Codling moth is the main cause of damage to apples and pears in the United States and they are found extensively throughout the Treasure Valley, year after year. You will see the codling moth fluttering around each spring and they themselves are not the cause of fruit damage but the larva itself that creates havoc with apples and pears.
The best time to find them in your fruit orchard is during the night and early morning hours. Codling moth has been known to attack cherries, apricots, nectarines, and peaches, however this is uncommon. Many folks forget about spraying crabapples when attempting to control this insect; however it’s often a host for codling moth. An adult codling moth is approximately one-half inch in length and the color of an adult is grayish in appearance with slightly narrow bands of creamy white and brownish-gray colors. The tip of each wing is coppery in color. When night time temperatures are approximately 62 degrees, the codling moth is most active and may lay eggs on both the leaves as well as the blossom. Codling moths can produce egges two or more times a year and a female codling moth can lay between 25 to 100 eggs and they will begin hatching out as our temperatures warm up. The time frame is typically between 10 and 14 days from egg to hatch. As they hatch, they will burrow into the fruit. As you inspect an apple, it’s not uncommon to find several larva in an apple. The larva is creamy white when young and can change to a slight pinkish color as the season progresses. The larva will have a rather large brownish-color head. Later, the larva leaves the fruit and creates a cocoon where they change to an adult. The codling moth (caterpillar) will spend the winter in this cocoon, pupating in early spring. The cocoon may be found on the fruit tree or on the ground beneath bark or other debris. Although uncommon in our area, it’s possible for codling moths to mate more than once in a season.
Some gardeners rely on codling moth traps which contains a pheromone to attract them. Codling moth traps may eliminate a few codling moths, but certainly not all of them. You should provide at least one trap for each tree and replace them once a month. Of importance is that no matter how great you do at controlling them on your property, if your neighbor doesn’t effectively control them, your efforts may not be completely satisfying.
We have found that codling moths attack the fruit at various stages of growth. They often lay their eggs in the blossom of apples and pears, causing damage throughout the summer and then bore out in the fall. To prevent this from happening, spray the blossoms with Ferti-lome ‘Fruit Tree Spray’ when approximately 10% of the blossoms are open and again when 90% of the blossoms have fallen from the tree. When applying any insecticide, fungicide or herbicide, you should always wear goggles, a long-sleeved shirt and protective gloves or other protective gear. As a note of precaution, you are required to follow Federal Regulations when using any product that is labeled with their warning. Codling moth may also bore into the fruit at a point called a ‘Sting”. This may be found when closely examining the fruit and noticing a small amount of excrement at the entry point on the fruit. Throughout the season, codling moth larva will tunnel the fruit and feed on the seeds.
Another recommendation for controlling insects on listed fruit trees is Ferti-lome systemic ‘Tree & Shrub’ insect control. On cherries and other fruit listed on the package, this product has been found to be effective at controlling many insects, both on fruit trees as well as other shrubs and trees. Controversy has arisen concerning the safety of neonicotinoids, an active ingredient found in this product. Reference is sometimes made to it perhaps killing bees. Always apply this product according to the directions printed on the container; we have found it to be as safe as many other products available. In part, this is due to the fact that when using this product on fruit trees, it recommends applying it to the trunk and surrounding soil of the tree, not where bees are typically found. Products including Insecticidal Soap, Neem Oil, and Spinosad will kill bees if sprayed directly on a beneficial insect.