Mandible (insect mouthpart)

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The mandibles of a bull ant Bullant head detail.jpg
The mandibles of a bull ant

Insect mandibles are a pair of appendages near the insect's mouth, and the most anterior of the three pairs of oral appendages (the labrum is more anterior, but is a single fused structure). 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.

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Grasshoppers, crickets, and other simple insects

The mouthparts of orthopteran insects are often used as a basic example of mandibulate (chewing) mouthparts, and the mandibles themselves are likewise generalized in structure. They are large and hardened, shaped like pinchers, with cutting surfaces on the distal portion and chewing or grinding surfaces basally. They are usually lined with teeth and move sideways. Large pieces of leaves can therefore be cut and then pulverized near the mouth opening. The specific derived morphology of the teeth on the mandible varies depending on whether the insect eats broad-leafed herbs or grasses.[ citation needed ] This same simple structure is seen in all of the remaining Polyneopteran insect orders, with the exception of the Paraneoptera (Hemiptera, Thysanoptera, and Phthiraptera).

The mandibles of adult and larval Odonata appear simple and generalized, although there are typically six or seven mandibular muscles. [1] Ephemeroptera rarely feed as adults, though the nymphs have simple mandibles. [2]

True bugs

The Hemiptera, and other insects whose mouthparts are described as piercing-sucking, have modified mandibles. Rather than being tooth-like, the mandibles of such insects are lengthened into stylets, which form the outer two parts of the feeding tube, or beak. The mandibles are therefore instrumental in piercing the plant or animal tissues upon which these insects feed, and in helping draw up fluids to the insect's mouth.

Beetles

Stag beetle with mandibles modified no longer used in feeding Lucanus cervus.jpg
Stag beetle with mandibles modified no longer used in feeding

Nearly all adult beetles, and many beetle larvae, have mandibles. In general form they are similar to those of grasshoppers: hardened and tooth-like.

Beetle mandibles show a remarkable amount of variability between species, and some are very highly adapted to the food sources or other uses that the species has for them. Certain firefly larvae (family Lampyridae) that feed on snails have grooved mandibles that not only physically break down their prey, but also deliver digestive fluids by these grooves. Ground beetles (family Carabidae) of the tribe Cychrini have long mandibles that project far in front of them, which aid them in feeding on snails inside their shells.

Members of the stag beetle family (Lucanidae) have greatly enlarged mandibles that are often forked, resembling the horns of various deer, from which their common name comes, and similar modifications appear in various scarab beetles and longhorn beetles. Males of these beetles use their mandibles to grasp or displace each other as they compete for mates.

Lice

The mandibles in Phthiraptera (lice) are also modified into piercing stylets.

Thrips

Thysanoptera (thrips) have a variation of piercing mouthparts. During development they lose one mandible, so only the left mandible is present, modified into a stylet. [3]

Neuropteroids

Within the Neuropterida, adults have chewing mouthparts, but the mandibles of male dobsonflies are non-functional in feeding. The larvae in many lineages are predatory, with mandibles modified with grooves along which digestive saliva flows, while the larvae of the family Sisyridae have the mouthparts developed into a sucking tube which they use to feed on the liquid tissues of freshwater sponges.

Ants, bees, and wasps

Musculature of ant mandibles AntMandible.jpg
Musculature of ant mandibles
Wasp drinking; the yellow mandibles can be seen on either side of the mouthparts Vespula germanica 2.jpg
Wasp drinking; the yellow mandibles can be seen on either side of the mouthparts

Most adult Hymenoptera have mandibles that follow the general form, as in grasshoppers. The mandibles are used to clip pieces of vegetation, gather wood fibers, dig nests, or to capture and disassemble prey. What is unusual is that many Hymenoptera have the remaining mouthparts modified to form a proboscis (a "tongue" used to feed on liquids), making them virtually the only insects that normally possess both chewing mouthparts and sucking mouthparts (a few exceptional members of other orders may exhibit this, such as flower-feeding beetles that also have "tongues").

Trigona corvina , and other stingless bees, utilize their mandibles for defense purposes and typically interlock them with other individuals while fighting for resources. [4]

Flies

Several families of flies, notably mosquitoes (family Culicidae), have mandibles that are modified into stylets for piercing, similar to the true bugs.

Flies of the Muscomorpha, including the house fly, Musca domestica, stable fly, Stomoxys calcitrans, blow flies (family Calliphoridae), and many others, lack mandibles altogether, and the mouthparts are designed for sponging up liquids.

Butterflies and moths

All but a few adult Lepidoptera lack mandibles, with the remaining mouthparts forming an elongated sucking tube. The exception is the mandibulate moths (family Micropterigidae), which have fully developed mandibles as adults.

See also

Related Research Articles

<span class="mw-page-title-main">Mosquito</span> Family of flies

Mosquitoes, the Culicidae, are a family of small flies consisting of 3,600 species. The word mosquito is Spanish and Portuguese for little fly. Mosquitoes have a slender segmented body, one pair of wings, three pairs of long hair-like legs, and specialized, highly elongated, piercing-sucking mouthparts. All mosquitoes drink nectar from flowers; females of some species have in addition adapted to drink blood. Evolutionary biologists view mosquitoes as micropredators, small animals that parasitise larger ones by drinking their blood without immediately killing them. Medical parasitologists view mosquitoes instead as vectors of disease, carrying protozoan parasites or bacterial or viral pathogens from one host to another.

<i>Mallophaga</i> Suborder of lice

The Mallophaga are a possibly paraphyletic section of lice, known as chewing lice, biting lice, or bird lice, containing more than 3000 species. These lice are external parasites that feed mainly on birds, although some species also feed on mammals. They infest both domestic and wild mammals and birds, and cause considerable irritation to their hosts. They have paurometabolis or incomplete metamorphosis.

<span class="mw-page-title-main">Fly</span> Order of insects

Flies are insects of the order Diptera, the name being derived from the Greek δι- di- "two", and πτερόν pteron "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced mechanosensory organs known as halteres, which act as high-speed sensors of rotational movement and allow dipterans to perform advanced aerobatics. Diptera is a large order containing an estimated 1,000,000 species including horse-flies, crane flies, hoverflies, mosquitoes and others, although only about 125,000 species have been described.

<span class="mw-page-title-main">Hemiptera</span> Order of insects often called true bugs

Hemiptera is an order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from 1 mm (0.04 in) to around 15 cm (6 in), and share a common arrangement of piercing-sucking mouthparts. The name "true bugs" is often limited to the suborder Heteroptera.

<span class="mw-page-title-main">Thrips</span> Order of insects

Thrips are minute, slender insects with fringed wings and unique asymmetrical mouthparts. Entomologists have described approximately 7,700 species. They fly only weakly and their feathery wings are unsuitable for conventional flight; instead, thrips exploit an unusual mechanism, clap and fling, to create lift using an unsteady circulation pattern with transient vortices near the wings.

<span class="mw-page-title-main">Pentatomoidea</span> Superfamily of true bugs

The Pentatomoidea are a superfamily of insects in the suborder Heteroptera of the order Hemiptera. As hemipterans, they possess a common arrangement of sucking mouthparts. The roughly 7000 species under Pentatomoidea are divided into 21 families. Among these are the stink bugs and shield bugs, jewel bugs, giant shield bugs, and burrower bugs.

<span class="mw-page-title-main">Haliplidae</span> Family of beetles

The Haliplidae are a family of water beetles that swim using an alternating motion of the legs. They are therefore clumsy in water, and prefer to get around by crawling. The family consists of about 200 species in 5 genera, distributed wherever there is freshwater habitat; it is the only extant member of superfamily Haliploidea. They are also known as crawling water beetles or haliplids.

<span class="mw-page-title-main">Asilidae</span> Family of flies

The Asilidae are the robber fly family, also called assassin flies. They are powerfully built, bristly flies with a short, stout proboscis enclosing the sharp, sucking hypopharynx. The name "robber flies" reflects their expert predatory habits; they feed mainly or exclusively on other insects and, as a rule, they wait in ambush and catch their prey in flight.

<span class="mw-page-title-main">Arthropod mouthparts</span> Mouthparts of arthropods

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.

<span class="mw-page-title-main">Mandible (arthropod mouthpart)</span> Pair of mouthparts used either for biting or cutting and holding food

The mandible of an arthropod is a pair of mouthparts used either for biting or cutting and holding food. Mandibles are often simply called jaws. Mandibles are present in the extant subphyla Myriapoda, Crustacea and Hexapoda. These groups make up the clade Mandibulata, which is currently believed to be the sister group to the rest of arthropods, the clade Arachnomorpha.

<span class="mw-page-title-main">Maxilla (arthropod mouthpart)</span>

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.

<span class="mw-page-title-main">Insect mouthparts</span> Overview of mouthparts of insects

Insects have mouthparts that may vary greatly across insect species, as they are adapted to particular modes of feeding. The earliest insects had chewing mouthparts. Most specialisation of mouthparts are for piercing and sucking, and this mode of feeding has evolved a number of times independently. For example, mosquitoes and aphids both pierce and suck, though female mosquitoes feed on animal blood whereas aphids feed on plant fluids.

<span class="mw-page-title-main">Insect morphology</span> Description of the physical form of insects

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, three pairs of legs, and mouthparts located outside of the head capsule. This position of the mouthparts divides them from their closest relatives, the non-insect hexapods, which include Protura, Diplura, and Collembola.

<span class="mw-page-title-main">Paraneoptera</span> Superorder of insects

Paraneoptera or Acercaria is a superorder of insects which includes lice, thrips, and hemipterans, the true bugs. It also includes the extinct order Permopsocida, known from fossils dating from the Early Permian to the mid-Cretaceous.

Dipteran morphology differs in some significant ways from the broader morphology of insects. The Diptera is a very large and diverse order of mostly small to medium-sized insects. They have prominent compound eyes on a mobile head, and one pair of functional, membraneous wings, which are attached to a complex mesothorax. The second pair of wings, on the metathorax, are reduced to halteres. The order's fundamental peculiarity is its remarkable specialization in terms of wing shape and the morpho-anatomical adaptation of the thorax – features which lend particular agility to its flying forms. The filiform, stylate or aristate antennae correlate with the Nematocera, Brachycera and Cyclorrhapha taxa respectively. It displays substantial morphological uniformity in lower taxa, especially at the level of genus or species. The configuration of integumental bristles is of fundamental importance in their taxonomy, as is wing venation. It displays a complete metamorphosis, or holometabolous development. The larvae are legless, and have head capsules with mandibulate mouthparts in the Nematocera. The larvae of "higher flies" (Brachycera) are however headless and wormlike, and display only three instars. Pupae are obtect in the Nematocera, or coarcate in Brachycera.

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.

<span class="mw-page-title-main">Parasitic flies of domestic animals</span> Overview of parasite-transmitting flies

Many species of flies of the two-winged type, Order Diptera, such as mosquitoes, horse-flies, blow-flies and warble-flies, cause direct parasitic disease to domestic animals, and transmit organisms that cause diseases. These infestations and infections cause distress to companion animals, and in livestock industry the financial costs of these diseases are high. These problems occur wherever domestic animals are reared. This article provides an overview of parasitic flies from a veterinary perspective, with emphasis on the disease-causing relationships between these flies and their host animals. The article is organized following the taxonomic hierarchy of these flies in the phylum Arthropoda, order Insecta. Families and genera of dipteran flies are emphasized rather than many individual species. Disease caused by the feeding activity of the flies is described here under parasitic disease. Disease caused by small pathogenic organisms that pass from the flies to domestic animals is described here under transmitted organisms; prominent examples are provided from the many species.

<i>Heliothrips haemorrhoidalis</i> Species of thrip

Heliothrips haemorrhoidalis is a species of thrips in the family Thripidae. It is most commonly known as the greenhouse thrips, the glasshouse thrip or black tea thrips. This species of thrips was first described in 1833 by Bouché in Berlin, Germany. H. haemorrhoidalis also has many synonyms depending on where they were described from such as: H. adonidum Haliday, H. semiaureus Girault, H. abdominalis Reuter, H. angustior Priesner, H. ceylonicus Schultz, Dinurothrips rufiventris Girault. In New Zealand, H. haemorrhoidalis is one of the four species belonging to the subfamily Panchaetothripinae.

<span class="mw-page-title-main">Allantonematidae</span> Family of roundworms

Allantonematidae is a family of insect-parasitic nematodes from the order Tylenchida. Allantonematid nematodes infect a variety of insects including beetles, butterflies, flies, thrips, ants, and more. For instance, the nematode Howardula aoronymphium parasitizes mushroom-feeding fruit flies, Formicitylenchus oregonensis parasitizes carpenter ants, and Metaparasitylenchus hypothenemi parasitizes a pest of coffee beans, the coffee berry borer.

References

  1. David, Sina; Funken, Johannes; Potthast, Wolfgang; Blanke, Alexander (1 April 2016). "Musculoskeletal modelling of the dragonfly mandible system as an aid to understanding the role of single muscles in an evolutionary context". The Journal of Experimental Biology. 219 (7): 1041–1049. doi: 10.1242/jeb.132399 . PMID   26896542.
  2. National Park Service - Insect Design - Insect Mouth Parts
  3. "Thrips (Order: Thysanoptera)". Amateur Entomologist's Society.
  4. Johnson, Leslie K.; Hubbell, Stephen P. (1974-01-01). "Aggression and Competition among Stingless Bees: Field Studies". Ecology. 55 (1): 120–127. doi:10.2307/1934624. JSTOR   1934624.