The Bug Box: Coddling moth

Scott Bauer, USDA

J. Brunner

This bug is creeping around your property. He may be friend or foe.

Name: Cydia pomonella

Alias: Coddling moth. This is the worm referred to in the joke “What’s worse than finding a worm in your apple? Finding half a worm in your apple.” Adults are a brown moth that lay eggs on fruits or leaves of fruit trees. Once the egg hatches, the tiny larva tunnels into the fruit, feeds and matures and then emerges as a much bigger larva. It pupates and finds a mate outside of the fruit. It can produce one to five generations a year, depending on temperature and growing season. If the winter is too cold, as eastern Idaho often sees, pupae do not usually survive the winter. Unfortunately, they can travel a long way in the wind, making them a problem year after year regardless of how cold our winter is.

Crimes: Larvae tunnel through pome fruit (apples and pears) where they can feast like royalty away from predators. Affected fruit is unmarketable.

Redeeming Qualities: Additional protein in your fruit diet

Sentence: Many over-the-counter insecticides are labeled for codling moth control. Sinosad, Carbaryl, Permethrin and Malathion are the most common. Usually an application 10 days after petal drop will control the population for the year, around late May to early June. Another generation can emerge and a second application may be needed around mid-July. If you are seeking to avoid chemical options, you will have to accept a certain percentage of crop loss. There are parasitoid wasps that will kill codling moth eggs, reducing their numbers dramatically. There are pheromones that can be exposed in an orchard to prevent the moths from mating and laying eggs. There are also pheromone traps, which are really more for monitoring purposes, but could prove useful for a homeowner with one or two trees.

For more information on dangerous and beneficial bugs, call UI Extension educator Joseph Sagers at 208-270-4031 or email