Mexican cotton-boll weevil in 1897

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Mexican cotton-boll weevil in 1897
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Howard, L. O ( Leland Ossian ), 1857-1950
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U.S. Dept. of Agriculture, Division of Entomology ( Washington, D.C )
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LIBRARY
STATE PLANT BOARD

5
CIRCULAR NO. 27, SECOND SERIES.
United States Department of Agriculture,

DIVISION OF ENTOMOLOGY.


THE MEXICAN COTTON-BOLL WEEVIL IN 1897.

PREVIOUS PUBLICATIONS.
Soon after the Mexican cotton-boll weevil (Anthonomus grandis)
made its appearance in Texas cotton-fields a circular (No. 6, n. s.)
was prepared by the writer and distributed during April, 1895, to
cotton planters living in the infested regions. The results of the
work during 1895 were published in Circular No. 14, of this series,
and distributed to Texas cotton planters in February, 1896. An
edition of the same circular in Spanish was published during the
same month. The results obtained by the work of 1896 were given
in the circular (18 of this series) published in February, 1897. This
Circular No. 18 gives in complete form the life history of the insect,
its habits, and the remedy to be used against it. It also contains
information regarding its distribution in Texas at the close of the
season of 1896. Editions of this circular in the Spanish and German
languages were published during the same month for distribution to
Mexicans and Germans living in south Texas, who are more familiar
with their native language than with English.

SCOPE OF PRESENT CIRCULAR.
The ground of the natural history of the insect and the remedies
having been so fully discussed in Circular No. 18, the edition of
which is as yet by no means exhausted, it will be necessary at this
time simply to give the facts concerning the work of the insect dur-
ing the summer of 1897.

THE OBSERVATIONS OF THE SEASON OF 1897.
As injurious as this insect has been, especially during the summer
and autumn of 1895, and less so in the two succeeding years, to the
planters whose fields it has actually entered, a greater cause for
alarm existed through the probability of its spread into more impor-
tant cotton-growing regions. Thus the reports of damage in 1895
greatly disturbed the cotton planters not only of the rich country
lying to the north and east of the infested region in the State of
Texas, but also the planters of Louisiana, Mississippi, Alabama, and
Georgia. It was at first thought that the spread of the insect into
these regions would be certain and rapid. The investigations of the
first season largely negatived this possibility, and now, after three
seasons' observations, it appears that the spread of the insect toward


A~








the north and east has been very slow; that this spread is practically
checked by the first heavy frost, and that it is doubtful whether it
will spread to any great extent beyond the region of growth of
volunteer cotton.
In the early part of the season an agent of this office, Mr. C. H. T.
Townsend, was commissioned to investigate wild and cultivated cot-
ton in south Mexico, which was assumed to be the original home of
the insect, although the greatest reports of damage in Mexico have
come from more northern counties. Mr. Townsend was stationed
during the spring and early summer months in the State of Tabasco,
and had no difficulty in finding the weevil breeding very extensively
as early as February in the squares of wild cotton and in following
it on until July in the bolls. He reared many specimens of the
weevil, but was unsuccessful in finding any parasites. He had been
sent down there to see whether native parasites could be found which
might be introduced to advantage into Texas cotton fields. He sent,
during this time, from Tabasco to this office in Washington, numerous
specimens of bolls containing this insect in different stages; and the
writer has also been unsuccessful in rearing any parasites, although
dried fragments in some of the bolls indicate that such a parasite
does exist; probably, however, in insignificant numbers. The very
fact of the occurrence of the weevil in such quantity in Tabasco is
in itself an indication that no effective parasite is to be found there.
In October and early November Mr. Townsend was sent through
the infested region in Texas for the purpose of examining the con-
ditions and learning whether the insect had spread. Such an inves-
tigation was not necessary in the early season of the year for the
reason that previous experience has shown us that the spread of the
insect takes place in the autumn if at all. The early generations in
the more northern portions of the range of the species are not so
numerous as the later ones and the migratory instinct does not become
developed as long as there is plenty of food. Wherever in a weevil-
infested field the reasonably complete loss of the top crop through
drought or from some other cause brings about a lack of food for the
weevils in October or later, they then migrate in search of food and
proper places to lay their eggs.
The statements which follow have been derived largely from Mr.
Townsend's reports.

CONDITIONS AND SPREAD DURING 1897.
In all the infested region the crop this year seems to have been very
short, ranging from 1 bale to 6 acres to 1 bale to 10 or even 15 acres
on uplands. This condition is largely attributed to drought. In the
bottom lands at Victoria the yield was from one-quarter to one-half
bale per acre, and had it not been for the weevil a good top crop
would have been realized. On the uplands almost no top crop was
made, although there was a slight yield here and there in occasional
fields, as at San Antonio, Gonzales, and Goliad. At Kenedy Mr.
Townsend found that the yield averaged 1 bale to 10 acres; at Cuero,
1 bale to 8 acres; at Victoria, 1 bale to from 2 to 25 acres, varying
from bottom lands to uplands; at Goliad, 1 bale to 6 acres; at Bee-
ville, 1 bale to 8 acres. This will show about the yield of the central
portion of the area heretofore known to be infested by the weevil.









Where it was found that there was no top1) crop there wenr very
few weevils present in the fields. There were almost no squr1res and
but few bolls. In the lowlands, however, and where the plants
showed some growth of squares, the weevil and its work were alulild-
ant. Careful investigation of the country adjoining the borders of
the infested area of 1896 showed only one important extension of
spread, this being immediately to the north of Cuero. Here the
weevil has extended as far to the north as Harwood, Thompso iville,
and Moravia, entering the country around Yoakum and Gonzales
and extending probably to within 5 or 10 miles of Hallettsville and
Luling. It was especially noticed that in these outlying areas of
spread the weevil is more or less confined to the valleys of streams
or the low-lying lands, and that the adult weevils are frequently very
numerous, with few or no larva, indicating that the weevils had
arrived very recently. However, near Thompsonville, which is about
9 miles east of Harwood and the most northerly point at which the
weevil has been found, a one-fourth grown larva was discovered in
a square on November 6. Between Thompsonville and Harwood
some few squares in the fields show their work, but adult weevils are
not often to be found, except near Harwood where they were more
plentiful.
At Victoria, in the bottom lands where the cotton was not hurt by
drought and was full of squares, the weevils were very numerous.
The following is a table of the localities examined by Mr. Townsend,
showing those in which the weevil was present and those in which it
was absent:


Present.
San Antonio (very scarce).
Kenedy (scarce from lack of food).
Cuero (not abundant).
Victoria (abundant with plenty
food).
Beeville (not abundant).
Yoakum (numerous where there
squares).
Gonzales (numerous).
Moravia (numerous near live
stretches).
Harwood (numerous where there
squares).
Shiner (numerous where there
squares).
Thompsonville (scarce).
Port Lavaca (reported sparingly
not visited).


are

oak
are
are

but


Absent.
Hallettsville (probably approach within
5 or 10 miles to west).
Luling (probably extend to within 5
miles to south along river).
Seguin.
Marion.
Converse.
Lacoste.
Pearsall.
Moore.
Wharton (probably approach no far-
ther than Edna).
Hungerford.
East Bernard.
Columbus.
Schulenberg.
Flatonia.


At Columbus, Wharton, East Bernard, and Hungerford there was
as a rule a good top crop, this being in or bordering the Colorado
bottom lands, while at San Antonio, Luling, and Gonzales there was
only a partial crop. The territory to the south of Beeville was not
explored by Mr. Townsend on account of its lack of significance as
affecting conditions of possible spread. Judge S. G. Borden, of
Sharpsburg, however, informs us, under date of December 28, that
the weevil did very considerable damage in San Patricio and Nueces
counties during the season. He estimates that about one-half the
crop was destroyed by weevil. He thinks, however, that they were
not as numerous as in either 1895 or 1896.








PROSPECTS FOR NEXT SEASON.
At the close of 1895 it was feared that there would be a consider-
able spread during 1896. The severe midsummer drought in 1896,
however, resulted in not only limiting this spread but in bringing
about a shrinkage of the territory infested. Probably another factor
which assisted in this shrinkage was the severe frost of the first week
of December, 1896, which certainly resulted in the destruction of the
majority of the insects at San Antonio, and probably also at Whar-
ton, where the weevil was abundant in a certain field and where it
has not since been found. At San Antonio, by the way, in a field
which was very badly infested in November, 1895, no specimens of
the insect were found during 1896 and but a single adult weevil was
captured in October, 1897. The slight spread to the north and east
during 1897 renders it difficult to premise as to 1898. The almost
uniform absence of a top crop over regions where the insect has
previously been abundant, resulting in a great scarcity during Octo-
ber, will probably make the insect scarce in numbers in the fields
next spring. The writer would not be inclined to expect any great
damage in such localities in the early part of 1898.
Mr. Townsend writes: "I consider that the weevil has been set
back greatly over nearly the whole of the infested district this year."
The spread which did occur, however, although not a great one, is
serious from its direction. With heavy frosts in the early winter the
prospects for the further spread of the insect in the same general
direction next summer will be very slight. Without such frosts it is
to be feared that toward the end of the summer of 1898 there may
be a further spread toward the Colorado River.
In general terms it may be said that the damage done by the weevil
bears a direct proportion to the value of the top crop, and since in
southern Texas the top crop is probably proportionately more valu-
able than in other portions of the cotton belt, owing to the greater
length of the season, it is here that the damage from the weevil must
always be greatest.
THE WEEVIL IN GINNED SEED AND SEED COTTON.
It was the writer's first supposition that the insect was brought
from the comparatively isolated region about Matamoras, Mexico,
and Brownsville, Texas, to Alice or San Diego or Corpus Christi in
unginned cotton. Later observations seemed to negative this suppo-
sition, since the insect was not found about the gins. Mr. Town-
send, however, the present fall, in visiting a gin at Victoria, found
numbers of lively adult weevils crawling about not only in the
unginned seed cotton but even in the ginned cotton after it had
passed through the machine. Many gins had been examined before
this in both Texas and Mexico, but such facts had never before been
observed. This indicates the possibility that the weevil may be
taken from place to place in ginned seed as well as in ginned cotton.
ANOTHER WEEVIL MISTAKEN FOR THE COTTON BOLL WEEVIL.
In the first two circulars published about this insect the writer
referred to several insects which were mistaken for the true cotton
boll weevil and figured one of them, viz., the form known as the








"sharp-shooter," a leaf-hopper scientifically know inas llialo coagutlata. The figure was omitted from thle last two circulars
since it was found that illiterate persons looking at the circular
believed that the figure represented the true weevil. Moreover, a
growing and more definite acquaintance within the true weevil rend-
ered mistakes much less frequent. The present year, however, there
has been an extraordinary abundance of an acorn weevil which has
flown to the lights in Victoria, Cuero, Beeville, Goliad, and many
other towns to the north. These occurrences began in September
with the first northerr," the weevils swarming in the open houses
at light in the evening. They were universally thought to be the
cotton weevil and created much alarm. Specimens were sent by a
number of different correspondents to this office, among them a very
great number which were collected by the Hon. J. D. Mitchell, at
Victoria, in some experiments which he was making with a trap-
lantern during that month. Mr. Townsend was able to allay the
alarm to a considerable extent. The mistake was by no means a
bad one, since the acorn weevil bears a strong superficial resemblance
to the Mexican cotton boll weevil. It is a somewhat larger insect,
however, and has a longer and thinner beak.

MACHINES FOR THE DESTRUCTION OF THE INSECT.
In Circular 18 we mentioned a machine invented by Mr. Stronhall,
of Beeville, and which was intended to jar the affected squares and
blossoms from young cotton plants and to collect them at the same
time. Mr. Stronhall has been working upon this machine during the
summer, and is now endeavoring to perfect it so as to crush the wee-
vii between rollers when collected. He is also endeavoring to render
it less expensive in price. Mr. Townsend was told that this gentle-
man himself used his old machine on his plantations 12 miles south
of Beeville and secured one-half bale to the acre, also getting some
top crop.
Another machine, for the distribution of dry poison, has been pat-
ented by Mr. Richter, of Moravia. This machine, which Mr. Town-
send saw in operation, and of which he has sent the writer photo-
graphs, is well adapted to its purpose, and Mr. Townsend writes is
very successful as a distributor of dry dust. Whether it can be used
to advantage against the weevil is yet a question in our minds, but
it will be an excellent machine to use against the cotton caterpillar.
The machine is drawn by a pair of horses, straddling a row and dust-
ing three to five rows of cotton at once. The horses must be driven
at a smart trot so as to blow the poison out rapidly. Ten acres can
be dusted in an hour with poison for the cotton worm.

THE VALUE OF DOMESTIC FOWLS AS DESTROYERS OF THE WEEVIL.
We are indebted to Mr. F. M. Howard, county clerk of Bee County,
living at Beeville, for an interesting account of the incidental value
of keeping turkeys. He writes that he found one farmer who during
last winter had put 100 turkeys on his farm, had planted 75 acres,
and made 26 bales, and was not troubled with the weevil during the








season, while a neighbor, who had no poultry, planted 450 acres and
gathered less than 50 bales, the land being exactly of the same class
of soil. Mr. Howard also states that all the quail killed near Beeville
have their crops filled with the weevil.

REMEDIES.
We have nothing to add to the remarks published in Circular 18
on the subject of remedies. In the cultural method of control (there
mentioned in detail) we believe that a practically complete remedy
for the insect will be found. We may briefly reiterate the recom-
mendations regarding this method:
"The careful investigation of this weevil during the past two or
three years by the Division of Entomology has fully demonstrated
the supreme importance of the cultural method of control, to which
fact we gave special prominence in our first circular on this insect.
There can be no question now that in the proper system of growing
cotton a practically complete remedy for the weevil exists. In the
first place, it has been established beyond question that the conditions
of cultivation which make volunteer growth possible also make the
continuance of the weevil inevitable. Of first importance is the
early removal of the old cotton in the fall, preferably in November
or earlier. This can be done by throwing out the old plants with a
plow, root and all, and afterwards raking them together and burning
them. This treatment should be followed, as promptly as may be,
by deep plowing, say to a depth of 6 or 8 inches. This leaves the
field comparatively clean of old cotton stalks, facilitates thorough
cultivation the following year, and, at the same time, collects and
destroys all of the weevil larvae and pupe in the cotton at the time,
and also most of the adults. The escaping beetles will be buried by
deep plowing, and will not again reach the surface. Few, if any,
of them will succeed in hibernating in the absence of the ordinary
rubbish in the fields in which they winter. Fields treated in this
way have given a practical demonstration of the usefulness of this
method.
"The greatest danger from the weevil is due to the presence of
volunteer cotton, which means early food for the weevils in the
spring and abundant means for their overwintering, and the effort
made to retain volunteer and get early cotton, or the 'first bale,'is a
very serious menace to cotton culture within the weevil district.
"This cultural method, if generally practiced, will undoubtedly
prove a perfect remedy for upland cotton, and will vastly reduce
weevil damage in the lowland, where the weevil is more apt to
winter, perhaps in adjoining woods or roadside vegetation. The
early removal of cotton by the means suggested is especially advised
whenever the presence of the weevil shows that the picking of a top
crop is problematical. In such instances it would be well to uproot
and destroy cotton stalks in September or October. If this cultural
method can be enforced, either by State legislation or by the cooper-
ation and insistence on the part of landowners that their renters shall
carry out the system outlined, the weevil difficulty can undoubtedly
in very large measure be overcome.








"In connection with the system of fall treatment of the cotton,
constant and thorough cultivation of the growing crop as late as pos-
sible is of considerable value, and is also what should be done to insure
a good yield. With a crossbar to brush the plants many of tihe blos-
soms and squares containing weevils will be jarred to the ground
and buried, together with those already on the ground, in moist soil,
and a large percentage of the material will rot before contained in-
sects have developed."
L. 0. HOWARD,
Approved: Entomologist.
JAMES WILSON,
Secretary.

WASHINGTON, D. C., December 31, 1897.

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