Codling Moth Identification

Adult Moth

The adult moth is about 10-12 mm long. It is mottled brown and grey in colour with bronze-coloured bands on the end of its wings. It is relatively rare to see an adult codling moth in flight. They generally fly at dusk and usually will stay close to the host tree. It is more common to locate the damage caused by the larvae to the fruit.

Larvae

It is the larvae of the codling moth that causes the damage to the fruit of host trees. Each larva is about 12-20 mm long. It is pinkish-white in colour with a black or mottled-black head.

Damage

The damage caused by the codling moth larvae is quite distinctive. The larvae burrow into the fruit, tunneling toward the center, where they feed on the seeds. As the larvae tunnel inwards, they push their excreta (called "frass") out behind them. The frass builds up in the tunnel and protrudes out of the entry hole.

Cutting open fruit infested with codling moth reveals the tunnel created by the burrowing larva, as seen below. The area around the feeding tunnel turns brown, showing signs of rot.

The larva can often be found in fruit when the fruit is cut open. However, if it is a new entry, the larva will be quite small and can be difficult to see. Generally, the beginnings of a feeding tunnel, along with some amount of frass buildup, can still be seen. Once the larva has matured it will exit the fruit. Exit holes in infested fruit may be evident.

Be aware that entry holes may be present on the calyx end of the fruit, making it more difficult to spot.