328 



NATURAL HISTORY OF ARTHROPODS. 



mottled with cream white. Ptychodes vittatus is slender, about an inch long, with 

 very long antenna? and legs, and is of a rich brown ground color, with sutural and 

 marginal stripes of white. Both the above-mentioned species are found in the south- 

 western United States. In Europe a closely allied longicorn, Lamia textor, bores, in 

 its larval state, in willow twigs. The beetle is from 1 to 1.25 inches long and nearly 

 half as broad, of a dark brown color, with fine yellowish pubescence, through which 

 glimmer little black points ; its antenna? are about two-thirds as long as its body. 



Psenocerus supernotatus is a beetle only about 0.25 of an inch long, whose larva bores 

 in the twigs of different kinds of currants. Its front coxal cavities are angulated, its 

 prothorax is constricted behind and the humeral angles are distinct. The ground color 

 of the beetle is black, the prothorax and margins of the elytra are pale brown, and 

 there are a few white or gray spots on the elytra. Mr. William Saunders has well 

 described the life-history of this species as follows : " Early in June the parent beetle 

 of the native currant borer deposits her eggs upon the ciirrant stalks, where they soon 

 hatch into tiny grubs, which burrow into the heart of the stem and, feeding on its pith, 

 reach full growth before the close of the season. They are footless grubs, which 

 measure when full grown about half an inch in length. The head is scarcely half as 

 broad as the body, is of a dark brown color, with black jaws. The body is whitish 

 with some brown dots along each side, and is slightly clothed with very fine short 

 hairs. When full grown and about to change to a chrysalis, the larva gnaws a channel 

 through the woody fibre to the outer bark, so that when changed to a beetle it can 

 make its escape by merely rupturing the bark. The cavity thus made is filled with 

 little chips to prevent the bark from being prematurely broken, and below this stuffing 

 the insect constructs a bed of short woody fibres, packing the passage below with a 

 finer material resembling sawdust. Within this enclosure, which is about half an inch 

 in length, the larva changes to a chrysalis and reposes until the fully formed beetle is 

 ready to emerge ; then, gradually drawing away the obstacles to its egress, it finds its 

 way to the end of the passage, and gnawing a small round hole through the bark, 

 effects its escape." As the lame remain in the twigs during the winter, an easy mode 

 of destroying these longicorus is to break off the dead twigs in early spring and 



burn them. 



Dorcadion is a well-represented genus in south- 

 ern Europe. The humeral angles are not prominent, 

 and wings are absent; the palpi are slender, the 

 support of the labiurn distinctly visible, the an- 

 tennas not surpassing the body in length, and the 

 prothorax with a spine on each side. D. crux is 

 velvety black, with silvery white markings in a 

 cruciform arrangement as seen in the figure. 



Turning our attention now from the Lamiinae 



^7 



to the Cerambycinae, we have to deal with longi- 

 corns which have marginless prothorax, palpi never 

 acutely pointed, and the anterior tibias without 

 grooves on the inner side. 



The genus Leptura and some genera associated 

 with it have the head distinctly narrowed behind 

 the eyes to form a sort of neck ; their front coxae are conical ; their eyes are nearly 

 or quite round, not, as in many Cerambycidse, more or less enveloping the base of the 





FIG. 304. a, I'lytus arietis ; b, Necydalis 

 major; c, Dorcadion crux. 



