37 



country. Naturally, then, we must needs turn to a study of the habits 

 of the pest to point the way to means by which either it may be itself 

 destroyed or its great destructiveness prevented. 



FOOD HABITS. 

 LARVAL. 



It is plainly the intention of the mother weevil to deposit her egg so 

 that the larva upon hatching will find itself surrounded by an abun- 

 dance of favorable food. In the great majority of cases this food con- 

 sists principally of immature pollen. This is the first food of the larva 

 which develops in a square, and it must be both delicate and nutritious. 

 Often a larva will eat its way entirely around a square in its pursuit 

 of this food. In most cases the larva is about half grown before it 

 feeds to any extent upon the other portions of the square. It may 

 then take the pistil and the central portion of the ovary, scooping out 

 a smoothly rounded cavity for the accommodation of its rapidly 

 increasing bulk (PL I, fig. 7; PL III, fig. 15; PL IV, fig. 24). So 

 rapidly does the larva feed and grow that in rather less than a week 

 it has devoured two or three times the bulk of its own body when f ully 

 grown. It sometimes happens that the square is large when the egg 

 is deposited therein, and the bloom begins to open before the injury 

 by the larva is sufficient to arrest its development. In many cases of 

 this kind the larva works its way up into the corolla and falls with it, 

 leaving the } 7 oung boll quite untouched (PL V, fig. 27). Occasionally 

 the flower opens and fertilization is accomplished before any injury 

 is done the pistil, and in rare cases a perfect boll results from a truly 

 infested square. Sometimes the larva when small works its way down 

 into the ovary before the bloom falls, and in such cases the boll falls 

 as would a square. 



In large bolls the larvae feed principally upon seed and to some extent 

 upon immature fiber. A larva will usually destroy but one lock in a 

 boll, though two are sometimes injured (PI. V, fig. 28). 



ADULT. 



Before escaping from the square the adult empties its alimentary 

 canal of the white material remaining therein after the transforma- 

 tion. The material removed in making an exit from the cell is not 

 used as food, but is cast aside. Weevils are ready to begin feeding- 

 very soon after they escape from the squares or bolls in which the 

 previous stages have been passed. For several days thereafter both 

 sexes feed almost continuously and seem to have no other purpose in 

 life. They will take squares, bolls, or leaves, but they much prefer 

 the squares, and when squares are present in the field it is probable 

 that leaves are seldom touched. As has been shown, however, weevils 

 can live for a long time upon leaves alone when squares and bolls are 



