THE MOUNT DESERT REGION 173 



ScoLYTroAE. The Bark Beetles 



These are to be found in dead trees. Caging dead limbs is 

 an easy way to collect them. 



PoLYGRAPHUS Erichson 



P. RUFiPENNis (Kby.) (18193). The Spruce Bark Beetle. It 

 infests dying and felled spruce. N. E. Harbor ; S. W. Har- 

 bor, June. 



Dendroctonus Erichson 



D. VALENS LeC. (18231). The Turpentine Beetle. Corfield 

 flying, June 16. Dug from dead spruce Bar Harbor, Oct. 8 

 (Br.). 



Leperisinus Reitter 



L. ACULEATUs (Say) (18252). The host is ash from which it 

 was taken, Corfield, Sept. 13; Indian Point, Sept. 23. 



Trtpodendron Stephens 



T. RETUSUM (LeC.) (18306). On poplar catkins, Apr. 26 (Br.). 

 T. BiviTATTUM (Kby.) (18309). Mt. Desert, May 7 (Br.). 



Gnathotrichus Eichhoff 



G. MATERiARius (Fitch) (18400). The Pine Wood Stainer. 

 Excavates galleries in the sapwood and heartwood of dying 

 and recently felled pine and spruce. Bar Harbor, June 16. 



CoNOPHTHORUS Hopkins 



C. coNiPERDA (Sz.) (18410). Bar Harbor, May 4 (Br.). 



