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Four experimental releases of the parthenogenetic strain of Microctonus aethiopoides from Ireland were made in early 2006 in the Waikato Manawatu (two sites) and Hawkes Bay By early winter establishment was confirmed at all sites with parasitism levels exceeding 10 in the target host Sitona lepidus a serious pest of white clover in New Zealand Subsequent monitoring revealed considerable betweensite variation At the Hawkes Bay and Manawatu Feilding sites where overwintering weevil adults were still present in October over 30 parasitism was found in newly emerged weevils in December 2006 In contrast at the Waikato and Manawatu Bulls sites where there was no overlap of host generations parasitism was below detectable levels during spring and early summer but recovered subsequently The Irish M aethiopoides appears to have four generations a year and diapauses over winter as a first instar larva Following the initial success releases have commenced in other regions

The bacterium Serratia entomophila is a naturally occurring pathogen causing amber disease of the New Zealand grass grub (Costelytra zealandica) A novel granular formulation of S entomophila Bioshieldtrade; was applied to 18 pasture sites in a largescale programme to demonstrate efficacy against grass grub No significant difficulties were encountered in application of the granules through conventional machinery There were high populations of the applied bacteria in soil within the first week of application and within 6 weeks of application there was an average of 3 x 104 viable S entomophila of the applied strain per gram of soil This resulted in a significant (Plt;005) 20 increase in the incidence of amber disease in the treated grass grub populations compared to untreated populations Successful establishment of the bacteria in the soil and target population following Bioshieldtrade; granule application was demonstrated on a wide range of sites under various farming conditions