Meteorus wasp approaches a caterpillar host. Biocontrol agent:
The larvae of at least 21 moth species are host to Meteorus pulchricornis, a small parastic wasp. These include native insects such as the kowhai moth and the kawakawa moth - whose larvae make the distinctive holes in kawakawa leaves - and also pest moth caterpillars such as the tomato fruitworm. It also attacks the larvae of the Tropical grass webworm which has caused serious kikuyu pasture damage north of Kaitaia.
What do they look like?
The adult Meteorous pulchricornis measures about 4mm long and is a semi-transparent yellow/orange colour.
What about their life cycle?
The egg hatches into a larva that feeds and develops inside the caterpillar, eventually killing it. The larva leaves the caterpillar to pupate in a cocoon of 3-4mm long suspended from a distinctive, predator-deterring thread anchored to foliage.
Where are they established?
It was first found in New Zealand in 1996, and is now generally resident in cropping areas around the country.
How are they best harvested for redistribution?
Collect parasitized caterpillars and place in two-litre ice cream containers, along with some of the plant material on which the caterpillars have been feeding. The wasp larvae will emerge and form the cocoons, which may then be transferred to new sites, along with any wasps that may have emerged. Alternatively, pupae can be collected from plants infested by kowhai moth caterpillars, including kowhai, gorse, lupin, broom and genista.