For pest description, crop damage, biology, life history, and cultural management
Spotted-wing Drosophila: An Emerging Berry and Stone Fruit Pest
Pest monitoring Monitor for spotted-wing drosophila (SWD) with clear quart-sized plastic deli cups with lids. Drill or puncture about ten 3/16 inch holes near the rim of the cup for fly entry. Bait traps with pure apple cider vinegar plus a drop of unscented liquid soap. Hang the trap in a shady, cool location within the plant tree canopy. Place as many traps as you can maintain in your susceptible crops just before fruit starts to ripen. Check traps weekly. There are various kinds of flies that will be captured in this non-specific trap so learn to identify SWD and have positive catches confirmed by your local Extension office. Adult SWD males have spots on their wings. Treatment thresholds have not been established, but preventive measures should be taken when the first SWD is captured and fruit starts to ripen. SWD have been captured in mid-May in the Mid-Columbia area, earlier west of the Cascades. Watch the SWD website for regional detections of SWD (http://spottedwing.org). Monitoring guidelines are based on the data currently available and designed for ease of grower adoption and use.
Spotted-wing drosophila larvae can develop in either ripening or dropped fruit of many fruits and berries, both wild and cultivated. Harvest fruit in a timely manner and clean up dropped or infested fruit. Eliminate excess vegetation that can provide refuge and reproductive habitat. SWD prefer high humidity and shelter from direct sunlight. Manipulation of the microclimate can provide important population control for this pest. Drip irrigation, weed barrier fabric, and heavy pruning to create an open canopy have all been shown to reduce infestation.
Management-chemical control: HOME USE
- azadirachtin (neem oil)-Some formulations are OMRI-listed for organic use.
- kaolin-When sprayed on leaves, trunks, and fruit, kaolin acts as a repellant to some insects. Some formulations are OMRI-listed for organic use.
- insecticidal soap-Avoid spraying when blossoms are present. Complete coverage, especially undersides of leaves, is essential. Some formulations are OMRI-listed for organic use.
- pyrethrins-Highly toxic to bees. Some formulations are OMRI-listed for organic use.
- spinosad-Some formulations are OMRI-listed for organic use.
- zeta-cypermethrin-Highly toxic to bees.
Management-chemical control: COMMERCIAL USE
Spring and summer sprays
- diazinon (Diazinon 50W) at 1 lb/100 gal water (4 lb/A). REI 4 days. PHI 21 days. A maximum of one in-season foliar applications regardless of target pest.
- esfenvalerate (Asana XL) at 2 to 5.8 fl oz/100 gal water (4.8 to 14.5 fl oz/A). REI 12 hr. PHI 14 days. May disrupt beneficial mite populations. Extremely toxic to fish and aquatic invertebrates; avoid spray drift and runoff to surface waters.
- lambda-cyhalothrin (Warrior II 1CS) at 1.3 to 2.5 fl oz/A. REI 24 hr. PHI 14 days. May disrupt beneficial mite populations. Extremely toxic to fish; avoid spray drift and surface runoff.
- malathion (Malathion 57EC) at 2 pints/A. REI 12 hr. PHI 6 days. Maximum number of applications per year is two.
- spinetoram (Delegate 25WG) at 4.5 to 7 oz/A. REI 4 hr. PHI 14 days. Apply at least 1 week apart, with a maximum four applications per season.
- spinosad (Entrust 80W) at 0.4 to 0.8 oz/100 gal water (1.25 to 2.5 oz/A). REI 4 hr. PHI 14 days. OMRI-listed for organic use. May act slowly.