Tag Archives: evergreen bagworm moth (Thyridopteryx ephemeraeformis)

The other bagworm

Two bagworm moths live around these parts.  One, the very small and oft unseen Dahlica triquetrella (seen in the first image here) never grows longer than about half an inch/twelve millimeters.  Being so thin and so well camouflaged, they’re usually mistaken for small bits of dirt or wood.

The other species, the evergreen bagworm moth (Thyridopteryx ephemeraeformis), can have bags up to two inches/50 mm in length, yet their size does little to make them more obvious.  Take this one as an example:

An evergreen bagworm moth (Thyridopteryx ephemeraeformis) hanging from a tree limb (2009_07_04_025856)

Hanging on a tree like that, they easily can be confused with some kind of seed pod or cone growing from the tree itself.

An evergreen bagworm moth (Thyridopteryx ephemeraeformis) attached to the side of a building (2009_07_04_025850)

But when they’re stuck to the side of a building—or in this case, the side of an outhouse—even the best camouflage fails to hide the fact that something more than plant material lurks beneath all that collected debris.

Which brings me to the sky is falling…

As I stood in the riparian woods along Dixon Branch watching a yellow-crowned night-heron (Nyctanassa violacea), something dropped ever so slowly onto the top of my head.  I reached up and gently lifted it out of my hair.

An evergreen bagworm moth (Thyridopteryx ephemeraeformis) hanging from a thread of silk (2009_07_25_027685)

Ah, an evergreen bagworm moth.  It dangled from a tether of silk that stretched some 30 feet/ten meters into the treetops.  Given the length of thread and the light weight of the larva, slight breezes that I couldn’t even feel sent the little critter swinging like a pendulum.  And that its descent was painfully slow meant it spent more time swinging than it did dropping toward the ground.

An evergreen bagworm moth (Thyridopteryx ephemeraeformis) dangling from a thread of silk (2009_07_25_027686)

From that heavily cropped version of the previous image you can see the larva leaning its head back through the top of the bag.

It is unfortunate that when I decided to swap lenses for better close-ups, the camera likewise decided to die.  Very dead.  And why did that happen?  Sweat.

I apparently had been dripping large amounts of sweat from my forehead directly onto the seams of the camera body.  How much I don’t know, but I do know I had to blow-dry the innards for 15 minutes before it would even power on.  Lesson learned.