3 
attack the crop of the following season are among those developed 
latest in the fall and which, in consequence of that fact, have not 
exhausted their vitality by depositing eges for any considerable 
length of time. Fall destruction of the plants, increasing the length 
of the hibernating period, reduces many fold the number of weevils 
in the fields that would otherwise emerge in the spring to damage the 
cotton. 
Fourth.—Clearing of the field in the fall makes it possible to prac- 
tice fall plowing, which is not only the proper procedure in any 
system of cotton raising, but also ereatly facilitates the early plant- 
ing of the crop the following spring. The ground becomes clean by 
this practice, so that but few places for shelter are left for the 
weevils, and various climatic conditions still further reduce the num- 
ber of the survivors. 
DATA UPON WHICH THE FOREGOING REASONS ARE BASED. 
The reasons for fall destruction given above are based upon a very 
large amount of data from actual experiments and the work of 
various planters. The information at hand was greatly amplified in 
a series of large-scale experiments carried on during the winter of 
1906-7. Three large cages (50 by 20 feet) were built over growing 
cotton at Dallas, Calvert, and Victoria, in Texas. In different com- 
partments of these cages nearly 70,000 weevils were placed; several 
thousand in each compartment. After the weevils were placed in- 
side, the plants were removed from the first section about the middle 
of October. At regular subsequent dates other sections were treated 
in exactly the same manner. Consequently the results for each 
locality show exactly what a farmer could have accomplished by the 
destruction of the plants at different times. The full results will 
be published in a bulletin by Dr. W. E. Hinds and Mr. W. W. 
Yothers, who have had direct charge of the work. In this connec- 
tion it is necessary to call attention ‘to only a few features. 
In practically all cases the smallest survival of weevils was found 
in the cages from which the plants were removed at the earliest dates, 
and the number of survivors increased regularly as the dates of 
destruction became later. For instance, at Dallas out of between 
two and three thousand weevils in each cage, only 2.5 per cent sur- 
vived when the plants were removed on October 13; 4 per cent 
survived destruction of the food supply on October 16; 6.2 per cent 
survived destruction on October 19; 12.2 per cent survived destruc- 
tion on November 6, and 14.7 per Genk survived destruction on Novem- 
ber 12. These figures indicate that practically seven times as many 
weevils survived after destruction of plants on November 12 as sur- 
vived after a similar destruction on October 13. This is a most 
striking illustration of the effect of early destruction. 
In the cages at Dallas, Calvert, and Victoria, from which the 
plants were removed in November, 14.26 per cent survived, while 4.41 
per cent survived removal of the plants in October—that is, the 
cutting off of the food supply in November resulted in the survival 
of three times as many weevils as survived when the work was done 
in October. These figures are based upon averages of eight large 
[Cir. 95] 
