Evergreen Bagworm

Participants in today’s OGIA/OSU Greater Cincinnati Diagnostic Walkabout held at the Boone County Arboretum, Union, KY, discussed the current developmental condition of bagworms. The caterpillars have completed their development and “tied off,” marking a significant shift in management options.

Bagworms are the larvae (caterpillars) of a native moth. The caterpillars develop within silk bags festooned with pieces of their host plants. As the caterpillars mature, they begin weaving more host plant debris into the silk, which provides structural stability as well as highly effective camouflage.

Bagworm caterpillars have “tied off” and are pupating in southwest and northeast Ohio. This marks a significant transition period in management options. Insecticides are no longer effective, but plucking remains viable.

During this week’s BYGL Inservice, participants noted that Bagworms throughout Ohio have reached a point in their seasonal development where they are becoming noticeable. This is prompting questions to Extensioneers on managing bagworms in landscapes and Christmas tree plantations.

Bagworms (Thyridopteryx ephemeraeformis, family Psychidae) are the larvae (caterpillars) of a native moth that develop within silk bags festooned with pieces of their host plants. As the caterpillars mature, they begin weaving more host plant debris into the silk, which provides structural stability as well as camouflage.

Arborvitae is a plant that is widely used as an evergreen hedge or screen. Some are suffering or completely dead. What can be done?

BYGLers reported during yesterday’s Tuesday morning BYGL Zoom Inservice that overwintered Bagworm eggs are hatching or have hatched in Ohio meaning the “bagworm season” is now underway. Look closely at trees and shrubs festooned with last season’s bag abodes to detect newly hatched bagworms.

Overwintered Bagworm (Thyridopteryx ephemeraeformis) eggs are hatching in southwest Ohio meaning the “bagworm season” is now underway. Look closely at trees and shrubs festooned with last season’s bag abodes to detect newly hatched bagworms.

Evergreens are appropriately named as ‘Evergreen’. They don’t tend to lose their needles and come back to life. But in Ohio, there are 2 narrowleaf, deciduous trees that drop their foliage in the fall, and leaf out in Spring.

Look closely at trees and shrubs festooned with last season’s Common Bagworm (Thyridopteryx ephemeraeformis) bag-abodes. Overwintered bagworm eggs are hatching in southwest Ohio meaning the “bagworm season” is now underway.