INSECT ENEMIES OF WESTERN FORESTS 



41 



Figure 14. — The lodgepole terminal weevil (Pissodes terminalis) : A, Adults; 

 B, larvae and pupae in pith of terminal shoot; C, weeviled tip showing 

 emergence hole. Greatly enlarged. 



larly destructive in open-grown stands of young lodgepole pine in 

 California. 



Other species of Pissodes that may at times work in the termi- 

 nals of young pines include P. yosemite Hopk., P. schivarzi Hopk., 

 P. radiatae Hopk., and others that normally work at the base of 

 saplings (see p. 176). 



Certain species of the genus Magdalis are also twig borers dur- 

 ing the larval period (fig. 15) . The adults feed on the foliage and 

 make punctures in the twigs of conifers and broadleaved trees, in 

 which eggs are deposited. The grubs burrow beneath the bark and 

 into the wood and cause the death of small branches and terminal 

 twigs. The larvae are white, legless, and curled, and are practically 

 indistinguishable from those of Pissodes; but the work is usually 

 distinct in that Magdalis larvae tend to work into the wood more 



