128 FIELD CROPS FOR THE COTTON-BELT 



entered Louisiana in 1904, Mississippi in 1907, and Ala- 

 bama in 1910. In recent years it has spread eastward 

 much more rapidly than northward. There seems to be 

 little doubt but that within the next ten or fifteen years 

 it will spread over the entire cotton-belt of the United 

 States. 



149. Life history and habits. There are four stages 

 in the life history of the boll-weevil, the egg, the larva 

 or grub, the pupa, and the adult. The first three of these 

 four stages are spent within the cotton square or young 

 tender boll. By means of the mouth parts, which are 

 located at the end of the snout, the adult weevil eats a 



FIG. 19. Showing variation in size of boll-weevils. 



tiny hole into the square, in which an egg is deposited. 

 Within three or four days the egg hatches into a tiny white 

 larva or grub. This grub feeds upon the inner tissues of 

 the square, or the young boll as the case may be, becoming 

 full grown within six to twelve days after hatching, pro- 

 vided weather conditions are favorable. It is during the 

 larva stage that the greatest damage is done. After attain- 

 ing its normal size the larva passes into the pupa stage 

 or the intermediate stage between the larva and the adult. 

 The transformation from larva to adult usually requires 

 from three to five days after which time the adult eats 

 its way to the outside of the square or boll. The color 

 of the adult weevil depends upon its age. The recently 



