BEETLES. 



341 



FIG. 381. Balaninus nucum. 



larvae, or grubs, of JJ. cari/atripes. They reach full growth when the chestnut ripens, 



and then gnaw their way out of the nut in order to pupate in the ground. Some of 



the beetles appear the same autumn, and 



hibernate as irnagos ; others, probably the 



larger number, appear the succeeding 



spring. The beetle itself is dark brown, 



densely covered with yellow compressed 



hairs, which are somewhat irregularly 



distributed in spots upon the elytra. Its 



length is about 0.3 of an inch. J3. nas- 



icus lives in hickory nuts, and B. rectus 

 in acorns ; both species have a close re- 

 semblance to B. carijuti'ipes, and also to 

 B. nucum, the European species figured, 

 which attacks both acorns and hazel nuts. The larva of B. villosus, another European 

 species, feeds upon the inner portions of the apple-formed galls of Cynips terminalis, 

 on oak. 



Trichobaris trinotata, a black weevil about 0.2 of an inch long, receives its specific 

 name from three impressed, shining black spots near the base of the prothorax. It is 

 common in the middle and western United States, where its larva is a serious potato- 

 pest. The female weevil oviposits in oblong slits which she bores in the stems of 

 the potato, and the larva?, iipon hatching, penetrate downward toward the root of the 

 plant, causing its death. The larva is a legless white grub. It pupates in the stem 

 of the potato, the beetle emerging about the beginning of September. 



A small weevil that causes considerable injury to grapes is Craponius incequalis. 

 This insect is only about 0.1 of an inch long, of broad, almost circular, outline, grayish 

 black, the elytra striate with large punctures ; the legs reddish. In June and July 

 this species lays its eggs in grapes, causing a change of color of the berry near the 

 point of puncture. In August the larvae drop to the ground, in which they pupate, 

 the beetle emerging the next month. 



o o 



Analcis fragaricv is about 0.15 of an inch long, of a deep chestnut brown, with 

 the elytra slightly lighter colored ; the thorax is deeply punctured. The female 

 oviposits in the crown of strawberry plants, and the larvae bore down into the straw- 

 berry root. A. foveolatum, a black species with yellowish spots, is abundant upon 

 the evening-primrose (CEnothera biennis). 



Probably the weevil most injurious to agricultural in- 

 terests in America is the so-called plum-weevil, or plum- 

 curculio, Conotrachelus nenuphar. This beetle is oblong- 

 oval, about 0.18 of an inch long; dark brown, spotted in 

 places with black, yellow, and white. The head is small, 

 and when at rest is drawn back so that the eyes are nearly 

 hidden by the forward edge of the prothorax, and the 

 proboscis is received into a groove on the chest. The 

 elytra bear interrupted ridges, and cover the entire ab- 

 domen. Beneath, the sutures are curved, the coxa? are contiguous, the thighs 

 bidentate, and the claws divergent and toothed. This species is distributed through- 

 out the Atlantic slope of North America. It hibernates as imago, and when the 

 plums, cherries, and other stone-fruit begin to develop in the spring, the female 



FIG. 3%2. 



nenuphar. 



