26 Farmers’ Bulletin 1262. 
the winter. No other cotton was planted within 9 miles. On the 
experimental field, planting was deferred until June 10. In spite 
of this fact weevils appeared as soon as the plants were up and multi- 
plied so rapidly that the production was not sufficient to warrant 
picking. Similar experiments under different conditions by the State 
Crop Pest Commission of Louisiana*® agree in every way with those 
of the Bureau of Entomology in Texas. 
The habits of the insect explain the failure of late planting. In 
many cage experiments it has been found that the last emerging 
weevils in the spring appear well into the month of June. In fact, 
emergence has taken place as late as the 27th and 28th of June. 
Without any food whatever the emerging weevils are able to survive 
for some time. The maximum known survival of any hibernated 
weevil without any food whatever after emergence was 90 days, and 
a considerable number lived from 6 to 12 weeks after emergence. 
This ability to survive without food, together with the late emer- 
gence, renders it entirely out of the question to exterminate the boll 
weevil by late planting. Moreover, a considerable number of volun- 
teer plants, which come from seed scattered accidentally or blown 
from the bolls during the fall, are always to be found along roads, 
turn rows, in cotton fields, and elsewhere. These plants, starting 
early in the spring in such numbers as to be beyond control, would 
furnish a means for the weevils to subsist to the time of planting, 
however late it might be. In 1906, for instance, at Dallas, Tex.. 
volunteer plants appeared in the spring at the rate of about 1,000 per 
acre. . An investigation showed that the number of such plants in- 
creases to the westward as the climate becomes drier. Nevertheless, 
numbers of plants were found near Memphis, Tenn., and Vicksburg, 
Miss., in a region of more than 50 inches of annual precipitation. 
Similar observations have been made each season since 1906. 
WEEVIL AND SQUARE COLLECTION. 
The possibility of weevil control by ‘hand picking of the adult in 
the early spring and of the infested squares later in the season has 
been thoroughly tested on numerous occasions. Undoubtedly this 
method is efficient when practiced with sufficient thoroughness, but 
numerous attempts to carry it out on a practical scale have shown 
that the labor difficulties are almost always prohibitive. This work 
is of value only comparatively early in the season and thus falls at 
the same period when there is a very heavy demand for the labor for 
other purposes, and it is generally impossible to collect the weevils 
or infested squares without neglecting other more important work. 
3 Described in Bulletin 92 of the Louisiana Agricultural Experiment Station, published 
in 1907. ny 
