The caterpillars that look like aliens, skulls, and living sticks
Most of us don't give much thought to caterpillars, but nature is full of species with incredible creativity. From transparent skin to skull-like masks, these creatures use amazing survival strategies to avoid becoming a meal for birds and insects.
Most of us don't give much thought to caterpillars, except perhaps for that one time we were read "The Very Hungry Caterpillar". But it turns out that in nature, there are caterpillars that have received much more creativity than we would expect from a small creature whose only role, apparently, is to eat leaves and one day turn into a pupa and then into a butterfly or moth.
There are animals that look as if evolution worked on them gently, and there are caterpillars that look as if someone opened a drawer of strange ideas and used them all at once. Soft thorns that pose as armor, transparent skin that reveals what is happening inside, a body that looks like a dry stick, a noise that sounds like static spitting, and a fake face of a skull - all these are not intended to impress us, but to help small and soft creatures stay alive for one more day.
For caterpillars, this stage of life is particularly dangerous. They are slow, nutritious, almost defenseless, and just the right size for birds, spiders, and predatory insects. Therefore, some of them have developed solutions that seem extreme even for the insect world: looking poisonous, disappearing on a leaf, pretending to be a branch, or turning their back into a mask of horror. Here are six caterpillars that look like they shouldn't be real - but they all exist entirely.
The caterpillar that looks like a spiky alien - but you can eat it
Bunaea alcinoe caterpillar lives in tropical Africa and belongs to the Saturniidae family, a family that includes some of the largest moths in the world. In its caterpillar stage, it looks much less like a future butterfly and much more like a creature someone would try to run away from in a science fiction movie.
This caterpillar can reach a length of about 7 centimeters. Its body is dark or colorful, and it has white, yellow, or orange spiky bumps on it. This look does the job: it looks dangerous, poisonous, or at least something you shouldn't bite into. In practice, its thorns are not real weapons. They are relatively soft and are intended mainly to deter predators.
Here comes the twist: this threatening caterpillar is considered food in certain areas of Africa. Due to its size and nutritional value, it is eaten roasted, dried, or cooked, and in some places, it is also considered an economic resource. In other words, what looks like a small monster with spiky armor is actually a local source of protein.
The caterpillar that "screams" without having lungs
Amphion floridensis caterpillar looks at first glance like another brown-reddish caterpillar, but when it feels threatened, it produces a strange defensive sound that sounds like a combination of a click, a spit, and static noise. Most caterpillars are quite quiet, except for the small sounds they make when they gnaw on leaves. This caterpillar acts differently.
The really strange part is that it does it without lungs. In humans and other vertebrates, sound is usually created when air comes out of the lungs and passes through the vocal system. Caterpillars do not have such a system. Air enters their body through tiny openings on the sides of the body, and not through lungs. Therefore, for years it was not clear how this caterpillar manages to produce its strange noise.
Researchers arrived at a surprising explanation: the caterpillar probably pushes air through a narrow passage between two parts of its anterior digestive system. In this sense, the mechanism is a bit like a whistling kettle. What is certain: for a small predator, a soft creature that suddenly makes a strange noise from its mouth is not such a simple prey.
The transparent caterpillar that you can see its heart
Brazilian skipper (Calpodes ethlius) caterpillar is common from southern Florida and southern Texas through the Caribbean islands and Central America to Argentina, and feeds mainly on Canna plants. What makes it one of the strangest caterpillars in the world is not its size, but what you see through it. In the caterpillar stage, its skin is semi-transparent, to the point where you can distinguish some of its internal systems. The dark line that moves along its back is not a decoration: it is the dorsal blood vessel, which functions in insects like a simple heart and pushes their body fluid.
The caterpillar that disguises itself as a stick - and also changes color
Peppered moth (Biston betularia) caterpillar is one of the most impressive cases of camouflage in nature. At first glance, it just looks like a small, dry, and uninteresting branch. Its body is elongated, uneven, with small bumps that resemble joints and defects of a natural stick. Studies have shown that Peppered moth caterpillars are able to match their body color to the background they are on, even when their eyes are covered. The researchers concluded that part of the ability to sense colors or shades is not limited to the eyes only, but is also related to other tissues in the body, including the skin.
The caterpillar with the skull mask on its back
Phyllodes imperialis caterpillar lives in areas between north-eastern Australia, New Guinea, and nearby islands. When it grows, two large spots appear on its body that resemble eyes, and white markings that look like teeth. The final result resembles a painted skull mask. When the caterpillar feels threatened, it arches its body, pulls its head in, and stretches the skin so that the markings on the back are fully exposed. This trick is sometimes called a "fake head", and it is intended to turn the small and vulnerable caterpillar into something that looks dangerous.
The caterpillar that disappears on a mango leaf
Euthalia aconthea caterpillar is an advanced lesson in disappearance. It lives, among other things, on mango leaves, and that is exactly where it is almost invisible. Its body is green, a light line runs down the center of the back, and thin extensions that resemble thorns or fibers of the leaf come out from the sides. When it sits along the central vein of a mango leaf, the line on its back continues the line of the leaf, and the extensions blend in with the texture around it. Unlike other species, it does not try to scare anyone. It chooses a quieter strategy: not to be there.
