UW-Madison/Extension Insect Diagnostic Lab Update
By: PJ Liesch, UW Insect Diagnostic Lab
The caseload at the UW Insect Diagnostic Lab (IDL) has been high over the last two weeks. Reports of fruit crop insect activity submitted to the IDL from the last two weeks are summarized below:
Eastern tent caterpillars spotted in the last week in central and west-central Wisconsin have been large (nearly 2” long) and should nearly be done for the year. Most recent reports have been from wild cherries, with one case from a backyard apple tree.
Gypsy moth caterpillar reports have been very low at the UW Insect Diagnostic Lab this year. The rainy conditions are likely encouraging the beneficial fungus Entomophaga maimaiga, which can cause high mortality of gypsy moths in rainy years.
Slug reports continue to trickle in to the UW Insect Diagnostic Lab from around the state. With the damp and overcast weather, conditions have been good for slugs. Growers with low-growing crops such as strawberries should continue to monitor for slug activity.
Springtails have been reported in many spots across the state by both home gardeners and commercial growers. Springtails can be very common in rich soil and simply scavenge on decaying plant materials and fungal spores in the area. Although they may be abundant and noticeable in low-growing crops such as strawberry, plant damage is unlikely.
Imported currantworms have recently been spotted on gooseberry in south central Wisconsin. The larvae of this insect (a type of sawfly) have the potential to defoliate gooseberries and currants. With two generations per year, scouting later in the summer is also advisable.
Sawfly larvae (Empria spp.) were recently spotted causing damage to strawberry foliage in south central Wisconsin. Sawflies are an uncommon and infrequently reported pest of strawberries and damage is likely isolated.
Grape flea beetle larvae are active with several recent reports of damage to grape leaves in south-central and west-central Wisconsin.
This article was posted in Insects and tagged gypsy moth caterpillar, Sawfly, slug.