August 10th, 2007
nothing wasted
Yesterday, while I was picking vegetables and herbs to make a tomato pie, I discovered two Black Swallowtail (Papilio polyxenes) butterfly caterpillars in the Dill plants. That wasn’t really such a big surprise, but it was neat to find that one of the caterpillars had just molted (see above photo – click on all photos for larger views). I’ve reoriented the above photo to the horizontal, but picture the caterpillar climbing upwards, leaving its previous outer “skin” behind. The remnants reminded me of a discarded leotard outfit. If you examine it closely, you’ll see that it has small spines sticking out in a few spots. That’s because the previous instar (life stage) of this caterpillar had spines before it molted. The current instar does not have spines — it left them behind when it “moved out”. The other caterpillar on the Dill hadn’t molted yet and still had spines. You can see that in the pair of photos that I took this morning (see below).
A little while after taking the above photo yesterday, I went back outside, intending to take a couple of more shots of the molted caterpillar. However, by the time I went out, the caterpillar had turned around on the dill and the skin was gone. As you might remember from last year’s post about the Monarch cats, I found them eating their molted skins, so that’s likely what happened in the case of the Black Swallowtail caterpillar. Lots of good nutrition there and in the natural world, very little is ever wasted. I wonder if the caterpillar ate the spines, or if it left them the way the Monarch cats left their little feet last year?
