A wasp is any insect of the narrow-waisted suborder Apocrita of the order Hymenoptera which is neither a bee nor an ant; this excludes the broad-waisted 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 Stinger their prey.
The most commonly known wasps, such as and , are in the family Vespidae and are Eusociality, living together in a nest with an egg-laying queen and non-reproducing workers. Eusociality is favoured by the unusual haplodiploid system of sex determination in Hymenoptera, as it makes sisters exceptionally closely related to each other. However, the majority of wasp species are solitary, with each adult female living and breeding independently. Females typically have an ovipositor for laying eggs in or near a food source for the larvae, though in the Aculeata the ovipositor is often modified instead into a sting used for defense or prey capture. Wasps play many ecology. Some are or , whether to feed themselves or to provision their nests. Many, notably the , are , laying eggs in the nests of other wasps. Many of the solitary wasps are parasitoid wasp, meaning they lay eggs on or in other insects (any life stage from egg to adult) and often provision their own nests with such hosts. Unlike true parasites, the wasp larvae eventually kill their hosts. Solitary wasps parasitize almost every pest insect, making wasps valuable in horticulture for biological pest control of species such as whitefly in and other crops.
Wasps first appeared in the fossil record in the Jurassic, and diversified into many surviving superfamilies by the Cretaceous. They are a successful and diverse group of insects with tens of thousands of described species; wasps have spread to all parts of the world except for the polar regions. The largest social wasp is the Asian giant hornet, at up to in length; among the largest solitary wasps is a group of species known as , along with the giant scoliid of Indonesia ( Megascolia procer). The smallest wasps are solitary parasitoid wasps in the family Mymaridae, including the world's smallest known insect, with a body length of only , and the smallest known flying insect, only long.
Wasps have appeared in literature from Classical era, 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.
The term wasp is sometimes used more narrowly for members of the Vespidae, which includes several eusocial wasp lineages, such as (the genera Vespula and Dolichovespula), (genus Vespa), and members of the subfamily Polistinae.
The Vespidae include the extinct genus Palaeovespa, seven species of which are known from the Eocene rocks of the Florissant fossil beds of Colorado and from fossilised Baltic amber in Europe. Also found in Baltic amber are crown wasps of the genus Electrostephanus.
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 , 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.
The largest social wasp is the Asian giant hornet, at up to in length. The various Tarantula hawk are of a similar size and can overpower a spider many times its own weight, and move it to its burrow, with a sting that is excruciatingly painful to humans. The solitary giant Scoliidae, Megascolia procer, with a wingspan of 11.5 cm, has subspecies in Sumatra and Java; it is a parasitoid of the Atlas beetle Chalcosoma atlas. The female giant ichneumon wasp Megarhyssa macrurus is long including its very long but slender ovipositor which is used for boring into wood and inserting eggs. The smallest wasps are solitary parasitoid wasps in the family Mymaridae, including the world's smallest known insect, Dicopomorpha echmepterygis (139 micrometres long) and Kikiki huna with a body length of only 158 micrometres, the smallest known flying insect.
There are estimated to be 100,000 species of Ichneumonoidea in the families Braconidae and Ichneumonidae. These are almost exclusively parasitoids, mostly using other insects as hosts. Another family, the Pompilidae, is a specialist parasitoid of spiders. Some wasps are even parasitoids of parasitoids; the eggs of Eucerotinae are laid beside larvae and the wasp larvae feed temporarily on their haemolymph, but if a parasitoid emerges from the host, the continue their life cycle inside the parasitoid. 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.
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. 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.
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. and construct mud cells in sheltered places. similarly build vase-like nests from mud, often with multiple cells, attached to the twigs of trees or against walls.
Predation 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 Cuckoo wasp, the cuckoo wasps, are Kleptoparasitism and lay their eggs in the nests of unrelated host species.
In addition to their large compound eyes, wasps have several simple eyes known as 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 , but their other mouthparts are formed into a suctorial proboscis, which enables them to drink nectar.
The larvae of wasps resemble , 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).
Predation 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.
The Pompilidae specialize in catching spiders to provision their nests.
Some social wasps are omnivorous, feeding on fallen fruit, nectar, and carrion such as dead insects. Adult male wasps sometimes visit flowers to obtain nectar. Some wasps, such as Polistes fuscatus, commonly return to locations where they previously found prey to forage. In many social species, the larvae exude copious amounts of secretions that are avidly consumed by the adults. These include both and , and may provide essential protein-building nutrients that are otherwise unavailable to the adults (who cannot digest proteins).
Pollen wasps in the subfamily Masarinae gather nectar and pollen in a crop inside their bodies, rather than on body hairs like bees, and pollinate flowers of Penstemon and the water leaf family, Hydrophyllaceae.
The Agaonidae () are the only pollinators of nearly 1000 species of Ficus, and thus are crucial to the survival of their host plants. Since the wasps are equally dependent on their fig trees for survival, the coevolution relationship is fully mutualistic.
The Ichneumonidae are specialized parasitoids, often of Lepidoptera larvae deeply buried in plant tissues, which may be . For this purpose, they have exceptionally long ovipositors; they detect their hosts by smell and vibration. Some of the largest species, including Rhyssa persuasoria and Megarhyssa macrurus, parasitise , large sawflies whose adult females also have impressively long ovipositors. Some parasitic species have a mutualistic relationship with a polydnavirus that weakens the host's immune system and replicates in the oviduct of the female wasp.
One family of Chalcid wasp wasps, the Eucharitidae, has specialized as Myrmecophily, most species hosted by one genus of ant. Eucharitids are among the few parasitoids that have been able to overcome ants' effective defences against parasitoids.
The roughly 140 species of beewolf (Philanthinae) hunt bees, including honeybees, to provision their nests; the adults feed on nectar and pollen.
Among the other clubs bearing the name are a basketball club in Wantirna, Australia, and Alloa Athletic F.C., a football club in Scotland.
H. G. Wells made use of giant wasps in his novel The Food of the Gods and How It Came to Earth (1904):
Wasp (1957) is a science fiction book by the English writer Eric Frank Russell; it is generally considered Russell's best novel. In Stieg Larsson's book The Girl Who Played with Fire (2006) and its film adaptation, Lisbeth Salander has adopted her kickboxing ringname, "The Wasp", as her hacker handle and has a wasp tattoo on her neck, indicating her high status among hackers, unlike her real world situation, and that like a small but painfully stinging wasp, she could be dangerous.
Parasitoidal wasps played an indirect role in the nineteenth-century evolution debate. The Ichneumonidae contributed to Charles Darwin's doubts about the nature and existence of a well-meaning and all-powerful Creator. In an 1860 letter to the American naturalist Asa Gray, Darwin wrote:
Sociality
Social wasps
Solitary wasps
Biology
Anatomy
Diet
Sex determination
Inbreeding avoidance
Ecology
As pollinators
As parasitoids
As parasites
As predators
As models for mimics
As prey
Relationship with humans
As pests
In horticulture
In sport
In fashion
In literature
In military names
See also
Notes
Sources
External links
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