Manage codling moth

If you have an apple tree, crabapple, pear or quince, it’s highly likely that you’ve come across codling moth (it may also affect walnut and stone fruit trees). It’s a serious pest that can potentially destroy all your fruit. The adult codling moth lays its eggs on or near the fruit. When the larvae hatch, they chew a channel into the fruit core. The entrance holes are initially small, so may go unnoticed, but as the larvae grow, so do their tunnels, as they feed and push excreta to the surface. They also usually chew a hole on their way out, and may munch on neighbouring fruit.

Once they’ve had their fill, the larvae work their way down the branches and trunk in search of a spot to spin a cocoon and pupate – a crevice, loose bark or in the ground. Two or three generations appear over the growing season. The last generation stays in their cocoons for winter, then completes pupation in spring, ready to take advantage of the next crop.

A mix of organic strategies can be put in place to manage this pest and minimise damage. Regularly remove flaking bark, and clean out leaf litter in branch crotches to reduce hiding places. Consider installing corrugated cardboard bands around the base of the trunk. These provide ideal alternative hiding places for pupating larvae, and can be removed, destroyed and replaced regularly to significantly reduce pest numbers. In winter, saturate the trunk with an oil-based spray to destroy any overwintering larvae.

During the growing season, inspect your trees weekly and remove any infected fruit. These can be fed to poultry, or you can place them in a black plastic bag and leave them in the sun to cook the larvae before adding them to the compost.

One of the most effective control measures is exclusion. Entire trees can be covered with pest-exclusion netting to keep moths out. Alternatively, cover individual fruits with pest-exclusion bags. Install these as soon as the fruit sets, then continue with the other controls mentioned.

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