Key winter pests on high tunnel spinach and effective options for management

High tunnels provide a compatible environment for growing spinach and other cold tolerant crops during the winter season. However, these conditions may also support the colonization and reproduction of pests, leading to building populations throughout the winter that results in high pest pressure during the spring. The first goal of this project was to conduct pest surveys under high tunnels at 15 farms during the 2022-23 winter season in Indiana. A second goal was to develop pest management recommendations for aphids that integrate Organic sprays and biocontrol agents that are effective in cold, winter conditions. Field studies on spinach and overwintering strawberry in high tunnels were conducted using four biocontrol agents (Aphidius ervi, Chrysoperla carnea, Orius insidiosus, and Adalia bipunctata) crossed with three Organic pesticide sprays (Silmatrix®, Pyganic® and Neemix®). A lab study was also conducted that mirrored treatment combinations and abiotic conditions (temperature, RH, and L:D) to serve as a controlled comparison to these field studies. For both field and lab experiments, biocontrol agent survival, prey consumption, and aphid knockdown were determined. Results of this ongoing study will be shared during this presentation to provide a recommendation on winter aphid management to reduce spinach yield loss and spring aphid outbreaks on overwintering crops.