Karl Foord, Extension Educator - Horticulture
The nylon apple maggot barriers are doing a pretty good job in protecting the apples from the attack by maggots (Photo 1). One fly did manage to oviposit her egg through the nylon mesh. The apple was ruined but at least the maggot was trapped in the barrier sock (Photo 2). Many of the unprotected apples were attacked at the flower end of the fruit (Photo 3). One of these fruits has been cut open to reveal the small apple maggot seen in the lower right half of the right hand slice (Photo 4). Photo 5 is a close up of the same slice. It is obviously critical to get these barriers in place prior to the arrival of the maggots.
The best system would have been to remove all the unprotected apples and give the maggots no chance to feed on any apples. Alas time did not permit. However, it would be best to remove the small damaged apples and get them off-site and not allow the population to build.