Rufus Isaacs and Steve Van Timmeren of Michigan State University Extension, Department of Entomology, note an increase of spotted wing drosophila populations in traps in the past few weeks in Michigan.
“For each of the last two weeks, the average catch has doubled, indicating that fly populations are building. This is particularly evident in the southwest and west central regions of the state where catches of SWD are highest. At some fields in this region, we are also finding low levels of larvae in fruit assessed with the salt test, further indicating that pest pressure is building,” they write.
Populations are building thanks in part to cooler temperatures in recent weeks because optimall temperature for SWD development if around 70 degrees. In addition, there has been a lot of rain which makes it tough to maintain an effective pest control program.
Isaacs and Van Timmeren’s crop protection, trapping, and testing advice can be found here.
Source: Michigan State University Extension