BEETLES. 



321 



broods yearly. J. A. Osborne found that parthenogenesis sometimes occurred in 

 G. raphani, a species found in England. 



The most brilliant perhaps of the American species of Chrysomelid83 belong to the 

 genus Chrysochus. This genus, and a few others associated with it, differ from 

 Chrysomela and the forms just described in that they have the third tarsal joints 

 bilobed. Chrysochus auratus, from the eastern United States, is oblong-oval, about 

 0.4 inch long, of a brilliant metallic green, which, viewed in different directions, changes 

 to deep red or bright blue shades. During July and August this species is very 

 common on dog-bane {Apocyinim). In the Pacific States C. cobaltinus, of a change- 

 able cobalt-blue, is very common. 



Belonging in the group with Chrysochus, but less brilliantly colored, are Adoxus, 

 Fidia, Colaspis, Paria, Scelodonta, and Pachnephorus. The larvae of Adoxus vitis 

 — a little pubescent black species with brownish-yellow elytra and legs, and with the 

 first four joints of the antennse pale — does much damage to the 

 grape in Europe and is found in America. It is about 0.1 inch 

 long. Fidia viticida, a chestnut brown species with short whit- 

 ish hairs, injures the grapes in the Western States by riddling 

 their leaves. The beetle is about 0.3 inch long. Colaspis 

 flavida, a clay-yellow species about 0.25 inch long, attacks the 

 grape, upon the roots of which its larvae feed. C. brunnea, a 

 brown species of which C. flavida has been considered a variety ; 

 Paria aterrima, a black species of about the same size as Colas- 

 pis; and Scelodonta nebulosus, an ashy gray species of like size, 

 aU feed as larvae upon strawberry roots, the larvae of three species 

 being very much alike. Pachnephorus cylindricus, which is fig- 

 ured, is from Europe and northern Africa. 



The species of Cryptocephalus are short, cylindrical, and generally small. They 

 resemble those of Pachybrachys, but in the latter genus the prothorax is margined at 

 the base and not crenulate, while in Cryptocephalus it is not margined at the base and 

 is crenulate. In both genera the prothorax is nearly as wide as the elytra are, and the 

 perpendicular head is set deeply into the prothorax ; the antennae are filiform. The 

 larvae inhabit little cases upon leaves of different trees. Beetles and larvae alike have 

 a habit of falling to the ground when disturbed, thus escaping observation. The 

 number of species of Cryptocephalus and Pachybrachys is large, there being in the 

 United States about forty described species of each genus. The species are usually 

 prettily marked with colored stripes or spots. Cryptocephalus con- 

 fluens, which is figured, will give a good idea of the form and of one 

 type of figuration in these genera. It is a pretty North American 

 species, in which the general coloration is yellow, that of the thorax 

 being tinged with brick-red, while three black longitudinal lines adorn 

 each elytron. Two of those lines are confluent upon the elytral 

 suture, whence the specific scientific name. Westwood mentions 

 that the larval cases of a species of Lamprosoma, a genus near 

 Cryptocephalus in classification, mimic with remarkable accuracy 

 the buds upon the bark of the trees on which the larvae feed. 

 In Europe there are numerous species of a genus resembling, in general, Crypto- 

 cephalus, but of larger insects ; this is Clythra. In Clythra, however, the antennae are 

 serrate and the anterior coxal cavities are confluent, not as in Cryptocephalus separated 

 VOL. n. — 21 



Fig. 356. — Pachnephorus 

 cylindricus. 



Fig. 357. — Crypto- 

 cephalus amfivj- 

 ens. 



