(BG) Araneus pegnia 9/29/12 PL DE - Tube retreat. I saw only two of this type of retreat. This one is located under a light fixure and the other was built under a ledge on a temp/humidity gauge.

I saw only two of this type of retreat. This one is located under a light
fixture and the other was built under a ledge on a temp/humidity gauge.

This one is semi-circular and the other seemed more like a 3/4-round.
This isn't the retreat I watched being built. What I found interesting
about the retreat above is that the spider had built a "wall" inside it and
that, of course, just set my imagination off to wondering about the
purposes for which just such a wall might be used. There was no wall,
as far as I could tell, in the one that I watched being built under the
gauge ledge. (To be clear, I understand that it might not be a wall, and
might simply be an addition to a pre-existing abode by this, or another
spider.)

The "color" of the spider didn't have anything to do with the size of the
retreat. This one has a red and brown swallowtail resident, the other
retreat the more normal (for this neck of the woods), paler marked
pegnia.

http://bugguide.net/node/view/737513/bgimage