COLEOPTERA 



171 



Fig. 302. — The Mexican cotton- 

 boll weevil, much enlarged. 



Fig. 303. 



egg is deposited in a young boll, which the larva destroys. The adults 

 (Fig. 302) also feed upon the young bolls and upon the leaves. This 

 species is a native of Central America. It spread through Mexico, and 

 entered Texas about 1890. Since that time it 

 has spread over a large part of the cotton belt. 

 Very extensive investigations of this pest have 

 been made by the Federal Government and by 

 several state governments ; and much literature 

 regarding it is available to those interested. 



The acorn-weevil, Balaninus 



rectus, has a slender snout twice 



as long as the body (Fig. 303). 



The female drills a hole in the 



young acorn with this snout and then lays an egg in the 



opening afterwards pushing it to the bottom of the hole 



with her snout. The grub devours the interior of the 



acorn. 



The hickory-nut weevil, Balaninus nasicus, breeds 



in hickory nuts and the chestnut weevil, Balaninus 

 probosctdeus, causes wormy chestnuts. Each of these weevils have a long 

 slender snout, longer than the body. 



Among the smaller members of this family are two exceedingly im- 

 portant pests of stored grains; these are the granary- weevil, Calandra 

 granaria, and the rice-weevil, Calandra oryzce. The rice-weevil is so 

 called because it was first found in rice in India; but it infests various 

 kinds of stored grain ; and in the South it is fully as important a granary- 

 pest as is the granary-weevil. 



The two species are quite similar in appearance; but the granary- 

 weevil is the larger, measuring from f to } of an inch in length ; while the 

 rice-weevil measures less than \ of an inch in length, and differs from the 

 granary-weevil in having the elytra marked with four reddish spots. 

 The thorax of the rice-weevil is closely pitted with round punctures; 

 that of the granary- weevil, with sparse elongate punctures. 

 The adult female of both of these species gnaws a tiny 

 hole in a kernel of grain and then deposits an egg in it. 

 The larva feeds on the grain, becomes full-grown, and 

 transforms within the kernel. The adult continues the in- 

 jury begun by the larva, eating out the inside of the kernel. 



Family Platypodid^e 



This is a small family, which is represented in our fauna 

 by a single genus, Platypus, of which only five species have 

 been found in America north of Mexico; these are found 

 chiefly in the South and the far West. 



Formerly this group was classed as a subfamily of the 

 Scolytidae. It is distinguished from the Scolytidae by the 

 fact that the first segment of the anterior tarsi is longer 

 than the second, third, and fourth together. The form 

 of the body is cylindrical (Fig. 304); and the head is 

 large, wider than the prothorax. 



Fig. 304. — Platy- 

 pus wilsoni, female. 

 (After Swaine.) 



