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Photo#871563
Unknown Bagworm - Astala confederata - male

Unknown Bagworm - Astala confederata - Male
Woodland Lakes, near Sullivan, Washington County, Missouri, USA
November 30, 2013
Size: 20mm
Found this little guy on the side of a house, and there were several more on the same wall. I assume it's a bagworm, but I don't know what species we have in our area. Also, I have never seen bagworms off of the plant they were eating. Are there some this small, or is it possibly still growing?

Nice addition to the guide!
Pictures of these seem to be nonexistent.

Moved
Moved from ID Request.

Not an expert
but may be Astala confederata, going by the description in Charley Eiseman's excellent book(1). I have a similar species here, Psyche casta, that is about half that size. Maybe Charley will chime in here.

Empty cocoon of an adult male
Given the pupal skin protruding from the end of the bag, we know this is an empty case of a mature male bagworm. This would explain why it's not on a plant; they attach their bags to all sorts of substrates when ready to pupate. If 20 mm is a precise measurement (does it include the pupal skin?), this is too large to be Psyche casta and too small to be Thyridopteryx ephemeraeformis, the two most commonly encountered species. I don't know offhand which species it would be.

 
Thanks for the quick ID!
20mm is the exact measurement, and it did include the pupal skin. This is all fascinating. How do the males move when ready to pupate? I assume they can crawl, but have never thought of any bagworms crawling other than newly hatched ones.

 
Crawling
Both males and females crawl around regularly, taking their portable shelters with them as they move to new feeding sites or when ready to pupate. The reason we know this is a male is that females pupate inside their "bags."

 
You beat me too it
was I way off base?

 
That has to be it
I was pretty sure there was only one possibility, but I didn't have my book out to look it up. I just checked (p. 249), and that's the one.

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