Manipulation of natural enemies of key arthropod pests in Oklahoma vineyards

A variety of arthropod pests are economically important to Oklahoma grape production, including those that sometimes serve as vectors of plant pathogens like Pierce’s disease. Integrated pest management (IPM) strategies include conservation of natural enemies (predators and parasitoids) via habitat manipulation, including incorporation of plants between vine rows that serve as refugia and pollen/nectar sources for adult natural enemies. This study has two primary objectives. First, we attempted to manipulate the diversity and abundance of natural enemies using ornamental plants between rows. We compared predator and parasitoid abundance and diversity in response to three treatments of between-row plantings: 1) native flowering perennials, including Achillea millefolium, Monarda punctata, Asclepias tuberosa, and Coreopsis lanceolata; 2) Upright grass, Pennisetum villosum or Miscanthus sinensis; and 3) pre-existing bermudagrass as a control. Our second objective is to gain a better understanding of the natural enemy activity in the vineyard using sentinel egg masses of black cutworm (Agrotis ipsilon) placed on vines in the flower, grass, and control treatments. We hypothesize that we will see more natural enemies in the flowering plant treatment compared to the upright grass treatment and bermudagrass control. We also expect to see differences in parasitism and predation rates on sentinel egg masses among planting treatments.