Fruitful Land

Apple Maggot (Rhagoletis pomonella) is a direct pest of apples that can be a serious pest for the homeowner. The adults are black flies with about 5 cm long with black stripes resembling an "F" on its wings.

Adult flies lay eggs on apples in mid to late June that cause scars on the fruit. Peak emergence can occur inmid to late July. The adults spend a few weeks feeding, then the females lay their 300 eggs over the next 30 days. You can see how effective it is to trap the females before they get started. Next eggs, if any were successfully laid, hatch and the larva emerge and dig brownish red trails through the flesh of the apple.

Red sticky spheres are the best way to monitor populations. If you only have a few trees you can trap out the maggots flies and avoid any pesticides. You should place 1 trap per 100 apples. This is  about 5 traps per tree. This method requires some knowledge of the pest and some attention to the timing and maintenance of the traps. It is somewhat gratifying though to actually see the maggot flies stuck on your traps and not flying freely in your orchard.

Learn more on Apple Maggot  from these online resources

Apple Maggot Management in Home Orchards from the University of Minnesota

Apple Maggot fruit IPM Fact Sheet from the University of Michigan