The codling moth (Cydia pomonella) is a notorious, worldwide pest of apple and also occasionally of pear, quince, peach and other fruits. It is very common in Europe.
Life cycle and appearance of Codling moth
The adults have a wing span of 15-22 mm, blackish-brown forewings, suffused with ash-grey and a large, metallic, bronzy black ocellus on the hind part. The hindwings are brown.
The eggs are about 1.3 x 1.0 mm, and whitish opalescent when laid. Later, the developing embryo is visible as a red ring. The larvae are up to 20 mm long, initially whitish and later pale pinkish white, with a brown head and a pale anal plate. The pupa is 8-10 mm long and yellowish brown to dark brown, with several hook-tipped bristles at the tip.
In Europe, the first generation adults appear from mid May onwards. Eggs are laid singly on leaves or developing fruitlets and hatch after 10-14 days. The first instar larvae burrow into the fruitlets, often through the calyx. Larger fruits are usually entered through the side or near the stalk. The larvae get through five stages in approximately 4 weeks. Fully grown larvae leave the fruits and spin cocoons under loose bark, cracks in trunks or supporting stalks, or other places.
Depending on the climate, there are one, two or more generations per year. The fully grown caterpillars of the last generation overwinter and pupate in spring. Larvae still in the apples at harvest can often be found in cracks in apple boxes or other places in the store.
After invading the fruit, the larvae first form a small cavity just under the skin. The entry hole can be seen and is usually plugged by dry frass. The larva then burrows towards the core and eats a large proportion of the flesh, leaving behind brown frass. The entry point is then greatly enlarged as the tissue beneath is eaten away. Infested fruits usually ripen prematurely and drop off.