49 



LAKVAL. 



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 the inside 

 of 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 accommoda- 

 tion of its rapidly increasing bulk (PI. I, fig. 4; PL III, fig. 10; PL 

 VI, fig. 25). 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 bod}^ when fully grown. It sometimes happens that the square 

 is large when the egg is deposited therein, and the bloom begins to 

 open before the injury done by the larva becomes suflficient to arrest 

 its development. In many cases of this kind the larva works its way 

 up into the corolla and falls with it when it is shed, leaving the young 

 boll quite untouched (PL VI, ^g. 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 trul}^ infested square^ 

 Sometimes the larva, when small, works its way down into the ovary 

 before the bloom falls, and in such cases the small boll falls as would 

 a square. 



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

 extent, upon the immature fiber. A larva will usually destroy but 

 one lock in a boll, though two are sometimes injured (PL VII, fig. 29). 

 When the infestation is severe a number of weevils, occasionally as 

 many as six or even more, may be developed in a single boll, which is 

 completely destroyed by the feeding of the larvae. 



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. The}^ 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 

 16780— No. 51—05 4 



