Evening star. [volume] (Washington, D.C.) 1854-1972, 1898-01-12
AN INJURIOUS INSECT
Results of Recent Investigation of the Mexi-
can Weevil.
1t Is Dangerous Pest and Very
Destructive 10 Growing
Cotton.

One of the latest circulars to be issued
by the Department of Agriculture is the
Mexican cotton boil weevl in 1897" The
circular states that injurious this in
sect has been, especially during the sum-
mer and autumn of 1875, and less SO in the
two preceding years to the planters whose
fields 1t has actually entered, a greater
cause for alarm existed through the prob
ability of its spread into more important
cotton-growing regions. Thus the reports
of damage in 1895 greatly disturbed the
cotton planters, lot only of the rich coun-
try lying to the north and east of the in
Tested region in the state of Texas, but
also the planters of louisiana. Mississippi
Alabama and Georgia. 1t was at frs
thought the spread of the insect into these
re gions would be certain and rapid. The
Investigations of the first season Largely
ne gatired this possibility, aEo now, after
three seasons observation it appears that
the spread of the insect toward the north
and east has been very slow: that THIS
spread is practically checked by the first
heavy frost, and that il is doubtful wheth-
er it will spread to any great extent be-
yond the region of growth of volunteer
cotton.
Studying the Insect.
In the early part of the season an agent
Mr.. c. II. T. Townsend, was commissioned
to investigate wild and cultivated cotton
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 extensive
ly as early February in the squares of
wild cotton and in following it on until
July in the bolls. He reared many speci-
mems 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 speci-
mems of bolls containing this insect in diff
erent stages: and the writer has also been
unsuccessful in rearing any parasites, al
though dried fragments in some of the
bolls indicate that such a parasite does
exists: 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 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 exam
lining the conditions and learning whether
the insect had spread. Such an investiga-
ton was not necessary in the early season
of the year for the reason that previous
experience has shown us that the spread
IL,
at ALL The early generations in the more
northern portions of the range of the
species are not so numerous the later
ones. and the migratory instinct does not
become developed as long 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 Il 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 re-
ports.
Short Crops In Infested Regions.
In all the infested region the crop this
year seems to have been very short, rang
ing from ole bale to six acres to one bale
to ten or even fifteen 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
weevll. 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
Kennedy Mr.. Townsend found that the yield
averaged one bale to ten acres; at Cuero,
one bale to eight acres: at Victoria, one
bale to from two to twenty-five acres, vary
ing from bottom lands to uplands: at Col
idQ, One Daie 10 SIX acres, AT be6V1lle, one
bale to eight acres. This will show about
the yield of the central portion of the area
heretofore known to be infested by the
weevil.
The Outlook for This Year.
At the close of 1895 it was feared that
there would be considerable spread during
1896. The severe midsummer drought in
1890. however, resulted in not only limiting
this spread but in bringing about shrink
age o. the territory infested. Probably an
other factor which assisted in this shrink
age was the severe frost of the first week
of December, 1896. which crtainly resultd
in the destruction of the majority of the
insects at San Antonio. and probably also
at Wharton, where the weevil was abund-
ant in a certain field. and where it has not
Stree been found. At San Antonio. by the
way, in field which was very badly in
tested in November, 1895. no specimens of
the insect were found during 1896 and but a
single adult weevil was captured in Oc-
tober, 1897.
The slight spread to the north and east
during 1897 renders 1t difficult to prev
as to 1905. The almost uniform abse