Recent introduction and establishment of the leafroller parasitoid Trigonospila brevifacies (Hardy) (Diptera Tachinidae) in Nelson

To assist the natural distribution of the leafroller parasitoid Trigonospila brevifacies to horticultural areas in the Nelson region 181 T brevifacies pupae and 329 adults were released in 1999 at four sites adjacent to apple orchards near Motueka Release material was supplied from fieldcollected parasitoids in Hawkes Bay and a laboratory colony held at the Mt Albert Research Centre in Auckland Successful establishment of the parasitoid was recorded at all four sites and at a nearby nonrelease site in 2000 In 2000 319 of fourth instar and older larvae were parasitised by T brevifacies while in 2001 parasitism was 1166 Important pest tortricid species including Epiphyas postvittana (Walker) (lightbrown apple moth) were among the hosts The successful establishment of T brevifacies in Nelson and its further natural dispersal will increase the potential for the reduction of economically important leafroller species by biocontrol agents