Spotted Wing Drosophila
Hosts: all fruits, especially soft fruits
Biology: Overwinter as adults and pupae; adults lay eggs inside fruit and maggots feed on pulp. SWD adults have been trapped in Utah orchards, but no fruit injury has been detected.
Symptoms/Damage: Sunken fruit; holes in fruit.
Monitoring: SWD has been found in northern Utah in low numbers, and in north-central Idaho in high numbers. Monitoring should be done using traps containing a cider vinegar or sugar-yeast bait. See the USU Spotted Wing Drosophila factsheet for more detailed information on monitoring techniques.
Treatment Threshold: None determined yet.
Degree Day Model:
- Lower threshold: 50°F
- Upper threshold: 88°F
- Start date: Jan 1
- Peak adult emergence: 755 DD after Jan 1
Management Considerations: Monitoring will help to determine if this pest has been introduced to your area.