By Jean Thomas
I was going through a bunch of photos the other day and found an assortment of pictures of caterpillars and butterflies and moths. One of the commonalities among them was the practice of mimicry. I decided to write about how these small creatures “practice to deceive.” The whole quote refers to a “tangled web,” but in insects, mimicry is a survival mechanism. There is a whole huge group of moths named for their markings that imitate owl eyes, and indeed, many butterflies have markings that look like eyes, whether owl or snake eyes. These have developed as defensive maneuvers to at least buy time to escape if they can fool a predator, even briefly. This is called “mimicry” by the scientists. Like scientists everywhere, they have created several categories of mimicry. I discovered this to my dismay when I began researching details about what I thought I already knew something about.
I did not know that there are several kinds of mimicry, either three, four or five depending on the scientists sorting them. Simplified, they are Batesian... to avoid and escape predators; Mullerian... toxic or distasteful types having similar appearance; and Aggressive... to hunt prey. Looked at individually, it goes like this: Batesian includes insects like the Swallowtail clan. Most have caterpillar stages that have fake eyes, although my favorite is the notorious “bird poop caterpillar.” It looks exactly like you'd expect, and it pupates into the Giant Swallowtail butterfly. This is that big (4-6”) mostly black butterfly with yellow and blue markings we see every summer fluttering around our flowers.
The Mullerian type of mimicry is what happens when insects that taste bad or are toxic begin to resemble each other, like the Monarch and the Viceroy. So any bird that has tasted either will avoid both for the rest of its days.
Other categories invented by the scientists are “aggressive,” which mimic their prey; “ant,” or practicers of “myrmecomorphy” which include many types of insects that try to look like ants for a multitude of reasons; and “sexual,” which I'm not going into because it rarely involves insects or amphibians or reptiles, which I'd rather talk about.
There are other small creatures that, in my mind, are mimics. The scientist types scorn the label for them, but I'm naming them anyway and you can decide for yourself. Luna moths have some eye-type markings, but they use their tails to confuse bats sonic systems with some kind of echo. The Hummingbird Moth is often mistaken for its namesake and sometimes even sounds like it. Other cousins of this moth are Sphinx Moth and Hawk Moth. All are pretty large, a deterrent in itself. And it gets better: the larva of these insects are the familiar Tobacco and Tomato Hornworms. These are scorned as mimics by some scientists, too, because they mimic their host plants for their disguise. They have stripes on their sides that resemble the veins of the leaves they eat, and many have scary eye markings and a fierce looking horn at one end. Unfortunately they are voracious eaters and hated by tomato growers.
I could go on for days about the various systems insects and other small creatures have devised for survival, including camouflage and fake ferocity, but I won't. I'm going outside to explore and make new friends. And while I do that, I'm going to be listening to the podcast episode about Monarch butterflies at: https://ccecolumbiagreene.org/gardening/nature-calls-conversations-from-the-hudson-valley/episode-57-monarch-butterflies
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