Predatory arthropods associated with potential native insectary plants for Australian vineyards

Abstract

Background and Aims We evaluated three native plants to determine their capacity to provide insectary benefits to predatory arthropods in vineyards, and thereby to enhance biological control of insect pests. Native plants are preferred as supplementary flora, as they are naturally adapted to Australia's climatic conditions. Methods and Results Stands of mature Bursaria spinosa, Leptospermum continentale and Rytidosperma ssp. located adjacent to or in the mid-rows of Adelaide Hills and Barossa Valley vineyards were sampled for arthropods in 2013/14. Vitis vinifera was also sampled. Twenty seven thousand and ninety-one individual invertebrate specimens were collected, comprising 20 orders and 287 morphospecies. Nine thousand and thirty-six predators, 6790 herbivores and 11 265 other specimens were collected. Predatory arthropods dominated the diversity of morphospecies present on each plant. Out of 100 predatory morphospecies, 69 were found on B. spinosa, 65 on L. continentale, 55 on V. vinifera and 37 in association with Rytidosperma ssp. The difference between predatory and herbivore morphospecies was highest on Rytidosperma ssp. (2.18:1 predators : herbivores), followed by L. continentale, V. vinifera and B. spinosa. Conclusions Bursaria spinosa and L. continentale have the potential to be used as insectary plants in association with Australian vineyards, as they support populations of predatory arthropods throughout the year. Rytidosperma ssp. could provide insectary benefits on sites where the black Portuguese millipede, Ommatoiulus moreleti, is not considered to be a problem. Significance of the Study This study confirms associations between predatory arthropods and three native plants. The opportunity to plant selected native insectary species could help winegrape growers save time and resources by producing fruit with lower pest incidence, while enhancing biodiversity of their vineyards.