Bu'. 48. Div of Entomology, U. S. Dept. of Agriculture. 



Plate XXI. 



Cb 



\ 



Dead Spruce; also Fir and Birch. 



It. i»l<l (Iciifl si-niiciiiiil II il.'ii.l tiircli in nitiitm: /,/. n-iniiiiis of vt-rv old iIi-ikI ^iiriiri' h' iitipcnr- 

 imrcof >i.riiif tr.TiiHiT II Inis l.crii .l.-n.l liw to Icii v.'iirs or more: .•. wliiic >i.rii(c il.-'n.l tlircc 

 or lour y.ar-: ./. •Iiixl spniir. tir. mix) l.inli. kill.il l.y liri-: t. lU-ail .Kpriin- nn.l (iron Miiiiinit of 

 lviim|. Moiiiitiiiu. >rmiu'. i From Bui. is. u. s.. I»iv. of Eiitomolofcv. V . .s. D<'|>l of \)frirulturi.' ) 



