Success battling the evil weevil

Adult clover root weevil

AgResearch’s worldwide search for
an effective biocontrol for the devastating clover root weevil (CRW) has paid off for our agricultural sector – with an introduced wasp having a substantial impact on the destructive pest at established sites.

CRW is a significant threat to forage clover. Clover is a crucial component of New Zealand farming systems as a feed for stock and through its ability to fix nitrogen in soil, and is worth an estimated $3 billion a year to our economy.

The AgResearch-discovered wasp attacks adult weevils, rendering females sterile, and breaking the life cycle. Since its first release in 2006, the biocontrol has proved hugely successful, spreading well in the North and South Island.