48 PROTECTION OF PLANTS, 1921-22 



ONION MAGGOT CONTROL 



In the Horticultural Gardens of Macdonald College 



I. — Plot consisting of one-third of an acre. 



Near old onion ground i-equiring 7 pans, block 1. 

 II. — Plot of one third of an acre in block II as a check two hundred feet away, 

 III. — Plot of one third of an acre in block IV seven hundred feet from the check 

 for the diagonal spray. 



Pans set out May 26th. Refilled 31st, June 6th, 14th. The first block 

 under the pan system was badly attacked as it was close to the old onion ground 

 of previous years. We estimated the damage at 15 — 20% on the one end. The 

 plot yielded 78 bushels. 



The second plot used as a check consisting of one-third of an acre was at- 

 tacked very lightly in spots. The damage was estimated at 5%. The total 

 yield could not be secured £ s 1-6 of the block was sold as bunch onions in August. 

 The other sixth yielded 45 bushels. 



The third plot for spraying was practically free of maggot as nearby were 

 planted two rows of seed onions which attracted the flies. This plot yielded 96 

 bushels. 



COST OF ONION MAGGOT CONTROL 



Cost of Pans, 20 per acre, at 73^c $ 1 50 



Sodium Arsenite, 2}^ oz at 60c lb , 10 



Molasses, 1}^ gallon at $1 35 1.69 



Cost of arranging and putting out pans, 2 hrs at 30c 60 



Cost of refilling pans 4 times, 4 hrs. at 30c 1 20 



Total cost of treating per acre $ 5 . 09 



THE DISTRIBUTION OF THE EUROPEAN CORN BORER IN CANADA 



AND THE UNITED STATES 



By W. N. Keenan, Assistant Entomologist, Division of Fore'gn Pests Suppres- 

 sion, Entomological Branch, Department of Agriculture, Ottawa. 



Out breaks of foreign insects usually do not occur until several years after 

 the species have been introduced into new environments. This rule seems to 

 have held in the case of the European Corn Borer, as the insect was not discov- 

 ered in the United States until 1917 (in the Boston vicinity), and its establish- 

 ment in Canada was not recognized until 1920, whereas there is almost con- 

 clusive evidence that it was first introduced in shipments of broom corn into 

 both countries about the vears 1909 or 1910. 



