driving the insects
to the more tender though more exposed portion of the plant. In con
nection with this statement the writer tells us that the insect occurs
in that southern latitude only in the short-winged form, and that in the
examination of thousands of specimens from that region he had never
found a single long- winged specimen. Under date of May 4, 1896, Mr.
W. H. Harrington wrote me of this species as follows: "In September,
1800, 1 found it at Aulac, almost on the border between Xew Brunswick
and Xova Scotia. It seemed not uncommon and occurred under stones,
about the roots of grass, in a pasture adjoining the marsh where I
found Diabrotica longicornis, the pasture being on the upland skirting
the marsh. Both the long and short-winged condition occurred, as in
Cape Breton. f Dr. A. S. Packard communicated to Dr. J. A. Lintner the
following extract from his diary, "June 17, 1871, at Salem, Mass., chinch
bugs with wing covers extending over the basal third of the abdomen,
seen in copula, end to end.t In the serious outbreak of this insect in
the timothy meadows of northern New York, in 188:2 and 1S83, about
20 per cent of the bugs were of this short-winged form*

Although Dr. Asa Fitch, as early as 1855, refers to this form along
with nine others, he does not give the source from which he obtained
specimens, but just previous to this he says (p. 287) that he had met
with but three specimens from his own State, and these were found on
willow in the spring of 1847.|| Had any of these been of the short-
winged form he would have been very likely to have mentioned the
fact. Mr. E. P. Van Duzeefl states that he had known of the occur-
rence of the species in western New York as early as 1874, and had
also found it at Bidgeway and Muskoka, Ontario. Ordinarily the

* Proo. Ent. Soo., Washington, Vol.1, p. 101. Read Noy.3, 1887.

t Canadian Entomologist. Vol. XIV. p. 218.

tLintner's Second Report. State Entomologist of New York, p. li>4.
$ Second Report, State Entomologist of New York. p. 156.
|| Second Report on Noxious Insects of New York. p. 291.
H Canadian Entomologist. Vol. XVII, pp. iV!>-10. L886.

70 THE CHINCH BUG.

short- winged form predominates, but in hot, dry summers they mostly
acquire fully developed wings. He had never found the species in
grain fields of any sort, but always in grass lands, generally in timothy
or clover, but sometimes in wild grasses. Of eleven specimens collected
from under the bark of an old log by Mr. J. Pettit, of Grimsby,
Ontario, in 1866, and sent to Mr. B. D. Walsh for determination, all
were of the short-winged form.* It was these specimens that doubt-
less led Dr. Eiley t to call attention to the fact that in Europe there are
many genera of half winged bugs which occur in two distinct or
" dimorphous" forms with no intermediate grades between the two,
viz., a short winged or sometimes a completely wingless type and along-
winged type. Frequently the two occur together and copulate pro-
miscuously, while sometimes the long- winged type occurs in particular
seasons, especially in very hot seasons, while more rarely the short-
winged type occurs in a different locality from the long- winged type,
and usually in that case in a more northern locality. In northeastern
Ohio the species occurs during some years in great abundance and very
largely at least on timothy. Here the short- winged form is very largely
in the majority, and in the spring of 1897, of 1,900 specimens collected
indiscriminately, only about 400 were of the long- winged type.

In northern Indiana, where the insect occurs but rarely, I have also
found this short- winged type, though I have not observed that it pre-
dominates; but aside from these two localities, with an acquaintance
with this species running over forty years, chiefly in Indiana and
Illinois, I have never met with the short- winged type, though I have
seen millions of adults. £ If this short- winged type occurs elsewhere to
the westward, except along the Pacific coast, where both forms have
been collected by Keobele and others, it has not been found by ento-
mologists, even to the northward as far as Minnesota, Winnipeg, and
Manitoba, while to the eastward of this Mr. Van Duzee collected the
brachypterous form on Muskoka River, Ontario, near the lake of that
name. § On comparing specimens from New York with a large series
from Kansas, the former were found to be quite uniformly more robust,
with longer hairs on the pronotum. ||

It seems to me that we here have evidence of two distinct tides of
migration, the one sweeping north and eastward, while the other has
mainly been to the north and westward, meeting the former in north-
eastern Ohio and northern Indiana, and possibly somewhere farther to

* Practical Entomologist, Vol. II, p. 21.

t Second Report on tlie Insects of Missouri, p. 22, 1870.

X Of a large number of adults collected late in April, 1898, while still in hibernation
among the dead leaves in vineyards near the shore of Lake Erie, in northwestern
Ohio, not a single brachypterous individual occurred, while of 66 specimens sent
me from Salem, in northeastern Ohio, 50 miles from the lake shore, May 31, 1898,
all but 6 were brachypterous, these latter being taken from a field of young corn,
8 acres of which had been totally destroyed by them.

§ Can. Ent. Vol. XXI, p. 3, 1889.

||Loc. cit. Vol. XVIII, p. 209.

PROBABLE COURSE OF DIFFUSION. 71

the north in British America. The two, besides differing in the length
of the wings, are sufficiently unlike in appearance to attract the
attention of students of Hemiptera.

RELATION OF THE INLAND AND SKACOAST SHORT-WINGED FORMS.

I do not wish to be understood as claiming that the short- winged
form of chinch bug found in Ohio is precisely the same form as that
found along the seacoasts, but it seems to me that the inland form
originating from this maritime short-winged element, instead of acquir-
ing wings of normal length as it drifted away from the coast, has really
moved in the other direction, and the wings have become still further
aborted.

It will be observed by the illustrations given of both the inland and
maritime short-winged forms (see figs. 3 and 4), that in some of the
former the wings have become so aborted as to become almost invisi-
ble, while in the latter, though the wings are very much shortened,
they are nevertheless very clearly to be observed. It would seem, then,
that we might reasonably presume that the species was originally
long- winged, but, living along the seashore, the winged individuals
have either flown each year inland or else been blown into the sea to
such an extent that a short-winged form has thus been evolved which
was unable to migrate and not easily blown into the sea. In pushing-
inland while the country was still inhabited by the aborigines another
source of destruction would confront these insects in the annual recur-
rence of fires whereby vast areas of country were burned over in
autumn, winter, or early spring, and these must have destroyed very
many of the hibernating insects, while such individuals as migrated to
sections not so burned over would escape destruction.

PROBABLE COURSE OF DIFFUSION.

Let us suppose that the species originally worked its way northward
from South America, or even Panama, along the lowlands between the
more mountainous interior and the Gulf of Mexico until it readied
Texas, with its vast areas of level country extending not only across
the State itself, but northward into British America, and. generally
speaking, with the exception of the Ozark Mountains in Missouri and
Arkansas, eastward to the Appalachian system extending from Gape
Gaspe, Quebec, Canada, to northern Alabama. This area is more or
less covered with a grass flora that affords ample food for these insects
and it would seem that there was here offered every incentive to migra-
tion broadly to the northward and eastward, and at the same time
there would be the Gulf coast along which those individuals which
either could not or did not migrate inland could make their way as hail
their progenitors along the coast in Mexico. (See lig. 17.)

Now, it would appeal as though the short winged individuals, it' there
were any such, would remain along the coast, while the long-winged

72

THE CHINCH BUG.

II

Ny^ //\ / / /y^nji |LL<

^&^i

JyAJS^Y //^7x&^

i K \ '^r'T^VO \ v^ \^ V

X\

1

/ V /pi. / // "'a* /"""" — /-— .
//P^W tf\J^ 111 ) "FT —

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\ \\ \ • • * V<v ' *\

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A'

Pi

ssp\

pM \

U V \ / / P^^Cr^\

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^3lrC?'u

r-fSE

Optra

4^%

- L

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rTi^l^

y*F$&(\ '

Tig. 17.— Map showing probable course of diffusion of chinch bug over Xortu America (author's illustration).

PROBABLE COURSE OF DIFFUSION. 16

individuals would, at least more or less of tliem. migrate inland, and
at least some of these, but far more of those unable to fly, would
be annually destroyed by the prairie fires, thus eliminating whatever
tendency there might be to perpetuate the brachypterous forms, and
develop a fully winged more or less nomadic race which, as it slowly
advanced inland, lost all vestige of its brachypterous ancestry, if such
had existed.*

On the other hand, we might expect the shore-inhabiting individuals
to continue in their progress along the coast, the winged individuals
continually migrating inland, leaving a mixture of the two forms to
push forward to the east coast of Florida and northward along the
Atlantic to Cape Breton. As soon as this migration had passed the
southern terminus of the Alleghany Mountains the inland spread
would, very largely at least, be restricted to the area lying between the
eastern slope of these mountains and the coast, thus leaving the whole
area to the west to be occupied by the northward tide of migration
instead of that from the east. East of the Mississippi River and south
of the Ohio Eiver the country is more heavily timbered and the prai-
ries are lacking, so that forest fires would here take the place of prairie
fires; but in the Southern States the woods are composed more largely
of pine, and Dr. Lugger, in Minnesota, finds that the chinch bug does
not invade the region on which only pine and other Conifene grow, but
that the more southern counties of his State, which are well wooded
with deciduous trees, are invaded. He also calls attention to the fact
that before the country was settled by the whites these timbered lands
were burned over frequently, probably annually, but now the wooded
areas are confined to small tracts interspersed among the farms, and
as these are not annually burned over they afford suitable shelters for
the chinch bug during winter, and the grain fields of the farmer afford
ample food during the summer, while on the prairies which are burned
over such is not the case, t

Along the eastern coast the chinch bug has never been especially
destructive to the wheat crop north of North Carolina, where, accord-
ing to Dr. Fitch, t the earliest depredations occurred in 1783, while
Webster § states that it threatened total destruction to the grain in
1785; but since that time the ravages have not been nearly as severe as
farther west in the Mississippi River valley. Strangely, too, nowhere
along the Atlautic coast do we find the short-winged form far inland
until we reach New York and the Xew England States, and what is

*Prof. H. A. Morgan, entomologist of the State experiment Station of Louisiana,
writing me under date of May 30, 1898, states that he lias never found the brachyp-
terous form of chinch hug in that State, and I did not observe a single individual
of these among the many macropterons specimens taken l>> myself in that State.

tFirst Annual Report of the Entomologist of the State Experiment station of the
University of Minnesota, 1895, p. L'ti.

t Second Keport on Noxious, Beneficial, and other Insects of New York, p. -7-.

v> Wehster on Pestilenee, Vol. I, 279.

74 THE CHINCH BUG.

equally perplexing, there it does not attack grain, but grass, whereas
to the southward it is the grain fields that are devastated. In other
words, throughout New England, New York, northeastern Ohio, north-
ern Indiana, and the Dominion of Canada we have both the long and
short winged forms occurring together, but depredating almost or quite
exclusively upon timothy (Phleum pratense).

In Ohio the line separating the habitat of the combined forms and
that of the macropterous form, exclusively, exactly marks the line of
separation between the most serious depredations and almost total
immunity of attack on timothy meadows by chinch bugs. This line of
demarcation at present may be indicated approximately by a line
drawn from the vicinity of the city of Cleveland, on Lake Erie, to the
point where the Ohio Eiver ceases to form the boundary between Ohio
and West Virginia and enters Pennsylvania. To the west and south
of this I have never seen a short-winged adult chinch bug, and timothy
meadows are seldom attacked, and then only where fields of small
grain or corn were not in easy reach; as, for illustration, where they
happened to breed in a wheat field surrounded by timothy, and, when
the grain was harvested, there was no other recourse left them but to
attack the grass. In the opposite direction from our line, however, the
conditions are quite the reverse. Here, while fields of wheat are occa-
sionally badly injured, thousands of acres of timothy meadow have
been entirely killed out from the attack of this insect during the last
few years.

So far as it is possible to determine, there are a considerable number
of winged adults produced in this area every year — perhaps from 30 to
50 per cent some seasons — and these breed in the grain fields; but at
wheat harvest, instead of migrating to the corn, as is done elsewhere,
they go by preference to the timothy meadows. In western New York,
where both the long and short winged forms occur, Mr. Van Duzee
writes me that he has never found an individual of either form in grain
fields, but that they both literally swarm in timothy during some years.
Dr. Lintner told me that in the serious outbreak of this pest in the
meadows of New York in 1882 and 1883 about 20 per cent were of the
short- winged form. Dr. Perkins has recorded an attack of chinch bug
in a timothy meadow in northern Vermont. Whether or not the short-
winged form was the depredator in this last-named locality I am unable
to say, but, generally speaking, the short-winged form is unknown at
any considerable distance from the coast, except in New York, Ohio,
Ontario, and northern Indiana, and but rarely does it occur in either
form in the two latter localities.

Just why this short-winged form should occur in such abundance in
the two States named is a matter that I am just at present unable
fully to explain; but it does seem that this difference in food habits as
between the two forms and the limited distribution of the short- winged
form inland might open the way to a solution of the mystery. I believe

HABITS OF THE EUROPEAN SPECIES. 75

that the insect is primarily a tropical macropterous species, and that it
has followed the coast from South America along the Gulf and Atlantic
northward to Cape Breton, and along the Pacific coast to San Fran-
cisco and possibly beyond ; also that it spread from northern Mexico
and Texas northward as far as Winnipeg, subsisting upon the native
grasses, and in the meantime spreading also to the eastward to northern
Indiana and Ohio, and that during this time, by force of circumstances,
it has again become fully winged and all trace of its former apterous
condition, if such exists, has disappeared.

On the other hand, from the Atlantic coast there has originated a
tide of diffusion the trend of which has been westward, the species
here partaking more of the nature of their seashore ancestry, and are
more or less of the short-winged form, which their less nomadic habit
has served to further emphasize. This tide of diffusion has encountered
what the western tide did not, at least until much later, namely, the
timothy meadows of the Caucasian agriculturist, and, adapting itselt
to this food plant, has held closely to it, thus avoiding the necessity of
seasonal migration; and that in northeastern Ohio and possibly in
northern Indiana it has met the east-bound tide of diffusion, and is
perhaps amalgamating with it. (See map, fig. 17, illustrating supposed
direction of diffusion of chinch bug.)

Although not at all conclusive evidence, I might add that the single
specimen taken at Winnipeg by Dr. Fletcher was of the macropterous
form, while the single example taken by Mr. Van Duzee at Muskoka,
Canada, was of the brachypterous form; and this, with the fact that
the specimens from the island of Granada were of the former and the
Florida coast specimens of the latter exclusively, shows that latitude
and climate have no effect.

HABITS OF THE EUROPEAN SrECIES (Bl%98U8 dorUv FeiT.).

Prompted apparently by a review of one of my papers read before
the eight annual meeting of the Association of Economic Entomologists
at Buffalo, in 1896, Prof. Karl Sajo, formerly of the Kg. Ung. Staat-
liche Entomologische Yersuchsstation, at Budapest, published in the
Illustr. Wochenschrift fur Entomologie, Vol. II, pp. 440-451, July IS.
1897, a short paper on "Unser Blissus dorice? which is so fall of interest
that I shall beg permission to present it here, together with figures of
the larval, pupal, and adult stages of the insect (Figs. IS and 19).

Professor Sajo writes as follows:

In the article on the eighth annual meeting of the Association of Economic
Entomologists (Xo. 26, pp. 401-403, Illustr. Wochenschrift fiir Entomologie), the very
instructive observations of Mr. Webster on the "chinch bug" (IUissii* leueopHnu)
in the State of Ohio were discussed.

In view of this communication I will give more in detail that which 1 have
observed concerning our European species of this genus, namely, Blistw dories Ferr.

Like the North American larger species, the smaller European one appears in
two forms, namely, the wingless and the winged. The first describe! oi this speoies,

76

THE CHINCH BUG.

Fig. 18— Blissus dorice: a. first nymph; c, second: b, third :
d, fourth. (From illustrations prepared in the Division
of Entomology.)

Ferrari, in Genoa, recognized only the wingless form, which with its aborted wings
looks very much like Hemipteron-nymphs, and probably by all entomologists who
previously saw it was not considered as a sexually developed adult, but only the
immature form of some already known species. I discovered the winged form seven-
teen years ago(1880)in the steppes
sand desert, called "Nyires" of
the Kis-Szent-Miklos, and de-
scribed the same."

I at that time made known
the characters of the immature
forms, which can not be confused
with the individuals which have
reached complete sexual devel-
opment, in that the immature
individuals are vermilion red
while adult individuals are dark
brown. It is interestiug that
the relationship between the
winged (macropterous) and the
wingless (brachypterous) indi-
viduals of the American and Eu-
ropean species is very different.
For while in America those individuals which reach maturity are almost always
winged, with us in Europe they are in general-only short-winged, and individuals
capable of flight are not observed; and the fully developed ruacropterous individ-
uals were not thus far, according to my knowledge, found in any otber place than
in the central Hungarian sand dunes already named, and here they occurred only
on a single little portion which only measured a few paces in diameter. It was
a "Dunenhugel" (sandy hill) covered with high, scattered poplars, whose fallen,
dried foliage sparsely covered the ground.

Here lived the colonies of Blissus doHce on the bases of the bushy, growing grass,
almost under the surface of the
ground, and well concealed. The
habits of the European species are
also in the main similar to those of
her American relative, since the latter
also lives only on grasses, and during
its development also lives very close
to the surface of the ground.

It is extremely remarkable that,
even though B. dorice is very widely
distributed here, and is met with
not only on the "Flugsande" (sand
drifts), but also in the hilly regions
(e. g., on the southern exposure of
the hill which stands between Duka
and Szod, in the midst of bluffs or
rolling hills), the winged specimens
were to be found only on the very

small lc Blissus Island" under the poplars. But here also they were found but
rarely, and only then when the transformation from the pupa to adult stage was
in full force. When there were no more pupre to be found, then also the search for
long-winged individuals was in vain.

*K. Sajo: Die bisher unbekannte makroptere Form von Blissus dorm Ferr. Ento-
molog. Nachrichten, 1880, p. 235.

Fig. 19. — Blissus dorice. Wingless form at left;
winged form at right. (From illustration pre-
pared in the Division of Entomology.)

HABITS OF THE EUROPEAN SPECIES. 77

This appearance I explain in this way: That the winged examples, as soon as they
were ahle to fly, quickly Hew away and disappeared in order that they might serve
as progenitors for new colonies.

But the place of discovery has since been transformed into an immense vineyard
by the Government, whereby grass, poplars, and also B. dorice had to disappear
from thence. For four years I have, though seeking with the greatest diligence,
been unable to get track of the winged specimens anywhere in this region, even
though I know of a number of colonies of this species upon my own premises.
While formerly I captured a few specimens each year and gave them partly to
museums and partly to entomologists, I scarcely hope to attain such interesting finds
in the future.

The difference just mentioned between those individuals capable of flight and
those not capable of flight in our species and also in the trans-Atlantic species can
hardly be accidental, but may be sought for in the influences of environment.

Next there crowds to the front the fact that in North America B. teucopterus is
continually subjected to the attack of its deadly fungus parasite to a high degree,
and its colonies die out as soon as rainy, moist atmosphere prevails. Consequently,
the Blissus species living there must always hunt new habitats and be wandering
continually to far distant localities. For this wings are of course necessary, and
only by means of these is the species enabled to sustain itself at such a high grade
of importance that it can, now here, now there, become a veritable plague to
agriculture.

With our European species it seems, on the contrary, in regard to many points to
be otherwise; for, while her habits in the main are similar to those of her sister
across the sea, yet there are found many important differences in their environment.

Blissus dorice never congregates in such close masses as we read of in the American
reports. It forms only insect islands, and even individual families seem to scatter
out to some distance. In the steppes, moreover, the growth of grass is not matted,
but stands in isolated bunches on the partially bare ground, the bunches being not
infrequently separated by several paces.

Our species will not go into cultivated fields. I have never found even a single
specimen among forage plants that have been sown, and already this condition is
one of the reasons why the European species does not cluster together in such
uninterrupted masses.

If, then, this is true the attacks of entomogenous fungi will hardly be able to
create such havoc in B. dorice as it does among 7?. Jeucopterus in America.

I have also during eighteen years never observed a wholesale dying' off in the
localities of occurrence known to me. The fungus S. globuliferum has perhaps
never attacked it, and even though the European form were susceptible to similar
pestilences, yet it is always hardly to be doubted that the fungus in the European
homes of B. dorice would not find favorable circumstances in that here during the
period of development of this species in normal years great drought prevails. Rains
lasting for a number of days, with continued moist and warm atmosphere belong.
with us, among the rarities, especially during the summer, and it is the young stages
that are especially sensitive to tho fungus attack, as has proven to be the case in
America.

Among insects there may possibly be found Blissus enemies, even though the
extremely penetrating odor of this bug, which is identical with that of the one living
in beds in houses, may serve as a protection.

Taking all of this together, we observe that our European species is in less danger
than the American, and that it is not subjected to catastrophes of total destruction.
so far as has yet been observable in the stationary localities of occurrence in the
open field, for I have never yet observed a sudden disappearance from the localities
known to me. It is not necessary, therefore, for it to be continually hunting up
new fields in which to thrive, and there was no apparent reason which in the
struggle for existence would have given preponderance to the long-winged form;

78 THE CHINCH BUG.

and so in time, in the generation of our species, which originally, perhaps, was full
winged, the winged form became less and less numerous, until to-day we see almost
entirely brachypterous individuals in the adult stage, exactly the same as in the
bedbug, Acanthia lectularia, with this difference, that among the swarming masses
of the latter nowadaj^s not a single example with fully developed wings can be
ound, fortunately for us.

It is evident that the long- winged tendency in B. dorice is disappearing, and the
time may come when one will be unable to find any long-winged specimens. The
designated dangers, on the contrary, against which the chinch bug must fight in
North America require very strong migratory powers, and, consequently, well-
developed wings, through which this especially significant difference between
B. dorice and B. leucopterus has been brought about.

As to the question whether or not our species shall be considered injurious, I can
answer that it in nowise belongs to the entirely indifferent insects, but, on the con-
trary, contributes to the complete drying up of the rather sparse grasses of our
steppe meadows during the summer. But since it has not thus far housed in the
cultivated fields, it can not be placed upon the black list of serious depredators.
Whether, moreover, in the future, when in consequence of the continued destruction
of its herding meadows, its original food plants disappear more and more, B. dorice
may become, like so many other insect species, a depredator through necessity can
only be conjectured. We have in this regard already recorded entirely too many
remarkable transformations in the menu of other species to disregard entirely the
possibility of a similar transformation in the life habits of our B. dorice.

I wish also at this time to state, for the benefit of our many readers who may not
be familiar with it, that in the dimorphic bugs, especially those in which the inacrop-
terous and brachypterous forms are found simultaneously, the former possess a much
strouger and broader thorax than the latter. As a result of this difference in their
physical structure, one is, when comparing them for the first time, easily inclined to
designate them as two distinct species.

In addition to this, there is in Blissus the strikingly beautiful coloration of the
long-winged specimens, whose clavus and corium are light ocher-yellow, and the
unusually large membrane, which is about twice as large as corium and clavus
together, and of an entirely milk-white color, making the long-winged individuals
very prepossessing. The individuals with rudimentary wings, on the contrary, are
of an obscure chocolate brown. The larvae are, as has already been stated, of a
bright vermilion-red color, marked with black.7*

With the foregoing relative to the habits of an allied species of
Blissus, it seems to me that we can the better understand how, under
one set of conditions, all traces of a short-winged form might entirely
disappear, while with another set of conditions this tendency might
not only be perpetuated, but greatly emphasized. The two species,
B. leucopterus and B. dorice, are fully illustrated in all stages of devel-
opment, as well as both macropterous and brachypterous forms. (See
figs, on pp. 19, 20, 76). For specimens of the latter species, B. dorice,
I am indebted to Professor Sajo.

PREVIOUS IDEAS ON THE DIFFUSION OF THE CHINCH BUG.

Formerly, it was supposed that the chinch bug was a native of the
Atlantic coast States, and that it made its way westward with the
advance of civilization and the consequent progress of wheat growing.

* Translated from the German by my assistant, Mr. C. W. Mally.

PREVIOUS IDEAS ON THE DIFFUSION. 79

This theory was based upon the fact that the original description was
drawn up from a specimen from the eastern shore of Virginia, collected
by Mr. Say himself,* and, as before stated, the earliest destruction on
record caused by this insect occurred in North Carolina, and they also
committed great depredations in Virginia in 1839. Up to this time it
had been supposed that it was a southern species, confined to the
country south of latitude 40° north. But about this time it appeared
in Illinois, at Nauvoo, simultaneously with the settlement of the Mor-
mons at that place, and as many supposed that this sect brought them
to the country with them, they were locally termed u Mormon lice.''

In his second report, page 284, Dr. Fitch states that Mr. William
Patten, of Sandwich, Dekalb County, 111., informed him that the
chinch bug first appeared in that locality iu 1850. Mr. Patten, the
father of Trof. Simon Patten, now of the University of Pennsylvania,
and the writer's father settled in the immediate vicinity of Sandwich,
111., in 1852. This was ten years after the Pottawattamie chief, Shab-
bona, and his tribe had migrated to Kansas or Nebraska, I do not
remember which, but do recall that it was about this time that the
prairie fires ceased to occur over any wide areas, as the prairies were
no longer fired annually by the Indians. The whole country was fast
being occupied, and I well remember that the settlers would decide
upon a certain date on which they would set fire to the wild grass — in
late autumn — so that all could be prepared. I may also state that
there were very few timothy meadows at that time, as the wild grass
afforded an abundance of hay, and not until years after did cultivated
grasses come into general use. The writer also knows from personal
experience and observation that with the decrease in prairie fires there
came an increasing abundance of chinch bugs, which attacked the
wheat fields of the farmer, f This was in a country where there was
comparatively little timber, the only forests, if such they could be
called, being along the streams of water. I am confident that the
chinch bug did not suddenly make its appearance in that section, but
that with the increase of grain growing and the decrease of prairie
fires its effects began to be more and more marked. Since then Prof.

*Tke complete writings of Thomas Say, edited by Le Conte, Vol. T. p. 329.

t Up to about 1862 these fields were largely of spring wheat, hut about that time
there was a rapid decline in the growing of this grain in northern Illinois. It seems
possible that spring wheat might bo more liable to attack from chinch bugs than
fall wheat, as the former is, at the time when chinch bugs seek out their breeding
grounds, more tender and inviting than the latter. Mr. Walter Young, writing me
from Galesville, Wis., states that his spring wheat was totally destroyed in lSMT,
though there had been none sown for ten years previous on the premises, and while
the chinch bug does not ordinarily do much injury, just as soon as spring wheat is
sown they return, as it were, and destroy it.

If spring wheat is so attractive to chinch bugs in spring as this would indicate,
might it not be used for baits instead of millet, as is advised further on. in order to
draw oil' the females in spring when seeking localities for oviposit .on I

80 THE CHINCH BUG.

S. A. Forbes has secured information of tbe occurrence of these insects
in sufficient numbers to attract attention as early as 1823 in southern
Illinois, and within 25 miles of New Harmony, Ind., where Thomas
Say resided and did the most of his entomological work.

REASONS FOR THE PRESENT THEORY OF DIFFUSION.

It seems to me that in all of this we have good grounds for suppos-
ing that the chinch bug occupied the most of the country prior to its
occupancy by the white man, and that its first depredations were
caused by its own advance coming in contact with the advance of
civilization ; and the simultaneous cessation of forest and prairie fires,
with the displacement of the native grasses by large areas of wheat,
so combined that the points of contact were in Illinois, in the West,
and Virginia and North Carolina in the East. Not until within the
last fifteen years has the chinch bug been known to work serious and
widespread injury east of the Allegheny Mountains, north of Virginia;
and west of these mountains they have done scarcely any damage
north and east of a line drawn from Chicago southeast to Cincinnati.
Thousands of farmers in Ohio never saw a chinch bug until within the
last four years, and there are thousands more in northwestern Ohio,
southern Michigan, and northern Indiana that, even yet, would not be
able to recognize one were they to see it among their growing grain, or
even if in abundance. But in considering this matter the fact must be
borne in mind that timothy meadows are not burned over annually as
were the forests and prairies, and the stubble does not die with the
harvesting of the crop as in wheat, and therefore does not necessitate
annual migrations in order to preserve life. In a timothy meadow the
species may live on and reproduce year after year without ever being
obliged to abandon the field. It was the wheat fields of the West that
the east-bound, macropterous tide of migration found confronting it in
Illinois, and the smaller fields of grain and timothy meadows that the
combined macropterous and brachypterous forms, more or less maritime
and north bound, came in contact with along the Atlantic coast, while
at the present time the two tides of migration have met in north-
eastern Ohio and northern Indiana.

In fig. 17 I have illustrated the theoretical directions and courses
taken by each of these tides of migrations from the tropical regions,
and in fig. 1 the areas over which the species is now known to occur
in Central and North America are indicated.

I believe that this same course of migration has been pursued, at least
in the West, by the several species of Diabrotica, and especially D.
longicornis Say, and to a less extent by another species of Hemiptera,
Murgantia histrionica Hahn., and possibly also by Dynastes tityiis Linn.,
while the two latter with others are now working northward along the
Atlantic coast. Besides, the westward tide of migration has been fol-
lowed in all probability by Pieris rapce Linn., Phytonomus punctatus

REASONS FOR PRESENT THEORY OF DIFFUSION. *1

Fab., Hylastinus trifolii Mul.,and Grioceris asparagi Linn., all of which
have first become destructively abundant west of the Allegheny Moun-
tains in extreme northeastern Ohio. The last four species having been
introduced from Europe, there is no doubt as to their migrating west-
ward.

An almost total lack of natural enemies in the United States, and
with nearly all of its closest allies belonging in Mexico and the West
Indies, it would seem as though we were in possession of additional
evidence of its tropical origin. Besides this the name uchinch bug" is
of Spanish origin, and this language has never been in common use in
North America except in Florida and the country along the Mexican
border.

The species certainly prefers the low country to the higher, and is
seldom found in any numbers at an altitude of over 2,000 feet. Gener-
ally its habitat is 1,000 or lower. The altitude where it was found
breeding on Volcan de Chiriqui, in Panama, is 6,000 feet; and of its habi-
tations in Guatemala, San Geronimo, is 3,000 feet; Panzos, 2,000 feet;
Ohamperico, sea level, and Rio Naranjo, about 2,000 feet, while in Colo-
rado it occurs sparingly near Fort Collins at an elevation of 5,500 to
6,000 feet, while Professor Cockerell did not find it at all in the same
State at elevations of 7,000 to 8,000 feet. On Mount Washington, in
New Hampshire, it has been found only once, and this time by Dr.
Packard, on the summit, which has an elevation of 6,500 feet.*

In my own experience, running over something like forty years, I
have never witnessed serious injury to crops on hilly laud by chinch
bugs. It may be stated, however, that all of my studies of the insect
have been carried on in a level country, Ohio being the most uneven
and hilly, but even here all of the outbreaks that I have observed were
on level areas. In Minnesota, however, Dr. Lugger has found that
those grain fields which are most seriously injured are located near the
edges of woods or on slopes. In some published observations of Pro
lessor Osborn, in Iowa, kindly placed at my disposal by Dr. Howard,
I find that in 1894, about 90 per cent of the infested fields examined by
Professor Osborn were on high ground and about 80 per cent of the
fields were hilly and ridges, in most cases the damage being first appar-
ent upon the higher portions of the fields. The exceptions were where
the chinch bug had evidently hibernated in wild grass and weeds occur-
ring in the lower places, and these had been very dry for the twelve
months preceding the damage of that year. Besides, both the Iowa
and Minnesota areas are below 1,000 feet elevation.

The area over which the chinch bug is more especially abundant and
destructive comprises such a variety of soils and geological formations
that a study of these factors at once shows that neither has any mate
rial intluence in the distribution of the species, at least in the United

See my paper on Origin ami Diffusion of Blissua leucopterna and Murgantia histri-
otiica, in Journal of Cincinnati Society of Natural History, Vol, Will. February . 1896,
5968— No. 15 0

82

THE CHINCH BUG.

States. In its north era most habitat it would not be at all surprising
that it should prefer a sandy, rather than a clay, soil, the former being
looser and warmer on or near the surface. (See fig. 6.)

In conclusion, then, on this point .it may be stated that if Blissus
leucopterus originated in the Western Hemisphere it was probably near
the tropics, and it is not impossible that its generic ancestors may have
beeu carried from Europe or Africa by either the north equatorial or
the main equatorial Atlantic currents, landing them on the northern
shores of South America or on some closely located islands, from which
the species has spread coastwise around the Caribbean Sea and the
Gulf of Mexico, as previously indicated. In this connection it is inter-
esting to note that specimens from Grenada, collected on the Mount
Joy and Caliveny estates by Mr. H. H. Smith in June and September,
show that the species here attains a large size and is more a ariable,
both in size and markings, than is commonly found to be the case
the eastern United States.*

* TJhier on Hemiptera-Heteroptera from St. Vincent and Grenada, Proc. Zool. Soc,
London, 1894.