Caseload at the UW Insect Diagnostic Lab (IDL) has increased over the last two weeks and is expected to increase further over the next two weeks.  Since the last issue of WFN, unseasonably warm temperatures led to significant accumulations of growing degree days and a distinct increase in insect activity. A summary of recent fruit crop insects reported to the UW Insect Diagnostic Lab as well as important insects to scout for can be found below:

Spongy moth (formerly known as “gypsy moth”): I saw a flurry of reports of spongy moth caterpillars last week due to the warm temperatures.  Thus far, all of the reports have come in from south-central and southeastern Wisconsin—especially Dane, Rock, Sauk, and Walworth Counties.  Spongy moth populations trended upwards in Wisconsin last year, so growers should be on the lookout for this pest as we could see significant damage in the state this year.  Spongy moth caterpillars are expected to emerge in more northern parts of the state over the next week or two. 

Eastern tent caterpillars:  During last week’s warm spell, I also saw my first reports of eastern tent caterpillars in southern Wisconsin.  Based on GDD accumulations, it’s been warm enough for ETC caterpillars to emerge in northern parts of the state as well.  Growers should be on the look-out for small silken tents and caterpillars.

Plum Curculio: I received my first report of plum curculio earlier this week from southern Wisconsin.  Overwintered adults are returning to orchards and can leave distinctive scars on small fruits.

Grape Flea Beetle: I’ve had a few cases of grape flea beetles in vineyards and backyard grapes over the last two weeks—primarily from the southwestern and south-central part of the state.

Pollinator activity: Pollinators such as mining bees, mason bees, bumble bees, and others are very active at the moment.  Growers should be aware of their activity and use caution when spraying to minimize impacts to these beneficial insects.

Reminder about diagnostic support from the IDL: Growers and consultants in need of insect diagnostic services are always welcome to submit a sample to the UW Insect Diagnostic Lab.  Lab services are provided free of charge.  You can find additional information about the IDL here: insectlab.russell.wisc.edu

This article was posted in Insects and tagged eastern tent caterpillar, Grape Flea Beetle, Insect Diagnostic Lab, insects, PJ Liesch, Plum curculio, pollinator activity, spongy moth.