WSU Tree Fruit Research & Extension Center

Tree Fruit Market Diseases

Thursday, November 23, 2017

WSU-TFREC/Postharvest Information Network/Tree Fruit Market Diseases/codlingmoth



Laspeyresia pomonella L.

The codling moth is one of the most serious insect pests of apples and pears. The fruits are injured by the burrowing of the larval or worm stage of the insect. The worms enter the fruits at the calyx, at the side, or through the stem end. After a short period of feeding just beneath the skin, the worms tunnel directly into the center of the fruit where they feed on the seeds and the core, leaving a mass of dark-colored frass and fragments of fruit tissues. When fully grown, the worms usually tunnel from the core to the side of the fruits, leaving masses of frass in the exit holes (top photo). The holes serve as portals of entry for fungi causing blue mold rot, alternaria rot, black rot, and other rot-producing fungi. A second type of injury, known as "sting injury" or "worm sting," consists in small, discolored, hardened, often depressed spots, usually with a tiny hole at the center. These spots are caused by larvae that have consumed a lethal dose of poison, but have managed to burrow a short distance into the fruit before death.

Codling moths winter as mature larvae in cocoons under loose bark of trees, in trash on the ground, and in orchard lug boxes. The worms pupate in the spring, and the adult moths begin to emerge soon after the trees have bloomed. Under favorable conditions as many as three generations of codling moths can develop in a single season. Insecticide spray programs will control codling moths. Recommendations of the State agricultural extension service or experiment station should be followed.

Codling moth injury
Codling moth injury

Codling moth larvae, Golden Delicious
Codling moth larvae, Golden Delicious

Codling moth larvae, Idared
Codling moth larvae, Idared

Codling moth injury, Golden Delicious
Codling moth injury, Golden Delicious

Codling moth injury, Golden Delicious
Codling moth injury, Golden Delicious

Tree Fruit Research & Extension Center, 1100 N Western Ave, Washington State University, Wenatchee WA 98801, 509-663-8181, Contact Us