, 1912-01-06
THE COTTON STAINER IN
TRINIDAD.

The Board of Agriculture, Trinidad, has
recently issued two circulars, prepared by
MI. ?. L. Guppy, Acting Entomologist, pro-
viding information as to the life-history,
habits and control of the cotton stainer.
The following notes are taken from the
circulars and shonld be of interest to cotton
growers in the West Indies, especially those
which refer to the methods Of control of the
pest.
The cotton stainer of Trinidad is Dysder-
Gus h0aoordj and is perhaps the worst
pest of cotton in that Colony. The life
cycle, from the time the egg is laid I'M
til the development is completed and the
adult insect appears, occupies a period of
from: thirty-six to forty-two days, divided
into, five stages-the egg, and four larvaI
stages-at the end of each of which the de-
veloping insect mouths, or sheds it's skin.
The cotton stainer5 are gregarious in all
the larval stages, and in the adult con lition.
The bright-red colours. of the young stain
es make them conspicuous objects, espe-
cially when they are congregated in masses
within the open bOlls, where they feed. The
adult insects, which are less bri lightly col
cured, and possess yellowish wings with
black tips, are to be found il. the same places,
as the young.
The cotton stainers feed on the seed in
the bolls, and stain. the lint with their ex-
croment, the injury to. the lint resulting both
from the feeding of the insects and from. the
staining of the cotton.
In hot, sunny weather these insects are
very active; but in the early morning, in the
evening, and on dull or rainy days they ATE
sluggish in their movements. The adults
are capable of long-sustained flight; but
they are not very ready to avail themselves
of this ability, and asa consequence do not
often use their power of flying for the pur-
pose of invading. new territory, as long as
their food supply continues in the old.
The suggestions for the control of the cot
ton stainers. include the old methods of hand
collecting and traps, and in addition a new
form of trap devised by Mr. Thomas Thorn
ton of Tobago.
This last method consists of the use of
stained Or damaged seed cotton, tied into
balls the size of a MANS fist and hung by
means Of a bent wire, on the branches Of the
cotton plants. The staipers collect on these
for the purpose of feeding, and may be
shaken off into a vessel containing kerosene
or crude petroleum and water. The balls,
are then again hung on the plants to attyact
a further lot of stainers. when the process of
collecting may be repeated. 1t should be
borne in mind, however, that the OIL should
not be allowed to come into contact with the
trap balls, as the odout would prevent the
sta ners from returning to them,
These traps should be visited every day,
aud the striuers collected When the Insects
are few, the traps neel not be placed close
together, but when they become more abuu-
dant, the. number of the form5r should be
increased.
The older methods of collecting from the
plants, and trapping by means of heaps of
cotton seed on the ground, are also des-
a,;l>.I ~, q ,oo1;6a1 Rnrpl
It is recommended that all leaves, trash,
etc, on the ground in the cotton fields
should be carefully cleared away from be-
meath the pants, and left in small heaps in
the spaces between the rows. Into each of
these heaps q small handful of cotton seed
is dropped, and each heap is then covered
with a broad leaf such as that of certain
palms.
The stainers on the plants are collected by
being Jared OF shaken into vessels of oil and
water. Many of those which fall to the
ground will take refuge in the heaps of trash,
and finding food there, are likely to remain.
The trap heaps should be regularly visited,
and the stainers which are collected there
1-IIol Nv noonc Of hot xvotor az lzouoc.oo