Distribution of clover root weevil
Clover root weevil is very widespread in the Northern Hemisphere, including all of Europe and North America.
North Island
CRW was discovered in Auckland and Waikato in 1996 and has since spread throughout the North Island, advancing approximately 35 kms per year.
South Island
CRW was first discovered in the South Island in late January 2006, when a single CRW was caught in an experimental trap at Christchurch International Airport. Extensive sampling of nearby pastures in the following month found only two more CRW out of several thousand other weevils collected.
A much bigger and more firmly established population was discovered at Richmond, near Nelson, in April 2006.
Following publicity around the Richmond find, several suspected specimens were reported by members of the public. As of 25 August 2006, only one of these, at Rai Valley, has been confirmed as CRW (with CRW detected both at the northern end of the valley as well as to the south near Canvastown). The rest have involved damage by the little fringed weevil, Atrichonotus taeniatulus, which causes similar notching on clover leaves.
The only places we are sure CRW is established in the South Island are at Richmond and Rai Valley. Please inform AgResearch as soon as possible if you think you have seen evidence of it somewhere else!
