Everybody Loves Milkweed
Sometimes blog ants get way ahead of themselves. I've had a heck of a couple of weeks, and I've been riding on posts prepared earlier--like this one. Rather than go in and edit this, I decided to post it just as it was, before it gets any older. Grabbing at straws...I'm going to be in and out of touch for the next two weeks. Darting here and there, preparing for my show in Millersburg, Pennsylvania Nov. 29-Dec. 1, sometimes away from my computer, always connected to my camera. I'll try to keep it up, but there may be a day or two here and there when I can't make it happen. I will say this: mounting a show of almost 70 works, during which I'll be giving a banquet talk, two gallery tours, a seminar, various TV and radio interviews, and dragging the whole family (including Chet Baker) along for the ride reminds me of the preparations for our wedding (though the kids weren't in on that one). The good part is that the Ned Smith Center for Nature and Art staff is doing all the planning. I'm only the bride, but still...Let's talk about milkweed, shall we?

I've enjoyed the meadow for its milkweed, and the milkweed for its monarchs. I read somewhere a wry complaint from a would-be student of caterpillars. She'd read that, to find caterpillars, all you have to do is look for their droppings. Find the droppings, and voila! you'll find the caterpillar. For some reason, she thought this was ridiculous.

One of my dearest friends from college, Martha Weiss, studies caterpillars, and what they do with their droppings, among other things. I so wish I had Martha's rollicking mind, wish I could channel her right now to explain this to you, but I'll have to stumble along by myself. Caterpillars know that their droppings can give them away to predators. And since the caterpillar's main function is to grow like Topsy, it eats constantly, and produces copious droppings. So many caterpillars construct hides of folded or chewed leaves stuck together with silk, and they have creative ways of making sure nobody finds them there. Some poop in the hide. Some climb out of the hide to poop. Some shoot their poop many feet through the air. It goes on, getting more whimsical all the time. Martha watches, discovers, and tells the scientific community and her classes at Georgetown University all about poop functions, hide building, caterpillar learning skills, and myriad other things most of us never think about. Lucky students! In another life I'd come back as one of Martha's grad students.
Monarch caterpillars don't think much about their poop, at least in a behavioral/evolutionary sense, because they don't have to. It's no big deal if a predator finds a monarch caterpillar, because they're poisonous. They pick up cardiac glycosides from their poisonous foodplant (milkweeds) and incorporate those toxins in their tissues. Just for good measure, they warn would-be diners with aposematic coloration. Black, yellow and white are a nice combo, don't you think?

When I was a kid in Virginia the big black oak in our backyard positively rained with orange-striped oakworms, a moth larva. I didn't know what they were, but their greasy, rubbery bodies strewn all over our slate patio at once fascinated and repelled me. I'm always rocketed back to childhood when I discover one in the driveway.



Speaking of other things that like milkweed, here are some milkweed bugs, Oncopeltus fasciatus. They use their long proboscis to pierce through the seedpod and feed on the seeds inside. You can raise them on hulled sunflower seeds in captivity. Who knew? Notice anything about their coloration? Ain't nobody eating milkweed bugs.
Besides chomping on our copious stands of milkweed, the monarchs were more than happy to lay waste to the butterfly weed in my garden. I don't mind. I can't think of a higher use for a butterfly weed that's almost done blooming than to surrender its leaves to beauty.

Shila found this magic capsule stuck to a plant support in the front garden. Note that, with its snazzy golden buttons, it's still telling you it tastes bad. I would love to have a silk dress of this exact chrysalid green. With gold buttons, of course.


The insect simply flops out of the chrysalis in one motion, its wings crumpled and wet, and over the next six hours it pumps fluid into the wings and they straighten out and harden enough to be useful.

If the new butterfly gets crowded or wedged up against something in this crucial period, its wings may dry crumpled, which is a sad thing. There was one with crumpled wings hanging around the garden for about a week. It could fly about a foot off the ground. Every time I found it I helped it onto a food plant, but I knew it would never make it to the mountains of Mexico like it wanted to.


Labels: aposematic coloration, caterpillar hides, milkweed, milkweed tussock caterpillar, Monarch caterpillars, Ned Smith Center, orange-striped oakworm, sexing monarch butterflies

<< Home