Biocontrol for Weevil in Southland

(Published on 24th November 2011)

Initially discovered in the Waikato in 1996, the Clover Root Weevil feeds exclusively on clovers and can severely reduce them from a pasture if left unchecked, removing the valuable contribution this plant makes to animal feed. 

Efforts to control the growing populations of the pest using a parasitic wasp Microctonus aethiopoides are now underway in Southland with initial releases taking place at Mataura and the Taieri Plain. Further wasp releases will take place in the same areas in the following months with the possibility of additional releases near Clydevale.

Colin Ferguson from AgResearch's Invermay Agricultural Centre has been monitoring the spread of the weevil in Southland and tells us;

"Essentially the weevil is well established on the Taieri Plain and reaching high numbers, it has patchy distribution from there to South Otago where there appears to be a concentration around Clydevale. It has also established around Gore, Mataura and Wyndham." 

Environment Southland has helped fund the biocontrol agent and also helped coordinate a farmer lead industry group. Additional support has come from NZ Landcare Trust, AgResearch, DairyNZ and Beef & Lamb NZ.

The Clover Root Weevil is a significant pest and farmers should be alert to its presence. Colin Ferguson says:

"Large numbers of adult weevils are appearing now in pastures where it is present and I expect a significantly obvious presence in the next few months – and a lot of new sightings."

A useful website has been created to provide information including useful pointers that will help with identification... more info>

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