Conservation biological control is a method of managing pests that involves habitat management to preserve or enhance natural enemies such as generalist predators and parasitoids. Increasing plant biodiversity has received increasing interest as a means of augmenting natural enemy populations and their related ecosystem services by providing pollen and nectar resources. In Ohio vineyards, the influence of native perennial flowering plants on arthropod natural enemies and pest suppression is unknown. This study attempts to determine if native perennial flowering plants influence populations of thrips (Order: Thysanoptera) and generalist arthropod predators and parasitoids in Ohio vineyards. In June 2019 five rows of Vitis vinifera vines, divided into ten panels each, had four consecutive panels selected per row. Each was randomly assigned as either a control, with no native perennials within the panel, or one of three treatments, with eight potted Echinacea purpurea per panel, eight Asclepias tuberosa per panel, or four E. purpurea and four A. tuberosa per panel. These panels were then sampled using a D-Vac bi-weekly through the end of July 2019. Specimens were identified to family and the relative frequency of natural enemy families and thrips families to arthropods in the overall sample were analyzed using R.
Results/Conclusions
No significant differences were observed in the median relative abundance of natural enemies for any of the treatments. Although the differences were not significant, median relative abundances of natural enemies in perennial treatments, particularly in the E. purpurea treatment, were somewhat higher than in the control. Similarly, no significant differences were observed in the median relative abundance of natural enemies for any of the treatments. Because medium relative abundance of natural enemies was low overall, even small differences in relative abundance of natural enemies may indicate an influence of native potted perennials on generalist arthropod predators and parasitoids.