Spider biodiversity in crop orchard systems (Te kanorau koiora o te pūngāwerewere i roto i ngā pūnaha hauropi huanga kai)

Abstract

Spiders are the dominant, most abundant, and most diverse natural enemies in agroecosystems. They are generalist predators of insect pests, comprising many different functional groups. Spiders contribute economically to crop protection by reducing pest invertebrate numbers both by direct consumption, and non-consumptive effects. Despite this, very few studies on spider biodiversity in crop systems have been completed in New Zealand; moreover, there are no published data on spider biodiversity in New Zealand orchard systems. My master’s research aims to answer three questions: 1) What spiders are present in kiwifruit orchards? 2) How does the spider species composition change as native plantings are incorporated into the orchard? 3) What is the consumption rate of one to two spider species of key pest insects? I am addressing these questions through fieldwork and lab studies. During my fieldwork I am using a selection of spider sampling techniques including pitfall traps, active day sampling, active night sampling, and sweep netting. Samples are being collected along a transect that runs from inside a kiwifruit orchard into adjacent native plantings. Lab studies will include consumption bioassays of key spider species found in the orchard with key insect pests found in the orchard. I will measure how many pest insects the spider eats in a certain period to get a measure of consumption rate. This research aims to align with Te Ao Māori goals of Taiao, environmental wellbeing, and contributes to industry goals of spray-free production. Interim results will be presented.