How Grasshoppers Hop and How Other Insects Use Their Legs
In a previous factoid we learned that dragonflies can catch their prey while flying. We found out that their unique wings helped them reach tremendous speeds and maneuverability to make it easier to catch the darting insects. Here we will see how the dragonfly uses his legs and feet to grab the insects it feeds upon from the air.
Let’s look at the legs of the dragonfly; every dragonfly has six legs. Its legs are short because it doesn’t run or walk or dig, therefore it doesn’t need large, strong legs. All six of the dragon fly’s legs are reaching forward to help it catch insects. He catches one fly or mosquito after another with his feet while he is flying. He doesn’t even land to feed; he eats on the fly. Dragonflies also use their feet to cling fast to objects.
The legs of the dragonfly are jointed so that they can fold them up. Without joints they would be stiff and straight and nearly useless. Like the wings, the legs are attached to the thorax.
The praying mantis has front legs that are specialized for hugging its prey tightly in a pair of spiked trap-like hands while it devours it alive.
Do you ever wonder how grasshoppers can hop such great distances? Like all insects, the grasshopper has six legs. He uses them all for walking, but it does more than walk with its hind legs. These legs are long and large and used for jumping. It jumps by drawing these long hind legs close up to its body and then suddenly straightening them out. The legs work like a spring allowing it to leap several times the length of its body. By closely examining the grasshopper’s legs segment by segment we can learn a lot about the legs of all insects. A segment of a leg is the part between two joints, and the joints are where the leg bends. Here is the nomenclature or structure of the insect leg.
There is a tiny segment attached to the thorax called the coax. Next to the coax is another small segment called the trochanter. You will need to look closely because it is hard to see both of these tiny parts. Sometimes it can look like a single segment.
Next there is a long, strong segment that is called the femur. Attached to the femur is the tibia. The rest of the leg (or foot) is called the tarsus and it is made of several short segments. All insects have these leg parts and they are useful in identification of the kind of insect you are examining. All legs are made with a common plan and it is the modifications of these segments that differentiate them.
If it were not for the having a long femur and an elongated, slender tibia the grasshopper would not be able to hop at all. He draws the tibia close up to the femur and straightens those long legs out with a jerk and away he goes.