Caseload has remained steady at the UW Insect Diagnostic Lab over the last two weeks.  A summary of recent fruit crop insects reported to the UW Insect Diagnostic Lab can be found below:

Japanese beetles: I continue to receive low-level reports of Japanese beetles from around the state.  Activity seems to be on the downswing in many areas, with little notable damage occurring at this time based on reports.  As we get into September this species generally starts to decline for the year. 

Bumble flower beetles: These scarab beetles have a distinctive appearance.  They are a mottled brownish color with a somewhat “hairy” appearance.  Adults can be active this time of the year and are scavengers that will readily go to sugary materials.  In fruit crop settings, they’re primarily associated with fruits that have been damaged by insects, physical/mechanical injury, or disease.  They can be common around the time of harvest, but typically leave healthy fruit alone. Recent reports of this species have come in from south central Wisconsin, although the species is widely distributed.

Pearslug sawfly: I’ve had recent reports of damage to fruit trees in northern parts of the state.  This pest has two generation per year with the second generation of larvae being present in August and September.

Brown Marmorated Stink Bug: Both adults and later-stage juveniles are being reported in southcentral and southeastern Wisconsin.  Growers with a history of BMSB in their area should be on alert for this species.  BMSB adults can feed on a wide range of fruit crops and can also be a contamination concern at the time of harvest.

Social Wasps: As expected for the time of the year, activity of yellowjackets, bald-faced hornets, and paper wasps has increased over the last two weeks around the state.  In late summer, colonies are at peak size and the wasps are desperate for resources for the colony.  They can be problematic at the time of harvest when they scavenge upon compromised fruits.

This article was posted in Insects and tagged Brown Marmorated Stink Bug, bumble flower beetles, Insect Diagnostic Lab, insects, Japanese Beetles, Pearslug Sawfly, social wasps.