bagworm

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.

Common bagworms (family Psychidae) are so-named because the native moth caterpillars live in silk bags festooned with plant debris. It’s the perfect camouflage allowing them to remain undetected until their damage is revealed by their voracious appetites. The “bagworm season” is ending with the caterpillars transitioning from life in a tote bag to life in a sleeping bag.

Common bagworms have been with us for a while. Overwintered bagworm eggs began hatching in southwest Ohio at the end of May (see “Bagworm Eggs are Hatching: The Game’s Afoot!,” June 1, 2022). However, it’s amazing how long these general defoliators can continue to crawl below our radar as they chomp on evergreens and deciduous trees and shrubs before their cumulative damage and size finally make them apparent.

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.