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The Permacultivator - Journal of Cool Climate Permaculture
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Controlling Codling Moth

By Alan Broughton of the East Gippsland Organic Agriculture Association

One of the very worst pests that an orchardist or gardener is faced with is codling moth. It affects apples in particular, but also pears and quinces, making the fruit unpalatable. It is a hard pest to control because once the grub is inside the apple it is safe from all predators and all but the strongest systemic sprays that poison the fruit itself.

You can, without a big effort, produce fruit with neither the grub nor the insecticide. There are several control measures you can take. You’ll get the best results if you take all of them, but any one of them will help. You need to know a little about the habits of codling moth in order to strike at the times that it is most vulnerable, that is, when it is outside the apple.

During the winter the grubs hibernate either in the litter underneath the tree or in crevices in the bark. In the spring they pupate quickly and the moths hatch out. The males fly away to find a mate; the females can’t fly at all, but flutter or crawl up the trunk to where the apples are starting to form, often at flowering time. The female waits for a male to find her, then they mate and she lays her eggs on the twigs or leaves or on the forming apple. As soon as the eggs hatch the grubs burrow into the apple and feed there until they are mature. Then they drop to the ground and find a place to pupate, in the leaf litter or in crevices in the bark. There are three generations in a season.

The easiest method of attack is to run poultry in the orchard. Chooks will search for and destroy pretty well 100% of grubs and pupae on the ground. They will also dispose of all fallen fruit which is often infected. Sheep and rabbits will do that too. Some people I know have their own orchard infested with codling moth, which they do nothing about, but beside their road is a wild apple tree which produces loads of small but delicious fruit, unaffected by codling moth. I think the rabbits are responsible; perhaps birds help too and there might be other factors. With animals clearing up the ground layer, then a large part of the problem is solved.

If there are still a lot of grubs it is because they are pupating in the trunk and branches of the tree. This happens especially with older trees with rough bark. In this case, wrap corrugated cardboard around the trunk and main branches. This provides a perfectly shaped place for the grub to spin its cocoon. You need to do this from December to May; remove the cardboard periodically and burn it. Also you could remove the loose bark from the trunk that they might hide under. Another method is an ancient one. Wrap sticky tar paper around the smaller branches to catch the female moths as they make their way to the fruit to lay eggs.

You can, as a last resort, spray the female moths with pyrethrum, a safe insecticide allowed in organic agriculture, between the time they emerge from their cocoon and the time they lay their eggs; but you are in danger of killing insects you want like bees or ladybirds. In order to tell when the females are active, place a mixture of molasses and water with a little port wine in jars in the tree. Place a 5mm mesh over the top to keep out larger insects. This attracts the males, and if the males are active the females are too. When you find males trapped in this mixture, then it is time to spray, just after sundown that day. You need to check every day to see when they are active. Aromatic herbs such as Tansy, Lemonbalm and Southernwood are also good for repelling the insects, and are very easily grown and will help discourage codling moth.

J21 Aug98