Caseload at the UW Insect Diagnostic Lab has increased steadily over the last two weeks and is expected to continue to increase in the near future with rising temperatures.  A summary of recent fruit crop insects reported to the UW Insect Diagnostic Lab can be found below:

Eastern Tent Caterpillar: In the last two weeks I’ve had many reports and sightings of eastern tent caterpillars from across the state.  At this point, caterpillars and silken tents will be small and can easily be removed by hand or spot treated as necessary.  This insect is particularly fond of black cherries in woodlot settings but can also be associated with fruit trees in general. 

Gypsy Moth: I’ve recently had a few reports of caterpillars from south central and southeast Wisconsin.  Overall, gypsy moth numbers trended upwards in 2020, so growers should remain vigilant for activity in their area.  Gypsy moths can feed on a very wide range of plants, including landscape and forest trees such as oaks, but can also pose a threat to fruit trees.

Humped Green Fruitworm: I’ve recently had a few cases of humped green fruitworms from eastern Wisconsin.  Like gypsy moth, this species can feed on a wide range of trees (including landscape trees) but will also readily feed on fruit trees. 

Tarnished plant bug: I’ve recently had two reports of tarnished plant bug adults associated with strawberries in southwestern and southcentral Wisconsin.  This species can be a notable pest of strawberries but can also cause damage to other fruits, such as apples and pears.

Brown Marmorated Stink Bug: Sightings of the invasive brown marmorated stink bug continue to trickle in from southcentral and southeastern Wisconsin as well as the Fox River Valley area.  Growers with a history of this pest should remain vigilant this year as populations continue to trend upwards in the state.

Walnut Damage: Although not from Wisconsin, I recently received a photograph of small beetles feeding on walnut buds in an orchard setting in southern Ontario.  The insect involved was one of the leaf beetles species from the genus Paria (likely Paria quadrinotata); these are known to be associated with Juglans spp. and other hardwood plants.  The report did not indicate the extent of the damage, but commercial nut growers should add this to a list of possible insects they might encounter.

This article was posted in Insects and tagged Brown Marmorated Stink Bug, eastern tent caterpillar, gypsy moth, humped green fruitworm, Insect Diagnostic Lab, insects, Tarnished Plant Bug, walnut damage.