UW-Madison/Extension Insect Diagnostic Lab Update June 25, 2020
Caseload at the UW Insect Diagnostic Lab has been very 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:
Tent Caterpillars: I had many reports of tent caterpillars this spring from around the state. While reports continue to trickle in, in most cases the caterpillars are large (close to 2” long) and are nearly ready to pupate. With that said, damage from these insects should be wrapping up in the state soon if it hasn’t already.
Gypsy Moth Caterpillars: Increased reports of caterpillars and damage from around the state have suggested that the gypsy moth numbers may be up this year. While this is primarily a pest of landscape trees such as oaks, fruit trees can be attacked. Recent reports have indicated that caterpillars are large (1.5 – 2” long) and are nearly done feeding for the year. Growers that did notice activity in their area can begin to monitor for egg masses (1-2” long, fuzzy and beige) starting in late summer. Each egg mass can contain 500- 1,000 eggs, so scouting for and removing egg masses before they hatch next spring can be a worthwhile activity once things quiet down after harvest in the fall.
White-Marked Tussock Moths: Over the last two weeks, I’ve seen a number of reports of white-marked tussock moth caterpillars from southern Wisconsin. These caterpillars are an occasional/minor pest of fruit trees, and rarely occur in large numbers.
Raspberry Sawflies: I’ve recently seen a few cases of raspberry sawflies from the southern half of the state.
Brown Marmorated Stink Bug: Reports of adults from southern Wisconsin continue to come in. I recently saw my first case of juveniles from Dane County.
Rose Chafer: Rose chafers have been very active around the state over the last two weeks. This beetle occurs in areas with sandy soil and can cause damage similar to Japanese beetles. The beige adults will be active for a few more weeks and can feed on fruit trees, grapes, caneberries, and other fruit.
Japanese beetle: In the last week, I’ve had three reports of adult Japanese beetles from southern Wisconsin. Growers with a history of Japanese beetles in their area should expect these beetles to emerge over the next several weeks. Japanese beetles can be highly damaging to a wide range of tree fruit.
This article was posted in Insects and tagged Brown Marmorated Stink Bug, eastern tent caterpillar, gypsy moth caterpillar, Insect Diagnostic Lab, insects, Japanese Beetles, raspberry sawflies, Rose chafer, white-marked tussock moths.