The UW Insect Diagnostic Lab is in full “summer mode” based on the high caseload coming into the lab.  A summary of recent fruit crop insects reported to the UW Insect Diagnostic Lab can be found below:

Forest tent caterpillar: forest tent caterpillars continue to be spotted in northern parts of the state.  I’ve recently had a few reports from fruit trees in north central Wisconsin.  By now, the larvae are large (~1.5”+), meaning that they’re nearly ready to pupate.

Gypsy Moth: I continue to receive reports of gypsy moth from various parts of the state, including southcentral, southeastern, and northeastern Wisconsin.  Caterpillars are generally a mixture of sizes, although some are quite large (~2”), meaning that they’re nearly done feeding for the year.  Smaller caterpillars will continue to feed for a while longer.  Larger gypsy moth caterpillars tend to feed nocturnally, so if damage is suspected but caterpillars cannot be found, scouting after dark can be helpful.  Alternatively, if gypsy moth caterpillars have been noted in your area, the burlap-band method can be used to trap them on tree trunks, although daily removal of caterpillars is needed.

Leafrollers: I’ve had a few reports of leafroller damage over the last two weeks, primarily from home fruit growers.  These reports have come in from northwestern and northeastern Wisconsin.

Brown Marmorated Stink Bug: I continue to receive reports of brown marmorated stink bug adults from southeastern and southcentral Wisconsin.  Young nymphs are out as well, so growers should be vigilant if they have a history of this invasive pest in their area.

Rose chafers: Rose chafer adults are active in parts of the state with sandy soil.  I’ve recently had reports from central and eastcentral Wisconsin.  Adults are often active for several weeks and cause similar damage to Japanese beetles.  Fruits damages include tree fruits, grapes, and cane fruits. 

Japanese beetles: Japanese beetles are beginning to emerge in Wisconsin.  An adult was spotted in Dane county on June 15^th with other sightings from southeast Wisconsin that same week.  Growers should increase scouting efforts as Japanese beetle emergence is expected to pick up over the next two weeks across the state.

This article was posted in Insects and tagged Brown Marmorated Stink Bug, forest tent caterpillar, gypsy moth, Insect Diagnostic Lab, insects, Japanese Beetles, leafrollers, Rose chafer.