It uses a hook-covered appendage called a cremaster to attach itself to this pad. It twists around, embedding its cremaster firmly in the silk. Then, it sheds its skin, revealing the chrysalis. The chrysalis hangs upside down from the cremaster until the butterfly is ready to emerge, or eclose. Other caterpillars use variations on this process when they pupate. Instead of hanging upside down, some make a silk sling from a tree branch to support themselves as they pupate right-side up.
Others create a silk hammock to support their chrysalis. The chrysalis starts out soft and skin-like, but gradually hardens to form a protective shell. Often, moth caterpillars spin a cocoon to protect their chrysalis, which starts out soft and skin-like. However, it will gradually harden to form a protective shell. The moth caterpillar may also disguise the cocoon with leaves or other debris. It's easy to think of a chrysalis as something a caterpillar makes, like a cocoon, but this isn't really true.
The body that the caterpillar reveals when it sheds its skin for the last time is the chrysalis. Along with the ability to occasionally twitch in response to threats, this shell is what protects the caterpillar while it transforms.
The transformation itself is amazing. Think of it as recycling -- if you drop a plastic bottle off in the recycling bin, it can be melted down into an entirely different shape. This is what happens inside the chrysalis. When the time comes to pupate, they simply do it inside their existing case.
The time of year a caterpillar makes its cocoon depends on its lifecycle. Some species move from caterpillar to pupa very quickly and will need to weave their cocoon in the summer. Other species plan to spend their winter in their cocoon, spinning it at the start of autumn and then spend many months in it. Caterpillars have a strong sense of where they need to be once its time to pupate.
Some will climb down their plant to bury themselves in the ground, whilst others will attach themselves to the bottom of a leaf or stem. Cup moth caterpillars spin amazing pear-shaped cocoons, which are hard and smooth, almost like an egg. They attach them to the underside of the twig and exit by opening a lid in the base.
The bumelia webworm creates a beautiful golden mesh-like cocoon suspended from the vegetation like a delicate decoration. It is thought that the open structure might help allow ventilation in a humid environment. The woolly bear cocoon looks like a dark reddy brown hairball, easily hidden amongst the foliage on the arctic tundra floor. Cocoons of different species vary greatly in shape, size and colour. The most famous cocoon is the silkworm, which is generally a smooth oval form, coloured white or cream.
It certainly sounds like a cosy way to spend your time, hidden away inside a bed of silk. Menu Skip to right header navigation Skip to main content Skip to secondary navigation Skip to primary sidebar.
Contents What is a cocoon? How does a caterpillar make a cocoon? But since there are many more moths than butterflies, the caterpillar that you found will most likely turn into a moth. No, and this is related to the process of metamorphosis.
Caterpillars are the larval stage of an adult butterfly or moth, and only the adults mate and lay eggs, not caterpillars. Look at it this way: the caterpillar's only job is to eat and get as fat as possible and store up fat for the adult stage; the adult's only job is to stay alive long enough to mate and lay eggs so the process continues.
Most caterpillars have six legs in the front, which have tiny claws for gripping and will eventually become the six legs of the adult insect. They also have soft, grippy "prolegs" in the back, which can be quite strong, especially in big caterpillars -- try getting a big caterpillar off of its stick, and you'll see what I mean.
Caterpillars use both kinds of legs together to walk around. Caterpillars in the moth family Geometridae have only two pairs of prolegs in back. They bring these legs on the rear end up to the front, making the body into a loop, and then reach out with the front legs.
They look like they're measuring, so they're called inch-worms. This is an excellent question. The process is unbelievably complicated and is the product of millions of years of evolution.
Basically, at the end of its eating time, when it's full-grown, the caterpillar sheds its skin for one last time, and this new version of the caterpillar has no arms or legs -- it's basically a pod. This is called a pupa, or a chrysalis. Inside the shell of this pod, the cells rearrange themselves into the form of the butterfly or moth. Then the insect sheds its skin one final time, and out comes the adult, a butterfly or moth with wings. Caterpillars are one of four stages in the life of a butterfly or moth.
They aren't exactly born -- they hatch out of eggs laid by the adult. The eggs are tiny and unremarkable, and the baby caterpillars are very small and defenseless. There are dozens and dozens of eggs laid by every adult, and most of the baby caterpillars are eaten by birds or ants long before they grow up. The surviving baby caterpillars eat a lot, and grow fast. About 4 or 5 times during their life they will shed their skin as they outgrow the one they're in. Sometimes the new skin looks a lot different from the old one.
When they're done eating they shed their skin again and become a pupa also called a chrysalis ; then that skin splits open and the butterfly comes out. A cocoon is a protective coat or shelter that keeps the pupa inside it warm and dry, and also out of the reach of birds, ants, and parasites. But a caterpillar will only spin a cocoon if it's a moth, not a butterfly. Butterflies don't spin cocoons, and most moths pupate underground. Only some moths make cocoons.
A cocoon is made from a liquid that comes out of the caterpillar's mouth. When the liquid hits the air, it turns into a thread or fiber; this is the cateprillar's silk. There's a special organ in the caterpillar's "lip," labrum, called a spinneret. This organ spools out the silk and the caterpillar builds the cocoon around itself. When it's time to hatch, the caterpillar produces a substance that dissolves one end of the cocoon, and the adult moth wriggles out.
The most accurate answer to this question is, "When they're good and ready. Usually this takes several weeks from the time they hatch out of the egg laid by the adult. Caterpillars can make cocoons at all times of the year, but it is by far most common for them to pupate over the winter.
They eat and eat while leaves are out in the summer, spin a cocoon when it gets cold in the winter, and hatch out as an adult in the spring. Then the adults mate, lay eggs, and the process repeats all over again. There's some folklore out there that says the width of the bands on the banded woolly bear, Pyrrharctia isabella , predicts the severity of the coming winter, but there's no research to back this up.
Banded woolly bear showing the red and black bands that do NOT predict winter weather Most caterpillars you find will turn into a moth, not a butterfly, because there are about a hundred times more moths than butterflies out there. Caterpillars with "fur," or very large caterpillars with horns or other decorations, are almost always moth caterpillars. Butterfly caterpillars are generally smaller and slimmer than moth caterpillars, and are either smooth or have branched spines all over them.
These are only general rules, though. If you found a caterpillar and you want to know what it is, have a look at my Caterpillar Identification Guide. This is a good question. Whether a moth or a butterfly species, caterpillars eat a lot -- in fact, eating is their only purpose in life, since they're the phase in the cycle of metamorphosis change in form that is tasked with accumulating enough fat and calories to produce a big, beautiful adult.
But they don't eat all of the time. If you raise a caterpillar, you will notice that they eat at certain times of the day, and rest at other times. Many caterpillars eat at night, when the predators that want to eat them are unable to find them in the dark. Caterpillars live on their food plant, and they basically never leave. They eat and rest, eat and rest, and shed their skin molt when the skin they're in gets too tight. Sometimes they come down to earth to prowl around for a good place to make a cocoon, and that's when most people find them.
There are only a few caterpillars that eat milkweed, and this is because the milkweed plant has poisonous, milky sap that it uses to protect itself from things that eat its leaves. But some insects have evolved to deal with the poison. The most famous of these is the monarch butterfly, scientific name Danaus plexippus. The brightly striped caterpillar of the monarch butterfly eats only milkweed. Sometimes the caterpillar will chew through the main vein of a leaf so there's not as much toxic sap in the part it wants to eat -- apparently evolution is not completely through!
There is another kind of caterpillar that eats milkweed. It's a brightly colored, furry orange and black species that turns into a pretty grey moth -- the milkweed tiger moth. There's only one kind of caterpillar that turns into the monarch butterfly, one of the most beautiful and recognizable of all North American insects. The caterpillar of the monarch eats only milkweed species, and the toxic sap from the milkweed is thought to make the caterpillar and butterfly taste bad to predators.
There are a few caterpillars that eat rose, and a couple of the most common ones also sting -- unusual in the caterpillar world. One of them is the io moth, a beautiful species. The caterpillar is green with a red and white line down its side and lots of sharp branched spines.
Touch these, and you'll think you've been stung by a bee! The other is known as the "stinging rose caterpillar. Caterpillars, like all insects, have an exoskeleton. This means that they have no inner support; it's all supplied by a tough but flexible outer shell.
When the insect eats, it grows, and the exoskeleton gets tight. In order to get bigger, the insect has to wriggle out of its old skin to reveal a new one underneath. This new skin is flexible enough to allow the caterpillar to grow larger -- until it reaches the end of the exoskeleton's flexibility, and needs to shed again. At the end of the metamorphosis process, the adult moth or butterfly emerges, and of course it too has an exoskeleton.
Leaving aside the fact that judgements like "bad" and "good" don't apply to caterpillars, which are insentient beings with no moral code, it's true that there are some that are more of a pain to humans than others.
Gypsy moth caterpillars, for example, eat a wide variety of trees and can occur in huge numbers, enough to destroy an entire forest. Cabbage white butterfly caterpillars are another persistent pest, on garden plants. There are very few butterfly pest species -- most of them are moths. No caterpillars are disease vectors, or any real kind of threat to humans. In a way, they're all "good"! Look at it this way: Every feature on a caterpillar, from color to shape to "decorations," have evolved over millions of years to help the animal survive and avoid predators.
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