42 ' E.C. Entojiolocical Society. 



are more subject to serious injury in Canadian forests. Those species which arc 

 able to liill healthy trees prove among the most destructive of forest insects. The 

 genus Dendroctonus contains a number of species most injurious to coniferous trees. 

 D. piceaperdu, Hopli:., in successful outbreaks, has liilled an immense amount of the 

 finest spruce timber in Maine and New Brunswick. This species is a constant menace 

 to the spruce forests of eastern Canada, but does not appear to be concentrated at 

 present in destructive outbreaks. D. valcns, Lee, is commonly found in dying bark 

 of spruce and pine stumps and logs, and, not rarely, is the primary cause of the 

 death of trees. It is assisting D. hrevicomis in killing bull-iMne in the south-western 

 part of this Province. In the timber attaclvcd this season, and still green, valeiis 

 is working in large numbers. It may be considered a destructive species in bull- 

 pine in British Columbia. 



An undescribed species of Dendroctonus breeds in immense numbers in the fire- 

 injured timber of northern Manitoba, and has killed a small amount of jack-pine 

 timber, mostly in the neighbourhood of the burns. D. simplex breeds abundantly in 

 dying larch-bark from Manitoba eastward, and apparently kills many trees weakened 

 by the larch sawfly. 



An undescribed species of Dendroctonus, assisted by species of the genus Ips 

 (TomiousJ , is apparently killing much fine white-spruce timber along the AthabasUa 

 River, above and below Athabaska Landing. This infestation has not yet been care- 

 fully investigated. D. pseudotsiigw, Hopk., breeds abundantly in logs of Douglas ■ 

 fir and western larch in British Columbia. It everywhere attacks and kills injured 

 and weakened trees, and frequently kills considerable green timber. 



D. m'onticolae, Hopk., has killed much western white-pine (Pinus monticolm) in 

 the Sugar Lake region of British Columbia, and the outbreak is still spreading. This 

 species also attacks and kills the black-pine in that district. D. hrevicomis is 

 destructive to bull-pine in British Columbia. 



In the Princeton section an outbreak by this species has been running for three 

 years and much valuable timber has been killed. The clumps of " red-tops " may Ijo 

 distinguished upon the mountain-side and in the valleys for many miles. Tlie 

 infestation is sijreading rapidly and threatens the entire bull-pine stand of that 

 region. The same trouble is appearing in other sections. D. monticolce and D. 

 valens are working in the same trees, and the former appears to be as destructive 

 as 'brev-icomis. D. engelmanni, D. horeaUs, D. murraijamr, and D. ohesies are 

 variably destructive to spruce and pine in different parts of the Province. The 

 habits of these and other ipid beetles of British Columbia are being carefully 

 investigated. 



Many species of the genus Ips (Tomicus) are abundant in dying bark of pine, 

 spruce, and larch. Most species of this genus found in Canadian forests are impor- 

 tant secondary enemies of trees, but are seldom found attacking green timber. 

 There are, however, several important exceptions. Ips Itulsaineus, Lee, is a serious 

 enemy to balsam fir throughout Ontario, Quebec, and New Brunswick, and to a 

 lesser extent is injurious to larch. Several species of the genus are injurious to 

 pine and spruce in British Columbia and Alberta. 



Potygraphus rufipennls, Kuby, and allied undescribed forms are everywhere 

 important secondary enemies to pine, spruce, and larch. They are usually found in 

 dying bark, but are apparently able to attack and kill healthy trees. Several species 

 of Phloeosinus are locally injurious to cedars. A large number of species belonging 

 to various genera are important secondary enemies, breeding in the bark of injured, 

 weakened, and dying trees. 



Certain twig-beetles of the genus Piti/ophthoriis excavate and kill the twigs of'^ 

 various pines, and at times become sufliciently numerous to check seriously or even, 

 rarely, to kill the infested trees. Such injury was common two years ago in southern 

 Quebec to white and red pine; and in this season abundant on jack-pine in northern 

 Ontario, and bnll-pine in British Columbia. 



