ATTACKING THE TRUNK. 



17 



surface are hoary-white, the antennae and legs gray. The 

 females are larger than the males, and have shorter antennae. 

 The beetle makes its appearance during the months of June 

 and July, usually remaining in concealment during the day", 

 and becoming active at dusk. 



The eggs are deposited late in June and during July, one 



Fig. a. 



in a place, on the bark of the tree near its base. Within two 

 weeks the young worms are hatched, and at once commence 

 with their sharp mandibles to gnaw their way through the 

 outer bark to the interior. 



It is generally conceded that the larva is three years in 

 reaching maturity. The young ones lie for the first year 

 in the sap-wood and inner bark, excavating flat, shallow 

 cavities, about the size of a silver dollar, which are filled 

 with their sawdust-like castings. The holes by which they 

 enter, being small, are soon filled up, though not until a 

 few grains of castings have fallen from them. Their pres- 

 ence may, however, often be detected in young trees from 

 the bark becoming dark-colored and sometimes dry and dead 

 enough to crack. Through these cracks some of the cast- 

 ings generally protrude, and fall to the ground in a little 

 heap; this takes place especially in the spring of the year, 

 when, with the frequent rains, they become swollen by 

 the absorption of moisture. On the approach of winter 



the larva descends to the lower Dart of its burrow, where 



2 



