. Circular. Insects. 3 THE LARGER CHESTNUT (Balaninus proboscideus Fab.) The larger chestnut weevil (fig. 2) is considerably the larger and more robust species. The female rostrum or beak, although proportion- 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 e
. Circular. Insects. 3 THE LARGER CHESTNUT (Balaninus proboscideus Fab.) The larger chestnut weevil (fig. 2) is considerably the larger and more robust species. The female rostrum or beak, although proportion- 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 egg is Small, about One-six- Fig. 2.âThe larger chestnut weevil {Balaninus probos- â ,-1 j» ⢠i l l £ cideus): a, Female beetle; b, same in outline from teentn or an men long, ana or side; c head , rostrum, and antenna of male. Three the Outline shown in figure times natural size (author's illustration). 3, d. It is nearly 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 transversely, and there are a few very short hairs scat- thor-s illustration). tered sparsely 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 to the body. The female pupa is illustrated in figure 3, 6, c. [Cir. 99]
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishe, booksubjectinsects
