Michigan State University is collaborating with researchers from across the country to address the invasive insect pest, spotted wing Drosophila (SWD). This pest is particularly challenging for organic growers due to the limited number of organically approved and effective insecticides. With funding from the USDA National Institute of Food and Agriculture Organic Agriculture Research and Extension Initiative (OREI), the team has been investigating behavioral, cultural and chemical management strategies for this pest. Results from those studies have been combined with other experience managing SWD to develop “Management Recommendations for Spotted Wing Drosophila in Organic Berry Crops.” Using a range of control techniques will help to reduce SWD infestation.
“Management Recommendations for Spotted Wing Drosophila in Organic Berry Crops” provides a list of recommendations that growers should consider.
- Monitor fields with traps and check the traps weekly starting from fruit set until the end of harvest. Check the trapped flies and correctly identify SWD to determine their presence and number. Sample ripening and ripe fruit regularly to determine whether your management program is working.
- Implement preventative management strategies prior to detecting SWD in traps or when berries are ripening or ripe, including using exclusion netting, pruning and weed mat mulches, and keeping your planting clean by removing and destroying leftover fruit or fruit processing by products.
- Implement cultural and chemical management strategies as soon as SWD is detected in traps or when berries are ripening or ripe, including decreasing your harvest intervals, keeping planting clean by removing and destroying leftover fruit or fruit processing by products, and using recommended NOP-compliant insecticides to protect the fruit, as necessary.
- While selecting insecticides for SWD control, take into account the efficacy, chemical class, harvest date, pre-harvest interval, re-entry restrictions and your target markets.
- If you are exporting fruit, check carefully on the maximum residue limits (MRL) for the destination country.
- Make insecticide application early in the morning or late in the evening to target peak SWD activity periods.
- Calibrate your sprayer before making insecticide applications to ensure proper coverage.
- Integrate cultural and physical control methods and rotate other classes of insecticides with Entrust sprays to delay the development of insecticide resistance.
- Continue monitoring to evaluate your management program and respond in a timely manner if needed.
- Stay informed of your regional SWD pressure and new management techniques by keeping in contact with your local MSU Extension personnel if you have questions.