Apple Maggots –
Apples, Pears, or Apricots Have Worms
Although they are hard to detect on the outside, sometimes white worms eat the flesh inside maturing fruit, digging tunnels into the flesh. These are apple maggots, the larvae of the apple maggot fly. They are white or yellowish and measure 1/4 inch long.
The adult fly is also 1/4 inch long. It is black with yellow legs, yellow markings across the abdomen, and bands that zigzag across the wings. These flies lay eggs in punctures in pear or apple skin.
Apple maggots spend the winter in the pupal stage around the base of apple or pear trees. The adult flies emerge in midsummer, typically between mid-July and early August, and lay eggs on the fruit. There is only one generation per year.
The best way to control apple maggots is to reduce the number of apple maggot pupae from surviving the winter and then preventing the adult fly from laying eggs which become the worms harming the fruit.
October – start feeding birds especially chickadees, nuthatches, titmice, and wood peckers; the songbirds that eat the pupae of the Apple Maggot throughout the winter.
Late February – When temperatures are above 40F spray all your fruit trees with dormant oil (sometimes called volck oil or heavy horticultural oil). Pay particular attention to the bark in the trunk area so you suffocate.
March – Continue to feed birds but cut the ration in half. Those key songbirds will continue to chomp on Apple Maggot pupae.
April – Spread 3 to 4 inches of organic mulch around each tree out to the drip line being careful to have no mulch actually touching the trunk. This mulch will become habitat to ants, spiders, and many kinds of ground beetles, all of whom will kill Apple Maggot pupae
June – Hang spherical red sticky traps in each fruit tree. Keep them clear of surrounding branches so the flies can see them. Use two traps per tree for dwarf and semi-dwarf pear trees and four traps for standard trees.
As soon as you see more than five Apple Maggot flies stuck to the traps, spray the trees with Spinosad which kills the flies on contact. Spinosad will also kill the maggots eating into the fruit causing them to stop eating and die. Repeat with the Spinosad spray every two weeks for two more applications and then you should maggot free fruit.
September - Remove traps after harvest and clean them off with alcohol or some solvent and store them to be used again next year. Clean up all fallen fruit immediately. Keep the trees mulched through the winter.
