Codling Moth

What it looks like

Adult codling moths are small and gray, with fine wavy lines across the wings and a shiny copper-brown patch near each wing tip. The caterpillars are pinkish white with a brown head.

After feeding in the fruit, full-grown caterpillars crawl down the tree and spin cocoons in bark cracks, under loose bark, and in debris at the base of the tree, where they spend the winter. They become moths in spring.

Damage

Codling moth is the most important insect pest of apples and pears. The caterpillars tunnel into the fruit to the core, leaving a hole filled with brown, crumbly droppings, and the fruit often drops early.

How nematodes help

The caterpillars sit in their winter cocoons for months, which makes them an easy target. Both Ecomask and Scanmask infect caterpillars in their cocoons. In European orchard trials, a fall nematode spray cut the next summer's fruit damage by about half.

How to apply

Treat with Ecomask from March to September. Fall and early spring sprays reach caterpillars in their cocoons on the trunk. Scanmask also works and does better in cool weather. Apply on a wet, mild evening, above about 50°F.

Spray the lower 5 feet of the trunk and the base of the tree, where the cocoons are, and keep the bark wet for several hours afterward.

See How to apply for step-by-step directions, or use the calculator on the Ecomask Spray page to see how much you need.