Thyridopteryx ephemeraeformis

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.

This is the time of the year when Common Bagworms come into clear focus owing to their size and noticeable damage. Overwintered eggs hatched in southwest Ohio in early June (see "Be Alert to Bagworms!" posted on June 6). However, it's amazing how well these native moth caterpillars crawl below our radar until their burgeoning appetites finally gives them away.

Overwintered common bagworm eggs are hatching in southwest Ohio. The 1st instar caterpillars are very small with their bags measuring around 1/8" in length.

Most of the Common Bagworms I looked at yesterday in southern Ohio and central Indiana had initiated their annual "tie-off" in preparation for pupation. Bags are tightly closed and tied with silk to a twig or other anchorage point. This means the damage caused by these caterpillars wrapped in silk bags festooned with host plant debris is drawing to a close.