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Wasp

Source: Wikipedia, the free encyclopedia.

Wasp
Temporal range: Jurassic–Present
A social wasp, "Vespula germanica"
A social wasp, Vespula germanica
Scientific classificationEdit this classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
(unranked):
Unicalcarida
Suborder: Apocrita
Groups included
Cladistically included but traditionally excluded taxa
  • clade
    Anthophila
    (bees)
  • family
    Formicidae
    (ants)

A wasp is any

sawflies (Symphyta), which look somewhat like wasps, but are in a separate suborder. The wasps do not constitute a clade, a complete natural group with a single ancestor, as bees and ants are deeply nested within the wasps, having evolved from wasp ancestors. Wasps that are members of the clade Aculeata can sting
their prey.

The most commonly known wasps, such as

pest insect, making wasps valuable in horticulture for biological pest control of species such as whitefly in tomatoes
and other crops.

Wasps first appeared in the fossil record in the

Mymaridae
, including the world's smallest known insect, with a body length of only 0.139 mm (0.0055 in), and the smallest known flying insect, only 0.15 mm (0.0059 in) long.

Wasps have appeared in literature from

Classical times, as the eponymous chorus of old men in Aristophanes' 422 BC comedy The Wasps, and in science fiction from H. G. Wells's 1904 novel The Food of the Gods and How It Came to Earth
, featuring giant wasps with three-inch-long stings. The name 'Wasp' has been used for many warships and other military equipment.

Taxonomy and phylogeny

common wasps and yellowjackets belong to one family, the Vespidae
.

Paraphyletic grouping

The wasps are a cosmopolitan

paraphyletic grouping of hundreds of thousands of species,[1][2] consisting of the narrow-waisted clade Apocrita without the ants and bees.[3] The Hymenoptera also contain the somewhat wasplike but unwaisted Symphyta
, the sawflies.

The term wasp is sometimes used more narrowly for members of the

eusocial wasp lineages, such as yellowjackets (the genera Vespula and Dolichovespula), hornets (genus Vespa), and members of the subfamily Polistinae
.

Fossils

Hymenoptera in the form of Symphyta (

Lower Cretaceous of the Crato Formation in Brazil, some 65 million years before the first fig trees.[5]

The Vespidae include the extinct genus

Florissant fossil beds of Colorado and from fossilised Baltic amber in Europe.[6] Also found in Baltic amber are crown wasps of the genus Electrostephanus.[7][8]

Diversity

Wasps are a diverse group, estimated at well over a hundred thousand

Chalcidoidea) that has co-evolved with it and pollinates it.[10]

Many wasp species are parasitoids; the females deposit eggs on or in a host arthropod on which the larvae then feed. Some larvae start off as parasitoids, but convert at a later stage to consuming the plant tissues that their host is feeding on. In other species, the eggs are laid directly into plant tissues and form galls, which protect the developing larvae from predators, but not necessarily from other parasitic wasps. In some species, the larvae are predatory themselves; the wasp eggs are deposited in clusters of eggs laid by other insects, and these are then consumed by the developing wasp larvae.[10]

The largest social wasp is the

Kikiki huna with a body length of only 158 micrometres, the smallest known flying insect.[18]

There are estimated to be 100,000 species of

haemolymph, but if a parasitoid emerges from the host, the hyperparasites continue their life cycle inside the parasitoid.[19] Parasitoids maintain their extreme diversity through narrow specialism. In Peru, 18 wasp species were found living on 14 fly species in only two species of Gurania climbing squash.[20][21]

Sociality

Social wasps

Of the dozens of extant wasp families, only the family

warning coloration, often in black and yellow, social wasps are frequent models for Batesian mimicry by non-stinging insects, and are themselves involved in mutually beneficial Müllerian mimicry of other distasteful insects including bees and other wasps. All species of social wasps construct their nests using some form of plant fiber (mostly wood pulp) as the primary material, though this can be supplemented with mud, plant secretions (e.g., resin), and secretions from the wasps themselves; multiple fibrous brood cells are constructed, arranged in a honeycombed pattern, and often surrounded by a larger protective envelope. Wood fibres are gathered from weathered wood, softened by chewing and mixing with saliva. The placement of nests varies from group to group; yellow jackets such as Dolichovespula media and D. sylvestris prefer to nest in trees and shrubs; Protopolybia exigua attaches its nests on the underside of leaves and branches; Polistes erythrocephalus chooses sites close to a water source.[22]

Other wasps, like Agelaia multipicta and Vespula germanica, like to nest in cavities that include holes in the ground, spaces under homes, wall cavities or in lofts. While most species of wasps have nests with multiple combs, some species, such as Apoica flavissima, only have one comb.[23] The length of the reproductive cycle depends on latitude; Polistes erythrocephalus, for example, has a much longer (up to 3 months longer) cycle in temperate regions.[24]

Solitary wasps

The vast majority of wasp species are solitary insects.[10][25] Having mated, the adult female forages alone and if it builds a nest, does so for the benefit of its own offspring. Some solitary wasps nest in small groups alongside others of their species, but each is involved in caring for its own offspring (except for such actions as stealing other wasps’ prey or laying in other wasp's nests). There are some species of solitary wasp that build communal nests, each insect having its own cell and providing food for its own offspring, but these wasps do not adopt the division of labour and the complex behavioural patterns adopted by eusocial species.[25]

Adult solitary wasps spend most of their time in preparing their nests and foraging for food for their young, mostly insects or spiders. Their nesting habits are more diverse than those of social wasps. Many species dig burrows in the ground.[25] Mud daubers and pollen wasps construct mud cells in sheltered places.[26] Potter wasps similarly build vase-like nests from mud, often with multiple cells, attached to the twigs of trees or against walls.[27]

Predatory wasp species normally subdue their prey by stinging it, and then either lay their eggs on it, leaving it in place, or carry it back to their nest where an egg may be laid on the prey item and the nest sealed, or several smaller prey items may be deposited to feed a single developing larva. Apart from providing food for their offspring, no further maternal care is given. Members of the family Chrysididae, the cuckoo wasps, are kleptoparasites and lay their eggs in the nests of unrelated host species.[25]

Biology

Anatomy

Vespa crabro

Like all insects, wasps have a hard exoskeleton which protects their three main body parts, the head, the mesosoma (including the thorax and the first segment of the abdomen) and the metasoma. There is a narrow waist, the petiole, joining the first and second segments of the abdomen. The two pairs of membranous wings are held together by small hooks and the forewings are larger than the hind ones; in some species, the females have no wings. In females there is usually a rigid ovipositor which may be modified for injecting venom, piercing or sawing.[28] It either extends freely or can be retracted, and may be developed into a stinger for both defence and for paralysing prey.[29]

In addition to their large

ocelli, which are typically arranged in a triangle just forward of the vertex of the head. Wasps possess mandibles adapted for biting and cutting, like those of many other insects, such as grasshoppers, but their other mouthparts are formed into a suctorial proboscis, which enables them to drink nectar.[30]

The larvae of wasps resemble maggots, and are adapted for life in a protected environment; this may be the body of a host organism or a cell in a nest, where the larva either eats the provisions left for it or, in social species, is fed by the adults. Such larvae have soft bodies with no limbs, and have a blind gut (presumably so that they do not foul their cell).[31]

Diet

Adult solitary wasps mainly feed on nectar, but the majority of their time is taken up by foraging for food for their carnivorous young, mostly insects or spiders. Apart from providing food for their larval offspring, no maternal care is given.[25] Some wasp species provide food for the young repeatedly during their development (progressive provisioning).[32] Others, such as potter wasps (Eumeninae)[33] and sand wasps (Ammophila, Sphecidae),[34] repeatedly build nests which they stock with a supply of immobilised prey such as one large caterpillar, laying a single egg in or on its body, and then sealing up the entrance (mass provisioning).[35]

Predatory and parasitoidal wasps subdue their prey by stinging it. They hunt a wide variety of prey, mainly other insects (including other Hymenoptera), both larvae and adults.[25] The

Pompilidae specialize in catching spiders to provision their nests.[36]