1864 EXPERIMENTAL FARMS 



5 GEORGE v., A. T915 



centage of destroj"ed seed in the fourteen samples was 10 per cent. As far as we know, 

 these are the tirst records of the insect having been found in clover seed grown in 

 -Canada. 



The Carrot Rust Fly {Psyla rosae Fab.). — In the Maritime Provinces the car- 

 rot and parsnip crops were considerably reduced by the larvae of this destructive insect. 

 In some districts in Prince Edward Island and New Brunswick, whole plantations 

 were affected and the crops practically ruined. Correspondents who applied kei'osene 

 emulsion to the rows of young carrots reporteil that little loss was occasioned by tlie 

 maggots. 



Thrips. — The occurrence of ^"white-eared" oats in Saskatchewan and Alberta 

 was again reported. It is evident that this injury, which my investigations have 

 shown to be most frequently due, in eastern Canada at least, to the Common Grass 

 Thrips (Anaphothrips striatus Osborn), is fairly widespread. In Alberta, Banner oats 

 were particularly affected; it is usually found that the late-flowering varieties suffer 

 most from Thrips injury.^ 



Root Maggots. — From all parts of the Dominion, reports have been received of 

 the destruction of cabbages, cauliflowers, onions, turnips, radishes, beans, etc., by the 

 different species of Root Maggots (Phorhia spp.). Experiments on their control have 

 been continued at Ottawa, and Mr. R. C. Treherne has carried on experiments at 

 Agassiz, B.C. As the experimental studies on the control of Phorhia hrassicoe and 

 P. ceparum have been continued each year since 1910, it is hoped that it will be 

 possible to issue a bulletin on the subject durin,g the next twelve months, after 

 •another season's work. 



Wheat Midge (Diplosis tritici'l). — Mr. Treherne studied this insect, which was 

 ■very prevalent at Agassiz, B.C. Particular attention was paid to the occurrence of 

 the larvse in the dift'erent varieties of wheat and barley. In 1905 and 1906 the crops 

 of spring wheat were seriously affected by the midge in the I^ower Eraser valley, and 

 in spite of discontinuing the growing of spring wheat for a year at Agassiz and in 

 the valley in 1907, the insect was again present in 190S. 



In.juries to Winter Wheat in Alberta. 



In my last annual report (p. .507) reference was made to the discovery of Eel- 

 worms in injured wheat plants from southern Alberta. This matter was more fully 

 investigated by Mr. E. H. Strickland, our Field Officer in Alberta, during the past 

 summer, and in September I visited the districts where the injuries occurred. The 

 ■extent of the injuries may be gathered from the following facts which I obtained in 

 certain of the localities visited, which were typical of many others. Mr. W. J. Glass, 

 of Macleod, Alta., one of the best growers of winter wheat, usually obtains an average 

 yield in good seasons of 33 bushels per acre. In the fall of 1912 T August) he seeded 

 ■220 acres to winter wheat; cutworms destroyed a portion of the crop, but the greater 

 portion died as a result of the injuries that we are investigating. Accordingly, he 

 reeeoded 100 acres to oats, and from 97 acres of winter wheat which was left he 

 thrashed out only 162 bushels. Mj. Becker, of Pincher Station, had 400 acres sown 

 to winter wheat, and in 1913 it averaged about 7 bushels to the acre instead of about 

 30 bushels. In one section of the infested land, only 150 bushels were thrashed off 

 100 acres. Similar losses were reported from this and other districts in southern 

 Alberta. 



The constant association of Eelworms with young injured plants led us to con- 

 clude in 1912 that they were responsible for the injuries. A further detailed study 



'- See C. Gordon Hewitt, " Sterility in Oats caused by Thrips." Journ. Econ Ent., vol. 7, pp. 

 211-518. 1 fig., .1 pi., 1914. 



Ottawa. 



