THE LARGER CHESTNUT WEEVIL. 



{Buhiiiinus iiroboscideus Fab.) 

 The larger chestnut weevil (fig. 2) is considerably the larger and 

 more robust species. The female rostrum or beak, although proi)ortion- 

 ately of about the same length 

 as in the lesser weevil, is per- 

 ceptibly more prominent be- 

 cause less curved, the curvature 

 being toward the tip. It is 

 also more widened at the base. 

 The body measures from one- 

 third to nearly one-half of an 

 inch in length, and the beak 

 of the female is often five- 

 eighths of an inch long. That 

 of the male (fig. 2, c) is nearly 

 as long as the elytra. The 



^SS ii^ small, about one-six- Fig- --—The larger chestnut weevll (iJa/a?u'/iu.v j^coftos- 

 . ,1 (• ■ 1 1 1 -P cideus): a. Female beetle; h, same in outline from 



teentn or an men long, ana or gj^jg. c, head, rostrum, and antenna of male. Three 

 the outline shown in figure times natural size (author's illustration). 



o, d. It is nearl}' white, partially translucent, and without sculpture. 



The larva (fig. 3, a) is 

 milk-white, robust, fully 

 three times as long as wide, 

 with the dorsal or upper 

 portion rounded and con- 

 vex. The entire surface is 

 very strongly wrinkled 

 a 3. h c transversely, and there are 



FiCi. 3.— Larger chestnut weevil {Balanivuf: proho»cideus): fj feW VCrV sllOrt hairS SCat- 

 a. Larva: b, c, female pupa; (/, eggs. All enlarged (au- - ' it/. 



thor's illustration). tcrcd sparscly over the dif- 



ferent .segments. The head (fig. 4) is about one-fourth as wide as 

 the widest portion of the body. It is provided with _ 



short but strong mandibles, by means of which it gnaws 

 the kernel constituting its food. The fully developed 

 larva in ordinary resting position measures nearly half 

 an inch. Although the larva has no true legs, it is able 

 to crawl, slowly and clumsily, it is true, by means of 

 of the flattened lower surface, locomotion being aided 

 by transverse wrinkles. 



The pupa is of a clearer whitish color than the larva, 

 and shows the principal external organs of the body of 

 the future beetle, all, except the beak, folded tightly 

 The female pupa -is illustrated in figure 3, 6, c. 



[Cir. 99] 



Fig. A.—Balaninus 

 proboscideu s: 

 Head. Much en- 

 larged (author's 

 illustration). 



to the bodv. 



