Spiral cocoons -- need help with ID

rjlittlefield · Post by **rjlittlefield** » Wed Dec 26, 2007 11:19 pm

Natural appearance:

Cut open with razor blade:

The photo setup:

Sure, I know this forum is not BugGuide, but I already tried there (months ago) and didn't get any help

. Besides, the images that I'm posting here are much higher quality than what I did for them.

I don't know much more about these beasts than what you see in these pictures.

Small spiral cocoons, typical 2-1/2 turns forming a cone, now rigidly fastened to the substrate with silk. Covered with sand on the outside, white silk on the inside. Contains the shell of some pupa, which apparently has exited about 1/2 turn from the pointed end of the cone.

I have seen these things in two places. First was on the leaves of some sumac bushes, in sagebrush country in north central Washington, just south of Canada. Second is in my back yard garden, in small numbers on and around the leaves of some strawberry plants, and in the aggregations you see here, inside a garden shed about 5 feet above ground level. I did not study very closely, but I recall that the ones on leaves seemed to contain small caterpillars and were not fastened down rigidly.

So, I presume that what we have is the tube of some sort of "bagworm" type critter that carries its bag around as a caterpillar, then fastens it down to pupate inside.

But I would just love to get a solid ID.

Anybody know these things?

--Rik

PS. Yes, what's shown is a piece of the shed. No, I did not rip apart the shed just to get these pictures. It was 25+ years old, and thoroughly decrepit when it got replaced this summer. This one piece is all that's left, except that the neighbor salvaged most of the sheet metal for a wood drying box that he was building.

Technical: Canon 300D, 80 mm f/4 Olympus bellows macro lens at f/5.6, stacked at 0.010", illumination as shown except that second fiber head does not appear in this photo.

Ken Ramos · Post by **Ken Ramos** » Thu Dec 27, 2007 5:08 am

You know I am not sure but since these were found in an old shed, they just might be spiders. I searched around for a while looking mostly for insects that have cocoons and not cocoons themselves and ran across a few species of spiders, small ones, that build a silken cocoon along with grains of sand but I can't say for sure this is what you have but I would suspect so. On another note, the cocoon I posted here a while back, Cocoon , I was able to ID as a Polyphemus moth cocoon. Good thing you suggested leaving it out of doors too. It should hatch open around April if all goes well.

jmlphoto · Post by **jmlphoto** » Thu Dec 27, 2007 10:59 am

ive seen wasps and bees that make there cocoons/eggs cases out of sand/dirt/something sticky. found a pretty ##### large one not too long ago it was an old one though.

MacroLuv · Post by **MacroLuv** » Fri Dec 28, 2007 9:36 am

Rik, did you find it near the water?
Could be a Caddisfly of some sort.

They are known as "underwater architects" making portable cases using silk along with substrate materials such as small fragments of rock, sand, small pieces of twig, aquatic plants, or sometimes silk alone. Many use the retreats or cases throughout their larval life, adding to, or enlarging them as they grow. These may look very much like bagworm cases, which are constructed by various moth species that are not aquatic.
See wikipedia.
Aquatic Entomology:Trichoptera and Lepidoptera with special reference to Texas

rjlittlefield · Post by **rjlittlefield** » Fri Dec 28, 2007 12:17 pm

Gee, I was hoping that somebody would immediately recognize this unusual form. Apparently I should not be too embarrassed by the fact that I don't either!

Caddisflies and spiders can be ruled out by the environment and the form of the bug. I can't rule out hymenoptera, though I also can't recall ever reading of a hymenoptera larva carrying around a case.

I'll see if I can tease out one or two of the pupal shells. It might give some extra clues, though it might also be misleading. Several years ago I harvested a bunch of cased critters from tumbleweed (like here, image #2, the candle-like things). What eventually came out was about half moths, half wasps -- presumably the original makers and their parasitoids.

--Rik

Ken Ramos · Post by **Ken Ramos** » Fri Dec 28, 2007 3:06 pm

Well Rik, this is a real puzzler for sure.

I kind of figured one of our "bug" people would have figured this out by now.

I have searched wasps, more spiders, and anything else I could think of that would hide in a shed and call it home but have yet to come up with "diddlie!"

Gordon C. Snelling · Post by **Gordon C. Snelling** » Fri Dec 28, 2007 6:11 pm

Almost certainly a moth of some kind. Best bet would be to collect some active ones next time you see them and rear them out. Very cool find.

Planapo · Post by **Planapo** » Sun Dec 30, 2007 6:20 am

Eye-pleasing photographic documentation, Rik!

Well of course, I don´t know your Lepidoptera fauna over there, but from over here I know of a rare moth that builds such a kind of helical sack covered with sand grains. As far as I know its, at present

, valid name is Apterona helicoidella (VALLOT, 1827) (Lepidoptera: Psychidae). One of the synonyms of this genus used in older lit. is Cochliotheca.

And a quick search on google for Apterona in North America found me the name "Snailcase bagworm, Apterona helix" (see http://lamar.colostate.edu/~gec/ms.htm and http://bugguide.net/node/view/156648#207682).

Although, due to negative experience, I recommend to be sceptical when using reference to internet material from people whose reliability one can´t evaluate, even from .edu domains, I´d say you now have a strong toehold

.

Best wishes,
Betty

rjlittlefield · Post by **rjlittlefield** » Sun Dec 30, 2007 9:03 am

Betty, you have come through again with flying colors! This looks like a "strong toehold" indeed! Thank you, thank you!!

--Rik

Tony T · Post by **Tony T** » Sun Dec 30, 2007 9:03 am

Excellent detective work. Only 1 sp. listed in the most recent NA catalogue: A. helix, so I'm quite certain that is it.

Planapo · Post by **Planapo** » Sun Dec 30, 2007 9:07 am

Always a pleasure to be at your service!

--Betty

rjlittlefield · Post by **rjlittlefield** » Sun Dec 30, 2007 9:28 am

And there's a lot of good textual information found by searching for Apterona Washington.

http://cru.cahe.wsu.edu/CEPublications/ ... b1485.html issued by the Washington State University looks like a good starting point. Their range distribution map shows (in 1988) known infestations within 50 miles of both places where I have seen the beast.

That paper notes the fascinating snippet that this moth "is parthenogenetic, which means a female can reproduce without fertilization by the male". It also notes that "Within a couple of weeks the ADULT female appears, looking more like an amorphous sack than a typical moth." Another ref from Michigan State University (here) says "males not known for this species".

It's interesting to note that the third picture at the BugGuide link shows a perfectly normal looking moth, which is a bit of a head-scratcher. But digging down reveals buried in the comments for that picture that this is a different species, "Not related to the bagworm cases."

--Rik

Edit May 20, 2015: The links given above have rotted. Current links are http://ento.psu.edu/extension/factsheet ... se-bagworm and https://pubs.wsu.edu/ItemDetail.aspx?ProductID=13611.

beetleman · Post by **beetleman** » Sun Dec 30, 2007 9:47 am

It looks like a species worth further study Rik. Betty is pretty amazing with her knowledge. The excellent photos help also

Gordon C. Snelling · Post by **Gordon C. Snelling** » Sun Dec 30, 2007 5:56 pm

Good job Betty.

Ken Ramos · Post by **Ken Ramos** » Sun Dec 30, 2007 8:26 pm

Well that was pretty neat.

Congrats and a tip o' the hat to Rik for providing the puzzle and to Betty for being such a terrific sleuth.

That caterpillar thing was pretty good too but I just can't imagine having ones face fall off in the dirt. Let alone ending up on a pin in front of Riks camera and ping pong ball set up.