|Head out of the bag - REK from WOLF|
This is the common Evergreen Bagworm - Thyridopteryx ephemeraeformis. Most of us know them only by their shelters. Back then I would cut them open to extract the "worm," never appreciating that it might actually be a gravid mother full of eggs! Legless and grub shaped it wasn't impressive at all.
|Adult male - Andy Reago & Chrissy McClarren|
Only the head and thorax come out of the bag as they move along feeding and dragging their bags with them as you can see in this video. They will go through 7 molts in around 4 months. They will continually enlarge their bags using silk and what ever vegetation they are on, ranging from cedar to sycamores. Finally they attach the bags to a branch and pupate in it.
|Ted C. McRae|
Pictures of the various instars.
More information is at Beetlesinthebush
and detailed information is in this Smithsonian Institute paper.