Worms In Your Apples?

It is such a satisfying experience to succeed in up into a fruit tree and pluck a shiny apple from a branch. But if you’re taking an enormous, juicy bite and see that the remaining apple in your hand has brown yuck and half a worm inside — and you only swallowed — it’s going to be time to require out the artillery!

The codlin moth lays its larvae on the developing fruit and leaves of apples and pears, and it also can attack walnuts. When the eggs hatch, the young caterpillars prey on the surface of the fruit for a couple of days, then burrow into the middle. They feed about three weeks, then tunnel out of the fruit and find an area to spin a cocoon. 

Biological control has been so successful for codlin moth that chemical pesticide use has been greatly reduced. Several effective, non-chemical techniques are available for home gardeners. These include the care of trees and fruit, trapping techniques, and beneficial insects. For best results, use a mixture of techniques.

Identifying Codling Moths

The codlin moth may be a gray moth 1/2 to 3/4 inch long with mottled gray wings that blend well with most tree bark. the ideas of the wings are marked with copper lines and a gold or bronze spot. The larvae are white to light pink “worms” with a dark brown head. Though we all recognize “wormy” apples, the larvae are literally caterpillars. A mature caterpillar is about 3/4 inches long.

codling moth

Codling moth photo by Scott Bauer, USDA Agricultural Research Service, Bugwood.org

You need to know their Life Cycle to successfully manage codling moths. They spend the winter as a caterpillar during a cocoon, usually under loose bark on a trunk, debris under the tree or in another protected spot. Adults emerge from the cocoon in April or May. The females lay eggs on leaves and little fruit for a few months. The moths are only active a couple of hours, before and after sunset, and that they mate when the sunset temperatures exceed 62°F. After mating each female deposits 30 to 70 tiny, disc-shaped eggs on fruit, nuts, leaves, or spurs. After the eggs hatch, young larvae hunt down and bore into developing fruit or nuts. once they reach full maturity they leave the fruit and drop from the trees to look out pupation sites and continue the life cycle within the soil or debris. Some crawl copy the tree to pupate in bark crevices. the speed of development will vary with temperature, proceeding sooner in warmer weather and climates. counting on the climate, codling moths can have two to four generations per annum.

Codling Moth Damage

If the codlin moth is left uncontrolled, they will cause substantial damage, often infesting 20 to 90% of the fruit, counting on the variability and site. The larvae penetrate into the fruit and tunnel to the core, leaving holes within the fruit that are crammed with reddish-brown crumbly droppings called frass.


Codling moths are often very difficult to manage, especially if the population has been allowed to create up over a season or two. it’s much easier to stay moth numbers low from the beginning than to suppress a well-established population. Begin implementing control measures early within the season.

If a backyard tree or orchard has high moth populations, it’s going to take several seasons diligently practicing these non-chemical control methods to scale back codlin moth damage to about 10 to twenty of fruit infested. If you’ve got nearby orchards or backyard trees that haven’t any control this will be a continuing source of codling moths.

Select varieties that are less vulnerable to damage, like early maturing apples and pears.

Prune trees to a height where the cover is straightforward to succeed in to facilitate non-chemical management of this pest.

Thinning when the fruit is little (the size of a marble or walnut) in order that there’s just one apple or pear per fruit cluster may be a good practice to encourage a bigger fruit size and supply less optimal laying sites.

Be sure to get rid of any fruit that has small holes made by codlin moth caterpillars. Composting doesn’t destroy all the caterpillars, so place during a bag and put in your trash. Collect dropped apples weekly because caterpillars move out of the dropped fruit quickly.

Check fruit on trees for signs of injury hebdomadally or two, beginning 6 to eight weeks after bloom and take away any worm-damaged fruit.

codling moth combat kit

Trapping Moths

Hanging pheromone traps in each susceptible fruit or angiospermous tree can help to scale back codlin moth populations but won’t completely eliminate damage. The pheromone lure mimics the scent of a female moth, attracting males to the sticky trap. To use pheromone traps, start in early spring, right at the start of bloom. Hang one to four traps per tree (depending on the dimensions of the tree) as high as you’ll reach.

Check the traps hebdomadally or two to get rid of dead moths and stir the adhesive to take care of its sticky quality. Refresh pheromone lures and alter the sticky bottoms every 4 weeks or sooner if they become too dirty to capture moths.

Trunk Banding

If you’d wish to do this as a supplemental control, try Tanglefoot Tree Care Kit. Or use the Paper Tree Wrap with the Sticky Stuff Sticky Coating. Remove the bands and destroy at the top of codling mating season, end of June or mid-July. make certain to crush and kill any pupae remaining on the trunk after you remove the band.

To help control the overwintering generation, put new trunk bands up in mid-August and take away and destroy them between November and January.


Excellent control is often achieved by enclosing young fruit in Maggot Barrier bags right the tree to guard them against the codlin moth. this is often the sole non-chemical control method that’s effective enough to be used alone and in higher population situations. However, it’s quite a time consuming, so this method is most manageable on smaller trees with fewer fruit. you’ll bag all the fruit on the tree or simply as many fruits as you think that you’ll need. confine mind that any un-bagged fruit is probably going to function a number and increase the pest population so it might be prudent to use sanitation and mass trapping to stay the population in restraint. Bagging won’t affect the maturity or quality of the fruit, but it’ll prevent full-color development on red varieties. Leave the luggage on the tree until harvest. the luggage also protects the fruit from sunburn.

To increase the success of this system inspect Surround, derived from kaolin clay. This product label says it forms a hostile barrier to insect pests without affecting fruit growth.

Codling Moth Virus

The codlin moth granulovirus, CYD-X offers efficient and selective control of codlin moth and is OMRI Listed. The virus is extremely specific to the codlin moth and can not affect native pollinators. The virus is out there from PVFS and will be applied weekly for the best results.

Worms In Your Apples?

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