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

Japanese beetle (Popillia japonica): Japanese beetle are active in many parts of Wisconsin and reports have suggested that populations are variable depending on location.  Recent reports of Japanese beetle activity have come in on grapes, raspberries, and fruit trees over the last two weeks.  Growers should continue to monitor this pest as it will remain active and will pose a threat to fruit crops into September.

Pearslug Sawfly (Caliroa cerasi): Cases of pearslug sawfly continue to come in from around the state this month.  The dark, slug-like larvae of this species can be encountered on a wide range of fruit trees, including pome and stone fruits, as well as landscape plants from the rose family.  The larvae feed on the upper surfaces of leaves, leaving behind brownish, lace-like patches on foliage.  Damage is rarely severe but can grab your attention while scouting.

White-marked tussock moth (Orgyia leucostigma): As is typical for this time of the year, I’ve been getting reports of white-marked tussock moth caterpillars from around Wisconsin.  These distinctive caterpillars are yellowish and “fuzzy”, with a red head, long black filaments coming off the front of the body and four whitish tufts on the dorsal surface just behind the head.  Caterpillars of this species can feed on a wide range of fruit trees and landscape plants.  While damage is often minor, this species does have the potential to cause notable defoliation on occasion.  I recently had a report of trees in southeastern Wisconsin that experienced severe defoliation.

Brown Marmorated Stink Bug (Halyomorpha halys): Reports of brown marmorated stink bugs continue to trickle in from southcentral and southeastern Wisconsin.  Many of these recent reports have been of eggs and early instar nymphs (1^st – 3^rd instars).  Expect these juveniles to grow larger in the coming weeks.

This article was posted in Insects and tagged Brown Marmorated Stink Bug, Insect Diagnostic Lab, Japanese Beetles, Pearslug Sawfly, white-marked tussock moths.