TIIK WKSTI-iKN I'l N K-DKS'I'Ko V I N( ; K.\ UK HKKTLK. 21) 



■\vliicli iiuist occur in liifi^c minil)crs hcforc tlic^' can at lack and kill a 

 tree. Sonic of the livini; trees in the immediate neii,dd)()rhood of the 

 ti'ap 1 ices may he attacked hy heeties atti'aeled to the vicinitv h\' the 

 felled or (girdled trees. These should he felled and treated the same 

 as traj) trees. 



If the conditions appeal' to warrant it, additional trees should he 

 ij:ii-dle(l or felled about the first part of Au<;ust to catch the second 

 brood. Tlu>se may be barked, to kill the broods, any time betAveeii 

 the first j)art of October- and the first part of the following May. 



SUMMARY. 

 ll.MUIS AM) l.IKK IIISTOUV. 



The western |)ine-dest royini: bai'kbeetle usually attacks and kills 

 th(> best examples of western yellow pine and siii^ar |)ine. 



If nei!:leeted and under certain conditions favorable to the specie.s, 

 it is capable of devastat im,^ the pine forests over lar^'c areas. The 

 l)roods of the beetle ])ass the winter in the outiM' bark of tr(>es killed 

 hy it the jirevious summer. The adults of the overwinterini: broods 

 <Mnei"<i:e and lly in May, dune, and .luly, the be^inninir i»nd endinir <»f 

 the ])eriod varying with the seasons, latitude, and altitiid(\ 



I'lie first ei,'i^s from the first generation are (l(>|)osited in dune or 

 duly, and in some of t he warm localities possibly as early as t he middle 

 of May. In localities intermediate l)(>tweon the colder and warmer 

 re^^ions the majority of the adults of the first ixeneration evidently 

 develoj) and enier<!;e in Au^nist, but some individuals may remain in 

 the trcM's until dune of the next year. 



The (irst e<2:^s of th(> second i^eneratioii are evidently de|)osite(l in 

 Aiii^ust and September, dependin<^ on locality, and it would ap|)ear 

 that in intermediate localities all of the broods of this ijeneration |)ass 

 the winter (hibei'iiate) in the larval stai;e in the outer bark. In the 

 warmer localities .some of them may develop and emerLTc in the fall. 

 \vhile in the coldei" localities t liei'e may b(> but one generation. 



The (irst evideiK-e of attack on livini; trees is tlu^ presence of pilch 

 tubes {ii<;s. II and ]'_', c) on the bark or of reddish borini,rs lodged in 

 the crevic(>s and around the base of the tree. 



During the fall, winter, and ftdlowint; sprini,', after a su<'cessful 

 attack, the infested trees will be indicated by the fadinix yellowish 

 and reddish leaves. 



The Work of the insect will he indiciiled hy the windimr ijalleries 

 throu}.rh till' iinier hark (iij;. S). 'frees from which the broods have 

 emer»re(l will be indicated by l;ir^^' numbers of small holes t lii"oui,di the 

 outer bark (!!<;. IL'). 



KKMKUIKS. 



The ]>rinci|)al anvis of infestation and the principal j)at(dies of 

 infested tn^es should be locatecl in September and ()ctol)(>r. 



