Project details


Can sterile codling moths reproduce?
The dose of irradiation (200 Gy) applied completely sterilises the female moths and produces a high level of sterility in the male moths so that very few viable offspring are produced from wild-sterile matings.

How can I tell the difference between a wild and sterile codling moth?In the rearing facility, codling moth larvae (caterpillar) are fed a diet containing red food dye. This red dye remains in their bodies as adults. Squashing a sterile moth releases the bright red body contents so that they are easily distinguished from wild moths.

Do wild females still lay eggs after mating with a sterile male?
Yes, the female can still lay eggs but these either don’t hatch or produce sterile offspring.

Does a female codling moth mate multiple-times or just once?
In an orchard situation, female moths commonly mate 2- 3 times.

How many eggs does a codling moth lay?
The adult female codling moth typically oviposit 50-100 eggs, about the size of a pinhead, on the surface of the leaves, fruit or spurs when the average temperature is over 15 degrees in spring and early summer.

Codling moth eggs hatch after 10 days and the small caterpillars (larvae) emerge to feed on the leaf surface and make their way to the fruit. They burrow into the fruit and head for the core. They will spend about three to five weeks inside the fruit feeding and putting on body mass until they are ready to emerge and find a place to pupate. By this time they are about 20mm long and cream to pink in colour.