Optimising methods for collecting Hymenoptera, including parasitoids and Halictidae bees, in New Zealand apple orchards

Abstract

We monitored four groups of Hymenoptera in organic apple orchards in New Zealand in order to assess different trapping methods. The factors assessed were trap type (pan traps vs. sticky traps), trap colour, preservative type and trap position within the orchard with regard to the shelterbelt.Yellow sticky traps were the most effective trap type overall for sampling the order Hymenoptera, and the two parasitoid species Anagrus sp. and Aphelinus mali (Haldeman). White pan traps were best for sampling native bees from the family Halictidae. Choice of preservative in the pan traps significantly affected the catch of Hymenoptera overall and Halictidae. Most Hymenoptera were more abundant within the orchards than at the shelterbelt, except the Halictidae, which were more abundant at the shelterbelt. The results support the notion that Hymenoptera surveys should be conducted using methods appropriated for targeted taxa, due to differences in their behavioural responses and ecological trends.