Five Types of Insect Legs

1. Cursorial legs. These are the types of legs most people likely think of if they’ve ever pondered insect legs before. Cursorial is a fancy word for running, so these are the kinds of legs you see on swiftly moving insects such as roaches and tiger beetles. Cursorial legs tend to be long and narrow and are designed so that the insect can move very quickly. Things with this type of leg are often hard to catch – or hard to step on if you’re dealing with roaches.

2. Saltatorial legs. Saltatorial legs are jumping legs. You’ve all seen these kinds of legs before! Grasshoppers are the poster insects for saltatorial legs, but other jumping insects like fleas have them as well. Saltatorial legs work well for jumping because they are enlarged legs filled with bulky, strong muscles. All those muscles allow insects with this type of leg to jump, propelling themselves forward very long distances very quickly. Saltatorial legs are usually hind legs.

3. Raptorial legs. You are likely familiar with this sort of leg too. Raptorial legs are hunting legs, the kinds of legs you see on predatory insects such as mantids and giant water bugs. Like the saltatorial legs, these are enlarged legs full of strong, powerful muscles. However, these legs are usually at the front of the insect and are used to grab and hold prey while they eat. Many insects with raptorial legs hold them out in front of their bodies, positioned so that they can strike at prey at any time.

4. Natatorial legs. Natatorial is another word for swimming, so insects with natatorial legs are aquatic insects that require modified legs to move easily through water. Natatorial legs are often flattened, broad, and fringed with dense hairs, as in the image of the predaceous diving beetle hind leg pictured at right. These adaptations have the same sort of effect as a human wearing flippers as they swim – they increase the surface area of the legs as they kick, allowing the insect to move more easily through water. Many aquatic insects exhibit natatorial legs, especially in the hind and middle pairs of legs, but not all of them do. They are especially common in aquatic beetles and bugs.

5. Fossorial legs. Insects with fossorial legs live underground and use their highly modified legs, usually the forelegs, to dig burrows. The mole cricket, the forlegs of which are pictured at left, are a prime example. Fossorial legs tend to be very broad, very flat, and very dense. They often have big, strong claws. Fossorial legs work somewhat like shovels to rip soils apart quickly and easily and allow the insect to bury itself in the ground surprisingly quickly. This type of leg is much less common than the others, but it’s a thrill to find an insect that has them! They’re really impressive.

Source: https://thedragonflywoman.com/2010/12/10/insect-legs/