INJURIES BY KOUNDHEADED BOREKfcf. 



347 



individuals and according to age. The largest at maturity have been 

 found to measure slightly over 60 mm. in length and 9 mm. in 

 breadth at the broadest point. It appears 

 that normally there is one generation of this 

 species per year, with a partial second genera- 

 tion. Thus, a few larvae hatched from eggs 

 deposited in the spring go through their 

 changes to the adult form and the adults 

 emerge in the fall, while the larger number 

 of the larvae hatched from eggs deposited in 

 the spring and summer hold over until the 

 following spring, when the adults emerge. 

 The adult (fig. 21, j) is an elongate beetle 

 varying from 16 to 31.5 mm. in length and 

 from 5 to 10 mm. in width. The color is a 

 mottled gray and brown. In the male the 

 antennae ("horns") are very long, often be- 

 ing two or three times the length of the 

 beetle. In the female they are much shorter. 

 The principal time of emergence in the 

 Southern States seems to be March and 

 April. 



Injury to felled pine timber by this species 

 may be prevented in two ways. First, by 

 placing infested logs in water while the 

 larvae are still in the bark and before they 

 have entered the wood; and second, by re- 

 moving the bark from the logs before the 

 larvae have entered the wood. 



Trees or logs infested by this borer can be 

 readily recognized by the pits (fig. 21, a) ex- 

 cavated in the bark by the female prepara- 

 tory to depositing eggs. 



THE LOCUST BORER. 



(Cyllene robinicc Forst.) 



FIG. 22. Work of the lo- 

 cust borer (Cyllene ro- 

 Mniw). Section of trunk 

 of dying locust, showing 

 larval mines : a, Larva ; 

 6, adult. Insects natural 

 size. (Original.) 



So important and destructive an enemy of 

 the black or yellow locust has the locust borer 

 become that in certain sections of the country 

 the growing of these trees has been considered 

 unprofitable because of the widespread depredations of the borer. 

 Throughout the Eastern and Middle States scarcely a community 

 where locust triees occur is exempt from this insect. Many trees are 

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