Tuesday, March 16, 2010

Cattail Critters

Following in the footsteps of naturalists who have gone before (Gerry at Naturespeak and Seabrooke at The Marvelous in Nature), I wanted to see what critters might be lurking inside a cattail head.

So, yesterday, as I drove home from The City (Glens Falls), I pulled over at a wetland to gather me some cattails. There, on the other side of the road, was a state trooper, probably waiting to catch the unwary as they sped by. He kept an eye on me, as I exited my car, walked to the edge of the wetland and severed three cattail heads with my pocket knife. I gave him a jaunty wave as I climbed back into my car. I wonder what was going through his head as he watched this.

Anyway, when I got home, I brought the cattails inside and put them with the pile of stuff to go to work with me the next day.

This morning, I grabbed a paper plate and started to pull apart the first head.

Now, what I was in search of, specifically, were tiny wee caterpillars, the larvae of a tiny wee moth known as the Shy Cosmet (Limnaecia phragmitella). These caterpillars eat the tiny wee seeds of the cattail.

Anyone who is familiar with cattails knows that the brown hotdog-shaped head is a tightly compacted collection of millions and millions of seeds. All things being equal, these seeds are just waiting for something to trigger their release, when they will suddenly puff out, like someone pulled a cord on an inflatable life raft.

For the caterpillars, this isn't a good thing. If the seeds puff out and then blow away on the wind, the larvae will be left to starve. So, to combat this, these clever little critters spin a silken hair net over the cattail head. This fine webbing keeps the seeds in place throughout the winter, as seen here:

This cattail hasn't puffed so much. I didn't pull this one apart, but I wonder if I had if I would've found any caterpillars. Perhaps there weren't any in it.

This is what a cattail hopes to look like by spring - a naked stalk that is free of seeds:

I love to pull off cattail fluff. If you are gently, it will peel off and just lie there, looking an awful lot like a freshly sheered sheep fleece.

So there I was with my paper plate and a partially fluffed out cattail. I grabbed a couple sharp pencils and started to dissect the thing. Each poke puffed out more seeds.

I was rewarded almost immediately with a very tiny larva (very tiny, as in, oh, it may have stretched all of 2mm):

A little more poking around, and a larger, older larva turned up:

All in all, I probably uncovered about a half dozen caterpillars. Unfortunately, the heat from the sun and the furnace had warmed these critters up and they weren't hanging around waiting for the census man. I really wanted to get a photo of one nestled in the cattail fluff, but by the time I found one, put my glasses back on, grabbed the camera and tried to focus, it was gone. These buggers can move fast!

Meanwhile, there were lots of other things crawling out of the fluffwork. They were all the same thing though: the bullrush,or reedmace, bug (Chilacis typhae). Here's an adult:

and a juvenile:

and one of each:

These insects are non-natives. Considered palearctic ("of or relating to the biogeographic region that includes Europe, the northwest coast of Africa, and Asia north of the Himalaya Mountains, especially with respect to distribution of animals"), which means they came from overseas, like the rest of us. Back in their native home, these insects infest bullrushes (aka: reedmace), where the adults overwinter in the seed heads (kind of like these here were doing in the cattails). Bullrush bugs (true bugs, in the order Hemiptera, so we can really call them "bugs") eat the seeds of the bullrush. I presume that they also eat the seeds of the cattails.

Like my little caterpillars, they were fast, zooming around so quickly it was very difficult to get any photos.
Here you can see the chase in action, as the bug tries to avoid the paparazzi by hiding in what seed fluff remained on the stripped cattail head:


  1. Amazing. Goes to show the value of looking in the smallest places. When you take out a tree, you aren't just taking out a tree. And when you take down a cattail, well...you showed us what that means!

  2. Ooh, you find the coolest stuff, Ellen! Now I can't wait to go find me some cattails and see what's lurking within.

  3. Glad you found some cattail caterpillars! I should look again sometime; my first and only search I only turned up the one. And I had no idea about the bugs, that's neat. Something to file away for use next winter when I'm struggling for things to write about.

  4. I used to worry about the early-arriving red-winged blackbirds. There is so often one big storm left after they return. What would they eat? Until I learned about cattail heads. There is so much out there we don't see.

  5. John - yes, indeed, the Big Picture can turn out to be overwhelmingly huge! Imagine what we'd find if we all had pocket electron microscopes!

    Jackie - just be sure to dissect your cattail heads out of a breeze! I made the mistake of opening the window and I think we'll be finding cattail fluff around the office for several weeks to come!

    Seabrooke - Having seen just how tiny these larvae can be, and how quickly they can move, I wouldn't be surprised if you just missed some. Of course, maybe the birds got 'em before you got there!

  6. Barefootheart - you took the words out of my mouth. After reading Bernd Heinrich's book about winter, in which he follows the life of a golden crowned kinglet, I have found myself amazed at the feeding strategies of small birds. Who else but these little feathered dynamos would've known that spiders and insects were around (and even active) in winter!

  7. And to think I was just taking photo of cattails a couple weeks ago. Never occured to me to bring one home and take it apart. You can bet I'll be doing that this weekend. Thanks for the heads up.

    Yesterday I ordered "Tracks and Sign of Insects and Other Invertebrates: A Guide to North American Species by Charley Eisman and Noah Charney". Have you seen it?

  8. Squirrel - have fun with the cattails - just don't open a window where you are pulling them apart!

    I don't know about that book - let me know what you think when you get it. I'd think tracking insects would be very difficult.