Caseload at the UW Insect Diagnostic Lab (IDL) has been high over the last two weeks. A summary of recent fruit crop insects reported to the lab as well as important insects to scout for can be found below:
Japanese beetles: Japanese beetles are out-and-about across most of the state. Recent reports have suggested more activity than two weeks ago, but 2022 does not seem to be a particularly bad year. Most of the reports thus far have been on raspberries , grapes, and tree fruits (apple and stone fruits) from the southern two-thirds of the state. I’ve also gotten scattered reports from fruit crops (raspberries) in northern Wisconsin. Growers should keep an eye on Japanese beetle over the next month as this pest typically remains active into September.
Stink bugs: I’ve seen an uptick in reports of stink bugs over the last two weeks. Most of these reports have been from southern Wisconsin. The commonest stink bugs reported to the UW Insect Diagnostic Lab over the last two weeks have been the green stink bug (Chinavia hilaris), the brown marmorated stink bug (Halyomorpha halys) and native “brown” stink bugs (Euschistus spp.). Recent reports have included an assortment of both adults and nymphs (juveniles); additional reports of adult activity are expected as the growing season progresses. Stink bugs can attack a wide range of fruit crops.
Social wasps: Reports of social wasps (yellowjackets & paper wasps) have increased recently, which is typical for this time of the year. Colonies reach peak size in late summer and fall, so tracking down and eliminating nests now can save headaches at the time of harvest. Activity has been noted around the state.
Grapevine Beetle: This scarab beetle (Pelidnota punctata) has a distinctive appearance and resembles a large, beige May/June beetle with several black spots on the wing covers. Although they are associated with grapes, they tend to be found in low numbers and are mostly a curiosity. I’ve recently had a few sightings from south-central and east-central Wisconsin.
Spotted wing Drosophila: I’ve recently seen an uptick in reports of spotted wing Drosophila in the state—mostly from homeowners and backyard growers with raspberry patches. Many growers have been dealing with this pest for over a decade, but should remain diligent with their scouting efforts, especially for crops such as raspberries.
Reminder about diagnostic support from the IDL: Growers and consultants in need of insect diagnostic services are always welcome to submit a sample to the UW Insect Diagnostic Lab. Lab services are provided free of charge. You can find additional information about the IDL here: insectlab.russell.wisc.eduThis article was posted in Insects and tagged grapevine beetle, Insect Diagnostic Lab, Japanese Beetles, PJ Liesch, Spotted Wing Drosophila, stink bug.