COTTON INSECTS 397 



to the appearance of the mature weevil is less than 25 

 days. Hinds and Hunter have estimated that the average 

 time between the egg-laying period of any two genera- 

 tions is about 43 days, and that a single pair of weevils 

 coming from their winter quarters in the latter part of 

 spring in Southern Texas, may there, before the occur- 

 rence of frost, have 250,000 living descendants. In south- 

 ern Texas there may be as many as five generations ; but 

 in the part of the cotton-belt farther north it is probable 

 that the usual number of generations averages four per 

 year. 



366. Where the winter is spent. The boll-weevil 

 passes through the winter in the mature or weevil stage. 

 Therefore the most effective means of fighting the boll- 

 weevil aim at reducing as low as possible the number of 

 adult weevils that live through the winter. Fortunately, 

 of the weevils that go into winter quarters the greater 

 portion die before spring. In Texas and Louisiana the 

 percentage of weevils living through the winter has varied 

 from less than 1 per cent to more than 50 per cent of those 

 that entered winter quarters. The proportion of those 

 that survive can be largely reduced by the destruction of 

 the trash under which they usually take shelter through- 

 out the winter. 



The hiding places preferred are : (1) in the empty cotton 

 burs and in other litter in the cotton field ; (2) in the fallen 

 leaves and in the bark and moss of the woods ; (3) in corn 

 stalks, grass, blackberry patches, and other litter or vege- 

 tation, adjacent to the cotton fields; and (4) around and 

 in buildings and haystacks. 



All of this suggests the need of plowing under deeply, 



