Pear: Codling Moth

Problem
Fruit is blemished by small holes surrounded by dead tissue. A brown, crumbly material that resembles sawdust may surround the holes. Brown-headed, pinkish worms up to 1 inch long may be found in the fruit. The interior of the fruit may be dark and rotted. Many pears drop prematurely.

Analysis
(Laspeyresia pomonella)

This worm, the larva of a small gray-brown moth, attacks apples, quinces, and several other fruit and nut trees in addition to pears. The moths appear in the spring, and lay their eggs on the leaves, twigs, and developing fruit. The eggs soon hatch, and the larvae that emerge tunnel into the fruit. They feed for several weeks, then emerge from the pears, often leaving a mass of dark excrement on the skin and inside the fruit. After pupating in sheltered locations on or around the tree, another generation of moths emerges in midsummer. Pears may be damaged by worms continuously throughout the summer. In the fall the mature larvae spin cocoons in protected places, such as under loose bark or in tree crevices. They spend the winter in these cocoons and, with the warming temperatures of spring, pupate and emerge as moths.

Solution
Once the worms have penetrated the pears, it is impossible to kill them. To protect uninfested pears, spray with an insecticide containing malathion, diazinon, or carbaryl at intervals of 10 to 14 days as directed on the label. Remove and destroy all fallen pears, and clean up debris around the trees. Next spring, spray 10 to 14 days after petals have fallen, according to label directions.