1912 ENTOMOLOGICAL SOCIETY. 53 



fires, killing many trees that would otherwise recover, and rendering others 

 unmarketable by their excavations and hastening decay by permitting the entrance 

 of wood-destroying fungi ; but that fires are often secondary to outbreaks of 

 insects, which leave the dying or dead trees in a favourable condition for the 

 spread of fire- Many square miles of burned-over areas in the Eocky Mountains 

 were primarily the result of the attacks of wood-boring beetles. 



In his admirable bulletin on the genus Dendroctonus, which includes the 

 most injurious enerhies of our coniferous forests, Dr. Hopkins has also shown 

 that while many species at times attack living trees when present in unusually 

 large numbers, certain forms, notably the Black Hills Beetle (Dendroctonus 

 ponderosoe, Hopk.), actually prefer healthy to weakly trees and may be the cause of 

 the destruction of the best timber over many square miles of territory. 

 He has further demonstrated that outbreaks of this kind may be prevented or 

 brought under control if prompt measures of the proper kind be taken. The 

 methods employed, however, vary according to the particular species involved, 

 so that it is necessary to have a precise knowledge of the species in question, 

 and of its habits and life-history. It is information of this kind that is lacking 

 respecting most of our forest insects in Canada. We want accurate knowledge 

 of the characteristics of each species, in order that nearly allied species, of perhaps 

 very different habits and economic importance, may not be confused; we want to 

 know their complete life-histories, their seasonal and geographical distribution, 

 the number of broods, their enemies, the species of trees they attack and the 

 effects they produce thereon; in fact all we can learn about them. Only in this 

 way can the best methods for their control be determined. 



Surely there is a splendid field here for the young entomologist, who i^ 

 anxious to take up a useful as well as attractive subject as his specialty. The 

 study is not an easy one. Nearly allied species in some of the groups such as the 

 bark-beetles (Scolytidce) are often exceedingly difficult to separate; life histories 

 are often difficult to follow out and material sometimes hard to obtain; never- 

 theless, the patient, accurate worker in this field will certainly be rewarded with 

 results that are well worth the labour spent upon them and may, perhaps, be of 

 much benefit to the community. 



Fortunately, we are not entirely without workers in this field in Canada. 

 Prof. Swaine, of Macdonald College, is well known for the excellent work he 

 has accomplished in the study of our bark-beetles (Scolytidae). He has published 

 a number of valuable papers in the Canadian Entomologist, and our Annual 

 Eeports, and we feel sure there are many more forthcoming. Much credit is also 

 due to the staff of the Division of Entomology at Ottawa for their work on the 

 parasites of the Larch Saw-fly and Spruce Bud-worm, two of the most serious 

 defoliaters of forest-trees in Canada. Dr. Hewitt's work in importing and dis- 

 tributing Mesoleius aulicns, a European parasite of the Larch Saw-fly, is of a 

 very important character, whether the experiment is successful or not, for our 

 only hope of getting control of this terrible pest is through the agency of its 

 natural enemies. The Division also deserves credit for the vigorous campaign it is 

 pursuing against the spread of the Brown-tail moth, which has, unfortunately, now 

 become firmly established in New Brunswick and Nova Scotia, whence it has spread 

 from the adjoining New England States. The ravages of this moth and the Gypsy- 

 moth (Porthetria dispar) are too well known to need mention here. Both have been 

 introduced from Europe without their natural enemies to keep their numbers 

 in check, and though their ravages have been the cause of the loss of hundreds 



