Caseload at the UW Insect Diagnostic Lab has remained high over the last two weeks.  A summary of fruit crop pests recently submitted to the UW Insect Diagnostic Lab can be found below:

Japanese beetle (Popillia japonica): Based on reports coming into the UW Insect Diagnostic Lab, Japanese beetle populations have varied around Wisconsin this growing season, with some areas seeing low pressure while other areas have seen significant plant damage.  Japanese beetle activity tends to drop once we make it into September, but growers should remain alert and continue to watch for beetle presence and activity in their area. These insects can damage both foliage and fruits directly.

Brown marmorated stink bug (Halyomorpha halys): I continue to receive reports of the at the diagnostic lab, mostly from southern parts of Wisconsin.  Ares in southern Wisconsin are now seeing late stage juveniles.  Growers with a history of BMSB in their area should monitor for this pest as BMSB can damage a wide range of crops as fruit mature.  These stink bugs can also pose a contamination issue at the time of harvest for crops that are pressed to make wine, cider, or other juices. 

Green Stink Bug (Chinavia hilaris): Over the last two weeks, I’ve had reports of both juvenile and adult green stink bugs from around the state.

Fall Webworm (Hyphantria cunea): By this time, silken “tents” of the fall webworm are conspicuous in the landscape.  Selective pruning or direct treatment of tents is often a quick solution.  Recent reports have come into the UW Insect Diagnostic Lab from around Wisconsin. 

Social Wasps (Family Vespidae): Our social wasps (paper wasps, bald-faced hornets, and other yellowjackets) have been very active the past few weeks around Wisconsin.  These insects start new nests every spring; colonies build up in size throughout the growing season and reach peak size in late summer.  While these wasps are generally not direct pests of fruits, they will scavenge readily available sugars from fruits compromised by physical or mechanical injury, disease, or damage from other insects.  In that regard, they can be a nuisance issue and stinging threat to workers at harvest time.  If nests can be located by observing the wasps, direct treatment of a nest may help reduce activity in a given area.  See this write-up for information on how to identify and manage our social wasps: https://extension.umn.edu/insects-infest-homes/wasps-and-bees.

This article was posted in Insects and tagged Brown Marmorated Stink Bug, Fall Webworms, green stink bug, Insect Diagnostic Lab, insects, Japanese Beetles, social wasps.