Spotted Wing Drosophila

Drosophila suzukii


Spotted-wing drosophila, Drosophila suzukii (SWD) is an invasive vinegar (AKA fruit) fly.  It attacks many soft summer fruits, including stone fruits, cherries, cane fruits and grapes as they ripen. Unlike other fruit flies which are attracted to damaged and overripe fruit, SWD attacks undamaged fruits. The female uses her serrated ovipositor to puncture the fruit flesh and deposit her eggs. Some fruits like raspberries and blackberries show little to no evidence of infestation until the fruit is completely ripe.
SWD is established in many Eastern States. It has recently been found in Idaho and Montana and was found in Ft. Collins, Colorado in 2012 and in other northeastern counties in 2013.

Drosophila larvae (not suzukii) found in
raspberries grown in western CO in 2013.

SWD trapCherries, raspberries, and grapes within the upper grand valley were monitored for SWD presence during the summers of 2010-2013?.  Red plastic drinking cups were used for trapping. Holes were punched just below the rim, cups were filled half full with apple cider vinegar and a clear lid attached. They were initially placed in cherry orchards and the trapping sites were moved to cane fruits and then grape as the crops matured. Ten or more traps were set out in each fruit type. Traps were checked weekly. Several species of fruit flies were captured, but no SWD were found in the traps. In 2012 and 2013 traps set out in Delta and Montrose counties also yeilded no positive captures. However, it is just a matter time before this insect pest makes its was to western CO.

Other Links
Utah Pests Fact Sheet
Bulletin from Michigan State University
Oregon State University Fact Sheet

UMass Amherst-SWD Identification and Control

This page was updated on December 16, 2013