The mandible is the upper jaw of an arthropod. This part of the oral apparatus consists of a pair of identical elements. In most insects, as well as in centipedes and crustaceans, the mandible exists to grind food. However, social insects have another function of this element - building nests.
Origin
Mandible is the same as mandibles. It represents the limbs of the head segments, which have changed significantly in the process of evolution. There is an assumption that these are transformed coxopodites and endites. Once upon a time, ancient crustaceans were supplied with them.
Mandibles are hard, sclera-covered segments with brushes and a variety of teeth. They seem to be behind the upper lip.
All representatives of the cryptomaxillaries have a feature of the structure of the mandibles. They are attached only at one point to the head. The sides of their oral cavity are securely fused with the lower lip (its lateral part). Accordingly, pockets are formed. The jaws are placed in them: both lower and upper. It is because of this feature that the entire class was called "hidden jaws".
In winged insects and bristletails, in addition to this lateral pointjoints, there is one more. Thanks to this, they have the ability to make powerful closing and spreading movements with their mandibles.
In all insects that have mandibles, tendons extend from the places of their articulation with the head. It is necessary for the attachment of the muscles that control these mandibles.
Features
The mandible in insects may vary depending on the type of mouth apparatus. Accordingly, you can see the mandibles are completely diverse in function, shape and even size.
So, Coleoptera, Hymenoptera and Orthoptera have very large mandibles. After all, they are necessary in order to grind, tear and hold food.
Flies, for example, have a licking type of mouth apparatus. Therefore, their mandibles are simply reduced. And bees are characterized by a gnawing-licking version of the oral apparatus. Accordingly, although they have mandibles, they are greatly reduced, and besides, they have lost serrations.
Beetles
The largest mandibles in Coleoptera, so in the stag beetle, the mandible is noticeable horns, which are additionally branched. The lumberjack beetle has incredibly strong jaws. In many ways, the shape and development of the mandibles depends on the food specialization of a particular beetle.
Beetles, for example, have long upper jaws. With their help, you can easily get the snail right out of the shell.
Bees, ants and wasps
For Hymenoptera, the mandible is the chewing upper jaws, which resemble their primitive type. They usethem for:
- Kill prey.
- Digging minks.
- Cutting plants.
- Building a nest.
- Holding your food.
At the same time, the lower jaws have a licking type and are designed to collect nectar.
In Diptera and Lepidoptera
Diptera's mandibles have noticeably changed. So, in mosquitoes and some flies that suck blood, the mandibles are stylets. With their help, the insect pierces the skin. But the housefly has completely lost its upper jaw. After all, she only needs mouthparts to eat liquid food.
All caterpillars, Lepidoptera have mandibles that have a gnawing type. True, only toothed moths retain them in their adult state. Many butterflies lose their mandibles. It transforms into a small sucking proboscis to absorb sweet nectar.
The mandible is the insect's jaws, which are located on top. Everyone has different mandibles, depending on their purpose.
