Investigations on Forest Insects, and Forest 



Protection. 



By C. Gordon Hewitt, D.Sc, Dominion Entomologist, Ottawa. 



The problem of the protection of iiistanc<'H nientiotwd by Dr. llopkiiiN. 



Canadfrs foiTsts i-csolvcs itself into a who is in char^?!- of th> 



4U('stion of coiitrolliMi; the destructive invest ij»at ions of the I ,,, 



agencies. Of these tii-e, beinjr so oh- Bureau of Hntomohjtry. may Ik? in- 



vions in its ouhreaks and spread, is lioiied. The l)ouj;laK fir tlirouKhoiit 



iTceivin}? inei-easiii^ly jji'eat attention the retrioii of the Hoeky .Mo' 



in Canada. Not less serious, tiiouyh from New .Mexico to ItritiNh ' 



usually unnoticed and very fr(M|uent- hia has sulTered severely from t 



ly attiihuted to othei- causes, are the ajjesof the l)ouKhi« *ir In-etle. with the 



(lepredations of forest insects which i-esidt that a lar^'c pen-c 



up to the present time have received tiud»er is found, much < ;. . 



practically no attention in Canada, he a total l(».ss. Duriujr the past tiitv 



We have studied the outhrealTs of the years the Hnjrleiiiiinii spiu<«- Uftle 



larch sawHy and the spruce hudwoi 111, has caused u idi-spit-.-id -! 



it is true, hut the injury caused l>y the jiocky .Moiuit.uu ic;:. ... 



these insects is sli«rht compared with of Kn^demann spruce, in whuc .v < 



the destruction which is ^oin«: mi tions killinjr from 7."i to \H) per rout. 



from year to year owin«; t<» the <lc- of the tindier of ne-rd 



predations of a ninnher of species of In the lilack Hills .\;'ti' 



widely spread haik beetles which d- - .South Dakota it is es! Mir- 



stroy the trees ])y attackiufr the bark, ing the past ten years more than a 



Theii- depredations are fi-e(|\ieiitly billion feet of timlM-r have Imm-m de- 



clo.sely a.ssociated with desti-uctiou by .stroycd as a direct r.>.iil' "f ttu '.vi.rk 



fire and are often ndstaken for it. of the hiaek Hills I 



^VIlcn they do not kill the trees before of the Kastern spru<i' iM-ctie. I>r ll<>p 



the advent of fire, theieby i-eiulering kins states that durinij the i ' 



areas more cond)Ustiltle. they wcakcFi tween iSls and lIKM) th< ». 



them beyond the i-eciiperative sta^.''. eral outbitaks of thlH i 



or they may follow tire an<l brinj? spruce forests of Nt»w York. .\«w Knu- 



al)Out the final desliiiction of tiiidM-r land and sonth ejistern Canada It 



which nd<iht otlierwi.se have recovcicl cau.sed the death of a very I.^l'. t«. - 



At piesent little or no informatiMii ceiitajre of the nuilure Kp' 



is at liaiKJ as to the extent of tin- A'- tliouMindM of H»\\i 



stniclion of Canadian forests l>y til>^c af;irrej;atf Mian\ 



in.sects. owiiij; to t!ie fa«'t that n<» ;<; the 1"^' ' ' • r ^ 



tention has been paid to these .!r>tt n - ihr 1. i« of 5 



tive aj;enci«'s; conse»|uently. in >! furnished tuel 



Hum this <|Uestion. it is impDvsil.i, lo tires with the i 



give actual instances. We }• > • .>"ly there was .i t. 



to go into the neighbouring 'f for the '^r 



the Cnited States, however, uii' • 

 considerable attention has b. .n ami is 

 being paid to the deprcdatmns of 



forest insects, to find evidcr.iivi <>f tn v. in i •"** i"- 



great destruction by them. The pi «!ipn«<ln 



35 



