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The mandible (from Latin : mandibula or mandĭbŭ-lum, a jaw) of an arthropod is a pair of mouthparts used either for biting or cutting and holding food. Mandibles are often simply referred to as jaws. Mandibles are present in the extant subphyla Myriapoda (millipedes and others), Crustacea and Hexapoda (insects etc.). These groups make up the clade Mandibulata, which is currently believed to be the sister group to the rest of arthropods, the clade Arachnomorpha (Chelicerata and Trilobita).
Unlike the chelicerae of arachnids, mandibles can often be used to chew food. Mandibulates also differ by having antennae, and also by having three distinct body regions: head, thorax and abdomen. (The cephalothorax (or prosoma) of chelicerates is a fusion of head and thorax.)
Insect mandibles are as diverse in form as their food. For instance, grasshoppers and many other plant-eating insects have sharp-edged mandibles that move side to side. Most butterflies and moths lack mandibles as they mainly feed on nectar from flowers.
Queen bees have mandibles with sharp cutting teeth unlike worker bees, who have toothless jaws. Male dobsonflies have slender mandibles up to 2.5 cm long, half as long as the insect's main body. Potter wasps use their mandibles to mix droplets of water with clay while constructing a nest.
Ants have long, broad, serrated jaws, used for digging, collecting food, fighting and cutting, and are probably the most important work tool ants possess. Ants typically bite each other when fighting. Some ants use mandibles to injure the enemy and squirt poison into the wound. Harvester ants use their mandibles to collect and carry seeds. Army ants have sharp mandibles that are better adapted for fighting than obtaining food or nursing the larvae. Carpenter ants make their nests in various wooden structures, which they hollow out with their sharp mandibles.
The shape and size of beetle mandibles varies from species to species depending on the food preferences. For example, carnivorous beetles have extended mandibles to seize or crush prey. Tiger beetles' mandibles (similar to the piercing canine teeth of tigers) are well adapted for killing prey. Diving beetle and firefly larvae have hollow mandibles, which can inject digestive fluid to liquefy the tissues of the prey. When this process is over, they suck the digested tissue through the mandibles.
The antlerlike jaws of stag beetles are essentially their namesake trait. In some tropical species they can be up to 10 cm, as long as the body of the beetle. These mandibles are primarily used in combat.
Caterpillars use sharp mandibles to cut leaves in side-to-side motions. Only a few moths have functional mandibles in the adult stage. The most notable example are members of the family Micropterigidae, small moths with toothed mandibles used for chewing pollen grains, lacking even the most rudimentary proboscis.
Among myriapods, centipedes have strong, bristly mandibles, which have a row of teeth in all centipedes except for members of the order Geophilomorpha. Millipedes have small mandibles, their only functioning mouthparts, as the maxillae are fused to the lower lip (labium).
Crustaceans have a pair of mandibles that typically consist of an enlarged basal segment (coxa) and a palp (sensory feeler) consisting of all other segments. In some groups, such as the Branchiopoda, the palp is reduced or absent. Crustacean mandibles may be equipped with special teeth (molar and incisor processes).
Uniramia is a group within the arthropods. In the past this group included the Onychophora, which are now considered a separate category. The group is currently used in a narrower sense.
Centipedes are predatory arthropods belonging to the class Chilopoda of the subphylum Myriapoda, an arthropod group which also includes millipedes and other multi-legged creatures. Centipedes are elongated metameric creatures with one pair of legs per body segment. Most centipedes are generally venomous and can inflict painful bites, injecting their venom through pincer-like appendages known as forcipules. Despite the name, centipedes can have a varying number of legs, ranging from 30 to 354. Centipedes always have an odd number of pairs of legs. Therefore, no centipede has exactly 100 legs. Similar to spiders and scorpions, centipedes are predominantly carnivorous.
The jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term jaws is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it and is part of the body plan of humans and most animals.
Myriapoda is a subphylum of arthropods containing millipedes, centipedes, and others. The group contains over 16,000 species, most of which are terrestrial. Although their name suggests they have myriad (10,000) legs, myriapods range from having up to 750 legs to having fewer than ten legs.
The Devil's coach-horse beetle is a species of beetle belonging to the large family of the rove beetles (Staphylinidae). It was originally included in the genus Staphylinus in 1764, and some authors and biologists still use this classification.
Histeridae is a family of beetles commonly known as clown beetles or Hister beetles. This very diverse group of beetles contains 3,900 species found worldwide. They can be easily identified by their shortened elytra that leaves two of the seven tergites exposed, and their elbowed antennae with clubbed ends. These predatory feeders are most active at night and will fake death if they feel threatened. This family of beetles will occupy almost any kind of niche throughout the world. Hister beetles have proved useful during forensic investigations to help in time of death estimation. Also, certain species are used in the control of livestock pests that infest dung and to control houseflies. Because they are predacious and will even eat other Hister beetles, they must be isolated when collected.
The antlions are a group of about 2,000 species of insect in the family Myrmeleontidae, known for the fiercely predatory habits of their larvae, which in many species dig pits to trap passing ants or other prey. The adult insects are less well known, due to their relatively short lifespans compared to the larvae and mostly fly at dusk or after dark, and may be mistakenly identified as dragonflies or damselflies; they are sometimes known as antlion lacewings, and in North America, the larvae are sometimes referred to as doodlebugs because of the strange marks they leave in the sand.
The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments are of Latin origin, and may be confused with terms for bones: coxa, trochanter, femur, tibia, tarsus, ischium, metatarsus, carpus, dactylus, patella.
This glossary of entomology describes terms used in the formal study of insect species by entomologists.
Insect mandibles are a pair of appendages near the insect’s mouth, and the most anterior of the three pairs of oral appendages. Their function is typically to grasp, crush, or cut the insect’s food, or to defend against predators or rivals. Insect mandibles, which appear to be evolutionarily derived from legs, move in the horizontal plane unlike those of vertebrates, which appear to be derived from gill arches and move vertically.
The mouthparts of arthropods have evolved into a number of forms, each adapted to a different style or mode of feeding. Most mouthparts represent modified, paired appendages, which in ancestral forms would have appeared more like legs than mouthparts. In general, arthropods have mouthparts for cutting, chewing, piercing, sucking, shredding, siphoning, and filtering. This article outlines the basic elements of four arthropod groups: insects, myriapods, crustaceans and chelicerates. Insects are used as the model, with the novel mouthparts of the other groups introduced in turn. Insects are not, however, the ancestral form of the other arthropods discussed here.
In animal anatomy, the mouth, also known as the oral cavity, buccal cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on the outside by the lips and inside by the pharynx and containing in higher vertebrates the tongue and teeth. This cavity is also known as the buccal cavity, from the Latin bucca ("cheek").
Mandibulata, termed "mandibulates", is a clade of arthropods that comprises the extant subphyla Myriapoda, Crustacea and Hexapoda. Mandibulata is currently believed to be the sister group of the clade Arachnomorpha, which comprises the rest of arthropods. The mandibulates constitute the largest and most varied arthropod group.
In arthropods, the maxillae are paired structures present on the head as mouthparts in members of the clade Mandibulata, used for tasting and manipulating food. Embryologically, the maxillae are derived from the 4th and 5th segment of the head and the maxillary palps; segmented appendages extending from the base of the maxilla represent the former leg of those respective segments. In most cases, two pairs of maxillae are present and in different arthropod groups the two pairs of maxillae have been variously modified. In crustaceans, the first pair are called maxillulae.
Insects have a range of mouthparts, adapted to particular modes of feeding. The earliest insects had chewing mouthparts. Specialization has mostly been for piercing and sucking, although a range of specializations exist, as these modes of feeding have evolved a number of times (for example, mosquitoes and aphids both pierce and suck, however female mosquitoes feed on animal blood whereas aphids feed on plant fluids. In this page, the individual mouthparts are introduced for chewing insects. Specializations are generally described thereafter.
The Myriochelata or Paradoxopoda, is a proposed grouping of arthropods comprising the Myriapoda and Chelicerata. It is the sister clade to the Tetraconata.
Insect morphology is the study and description of the physical form of insects. The terminology used to describe insects is similar to that used for other arthropods due to their shared evolutionary history. Three physical features separate insects from other arthropods: they have a body divided into three regions, have three pairs of legs, and mouthparts located outside of the head capsule. It is this position of the mouthparts which divides them from their closest relatives, the non-insect hexapods, which includes Protura, Diplura, and Collembola.
Leptanilla japonica is an uncommon highly migratory, subterranean ant found in Japan. They are tiny insects, with workers measuring about 1.2 mm and queens reaching to about 1.8 mm, and live in very small colonies of only a few hundred individuals at a time Its sexual development follows a seasonal cycle that affects the colony's migration and feeding habits, and vice versa. L. japonica exhibits specialized predation, with prey consisting mainly of geophilomorph centipedes, a less reliable food source that also contributes to their high rate of nest migration. Like ants of genera Amblyopone and Proceratium, the genus Leptanilla engages in larval hemolymph feeding (LHF), with the queen using no other form of sustenance. LHF is an advantageous alternative to the more costly cannibalism. Unlike any other ant, however, members of Leptanilla, including L. japonica, have evolved a specialized organ dubbed the “larval hemolymph tap” that reduces the damage LHF inflicts on the larvae. LHF has become this species' main form of nutrition.
Insects are among the most diverse groups of animals on the planet, including more than a million described species and representing more than half of all known living organisms. The number of extant species is estimated at between six and ten million, found in nearly all environments, although only a small number of species occur in the oceans. This large extant means that the dietary habits of taxa include a large variety of behaviors.
Zigrasimecia is an extinct genus of ants which existed in the Cretaceous period approximately 98 million years ago. The first specimens were collected from Burmese amber in Kachin State, 100 kilometres (62 mi) west of Myitkyina town in Myanmar. In 2013, palaeoentomologists Phillip Barden and David Grimaldi published a paper describing and naming Zigrasimecia tonsora. They described a dealate female with unusual features, notably the highly specialized mandibles. Other features include large ocelli, short scapes, 12 antennomeres, small eyes, and a clypeal margin that has a row of peg-like denticles. The genus Zigrasimecia was originally incertae sedis within Formicidae until a second species, Zigrasimecia ferox, was described in 2014, confirming its placement in the subfamily Sphecomyrminae.