2020-21 Rapid Ag: Rapid Response to Japanese Beetle as a New Pest of Wine Grapes and Raspberry
Adult populations of the invasive Japanese beetle (JB; Popillia japonica) have significantly increased over the last 10 years in Minnesota, with pest pressure becoming an increasing concern for specialty crops.
Adult populations of the invasive Japanese beetle (JB; Popillia japonica) have significantly increased over the last 10 years in Minnesota, with pest pressure becoming an increasing concern for specialty crops, and specifically for wine grape and raspberry production. Our focus is on two of the most valuable fruit crops in MN; the wine grape industry is valued in total, at $80 million, while the value of fresh raspberries is $7500/acre. With high levels of defoliation and few guidelines for management, producer sustainability is at risk. The beetle was first documented in the U.S. in 1916, with the first reports of JB in MN occurring in 1968. Despite being present in the state for over 50 years, there was minimal spread and historically few negative impacts for crop producers. The lack of an immediate threat to crops in the past led to a lack of R&D investment in integrated pest management (IPM) strategies. Also, recent changes in MN environmental conditions, in both temperature and rainfall, likely contributed to the increased spread and population growth of JB. In 2018, our preliminary data confirmed the highest infestations in wine grapes and raspberries, with peak trap catch at all locations exceeding 5,000 beetles per trap per week, with a peak one day trap catch of over 6,700 beetles in Rosemount, MN. Because adult JB has a wide host range and an intense feeding/aggregation behavior in grapes and raspberry, producers are faced with a new and challenging pest to manage, yet prefer to minimize insecticide use. The proposed research is foundational to developing IPM guidelines that can support sustainable production.
Project Goals and Objectives:
- Document season-long phenology of Japanese beetle (JB) in raspberry and wine grapes using commercial traps and lures for early detection, and evaluate intervals for trap checking and changing lures to confirm dates of first catch and peak beetle activity
- Assess JB crop injury, develop Economic Injury Levels (EIL) for raspberry and wine grapes, and subsequently develop economic (or action) thresholds, to develop objective guidelines for the need and timing of implementing insecticidal, or other control options for each crop
- Assess the efficacy and logistics of using poly based covers and exclusion netting with high tunnel (HT) structures for repelling JB adults in raspberry, and exclusion netting for protecting wine grapes from infestations of adult JB
- Assess varietal resistance in wine grape and raspberry to adult JB feeding using choice / no-choice laboratory feeding assays