Mallow, Under Seige

There is a teardrop in the center of our drive that hosts a perennial garden of sorts. It's not an intentional garden, it's more a garden of necessity. We needed some place to put some plants temporarily and this is the spot that Treebeard chose. Knowing us, it will remain the "some place" for quite some time to come. For me and Treebeard "temporarily" is a relative term.

One of the plants growing in this "temporary" garden is a swamp rosemallow, Hibiscus moscheutos. At the moment the poor thing is under seige. The seeds are being munched on by untold numbers of a seed-eating bug called Niesthrea louisianica, and the leaves are being consumed by no less than a dozen voracious io moth caterpillars.

Are you familiar with the io moth caterpillar? If you've ever tried to pick up one of these impressive giant silkworms you're probably nodding your head emphatically at this point. These beauties pack a punch. Yep, they are one of the "stinging" caterpillars.

These two are having a eating competition...
This one is enjoying having a leaf all to itself...
And this one is giving us an up-close look at its urticaceous setae, a.k.a. stinging spines.
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Stinging caterpillars don't have stingers in the conventional sense - nothing like the armament of a bee or wasp. Rather, most of the sting of the caterpillar comes from hollow spines attached to poison glands. The spines break, the toxin spreads out, the human (or other unlucky beast) says "Ouch!" and the caterpillar goes about its business.

I'm not familiar with the pupal stage of the io. I assume since they are considered to be one of the giant silkworms they spin a cocoon so I'll have to keep watch and see if I can find one. If I do, I'll be sure to share.


Ellen Rathbone said...

Great pics! And fat and happy caterpillars! I've never seen an Io up here...although I was thrilled with the cecropia and polyphemus we got this summer.

jason said...

Marvelous photos! These are such beautiful caterpillars who grow up into stunning moths. I hope you get to see the transformation.

swamp4me said...

I find polyphemus cocoons everywhere all the time yet hardly ever see the adult moth -- except for the occasional wing left behind by a feeding bat. Adult cecropias are a little easier to come by. We see the io adults on a pretty regular basis though.

I've done some reading and it sounds like my cats will overwinter as pupae, on the ground and either naked or in a flimsy cocoon. I tried, somewhat half-heartedly, to find a picture of the cocoon but was unsuccessful. Guess I will set up my own monitoring routine and try to follow their progress.