Q. As the apple maggot larvae live in the ground, is there an effective treatment to apply before they hatch? Is it time to start spraying my apple trees for the apple maggot?
A. This is a timely question since today’s Insect Alert is for the Apple Maggot. The larvae have been in the dormant pupae stage over the winter and are in the process of emerging from the ground as adult flies as you read this column. The first line of defense is laying out tarps under the trees in the fall to prevent infected apples from reaching the ground and releasing the larvae. The next step is larvae control. A specific species (Steinernema feltiae ) of beneficial nematode has been found effective for control of larvae in the soil. These beneficial nematodes are available online and sometimes can be ordered through garden centers. To determine presence of the adult flies (for the purpose of spraying) use either the sticky red apple traps or the yellow sticky traps. There is an organic spray made from kaolin clay (used in the food industry for its anti caking effect) and sometimes goes by the trade name Surround WP Crop Protectant. You can also monitor and manage the adults flies using the Apple maggot traps and lures None of these controls are perfectly effective so I always suggest protecting some of the fruit with plastic bags. Tie them around the fruit to prevent the flies entry. Be sure to leave enough room for developing fruit. This is an insurance policy for some larvae free eggs.