42 PROTECTION OF PLANTS — 1923-24 



latter year the Lesser Migratory Grasshopper, Mehnioplus atJanis Riley 

 was enormously abundant and, to a lesser extent, the Pellucid Grasshopper, 

 known in the west as the Roadside Grasshopper, Camnula pelhidda Scudd. 

 In these experiments the value of sawdust as a carrier for poison in bait mixtures 

 was demonstrated under field conditions. In 1915, Circular No 5 — "The 

 Control of Locusts in Eastern Canada" was published and given wide publicity. 

 For a number of years, the Cabbage Root maggot, Hylemyia brassicae Bouche 

 was studied and the results published (1906) in Bulletin No 12, prepared jointly 

 by the writer and Mr. R. C. Treherne. Since the appearance of this bulletin, 

 frequent demonstrations have been given in the Ottawa district, proving the 

 value of the corrosive sublimate remedy, which has now been widely adopted 

 by commercial growers not only in Canada but also in the United' States. 



In 1919, an intensive study of the Colorado Potato beetle was planned 

 by the writer and incepted at Ottawa, with the assistance of Mr. J. A. Flock. 

 This stud}^ has been continued at Fredericton, N. B., by Mr. R. P. Gorham, 

 and at Strathroj^ Ont., by Mr. H. F. Hudson. Much valuable data have been 

 obtained, which it is hoped to publish in the near future. 



White grubs have also been investigated, life-history notes on the following 

 species having been obtained: LacJmosterna fusca Froel., L. anxia Lee. and L. 

 draJcei Kby. In this work Mr. H. G. Crawford assisted. 



The value of aerial survey's in forest insect investigations was demons- 

 trated in 1920, when Dr. J. M. Swaine and Mr. M. B. Dunn made aeroplane 

 flights in Spruce Budworm-infested districts in Northern Ontario, especially 

 between Lakes Temiskaming and Temagami. In the same 3'ear two forest 

 sample plots were established on the shores of Lake Abitibi. 



The results of Dr. Swaine's studies of Canadian Bark-beetles were published 

 in 1917 and 1918; Part 1, Descriptions of New Species-in the former year; and 

 Part 2-A Preliminary Classification, with an account of the Habits and Means 

 of Control, in the latter year. This publication of 143 pages, (Bulletin No. 14) 

 has received widespread favour from entomologists and foresters. During 

 recent years Dr. Swaine and Mr. Ralph Hopping have made special studies 

 of groups in the family Cerambycidae and an important paper on the Leptu- 

 rini of North America has been completed. 



Mr. L. S. McLaine, Chief of the Division of Foreign Pests Suppression, 

 has been accumulating, at Ottawa, an interesting collection of insects found 

 on imported plant products. Largel}' through the efforts of Mr. R. C. Treherne, 

 Chief of the Division of Field Crop and Garden Insects, "The Canadian Insect 

 Pest Review" was established in April, 1923. This is a manuscript publication 

 prepared especially for the information of federal workers. Mr. C. R. Twinn 

 has assisted in the preparation of this review. 



For several years the same Division has prepared statements on insect 

 conditions for publication in the monthlj' "Fruit and Vegetable Crop Report" 

 publis-hed b}^ the federal Fruit Branch. 



The Vineland laboratory which is in the main building of the Vineland Hor- 

 ticultural Station and has been under the continuous direction of Mr. W. A. 

 Ross; an excellent insectary was erected in 1919. Mr. Ross during the 

 past ten years has established a close connection with the growers of the 

 Niagara Penninsula, and the result of the work undertaken has been of great 

 value to the district. The life-histories of such important pests as the Pear 

 Psylla, Psyllia pyricola Forst.; the Apple Maggot Rhagoletis pomonella Walsh.; 

 the Potato Leaf-hopper, Empoasca mali Le B.; the Plum Spider Mite, Parate- 

 tranychus pilosus C. & F.; the Grape Leaf-hopper, Erythroneura comes Say; 



