Skip to main content

Spotted Wing Drosophila

 

spotted wingspotted wing pattern

Hosts:  all fruits


Biology:
  Overwinter as adults and pupae, but it is unknown whether SWD can survive northern Utah winters.  Adults lay eggs inside fruit and maggots feed on pulp.


Symptoms:
  Sunken fruit; holes in fruit.


Monitoring:
  SWD has been found in northern Utah in very 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:  50F
  • Upper threshold:  88F
  • Start date:  Jan 1
  • Peak adult emergence:  755 DDs after Jan 1


Management Considerations:
  Monitoring will help to determine if this pest has been introduced to your area.