Goniozus jacintae, a parasitoid of leafrollers

Goniozus jacintae was probably already present in New Zealand when it was introduced in 1922 from Australia for control of lightbrown apple moth. However, it has also provided some biological control of brownheaded leafrollers. Further introduction of "Goniozus sp." in the period 1967-69 also included G. jacintae.

Goniozus is a genus of bethylid wasps which parasitise 3rd to 4th stage leafroller caterpillars. The larvae of the wasp feed externally on the caterpillar and are often seen in groups attached to the first abdominal segment. Goniozus ?antipodum was introduced to New Zealand in 1922 from Australia but is thought to have been already present in the country. It occurs commonly throughout New Zealand, and up to 8% of leafroller caterpillars have been found parasitised on apples in Auckland. Leafroller caterpillars often try to escape from attack by wriggling rapidly out of their leafrolls and descending on a silken thread. The adult Goniozus wasp has been observed to follow leafroller caterpillars down their thread and parasitise them, pulling them back up the thread to their leafroll.