Monday, April 28, 2008

Blanket on a stick

Every so often, I disover that I've been looking at something for a long time, but never really seeing it. Cattails, for example. They're those tall fluffy stalks in the swamp that the redwing blackbirds perch on just until I get the camera focused. And that denote a place too wet to walk without boots. That's it.

Blind as a bat.

Six weeks ago, on The Marvelous in Nature, Seabrooke wrote about Shy Cosmet moth larvae that spend the winter cosily snuggled inside a cattail head. She had brought a couple home and shredded them into a tub. Sure enough, she found a larva.

According to BugGuide, the Shy Cosmet doesn't live here on the West Coast, but the moths are smart; cattail fluff does make wonderful insulation. I promised myself to see if anything was taking advantage of it in our marshes.

Pillows of fluff.

I brought home a cattail head the next time I found one I could reach. Seabrooke (and Gerry Wykes) write that these larvae make a net of fine threads around the head, so that when it blows open, the seeds and fluff stay put, making a lumpy "cotton candy" blob. I forgot all that, and picked a nice, neat head that wouldn't fall apart in the car.

At home, I propped it in a bottle on the table and left it for later. I glanced that way after a while, and saw a head poke out, briefly. Aha! It's alive!

I put the cattail in a Tupperware dish and cracked it open, gingerly. Nothing but packed fluff. I pinched a bit and pulled.

Mistake. The fluff exploded. Fine, baby-hair-fine, downy fibers flew all over my desk, over my keyboard, in the air around my head, in my hair, in my nose. I sneezed. I had to clean out the air intake on the computer, and dust off the screen.

Fluff. With tiny seeds; that's what the larvae eat.

I went at the rest more cautiously, holding the bowl inside a large plastic bag, which was soon filled with fluff. When I took my hands out, more fluff came with it. I pulled out the bowl, carefully, sealed the bag and left that for later.

With a sheet of glass over the bowl, I could look for larvae safely. And there were dozens, all very active, about 3 or 4 mm. long.

These look very much like the one Seabrooke found. And like Gerry's handful. Maybe the Shy Cosmet has found its way out here, after all.

I didn't know what to do with the larvae after I'd looked at them. I put most of them back in the fluff, but kept a few to look at later; they went outside, with a tight lid on the container. Life got busy around then, and I forgot about the bugs.

All that fluff; what to do with it? Maybe the birds would like it for insulating nests. An old, broken-down birdhouse hangs on the wall; the juncos used to use it as a perch and feeder until the snowstorm a year ago turned it upside-down, but since then, it has been empty. It would be dry and accessible. I stuffed it full of fluff, packing it in through the door.

This last Friday, a bushtit was collecting cattail fluff. For a baby blanket, I hope.

Fuzzy photo; I was rushing to get it before she left.

I went out tonight and brought in the dish of left-over fluff and larvae. Three of them are still there, very much alive. There aren't too many seeds left, though; tomorrow I'll give them a pinch of stuff from the bird house.

Come to think of it, the bird house is probably packed tight with larvae.


  1. That's a neat,though fluffy, find. The larva looks the same to me. It would be interesting to find the moth stage, to see how it compares. I guess these are members of one of those groups of small, inconspicuous invertebrates where basic taxonomy has fallen behind. And they aren't making (or hiring) taxonomists anymore.

  2. Hugh,
    If I can keep my larvae alive, or if the birdhouse is full of them, I may be able to see what they turn into. I'll keep an eye on them.

  3. Great that you checked out what the situation was out your way! I'll be interested to see what they turn into, too. They sure do look similar; it could be another species in the genus representing the western sister species to our eastern Shy Cosmet. Or, it could just be we don't know all there is to know about the range of the Cosmet - which is entirely possible, given how little is known about most moths in general.

  4. According to BugGuide, the adults will appear somewhere around June. I will try to have several cattail heads on hand well before then, and shield them somehow so that any emerging adults will not fly away before I notice them.

    Hopefully, I can tie things together a bit.

  5. The adults are out! And they are Shy Cosmet.

    The post on them is here: Pure Gold!.


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