Published online by Cambridge University Press: 31 May 2012
Emergence of apple maggot adults, Rhagoletis pomonella Walsh, under field conditions at Guelph, Ontario, revealed that most maggots emerged from the apples between 2 July and 11 August. However, 12 of 673 emerged benveen 17 August and 16 September. Because this extended period of maggot emergence creates problems in visual certification of maggot-free export fruit, attempts were made to find a more effective trapping method than the use of bait pails for appraising maggot infestations.