Biocontrol agent risk assessment: A surprise find ...

Abstract


 
 
 A Better Border Biosecurity (B3)-funded project investigating the interactions between the self-introduced generalist hymenopteran parasitoid Meteorus pulchricornis and native parasitoids of lepidopteran larvae throughout Auckland involved three years of eld work. The last eld trip was to Te Hauturu-o-Toi (Little Barrier Island) in December 2016 to survey some of the least-modi ed native forest in the North Island. Forty Cleora scriptaria moth larvae were collected by hand from Piper excelsum (kawakawa) host plants into ziplock bags, with a small amount of leaf material to support feeding. They were transported to the laboratory and reared to fate in a temperature-controlled room. Of the 40 larvae collected, twelve were parasitised by M. pulchricornis. This is the rst record of M. pulchricornis from Te Hauturu-o-Toi. In addition, nine larvae were parasitised by an undescribed parasitoid (Casinaria sp. 3). This new species may be endemic only to Te Hauturu-o-Toi, but it may have been out-competed on the more modi ed habitat of mainland Auckland, and found refuge in a more pristine environment. Further surveys of island and mainland parasitoid complexes would provide better baseline risk-assessment data prior to border invasions or importing biocontrol agents.