D3057: Ecological-based pest management for tarnished-plant bug (Lygus lineolaris) and spotted-wing drosophila (Drosophila suzukii) in day-neutral strawberries (Fragaria x ananassa)

Day-neutral strawberry (Fragaria x ananassa) production in the Upper Midwest has created a larger and longer strawberry harvest compared to traditional June-bearing varieties. However, with the longer harvest season comes additional insect pest pressures and the need for novel integrated pest management strategies. Tarnished plant bug (Lygus lineolaris; TPB) and spotted-wing drosophila (Drosophila suzukii; SWD) concern farmers due to their impact on strawberry yield and fruit quality. Insecticides are the dominant management strategy for both insect pests, however, fewer effective insecticides exist in organic production systems. As an alternative to insecticides, we investigated whether interplanting alfalfa (Medicago sativa) and sweet alyssum (Lobularia maritima) with day-neutral strawberry plants 1) affected fruit yield and quality, 2) affected SWD infestation, and 3) affected beneficial insects or additional pests compared to an untreated control. Alfalfa was chosen because it is the preferred host of TPB, thereby serving as a potential “trap crop”. Sweet alyssum was chosen because flower volatiles have been shown to repel SWD and the abundant and continuous flowering may serve as a food resource for beneficial insects. Although the plots interplanted with alfalfa and sweet alyssum had significantly lower yields compared to the untreated control, there were no differences in pest infestation or damage. There were differences in insect abundances and diversity among the treatments, with the control treatment having significantly less insect abundance and diversity compared to the intercrop treatments. Intercropping may provide resources for arthropod communities, but at a trade-off to strawberry yield.