COMMON NAME: Codling Moth or Apple Worm
SCIENTIFIC NAME: Carpocapsa pomonella
DESCRIPTION:
Adult - Grayish-brown moth with irregular golden-brown lines on the forewings and paler, fringed hind-wings. Wing spread of about 1/2 to 3/4 inch. Usually found flying at dusk or early evening. Larvae - Pinkish-white caterpillar about 1/2 to 1 inch long with a brown head.
Pupae - Found in a silken cocoon located in bark crevices, orchard debris, in fallen fruit, or other protected place.
Eggs - Single, flat, white eggs are found on the upper surfaces of leaves, on twigs, fruit spurs, or developing fruit. They hatch in 5-20 days.
PLANTS USUALLY AFFECTED: Apples, pears, quince, and walnuts.
TIME OF YEAR: From early spring to fall. In Cochise County, Codling Moths usually produce three generations per year. The moths lay large numbers of eggs starting when air temperatures exceed 65? F for two or more consecutive days. They do not move about when the weather is too cold, wet, or windy. You can start looking for them in April or May (or a very warm March). The other two generations should appear in six-week cycles in about mid-July and mid-August.
PROBLEMS CAUSED: The overwintering larvae pupate when the weather starts warming up and then the newly emerged adults lay their eggs on the developing fruit blossoms. Upon hatching, the larvae enter the fruit (usually by way of the calyx cup at the blossom end, but they can enter anywhere) and tunnel directly to the center of the-fruit. They devour portions of the fruit and seeds and then tunnel their way back out, leaving behind masses of brown excrement. The fully grown larvae then travel to the tree bark (or other hiding place) to pupate and start the whole cycle all over again. The last generation of the season will overwinter in the larval stage in a protected place.
PEST IDENTIFICATION: Look for buds and/or fruit with small holes in them or early drop of immature fruit. Check trees and surrounding debris for adults, pupae, larvae, or eggs. Ripened fruit that is cut open will reveal the tell-tale entry and exit tunnels and excrement.
CULTURAL CONTROLS: Cultivate healthy trees. Remove and destroy immediately any infested fruit. Clean up the area of any debris that could be used as a hiding place for developing pests.
COMPANION PLANTING OR TRAP PLANTS: None known.
MECHANICAL CONTROLS, BARRIERS, AND TRAPS: Hand pick and destroy any eggs, larvae, or pupae that you can find. Hang sticky traps and/or pheromone traps at eye level when the trees begin to bloom. The traps will physically decrease the pest population as well as act as an "early warning system" to use with a timed spraying program. Put sticky bands, corrugated cardboard or burlap around the trunk of the tree to trap larvae (check frequently). Use bug lights to "zap" adults. Prepare bait cans using nine parts water, one part molasses, one part honey, and a little yeast (change weekly). Carefully scrape off loose bark. Use a hard spray of water or a soap (like Ivory) and water solution (1-2 TBS per gal. of water) to wash the trees and dislodge the pest. Destroy immediately any insects you find.
REPELLENTS: Try "bug juice" made from adults or larvae. Nasturtiums planted at the base of the tree may repel the pests and in any case don't do any harm, look nice, and are eatable.
NATURAL CONTROLS: Encourage birds, (especially woodpeckers), bats, toads, and lizards to hang around and hopefully they will dine on your pest population. Trichogramma wasps parasitize the eggs. Don't destroy the parasitized eggs if you happen upon them.
BIOLOGICAL INSECTICIDES: Bacillus thuringiensis can be used, but since the larvae spend so little time feeding on the surface, you would have to spray it at exactly the right time to catch them as they start to eat their way into the fruit. Apply it about one week after the temperatures start staying above 65?F, about 10-14 days after petal fall, or after your traps start catching at least 15 moths in a one week period. Ryania is very effective also, but because it also kills the bees needed to pollinate your trees, do not spray this insecticide until after petal fall.
CHEMICAL CONTROLS: Call your County Extension Agent or staff for current recommendations. Check at your favorite garden supply store or nursery to see what they have available. Remember to check the label to make sure that the Codling Moth is a listed target pest and FOLLOW THE DIRECTIONS EXACTLY. When it comes to pesticides, more is NOT better!! Wear protective clothing, watch out for non-target plants, pets, children, and other living things. Wash your skin and clothing after application, and take care not to get the substance into your eyes, mouth, or breathing passages.