Kazakhstan wasps to fight codling moths

3 News, Oct 31, 2012
by Charlotte Shipman

A species of Kazakhstan wasps has been released into orchards here in an attempt to help control one of the pipfruit industry's biggest predators, the codling moth.

It means New Zealand can keep its record of producing apples with the lowest levels of chemicals anywhere in the world.

The 1,000 Mastrus wasps released mark a new era in the control of a pest which has been here for more than 100 years.

The codling moth affects pipfruits like apples and pears, it's believed to have come to New Zealand from Tasmania or North America.

Plant and Food Research has spent the last four years on the Mastrus Wasp Project. The wasps are natives of Kazakhstan and are widely used in the United States to control the moth.

The female wasp attacks the cocoons of the codling moth by laying its eggs on the moth's larvae. When the wasp larvae hatch they feed on the codling moth larvae.

“We've spent the last two or three years testing it against a whole lot of other insects to make sure it only attacks codling moth and doesn't attack any of New Zealand's fauna and flora,” says Plant and Food researcher John Charles.

Controlling the moth costs the pipfruit industry around $10 million a year, but without control the industry wouldn't be a viable global export.

“There is zero tolerance of codling moth, particularly in some of the Asian markets,” says Mike Butcher of Pipfruit New Zealand.

If the wasps survive well in the Hawke's Bay the plan is to eventually release them to all apple and pear growing regions in New Zealand, and Mr Charles says it will benefit home gardens along with commercial orchards.

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