Catalpa Worms!

A cool and beautiful Sunday morning, and I'm at the early service on Dean's Fork. 

The Right Rev. Allis Chalmers presiding, with Wingstem and Ironweed in the choir.

"If you want to find caterpillars, look for their droppings." When I was a baby naturalist, this piece of (sound) advice seemed ridiculous to me. Who finds caterpillar droppings?

 

I do. All the time.  When I see a frass event of this magnitude, I look up.

Let's have a little closer look at those leaves. Catalpa leaves. Ah. These must be catalpa worms!

Though I couldn't remember having seen a catalpa sphinx caterpillar,** I had heard of catalpa "worms" in plague proportions. Wow. Coolio! They were eating the everlovin' crap out of a small row of catalpa trees deep down Dean's Fork.

**I now know to qualify such statements as "Though I'd never seen a..." because chances are I have seen it, looked it up, maybe even blogged about it in my 2,009 posts to date. I just don't remember having seen this or that.

It was hard to see their true colors against the light, as they were all on the undersides of the leaves.

So I turned a low-hanging leaf over and wow! I could tell they were sphinx caterpillars by the prong on the tail. It makes a convincing false head, looking more headlike to me than the actual head, which is to the right. This might make a bird grab for the tail, which would certainly be less lethal than having a hard beak nip your head capsule.

The catalpa sphinx, Ceratomia catalpae, is the only common sphinx that's gregarious though the middle instars, according to David Wagner's Caterpillars of Eastern North America. Caterpillars come in two or three generations through much of its range, with mature caterpillars from late June to November.

 

I didn't annoy these, but now I kind of wish I had. Wagner says, "Like many other sphingids, the Catalpa Sphinx is a 'barfer' and thrasher. When molested, the larva regurgitates a somewhat viscous green fluid from the foregut and thrashes violently, which, among other things, serves to spread its regurgitant over a potential predator." 

I could dig that. Remember my squeaking walnut sphinx?

You gotta go watch that video again, from just over a year ago.

 

I just love Wagner's writing. "Catalpa Sphinx caterpillars have been grown and sold commercially as bait in Florida and elsewhere. Evidently they work especially well for largemouth bass. The adult proboscis is short--the adult is not capable of feeding, and as a consequence, provides no pollination services for its host foodplant."

Hmm. They look sorta toxic to me, but they must not be, with all that defensive behavior and bein' bass bait and all.   

I thought about the fact that the adult sphinx cannot feed.  Kinda creeps me out, like luna moths do. It's no more than a DNA dispersal unit. A mouthless, gutless wonder, a winged carrier for gonads. Gonads with wings. But the catalpa sphinx really lives it up as a caterpillar. Even has a social life. Goes to instar graduation parties, I bet.

They had completely defoliated two smaller catalpas. Par-tay!

 Sorry--this is a zoomed up phone photo, best I could do. You should be able to make out two caterpillars, a healthy one on the left and a small black one on the right, dead center. It's covered with white parasitic wasp cocoons. I saw several like this. Nature strikes a balance. Or tries. I'm afraid this is it for the catalpa this summer, as it's too late for it to replace those leaves. It's having its own Early Autumn. (Know that standard? I love it so).

Just another wonder of Dean's Fork, my church and school.