Labellum (insect anatomy)

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Head morphology of Muscid fly.
labellum, showing pseudotracheae;
labium,
maxillary palp,
labrum;
subgenal area;
clypeus;
fronto-orbital area;
fronto-orbital bristles;
outer vertical bristle;
inner vertical bristle;
postocellar bristles;
ocelli;
ocellar bristles;
compound eye;
Frontal or ptilinal suture;
antenna;
arista;
vibrissa. Head morphology of Muscomorpha.svg
Head morphology of Muscid fly.
  1. labellum, showing pseudotracheae;
  2. labium,
  3. maxillary palp,
  4. labrum;
  5. subgenal area;
  6. clypeus;
  7. fronto-orbital area;
  8. fronto-orbital bristles;
  9. outer vertical bristle;
  10. inner vertical bristle;
  11. postocellar bristles;
  12. ocelli;
  13. ocellar bristles;
  14. compound eye;
  15. Frontal or ptilinal suture;
  16. antenna;
  17. arista;
  18. vibrissa.

In entomology, the term labellum has been applied variously and in partly contradictory ways. One usage is in referring to a prolongation of the labrum that covers the base of the rostrum in certain Coleoptera and Hemiptera. [1]

In contrast, the commonest current use of the term is in the anatomy of the mouthparts of Diptera, particularly those in which the labium forms the bulk of the proboscis, such as in the housefly family. Typically, the labium is expanded distally into a pair of fleshy labella. In the early twentieth century it was argued that the labella are the modified labial palps, and that point of view still is seen as having merit. [2] In flies such as the mosquitoes, that have long antennae, the labella are two separate organs, attached to the proboscis only at their bases, but in the flies with short antennae, such as the house fly, they are more or less fused to form a single structure. Flies with fused labella have food channels in the surface of the labella. These are called pseudotracheae. [3] They form the "spongy" part of a housefly's "tongue".

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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 and others, although only about 125,000 species have been described.

Weevil Superfamily of beetles

Weevils are beetles belonging to the superfamily Curculionoidea, known for their elongated snouts. They are usually small, less than 6 mm in length, and herbivorous. About 97,000 species of weevils are known. They belong to several families, with most of them in the family Curculionidae. Some other beetles, although not closely related, bear the name "weevil", such as the biscuit weevil, which belongs to the family Ptinidae.

Proboscis

A proboscis is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In invertebrates, the term usually refers to tubular mouthparts used for feeding and sucking. In vertebrates, a proboscis is an elongated nose or snout.

Horse-fly Family of insects

Horse-flies or horseflies are true flies in the family Tabanidae in the insect order Diptera. They are often large and agile in flight, and the females bite animals, including humans, to obtain blood. They prefer to fly in sunlight, avoiding dark and shady areas, and are inactive at night. They are found all over the world except for some islands and the polar regions. Both horse-flies and botflies (Oestridae) are sometimes referred to as gadflies.

Asilidae 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 notoriously aggressive predatory habits; they feed mainly or exclusively on other insects and as a rule they wait in ambush and catch their prey in flight.

Glossary of entomology terms List of definitions of terms and concepts commonly used in the study of entomology

This glossary of entomology describes terms used in the formal study of insect species by entomologists.

Arthropod mouthparts

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.

Empididae Family of flies

Empididae is a family of flies with over 3,000 described species occurring worldwide in all the biogeographic realms but the majority are found in the Holarctic. They are mainly predatory flies like most of their relatives in the Empidoidea, and exhibit a wide range of forms but are generally small to medium-sized, non-metallic and rather bristly.

Mandible (arthropod mouthpart) 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 referred to as 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.

Maxilla (arthropod mouthpart)

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.

Insect mouthparts

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.

Housefly Species of insect

The housefly is a fly of the suborder Cyclorrhapha. It is believed to have evolved in the Cenozoic Era, possibly in the Middle East, and has spread all over the world as a commensal of humans. It is the most common fly species found in houses. Adults are gray to black, with four dark, longitudinal lines on the thorax, slightly hairy bodies, and a single pair of membranous wings. They have red eyes, set farther apart in the slightly larger female.

<i>Hydrotaea</i> Genus of flies

Hydrotaea is a genus of insects in the housefly family, Muscidae. They occur in most regions of the world but are more populous in warmer climates. They are often found on feces in summer months, and are therefore generally found in close proximity to livestock. Among the 130 known species in this genus, one of the most commonly recognized is the dump fly.

External morphology of Lepidoptera

The external morphology of Lepidoptera is the physiological structure of the bodies of insects belonging to the order Lepidoptera, also known as butterflies and moths. Lepidoptera are distinguished from other orders by the presence of scales on the external parts of the body and appendages, especially the wings. Butterflies and moths vary in size from microlepidoptera only a few millimetres long, to a wingspan of many inches such as the Atlas moth. Comprising over 160,000 described species, the Lepidoptera possess variations of the basic body structure which has evolved to gain advantages in adaptation and distribution.

Insect morphology

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.

<i>Philoliche longirostris</i>

Philoliche longirostris is a fly of the Tabanidae family that is found in India, Nepal specifically the Himalayas. It was first described and given a binomial name by Thomas Hardwicke in 1823. Notable is its proboscis, which is "many times longer than its body". Adults of the species in the Himalayas are said to emerge after the rains in July and are not seen after September. Their emergence matches the flowering of several species of Roscoea and it has been suggested that they may have coevolved with Philoliche.

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.

Chloropidae Family of insects

The Chloropidae are a family of flies commonly known as frit flies or grass flies. About 2000 described species are in over 160 genera distributed worldwide. These are usually very small flies, yellow or black and appearing shiny due to the virtual absence of any hairs. The majority of the larvae are phytophagous, mainly on grasses, and can be major pests of cereals. However, parasitic and predatory species are known. A few species are kleptoparasites. Some species in the genera Hippelates and Siphunculina are called eye gnats or eye flies for their habit of being attracted to eyes. They feed on lachrymal secretions and other body fluids of various animals, including humans, and are of medical significance.

Parasitic flies of domestic animals

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.

References

  1. Smith, John B. (1906). Explanation of terms used in entomology. Brooklyn Entomological Society.
  2. Crampton, G. C.; The sclerites of the head and the mouthparts of certain immature and adult insects. Ann. Ent. Soc. Am. 14, pp. 65-103.
  3. Richards, O. W.; Davies, R.G. (1977). Imms' General Textbook of Entomology: Volume 1: Structure, Physiology and Development Volume 2: Classification and Biology. Berlin: Springer. ISBN   0-412-61390-5.