I had one of those “Hey! I know that!” moments earlier this week when, hiking through the woods on my snowshoes, I paused to check out a little bagworm case on the trunk of a young Trembling Aspen. It was complete coincidence – it’s not as if I don’t see lots of bagworm cases around, so why I stopped for that one, I don’t know – but in glancing the other way, at the aspen beside it, something else caught my eye. And I recognized it immediately. And was immediately excited for the recognition. (Naturally I didn’t have my camera, the one day in weeks I left it at the house, so I had to mark the tree and come back the next day with my macro lens).
Do you recognize it? I briefly mentioned something like it before here, when I posted my book review of Eiseman & Charney’s excellent work, Tracks & Sign of Insects. It reminded me of one of the photos on the cover of the book, and which I also posted a scan of the relevant page from inside.
Turns out it’s not quite the same thing. The one on the cover of the book is the cocoon of a spongillafly, a type of neuropteran (looks like a mini caddisfly) associated with freshwater sponges. But the spongillafly cocoons have a white inner cocoon that, even after they hatch and leave, remains behind. My lacy cocoon had no inner cocoon. Even besides that, the spongillafly outer cocoon is built in nearly hexagonal loops. In the one I found, the loops were more rectangular.
This was a key feature. Reading a bit more of the text, the authors say, “The bumelia webworm moth … spins a delicate, golden cocoon with a very coarse, rectangular mesh … Wockia asperipunctella, only recently discovered in Ontario, makes a similar cocoon on aspen and willow.”
Rectangular mesh – check! Found on aspen – check! Located in Ontario – check! Seems like a pretty good match to me!
Just to be sure, I posted it to BugGuide.net, and Charley Eiseman, one of the authors of the book who happens to frequently patrol BG generously helping out with IDs, agreed with me that this was the likely builder.
I haven’t ever seen the adult moth of Wockia asperipunctella, but it’s a micro, and unless the micros are particularly flashy or notable for some reason, I haven’t paid much attention to them. I’m still working on solidifying my macro identification. The species will be included in our field guide, though. Here’s one of the plate images we’ll be using. It has no official common name anywhere that I could find, but asperipunctella roughly translates to “shaggy-spotted” (and you can see why – the black spots have raised scales), so that’s what I named it: Shaggy-spotted Wockia. I had to resist really hard calling it a Wookie.
