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.
The vast majority of Common Bagworm caterpillars in southwest Ohio have initiated their annual "tie-off" in preparation for pupation. Bags are tightly closed and tied with silk to a twig or other anchorage point. Likewise, male bagworms in the northwest part of the state have tied-off; however, some female caterpillars are continuing to feed.