PLATE XII. 



Work of Dendroctonus frontalis and Dendroctonus terebrans. 



(From drawings illustrating Bulletin 56, W. Va. Agr. Exp. Station.) 



a, Dendroctonus frontalis : A, adult; B, pupa; C, larva; D, adult of Dendrocto- 



nus terebrans; E, larva. 



b, Dendroctonus frontalis: A, tibia; B, tarsus; C, D, E, antennse; F. G. mouth 



parts. Dendroctonus terebrans: H. tibia; J. tarsus; J, K, L, M, N, antenna — 

 all enlarged. 



c, Pitch tube made by Dendroctonus frontalis — natural size. 



d, Healing wounds, froni living pine tree, made by D. frontalis — reduced. 



e, Pupa cases of D. frontalis in outer pine bark. 



/, Dendroctonus frontalis: A. B, longitudinal section of primary galleries; C, 

 egg in egg cavity inside of gallery — the latter enlarged: others reduced. 



g, Healing wounds in living tree: E. Dendroctonus frontalis; F, Dendroctonus 

 terebrans. 



h, Work of Dendroctonus frontalis in pine bark is shown at A, C, D. E, F. G; 

 work of D. terebrans in pine bark at B, II, I: larva at work at H. 



Note. — Both I). frontalis and D. terebrans attack spruce. 



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