1913 ENTOMOLOGICAL SOCIETY. 67 



EECENT WOEK ON THE APPLE "MAGGOT IN ONTAKIO. 

 William A. Eoss, Division of Entomology, Ottawa. 



This past season I devoted most of my time to an economic study of the Apple 

 Maggot in Eastern Ontario. In this investigation I had a very capable and help- 

 ful co-worker in Mr. Chas. Good, a Guelph student, who acted under the instruc- 

 tions of Mr. Lawson Caesar, Provincial Entomologist. I am sorry I cannot 

 eulogize my other co-worker, the weather man. He served chiefly to try my 

 patience by substituting rain water for liquid baits, by drowning larvae, and by 

 making everything wet and unpleasant. 



I have now the pleasure of presenting to you a report of the investigation. 



Emergence of Adults, Etc. In the Bowmanville orchard in which we did 

 most of our work, adults were in evidence from the first week of July to mid-Sep- 

 tember. (The period of emergence in our rearing boxes extended from July 6th 

 to August 20th). However, no egg laying was noticed until the third week in 

 July. 



Some entomologists have an idea that flies, developed from maggots which 

 infested early apples during the previous season, leave the soil before those 

 developed from late fruit larvae. However, this is merely a supposition and not a 

 fact. According to our daily record of emergence, adults bred from fall varieties 

 actually commenced to leave the soil before those bred from early Harvest apples. 



Adults in Confinement. Our attempts to study the habits of adults in 

 confinement met with every indifferent success. Two cages made of fly screen were 

 hung on trees and each was so arranged that a branch bearing apples was inside 

 it. We also constructed from the ground up a cage big enough to enclose a large 

 branch well laden with fruit. Adults were confined in these cages. However, in 

 place of observing these flies at work, we spent most of our time replacing their 

 dead bodies with other adults — all, with the exception of two females, refused to 

 live longer than four or five days in confinement. One of the exceptions completed 

 lier third week and the other lived four weeks. When fourteen days old 

 the latter was found in copula with a sexually mature male which we had 

 introduced into her cage. 7'wo days after this she tried to oviposit; however, on 

 this occasion and on all later occasions her attempts were ineffectual. She would 

 extrude her ovipositor, raise herself and go through ovipositing motions, but she 

 seemed to be too sluggish and lazy to pierce a passage through the cuticle, the tip 

 of her ovipositor would merely slide up and down the surface of the apple. 



I cannot understand why these confined flies did not respond in a more satis- 

 factory way to our care. They were not cramped for room (especially in the large 

 cage). They were provided with nourishment and moisture and lived under con- 

 ditions as natural as possible. 



Incubation of Egg. In ascertaining the duration of incubatiou of the egg, 

 we marked newly made egg punctures, then four, five and more days after marking 

 them we opened the punctures and examined the eggs. The average period re- 

 quired for incubation was six days, the minimum, four and three quarter days; 

 the maximum nine days. 



The fact that the rate of growth of the larvae keeps pace with the maturing 

 of the fruit was noted by us, but as this interesting feature of larval development 

 has been commented on so frequently, I shall not dwell on it. 



