The SWD Insert and IPM Workshops Being Planned

Published: October 1, 2013

Spotted Wing Drysophila or SWD

Spotted wing drysophila surged across Missouri this summer, being especially problematic on blackberry and fall raspberry plantings. They begin building up their population after overwintering in relatively small numbers. So they don't seem to affect gooseberries or strawberries as bad. However, we did receive a report that high tunnel strawberries were more favorable to them. It may be because of the protected climate in a high tunnel.

Spotted Wing Drysophila fly on raspberry.
Photo by Tim Baker

This pest is new to Missouri and likely here to stay. It is very much an ongoing issue that will be changing. More insecticides will be labeled for their control and with more exacting recommendations (the insert has what is available now). Also ongoing will be the extent of the crops they plague. We believe they are likely to be a problem on cherry tomatoes. There were also reports that regular or large tomatoes with fruit cracks could be infested. This was considered more likely in a protected environment like a greenhouse or tunnel. However, we have not seen this yet.

I like to describe this little beast 'like a fruit fly with a knife'. The barrier to a common fruit fly is that it has to wait for a crack, fissure or other 'entry point' to get into fruit, then it can lay its eggs. And everyone knows how quickly they reproduce. One bad peach and poof, 5 days later it seems there is a million. SWD doesn't have to wait for the entry point. Once the fruit nears ripeness, then its egg laying 'ovipositor' can go through the skin to insert eggs. Can it get worse? Yes! You don't see any cuts, but open up the fruit, and there they are! Dozens of tiny squirming worms (maggot technically, these are flies after all). Yuck!

Three IPM Workshops Being Planned

Lincoln University has some funding to sponsor several IPM oriented workshops. We are considering three in February. Locations thought the best, as they have worked out well in the past, were Jamesport, Lamar, and Morgan County Seeds.