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?

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11 Responses to “nothing wasted”

  1. robin andrea Says:

    The detail in the first pic is just breathtaking. What a great moment, finding that discarded skin, and just in time. I finally found a few moths out and about. Of course, I can’t ID them, but I was delighted to find three different species! Yay, the sun is out.

  2. meeyauw Says:

    Thank you for this post; it is so beautiful and informative. I have been wondering what these butterflies look like before they “are.”

  3. bev Says:

    robin – Yes! I was quite excited to find the caterpillar with the skin. I so rarely manage to catch creatures just leaving their exuviae — for example, I’ve only photographed a couple of grasshoppers in the midst of a molt. Glad to hear that the sun is out and that you’re finding some moths. I’m hoping to see insects this autumn if I get out to the west — perhaps the season will straggle on for awhile as it has been cool so much. Here, with the heat and humidity, everything seems to be racing to an end.

    meeyauw – The Black Swallowtails are so beautiful. A few years ago, when I first found one of their caterpillars, it was nice to make the connection and found out what they turned into.

  4. John Says:

    Bev, beautiful photos! I thought of you yesterday as I stopped at a roadside information center, where there were literally dozens of HUGE cidacas littering the front entryway. If only I were a much better photographer and had a more cooperative camera, I would have captured shots and sent the me to you for analysis!

  5. pablo Says:

    I never knew that about caterpillars, but I can see how it would make sense to re-use the resources that way.

    Nice pix, by the way.

  6. Dave Says:

    How do you make a tomato pie?!

  7. Stuart Says:

    Hi Bev, love the pics especially the top one. I find it bizarre that they’d eat their own skin but as you say in the natural world very little is wasted.

  8. bev Says:

    John – Yes, I would have liked to see those cicadas as we seem to see mainly one species up in my area. Btw, most digital cameras do have a “macro mode” setting and can take respectable photos of insects from a few inches away. It would be worth checking to see if your camera has that. If you can’t figure it out, give me the model of your camera and I can probably find out fairly easily.

    pablo – I never knew that either until I raised the Monarch cats last summer. As you say, it makes sense.

    Dave – Maybe I should post the recipe. I’ll try to do that a.s.a.p.

    Stuart – Actually, it seems a natural thing in nature. When I kept a large herd of dairy goats, the mothers would lick off their newborn kids and also eat the placenta if I didn’t remove it from the pen immediately. I suspect it provides some nutrition, but perhaps more importantly, in the wild, it would have helped to prevent predators from being attracted by the scent of blood, etc… As there are so many predators of caterpillars, perhaps eating the molted “skin” serves a similar purpose — one less thing to attract unwanted attention.

  9. Cathy Says:

    Bev~ My jaw is on my chest in wonderment. These are the most fantastic photos! They turn around and EAT their discarded skins!? Well I’m just delighted with this bit of bug behavior. Those monarch feet! You are the BEST!

  10. Dylan Says:

    hi i enjoyed the read

  11. Randa Says:

    Hi Bev. I just posted a similar photo on my blog the other day, asking anyone who knew what it was to fill me in. As I posted it, I thought of you…”Bev would know for sure…” Happily I soon received a response, and was delighted to learn what it was. Interesting to see that you posted about it a week ago ;)

    P.S. The caterpillar is still hanging around my celeriac. I hope it stays for a while so that I can continue to watch it.