Readers’ wildlife photos

September 11, 2019 • 7:45 am

This will be the last installment of readers’ photos until Monday. In the meantime, feel free to send me your good photos (hi resolution, in focus, etc.)

Reader Marilee Lovit sent a beautiful sequence of Monarch butterflies (Danaus plexippus) eclosing from their pupae. Her caption is indented:

The close-up of a chrysalis’s apex shows the ridges that become pronounced shortly before the butterfly emerges. I think this is from pressure of the body segments, the body being in the top of the chrysalis. The lower part of the chrysalis starts to split open and the butterfly slides down head first.

Suddenly the body flops out and down, but it does not cause the butterfly to plummet to the ground because the rear legs are somehow hooked onto the inner part of the chrysalis. The body flopping out results in the butterfly briefly being upside down, but it quickly gets its front legs out from the chrysalis and hooked onto the outer part of the chrysalis, righting itself into a good position for remaining there while its wings expand, and more must be happening as well, before it can fly away. The wings must have this time to finish forming.

Twice this year I saw newly emerged butterflies that had fallen to the ground. They could not fly and were struggling in the grass. They grabbed onto my offered finger, and I transported them to a secure place, where they remained for the necessary time. Emergence from the chrysalis and getting a proper grip on it, takes about 2 minutes. The butterfly remains hanging on for an hour or more. The photos were all in early September near the coast of Downeast Maine.

24 thoughts on “Readers’ wildlife photos

  1. Last photo is stunning! But the blue and green colors? What causes that effect, is that normal, are there other shades that occur?

    Not knowing much, I would have been hesitant to try to help a struggling butterly, fearing I might do more harm than good. So thank you for the detailed butterfly first-aid lesson.

  2. Great series of photographs – should be in every intro biology book. Saw a monarch yesterday. That is ONE monarch when there were hundreds just a few years ago. And for the disbelievers – they do like dill as caterpillars. I’ve been gardening for 50 years.

    1. Are you sure the caterpillars on dill aren’t black swallowtail caterpillars? They look quite a bit like monarch caterpillars and their host plants are plants in the carrot family. Just asking.

  3. while its wings expand, and more must be happening as well, before it can fly away. The wings must have this time to finish forming.

    There has got to be some interesting – and potentially useful – biochemistry going on there. Soft malleable exoskeletal tissues that harden on … a signal … to become a stiff material with considerable tensile and torsional strength.
    The traditional description is along the lines of “hardens on exposure to air” … but the oxygen content of the blood (OK, “haemolymph”) of the pupa has got to be significant, so … there must be some other signal.
    Aren’t there insects which moult under water too? At least in some instar/ imago stages.

      1. Hmmm, well, it gives a name to the fluid. Which is a step forward.

        Once the wings have fully expanded, the meconium will be pumped back into the body of the butterfly.

        That would be a fairly impressive trick, unless there were vent holes at the ends of wing veins to let the air back in. Pumping fluid out of a closed-end tube … well, we’ve all seen barometers, haven’t we?
        There has got to be a lot more going on than that.
        Wiki gives a meaning that “Meconium is the earliest stool of a mammalian infant.”, which isn’t terribly helpful for insects (BTW, did you see about the Burgess chelicerate arthropod?).

        A wing consists of an upper and lower membrane which are connected by minute fibres and strengthened by a system of thickened hollow ribs, popularly but incorrectly referred to as “veins”, as they may also contain tracheae, nerve fibres, and blood vessels.

        Hmmm, OK, so my impression that the “veins” of insect wings are simple tubes is wrong. But my contention that there has got to be something else going on remains. What would work could be that the meconium is pumped into the wing (anatomically, a pump is needed ; any insect anatomists around? displacing either air (through tracheal stomata) or blood vessel contents. Then the stomata (or blood valve) closes allowing hydraulic pressure to build up and inflate the wing, guided by the “vein” pattern. (At work, I’d call this “inflating a packer”.) Then the putative blood valves re-open, and the valve in the meconium pump also opens and the veins are filled with blood in the blood vessels, displacing the meconium. One thing your video didn’t claim is that meconium leaks from the wings – so the putative stomata are still closed. The displaced meconium returns to the body cavity, and may then be voided.
        Sounds a complex system – nearly as bad as the cycle on an RTTS packer. But that does sound more like a normal hydraulic system than the quite complex biochemistry that the simple story implies.
        Insect wings – are they physiologically dead, or alive and capable of repair (which implies some blood circulation)? Or – most likely – it depends on the insect group you’re talking about?

        1. My guess is your assumption that the tubular veins contain air that must be displaced is incorrect. The veins might be formed in a collapsed state requiring only a fluid under pressure to inflate.

          1. With my background in pumping fluids through non-leaky pipes into holes of variable leakiness … the “pumped into the wings” story sounds incredibly simple. I don’t believe it is that simple. But, I’m not inclined to dig deeper.

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