Source: Doorworm
As we all know, the original function of insect feet when they are just formed should only be used for crawling, but as insects continue to spread to different environments, in order to adapt to the corresponding living environment and the needs of feeding, hiding, courtship and so on, their feet have also undergone a variety of specialization in morphology and become various shapes.
Walking foot is the most common type of insect thorax, in general, almost all insects will have at least one pair of walking feet in the adult stage, and insects with three pairs of pectoral feet are walking feet are also common. This type of pectoral foot has no obvious specialization in its various segments, and is suitable for walking reasons and is also called walking foot. Although the walking foot is the most common type of pectoral foot, the walking foot of each insect does not have much difference in morphology, but there are still slight differences in its auxiliary functions other than walking. For example, the walking feet of insects such as dragonflies are not suitable for walking, and more useful is to climb and land.
The catch foot is morphologically very easy to recognize. It is characterized by extremely elongated basal segments, coarse leg segments, and mutually embedded spine-like structures opposite the warp segments. The biggest use of this pectoral foot is to catch prey, but also has auxiliary functions such as defense. Catching feet are almost all forefoots in insect families, the most representative of which is the praying mantis. Of course, in addition to praying mantises, there are many insects whose forefoots are also catching feet, such as the peri-veined mantis and the hemiptera.2 It is worth mentioning that different insect species also have a large gap in the morphology of their catching feet. As in the hemiptera Scorpion bugs , the catcher foot extends outward , not in the usual anteroposterior and posterior expansion ; Another example is the capture foot of the Hymenopterae cetaceae that is specialized by the 5th segment and a claw, not the entire foot.
Jumping feet are also a very recognizable type of pectoral foot. It is characterized by an extremely developed and stout leg segment, with slender tibia and often a spine-like structure. Jumping feet are specialized from the hind feet in the insect family, and their main function is to bounce or quickly escape predators. The most representative insect groups are orthoptera, namely locusts, crickets, crickets and fleas. In addition, another type of jumping fleas in the insect family has a large gap with the real jumping foot in the form of its hind feet, and is not strictly speaking a jumping foot.
Excavated foot is not a very common type of thoracic foot. The foot is short and thick in general, but extremely hard and strong, with the tibia and tarsal joints often being broadly flattened, and having sharp teeth on the outside. The excavated foot is specialized by the forefoot of insects and is mainly used to excavate soil, so a large part of it is commonly found in insect families that inhabit the soil, the most representative of which is the forefoot of the orthoptera. In addition, cicada nymphs that inhabit the soil also have excavation feet.
Swimming foot as the name suggests is suitable for swimming foot. Its morphology is flattened as a whole, like a rowing oar, and the swimming foot as a whole has longer green hairs, especially on the tarsals. The swimming foot is specialized from the hind feet of insects, which are endemic to many aquatic insects, and the representative insects are the coleoptera diptera and the hemiptera backstroke bugs or scratch bugs. However, not all aquatic insects have swimming feet, and insects such as hemiptera possum bugs do not have swimming feet.
A pink foot is a foot that can carry pollen. The representative insect with pink feet is the bee. It is specialized from the hind feet of insects, and its morphology is more peculiar, the tibia are wide and flattened, and it has long hairs on both sides. On the outside, a pollen basket was specialized to carry pollen; The first tarsal segment, the basal appendage, is flattened and elongated, with 10 to 12 rows of hard fine hairs on the medial side, which help bees collect pollen stuck to the body hair, called pollen brushes. However, the pink foot is not a special pectoral foot that all bees have, and many bees that do not feed on pollen are still walking feet, such as wasps.
There's a classic joke like this: "A snail sees Ma Lu and curiously asks how having so many feet can do it without tripping over each other while crawling." Ma Lu said he had never thought about it before, and then he began to fall into contemplation. From then on, Ma Lu would never go smoothly again. "This joke shows that humans have a great interest in the way these multiplyed animals walk. Although insects do not have many feet in the arthropod family, their walking style is still explored by many entomologists. Studies have shown that in general, insects will divide six feet into two groups when walking, each group is triangular, that is, the left forefoot, the right middle foot and the left hind foot are a group, and the right forefoot, left middle foot and right hind foot are a group. When crawling forward, one set of feet is lifted, and the other set of feet is simultaneously landed on the ground to support the body, with the middle foot as the fulcrum of the center of gravity, and so on and so on. From a microscopic point of view, most insects move forward in a zigzag curve when walking.