Caterpillars have 6 true legs!
I bet you are thinking that I don’t know how to count, there has to be more than 6 legs. But it is true Just like all other insects a caterpillar technically only has 6 legs.
When you look at a caterpillar you probably notice the small suction cup-looking “legs” along its body. Those are not considered true legs, They are called prolegs.
What are True legs?
The caterpillars’ true legs are on the segmented legs closest to the caterpillar’s head. True legs always come in 3 pairs and look like small pointy claws. The caterpillars can use them like claws or pinchers to grab and hold on to plants or objects.
What are prolegs?
Despite their name prolegs are not real legs. Prolegs are like muscles protruding from their abdomen. They help the caterpillar move, climb and grip surfaces.
Prolegs aren’t used for walking like people or even other insects. Caterpillars move using their muscles. They start moving at the back of the body. As the muscles propel it forward the prolegs are used as anchors to keep the caterpillar steady.
Each proleg has a foot called a Crotchet. A crotchet is like acts as a fastener or a piece of velcro. The crotchet has little Barbs that help the caterpillar keep a good strong grip. The caterpillar’s feet also have tiny hairs that give information to the caterpillar. The hairs tell the caterpillar about the substrate and about the plants that they are on. The hairs even help the caterpillars taste the plants so they know if it is the right food for them.
Proleg VS True Legs How to Tell The Difference?
The best way to tell if you are looking at a leg or proleg is to see if it is segmented. If it is segmented and clearly defined it is a true leg. If it is not segmented and looks like a protrusion from the body it is a proleg.
How Many Prolegs Does a Caterpillar Have?
Most caterpillars like the monarch have 5 pairs of prolegs along their body. However, the Geometrid class of caterpillars, also known as inchworms, tend to have 2-3 sets of prolegs on the back of their body. Others like the Flannel moth have 7 pairs of prolegs.
The number of prolegs and location of the prolegs can help identify caterpillars.
The Rule Breakers – Slug Moths
Slug moth caterpillars are the rule breakers in the caterpillar world, including legs and prolegs. Slug moths are not tubular but flat, they look like colored or hairy slugs.
Some have the illusion of legs that protrude off their sides, they remind me of octopus legs.
Slug moths don’t have any true legs or prolegs, they have suction cup legs and glide around like slugs.
Conclusion
Caterpillars don’t all have the same amount of prolegs but they all have 6 true legs. The only exception is the Slug moth, which is the oddball all around.
