Apple Maggot: Expecting High Adult Emergence After Heavy Rains.

As we moved through the season from June into July we had no shortage of rainfall with over 7.00″ of rain in Highland for the month, providing ample soil moisture for apple maggot adults to emerge from the soil. However, adult populations have shown less then 2 per trap per week, quite low for this time of the season in an orchard with historically high populations. During July and early August proved to be warm and very dry with less then 1.5″ of rainfall. We did reach Apple Maggot threshold of 5 flies per trap, in a block of mixed variety apple in which we were monitoring baited red sticky spheres at the Hudson Valley Lab. The recent Tuesday rains have now provided optimum conditions for high adult emergence. Having refreshed and ready red sticky spheres out this week will provide important an monitoring tool for AM emergence. Certainly Ginger Gold and other early maturing varieties will be most susceptible as we near harvest over the next few weeks. Insecticide options can be found here.

The red spheres are very attractive to mature adult female AM flies, ready to oviposit. From work done by Chapman and Link, the apple maggot will first infest early apple varieties such as Ginger Gold, moving to later maturing varieties as the season progresses. Summer and early fall maturing varieties are particularly vulnerable, with thin skinned sweet and sub-acid varieties being most susceptible. These fruit should be protected upon trap threshold as they will be infested this week if emergence builds throughout the region from these recent and heavy rains.

Materials for management of the apple maggot should also be effective at controlling the codling moth (CM) as it continues to emerge this week.

The larva of the overwintering generation of Obliquebanded Leafroller should also be considered during the early part of next week.

Insecticides effective against both AM & CM include: