Buckeye Yard and Garden onLine

The caterpillars are covered in short, grayish-white hairs, and they have a distinct, unbroken white stripe down their backs. Eastern tent caterpillars prefer to feed on trees in the family Rosaceae, particularly those in the genus Prunus, such as cherries. However, once the caterpillars commence their food-seeking walk-abouts, they may appear on a wide variety of plants.

Joe noted that FOREST TENT CATERPILLARS (M. disstria) seem to be less synchronized compared to their Eastern tent cat cousins. He observed 2nd instar caterpillars feeding among 5th instars in southwest Ohio while Dave Shetlar observed 5th instars this past week in the central part of the state. Joe indicated that localized infestations are heavy in western Hamilton County with reports of "raining frass" and caterpillars spinning down on silk threads to entangle vegetation, slow-moving gardeners, etc. Noticeable defoliation is occurring on oaks and sugar maples, with lighter damage occurring on ash, sweetgum, birch, cherry and crabapples.

Unlike Eastern tent caterpillars, forest tent caterpillars construct only rudimentary mat‑like silk nests on leaves or bark. The caterpillars have short grayish-white hairs and a row of distinct white markings running down their backs. These markings have been variously described as looking like foot prints or as being keyhole‑shaped. The markings are flanked by cobalt-blue lines running the length of the caterpillars' bodies.

Small, recently planted trees that are heavily infested by forest tent caterpillars can be seriously stressed by the caterpillar's defoliation. The overall health of larger, more established trees is less affected. Small trees should be closely inspected. The caterpillars may be difficult to spot among the leaves, but they can be easily dispatched using the highly effective five-fingered smash and/or smear control method. The caterpillars are also susceptible to most pyrethroid or carbamate (e.g. carbaryl) insecticides labeled for the target host plant.

For more information, see:

• Tent Caterpillars, KY
• Forest Insect Leaflet