Caseload at the UW Insect Diagnostic Lab (IDL) has been very high over the last two weeks.  A summary of recent fruit crop insects reported to the lab as well as important insects to scout for can be found below:

Social wasps: I’ve seen a big increase in reports of social wasps from around the state over the last two weeks.  Growers can expect activity to further increase into early fall.  Social wasps such as yellowjackets, bald-faced hornet, and paper wasps will readily scavenge on damaged/compromised fruits and can be a sting concern at the time of harvest.

Stink bugs: I’ve also seen an increase in reports of stink bugs over the last two weeks.  I’ve had several reports of brown marmorated stink bug nymphs (juveniles) from southern Wisconsin and of green stink bug adults and nymphs from around the state.  Stink bugs can feed on a wide range of fruit and vegetable crops.

Spotted wing drosophila: similar to recent years, I’ve seen an increase in reports of spotted wing Drosophila from berry crops.  Many of my recent reports have been from northern Wisconsin, but this insect is active statewide.

Japanese beetles: Japanese beetles are active in Wisconsin and will likely be active for several more weeks.  Based on reports, many parts of southern Wisconsin are seeing limited activity this year, but some parts of northwest and north-central Wisconsin are seeing notable activity.

Pearslug sawfly: This is a pest of fruit trees in mid- and late-summer with two generations per year.  I’ve recently had a few reports of activity from southern Wisconsin.  Damage from this insect can resemble that of Japanese beetles, although the pearslug sawflies tend to feed only part-way through the leaf (causing damage sometimes referred to as “windowpane” damage).

Grape phylloxera: I’ve had several reports of grape phylloxera (foliar galls) from southern Wisconsin recently.  These reports have come from backyard fruit growers unfamiliar with this insect and its damage.

Obliquebanded leafroller: I’ve had two recent reports of caterpillars of the obliquebanded leafroller from south-central Wisconsin.  In both cases, the caterpillars were causing minor damage to leaves of fruit trees (apple and peach).  This insect does have the potential to cause direct damage to fruits.

ALERT Spotted lanternfly: to date, we have not had any live specimens detected in the state.  However, on 8/11 it was announced that the invasive spotted lanternfly had been detected in eastern Michigan (Oakland County) for the first time.  SLFs are an invasive planthopper from Asia and are a concern for grape growers; they were first detected in the US in Pennsylvania in 2014.  Growers should familiarize themselves with SLF and keep an eye out for the conspicuous adults. 

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 Brown Marmorated Stink Bug, grape phylloxera, green stink bug, Insect Diagnostic Lab, insects, Japanese Beetles, obliquebanded leafroller, Pearslug Sawfly, PJ Liesch, social wasps, spotted lanternfly, Spotted Wing Drosophila, stink bugs, SWD.