bagworms

This Alert is based on a site visit that I made yesterday and centers on the common misconception that bagworms only feed on evergreens. Although bagworms are frequently called "evergreen bagworms" in many southern states, the caterpillars may feed on over 125 species of evergreen and deciduous woody plants in 45 plant families.

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.

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.

Bagworms create bags from the hosts they feed on, causing damage to a wide range of hosts. Herein is a discussion of some bagworm biology and cultural connections.

Have you looked closely at your arborvitaes and other bagworm-susceptible evergreens such as Juniper?  Bagworms are a little easier to see now as the needle clad "bags" are beginning to turn brown.  These caterpillars can creep up on you and strip a plant before you know it so keep your eyes out and regularly inspect.  I have been watching a nearby arborvitae and noticed that the bags on this particular plant in Clark County are anywhere from 1/4" to 1" in size.  As they get bigger, they are much easier to spot.  When bagworms first hatch, it's even a challenge to the untrained eye to find...