22 



Tlie Red Spruce of the middle and northern Appahiehian.s, from West 

 Yirgi :i;i to northern New York and on through northern New Eng- 

 land to Canada and New Brunswick, has, from time to time during 

 the past century, suffered severel}^ from troubles, some of which are 

 known, and others believed to be, caused by bark-beetles. " 



A large amount of spruce was killed in West Virginia about 1885, 

 evidently by a bark-beetle, but the trouble was not investigated until 

 1890, so the exact species deserving the blame could not be determined. 



In 1892 the destructive pine bark-beetle spread in West Virginia 

 from the pine into the spruce, and caused the death of a large amount 

 of tlie best timber. 



The great destruction of spruce, which has attracted so much atten- 

 tion from New York to New Brunswick, was found, upon special 

 investigation, to be largely if not entirely due to the primar3^ attack 

 of the spruce-destroving l)eetle {Dendroctonus piceaperda Hopk. 

 MSS.).'' 



The Sithi Sjyruce of the Northwest has numerous enemies, among 

 which the Sitka spruce Dendroctonus {Dend7'octonuK ohexus Mann.) is 

 the principal depredator in the bark of living and declining trees, 

 while the spruce-destroying spanworm {Phlhdla puiictomacidarla 

 Hulst. 'i) may be considered as the greatest insect destroyer of 

 forests of this tree and the Western Hemlock.'' Scarcely anything is 

 known about the life history and haliits of this insect. Therefore it 

 presents a problem of special importance for investigation. 



The EngehiKtrni SjJi'iice has a number of insect enemies, one or two 

 of which ai'e capable of causing wdiolesale destruction. 



Vast quantities of dead spruce occur in different sections of the 

 Rocky Mountain region which, it would seem, bear no trace of having 

 been killed by tire, and the cause will probabl}^ be found to be the 

 attacks of some destructive ))ark-beetle or defoliating insect. 



THE HEMLOCKS. 



The Eastern Ilendoeh has a serious enemy in the hemlock destroj^er 

 {MeJanophiJa fidr()(/i(ttat((), which has caused the d(\ath of a large 

 amount of hemlock timber throughout the Appalachian and North- 

 eastern regions. 



TJie Western IleinlfH-l' has at least three destructive enemies of the 

 living trees: (1) The Western hemlock bark-borer {MrJaiiopli'da 

 druiiDiiond!)^ which is closely allied to the Eastern species, and like 

 it extends its burrows ))eneath the ])ark and either kills the trees or 

 causes serious gum-spot defects in the wood; {'2) the Douglas spruce 



«Buls. 17 and 56, W. Va. Agr. Expt. station, and Bui. 28 (n. s.), Div. Entom. 

 U. S. Dept. Agr. 



''Bnl. 28 (n. s.), Div. Ent., U. S. Dept. Agr. 



cBul. 21 (n. H.), Div. Ent., U. 8. Dept. Agr., 18»i», p. 18. 



