34 THE BOLL WEEVIL PROBLEM. 
drags, it is suggested that the principle be incorporated in some 
simple attachments to cultivators. 
The use of an arm or projection that will agitate the cotton plants 
has frequently been suggested. It was assumed that the knocking 
of the squares to the ground earlier than they would fall naturally 
would increase the effect of heat in destroying the immature stages 
of the weevil. It has been ascertained, however, that throughout 
much of the territory occupied by the weevil the destruction of the 
stages in hanging squares is much greater than in those that fall to 
the ground. For this reason it is evident that the best practice is to 
allow the squares to hang on the plants as long as they will. In 
addition to the effect of heat on the immature stages it is important 
to note that the attack of parasites is much greater in the case of 
hanging squares. On these accounts our advice is that cross arms 
or projections on cultivators should not be used except in central 
and western Texas, where the dryness of the climate brings about a 
very heavy mortality in fallen squares. In eastern Texas, Arkansas, 
Louisiana, Mississippi, and Alabama the mortality is greater in the 
hanging squares, and the planter who causes these squares to fall 
early merely assists the weevil. 
It is sometimes claimed that the use of a crossbar will cause many 
of the adult weevils to be knocked to the ground where they will be 
destroyed by heat. In repeated experiments in jarring and beating 
cotton plants in which known numbers of weevils were found it was 
ascertained that very few, if any, left the plants by reason of any 
agitation that would not break the branches or bark the stems. Occa- 
sionally, however, a weevil passing over a leaf is jarred to the ground. 
Often entirely too much stress is placed upon the importance of 
jarring the adult weevils to the ground. When specimens are col- 
lected by hand and thrown on the surface of the ground, especially 
if it be finely pulverized, the great majority will be killed almost 
instantly by the heat. This has caused the mistake on the part of 
careless observers of supposing that many weevils could be killed by 
jarring them to the ground. The difficulty, as pointed out, is that it 
is totally out of the question to jar more than one weevil out of many 
hundreds to the ground by any process that would not injure the 
plants severely. 
HAND PICKING OF WEEVILS. 
Gathering the weevils by hand is an operation of limited appli- 
eability. Where the fields of cotton are small and there is an abun- 
dance of labor it is sometimes practicable to pick the early emerging 
weevils from the plants and later to pick up the early fallen squares. 
dverything depends, however, on the conditions being favorable. On 
512 
