Spider and harvestmen biodiversity in New Zealand horticultural ecosystems

Spiders contribute to pest suppression in agroecosystems by direct and non-direct consumption. They provide an ecosystem service which provides economic gains to horticultural growing systems, such as apples, wine grapes, and kiwifruit. Very few studies on spider biodiversity in cropping systems have been completed in New Zealand, and no studies have been published for New Zealand orchard systems. In this study, spiders and harvestmen were sampled from vineyards, apple orchards, and kiwifruit orchards in three New Zealand locations, Waipara, Motueka, and Kerikeri. Spiders were sampled using pitfall traps, sweep netting, active day sampling, and active night sampling. A total of 1359 spiders and 87 Opiliones were caught in this study, from 17 families and 31 species. Sixteen of the 31 (51.6%) species found were introduced, 9 (29%) endemic to New Zealand, two species (6.4%) native to New Zealand, and four (12.9%) unknown. There were five dominant spider families caught (Araneidae, Lycosidae, Theridiidae, Linyphiidae, and Desidae), and of the adults, there were five dominant species: <i>Anoteropsis hilaris</i>, <i>Tenuiphantes tenuis</i>, <i>Cryptachaea veruculata</i>, <i>Cryptachaea blattea,</i> and <i>Steatoda capensis</i>. This study provides the first important step in describing the spider families and species found in three economically important New Zealand horticultural systems.