SWD in Florida: Monitoring, Alternative Hosts, Management, and Outreach

The spotted wing drosophila (SWD), Drosophila suzukii, is an invasive pest threatening Florida’s small fruit industry. Female flies lay eggs in ripe fruit, where larvae develop, resulting in unmarketable fruit. Since its introduction into Hillsborough County in 2009, SWD has been trapped in all major blueberry producing counties except DeSoto in the south. A strict monitoring program using a simple and effective trap-and-lure system is necessary to anticipate SWD outbreaks and guide control actions. Results from field studies comparing different trap designs showed little difference between designs baited with commonly used apple cider vinegar (ACV). The same designs baited with a yeast mixture captured more SWD in the field. Studies evaluating the attractiveness of different recommended baits for SWD in the field showed that yeast-based baits captured more SWD than ACV and a rice vinegar-red wine mixture. Trapping studies in blueberry fields also showed that fields adjacent to stands of wild blackberry (Prunus spp.) were more infested with SWD. Wild blackberry has been shown to be a viable SWD host and its prevalence in surrounding areas is an important consideration when developing management programs. Current management recommendations include sanitation and short harvest intervals to remove host material from the field. Multiple chemical control tools have shown to be effective when used in rotation to prevent pesticide resistance. Due to SWD’s increasing threat to Florida’s small fruit industry, research is occurring rapidly. Outreach workshops disseminate up-to-date research to growers, extension, and researchers and provide training on identification, monitoring, and control options.