FOREST LIFE. 



215 



INSECTS INFESTING THE TRUNKS AND BRANCHES OF 

 TREES. 



The insects that live within the trunks and 

 branches of trees are called borers. There are very 

 many species of these, and representatives of several 

 of the orders of insects, as well as of many different 

 families, are found among them. 



In the study of these insects larvas should be col- 

 lected from the infested trees from time to time and 

 preserved in alcohol ; when the insects have trans- 

 formed to pupas, these can be transferred to breeding- 

 cages and the adults reared. 



If the infested wood is dead, a piece of it contain- 

 ing the borers can be placed in a breeding cage at 

 once, as soon as the larvae are found, and the insects 

 bred in this way. 



Among the more common borers are the larvas of 

 the long-horned beetles, which constitute the 

 family Cerambycid^ (Cer-am-byc'i-djie). The 

 larvae are footless grubs of the form shown 

 in Fig. 182. The pupa state in some species 

 is passed within the burrows made by the 

 larvse ; in other species the larva makes a 

 little ring of chips around itself between the 

 bark and the wood, and changes to a pupa 

 within this rude cocoon. Several examples ^^^' ^^^' 

 of beetles of this family are represented on Plate V.* 



* Explanation to Plate V.— i. The ribbed pine-borer, Rhagium 

 h'neatum ; 2. The two-spotted Oberea, Oberea bimaculata, a borer in 

 blackberry and raspberry ; 3. The sawyer, Monohamus confusor, a borer 

 in pine and fir ; 4. The broad-necked Prionus, Prionus laticollis, a borer 

 in the roots of grape, apple, poplar, and other trees ; 5. The beautiful 

 maple-borer, Plaginotus spe<. iosus. 



