26 THE REPORT OF THE No. 36 



Ontario Department of Agriculture the Division has been allowed the use of an 

 office in the Jordan Harbour Experiment Station, and during the past summer 

 Mr. R. C. Treherne commenced several investigations on the Plum Curculio and 

 other insects, a brief account of which he gave in his report as Director of 

 Division N"o. 7. Mr. Treherne has now been transferred to British Columbia to 

 take charge of our work there, and next season Mr. W. A. Ross will continue his 

 work in Ontario, when it is my intention that he shall work on the Apple Maggot, 

 Plum Curculio and such other more serious species as may be determined later. 

 It is proposed to extend this system of field laboratories and to establish 

 one in ISIova Scotia, another in New Brunswick, where Mr. Tothill will continue 

 his investigations on Tachinid parasites with especial relations to the Brown- 

 tail Moth. I might mention here that we have started, through the kind co- 

 operation of Dr. Howard, the importation of the European Tachinid, Compsilura 

 concinnata, a parasite of the Brown-tail and Gipsy Moths, in the hope that it may 

 become established before the Brown-tail Moth attains any considerable magni- 

 tude in New Brunswick. We hope also to have a field laboratory in Quebec, and a 

 fifth in British Columbia, where Mr. Treherne will carry on investigations on 

 the Lesser Apple Worm, Oapsid Bugs and certain of the more injurious fruit in- 

 sects of that Province. 



During the past summer one of our cJiief investigations has been the study 

 of the parasites of the Spruce Budworm, to which work Mr- Sanders has devoted 

 most of his time. Arrangements were made for supplies of infested spruce, 

 balsam, etc., to be sient to the Division from different parts of Quebec and British 

 Columbia, and this material was used in our parasitic studies. In January and 

 February I visited a number of the more severely infested localities in Quebec, such 

 as Lake St. John region and the Rouge River, for the purpose of miaking field 

 observations. Reports were also obtained during the sumi^mer from the lumbermen 

 and others with regard to the depredations of the Spruce Budworm during the past 

 season. As a result of these ohservations and reports, conjoined with our study 

 of the parasites, we have been able to conclude that the result of the depredations 

 of the insect will not he of so serious a nature as many of the lumbermen and 

 limit-holders were inclined to fear. In fact, in some regions the parasites had 

 effectively gained control of the pest, and it is these parasites and their habits 

 that we have been studying. The most effective parasites would appear to be 

 the &gg parasites, the chief of which is PentartJiron minitum, which Mr. Sanders 

 has studied specially, and its habits and deadly effect may be gathered from the 

 following examples: In one lot of eggs which he collected at Ottawa he found 

 77 per cent, of the eggs parasitized by this species, and the eggs contained on an 

 average over two parasites per egg. In 33 egg masses there were 370 eggs, 286 

 of these eggs were parasitized and produced 639 parasites. Egg masses collected 

 at Maniwaki, P.Q., were similarly heavily infested : 93 egg masses contained 1,192 

 eggs, of which 902, or 75.6 per cent., were parasitized, 2,167 parasites emerged, 

 or an average of 2.4 parasites per egg. The larger ichneumon and other parasites 

 were also ahundant. From insects collected near Esquimault, B.C., the percentage 

 of parasites obtained was 43, and an equally high percentage was found in collec- 

 tions made in Quebec. A species of Apanteles, hitherto undescribed, was abundant, 

 both in Quebec and British Columbia. 



As a result of these studies we were able to calm the fears of those persons 

 on whose timber limits the depredations were noticed for the first time last year, 

 as the pest appeared to be spreading in an easterly direction and more reports 

 were received from the south side of the St. Lawrence. 



