DIVISION OF ENTOMOLOGY 511 



SESSIONAL PAPER No. 16 



IV.— INSECTS AFFECTING FOREST AND SHADE TREES. 



The appointment of Mr. J. M. Swaine as Assistant Entomologist to take charge 

 of Forest Insect Investigations enabled ns to extend our studies in this most 

 important branch, and Mr. Swaine has devoted his whole attention to this work, 

 studying, in particular, the Bark Beetles (Ipidae) which constitute the most deadly 

 and widespread enemies of our forests. In May, 1912, Mr. Swaine visited the Riding 

 Mountain Forest Reserve in Manitoba. The primary object of his visit was to 

 colonize a large collection of the cocoons of the Larch Sawfly, Ncmatu-s erichsonii 

 containing its parasite Mesoleius tenthredinis. These cocoons had been collected in 

 the English Lake district, which I visited with that object, as mentioned in my last 

 annual report. The weather conditions were not very favourable; nevertheless, fhe 

 parasitized cocoons were distributed by Mr. Swaine in two large tamarack swamps 

 in the Riding Mountains east of Clear lake. It was found that bark beetles were 

 present in the reserve in great numbers in fire-injured timber and in slash from 

 cuttings. Dendroctonus murraqfanoe Hopk. had destroyed some timber. D. simplex 

 was very numerous in dead and standing larches, and is no doubt serious as a co- 

 destructive agency with the Larch Sawfly. Ips perturbatus Eichh. and /. caelatiis 

 Eichh. were abundant in fire areas south of Clear lake, occurring chiefly in white 

 spruce which was badly injured by fire. Polygraphias rufipennis Kirby was found 

 common everywhere in dying bark of spruce, larch and jack pine. These were the 

 chief species of bark beetles found and they are able to kill weakened or injured 

 trees which might otherwise recover. Timber beetles of several species were plentiful, 

 the most common being the Poplar Timber Beetle Trypodendron retusis Lee. and the 

 Spruce Timber Beetle T. lineadas Ratz. in spruce and pine. The effect of Pissodes 

 injury was very noticeable in numerous, " double tops" on the spruce. 



A visit was made by Mr. Swaine to Algonquin Park, Ont., in July. Abundant 

 evidence of serious injury by bark beetles was found. Observations on the habits and 

 life histories and collections were made of the following: Dryoroetes eichoffi Hopk. 

 on birch, Dendroctonus and Dryoroetes in white spruce. Polygraphias rufipennis in 

 white and black spruce, Ips balsameus on balsam, Monohammus scutellatus, etc. 

 The timber limits of the Canada Paper Co., at Stoke, Que., were also visited and 

 important observations were made on the bark beetles and other forest insects pre- 

 valent in this important forest region of Quebec. 



TENT CATERPILLARS. 



Malcucosoma am&ricana and M. disstria were very abundant in certain parts of 

 Ontario, Quebec and New Brunswick, and particularly in the districts around 

 Ottawa and Montreal. M. disstria was responsible for extensive defoliation of forest 

 trees in the Gatineau region, north of Ottawa. The caterpillars were so numerous 

 that the trains on the Gatineau branch of the Canadian Pacific Railway were held 

 up on certain of the grades, in spite of double engines and mechanical devices for 

 clearing the rails. Very few parasites ware found, and, although the bacterial 

 disea-es were evident, the countless numbers of moths which deposited their egg 

 masae3 thickly on the trees indicate a more serious visitation next year, and a cir- 

 cular on Tent Caterpillars has been prepared by Mr. Swaine, and is now in the press. 



The Spruce Budworm, Tortrix fumiferana, appears to be gradually spreading 

 eastward, as more reports have been received from the region south and east of the 

 St. Lawrence, and it is more in evidence in New Brunswick. Districts in Quebec, 

 north of Ottawa, which were seriously defoliated in 1909, appear to have recovered 



