100 PROTECTION OF PLANTS — 1922-23 



Onion Maggot Control, 1922. — Mr. M. McEvoy, Rosemount, Que. 



Date sown 



Date 



of 



application 



Amount of 



material used 



per acre 



Labor 



Remarks 



4 acres below orchard 

 sown May 1st, 1922. 



May 24th. 



Mav27th. 



May 31st.. 

 June 6th. . . , 



June 11th.. 



20pans.4gaU 



20 pans. 4 gals. 



20pans.4gais. .. . 

 20p'an6.5gals. . . . 



20 pans. 5 gals. 



1 hour. . 



\ hour. 



i^hoiw. 

 14 hour. 



H hour. . 



Onions were sown with two 

 seeders one sowing much thicker 

 than the other, but there was a 

 very even strong stand of plants 



Adult flies were observed on the 

 20th. Four eggs were found on 

 trap onions on the 23rd. Adults 

 were observed on the pans on 

 the 27th. 



Pans evaporating very quickly. 



Thirty-seven adults found around 

 on pan. All pans gave high 

 counts of dead adults. First 

 wilting onions are now appear- 

 ing close to heavily infested 

 in area 1921. 



Fifty-seven dead adults found 

 around one pan. Onions are 

 looking splendidly and very few 

 appear to have been damaged 

 by the maggot. 



This -grower also treated another large block of onions four hundred yards further down his farm 

 and here again excellent control was recorded with the exception of one end of the block, which was 

 aaross the road from a heavily infested block ita 1921. Trap onions were not planted beside the bait 

 pens in this block and more plants wereinfested with the maggots than where the trap onions were used. 



The several species of cutworm were more prevalent than for many years 

 and completely wiped out the onion, carrot, beet and part of the turnip crops 

 growing in Mr. Paul Wattiez's garden in Outremout. Where this injury 

 occurred careful allowance was made so as not to confuse it with damage 

 caused by the onion maggot. 



One interesting observation on the poisoned bait which was noted by all 

 workers was the advantage of increasing the quantity of sodium arsenite to 

 one-half ounce per gallon. The greater strength killed the flies very quickly 

 and evidently accounted for the difference in the numbers of dead flies around 

 the pans. Repeated observations showed that the stronger solution pans 

 contained or had around them double the number of dead adults and where 

 two pans, one containing the standard solution of 3^ oz. per gallon and the 

 other }/2 oz. per gallon, the flies settled two to one on the stronger solution 

 pan. As the cost of sodium arsenite was onh' 65 cents per pound the increased 

 cost was only very slight per acre, and growers insist that the stronger solution 

 is preferable. 



