i6o 



ELEMENTARY ENTOMOLOGY 



large one and includes many serious pests, such as the round- 

 headed apple-tree borer and others with similar habits. Three com- 

 mon blackish species, brilliantly striped 

 with yellow (Fig. 234), are known as 

 locust-borer, hickory-borer, and sugar- 

 maple-borer, after their respective food 

 plants, which are frequently killed from 

 the work of their larvae. Among our 

 largest beetles are the prionids, the larvae 

 of which infest the roots of various fruit 

 and shade trees and herbaceous plants. 

 The broad-necked prionus is from one 

 to two inches long, pitchy black, with the 

 thin margin of the prothorax toothed, as 

 shown in 

 Fig. 232. 

 The oak- 



FIG. 232. The giant root-borer 

 (Prionus laticollis) 



(After Riley) 



primer is 



a slender, brown species, about three 

 fourths of an inch long, which lays 



FIG. 233. 



FlG. 234. The hickory-borer (Cyllene 

 pictns Dru.). (Enlarged) 



(After Webster) 



The oak-pruner (Elaphi- 

 dion parallelling 



a, larva ; />, pupa in its burrow ; <:, beetle ; 

 k, k, cut ends of twig. (After Riley) 



its eggs in the twigs of oak, maple, 

 and various fruit trees. The larvae 

 hollow out the interior of the twigs 

 which are broken off by the winds, 

 and in these they pupate. One of 

 our largest species is the common 

 sawyer, a large gray beetle one 

 and one fourth inches long, with 

 very long antennae, whose larvae 

 bore into the heart of felled pine 

 and other softwood trees, making 

 large holes half an inch in diameter. 

 The raspberry cane-borer (Ob ere a 



