INSECTS AFFECTINT. PARK AND WOODLAND TKEES 3-g 



after the attack has practically ended. h will Ix; observed that the inner 

 bark, is a mass of partially decayed tissues tunnelled ])y numerous larval and 

 adult galleries. I'igures 82, 84 represent the condition after the decayed 

 tissues have been removed. The adult galleries may be easily recognized 

 where they score the surface of the wocxl and here and there are peculiar 

 chambers a little to one side of an adult gallery. These are not central or 

 entrance chambers but are evidently little cavities hollowed out by the 

 beetles for the reception of balsam and show conclusivcl\- that the tree must 

 ha\e been alive at the time of the initial attack. Thi' hard, dried balsam 

 can easil)' be found in such caxities. 



b'igure S3 illustrates very iiiceK' how thoroughly this insect may girdle 

 twigs. It represents a small twig less than y, inch in diameter and shows 

 the adult galleries of two females passing from a central chamber around 

 the twig in opjjosite directions and overlapping each other on the farther 

 side by about ],, inch. 



The larvae or grubs pursue a rather tortuous course at api^roximately 

 right angles to the ])arental galleries and end their operations in a slightly 

 enlarged elliptic cell where the final transformations to the beetle occur 



Natural enemies. The writ(;r collected two ])arasites, .Sjjaihius 



t o m i c i Ashm., and Cos m o [) h o r u s h o ]> k i n s i i Ashm. \\\ the burrows 



of this bark borer. 



Bibliography 



1903 Felt, E. P. For. Fish iV fiame Com 7th Kcp't, \>. 519-22 



Spruce destroying beetle 

 Dcndroctoiius piccapcrda Hopk. 



A rather stout, brownish or Ijhick beetle about 3 ,0 incli long, makes longitudinal 

 galleries in tlie inner bark and outer sapwood of living spruce. These, in connection with 

 tlie mere or less transverse expanding larval galleries, frequently result in tlie destruction 

 of trees. 



This species, though only recently characterized, is an exceedingly 

 destructive form, and its ravages have l)een known for some years, though 

 the operations were usually attributed to another species. 



