REPORT OF THE ENTOMOLOGIST 233 



SESSIONAL PAPER No. 16 



Arrangements have been made for the study of the parasites of this insect and this 

 will be carried out during the coming summer. Only by a knowledge of the character 

 and extent of parasitism can the results of this outbreak be foretold with any degree 

 of certainty. If the parasites are found t® be increasing rapidly in number, as is 

 fiequently the case in outbreaks of insects native to the country, they will control the 

 pest before it has accomplished the severe destruction which alarmist minds might be 

 inclined to predict from the appearance of the forests last year. 



The Larch Sawfly. (Lygceonemat.us erichsonii Hartig). — The study of this 

 insect was continued. A beginning of the study of the European parasites of this insect 

 had been made by me before leaving England. This study was continued on account 

 of its importance in relation to the serious nature of this insect's history in Canada. 

 I am of the opinion that it was imported into North America and am supported in 

 this belief by the history of the Sawfly since it was first recorded on this side of the 

 Atlantic ocean, in 1881. 



My investigations showed, and were confirmed by the continued study in England 

 by Mr. Joseph Mangan, that the parasite, Mesoleius aulicus Grav., was not only the 

 chief parasite as had been previously shown*, but had increased sufficiently rapidly 

 to control the sawfly which was actually the case. It was found that over sixty per 

 cent of the sawfly larvae were parasitised. Accordingly arrangements were made for the 

 collection of the cocoons in that region in England where the parasites had been found 

 in so great abundance, and these parasitised cocoons are now on their way to Canada. 

 An endeavour will be made to establish the chief parasite, M. aulicus, in different 

 localities within the infested region which extends from Winnipeg, Man., to Cape Breton, 

 N.S., as shown in the accompanying map. A beginning has also been made of the 

 study of the native parasites attacking the sawfly larvas. The chief of these appears 

 to be a small Pteromalid Coelopisthia nematicida Packard, which deposits its eggs 

 inside the cocoon on the hibernating larva and this is destroyed. The European and 

 North American larvas and adults of the sawfly were studied side by side and there 

 is no doubt as to their being the same species. 



The Birch Sawfly (Hylotoma pectoralis Leach) defoliated birches in the neigh- 

 bourhood of Quebec and in Charlevoix county, Que., and was very destructive near 

 Charlottetown, P.E.I. The larva is about three-quarters of an inch in length, yellowish 

 in colour spotted with black and is usually abundant on birches in August and Sep- 

 tember. The Fir Sawfly (Lophyrus abietis Harr.) was abundant on spruce in Algon- 

 quin Park, Ont. Many pine trees near Magog, Que., were defoliated by Abbot's Pine 

 Sawfly (Lophyrus abbotii Leach) the larva of which is yellow, spotted black and • 

 having a black head. The full grown larva measures about an inch in length. 



The Spruce Gall Louse (Chcrmes abietis Choi.) was, as usual, abundant and in- 

 jurious to White and Norway spruce in Ontario and Quebec. Chermes similis Gillette, 

 was reported from Richmond, Que., and C. floccus Patch from Halifax, N.S., where it 

 was rather seriously affecting spruce. Miss Patch finds that this species migrates to 

 the needles of the white pine. C. pinicorticis was also abundant on the bark of white 

 pine. The Green Striped Maple Worm (Anisota rubicunda Fabr.) defoliated maples 

 near Newboro, Ont., and also along the shore of Georgian Bay. A. virginiensis 

 defoliated oaks in the former locality. The White Cedar Twig Borer (Argyresthia 

 thuiella Pack.) which causes the death and consequent brown appearance of the green 

 tips of the cedar was abundant in Algonquin Park and other regions in Ontario. 



INSECTS AFFECTING GARDEN AND GREENHOUSE. 



A small Collembolan which Dr. Folsom kindly identified as Xenylla humicola 

 (O. Fabr.) Tull., was received from Toronto and also from St. Thomas, Ont., where it 

 occurred in enormous numbers forming patches several inches across. The Tarnished 



* The Large Larch Sawfly, Ncmatus erichsonii Hartig. Journ. Board of Agr. vol. 15, 

 pp. G49-GG0. 1908. 



