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40-514: The superfamily Ichneumonoidea contains one extinct and three extant families, including the two largest families within Hymenoptera : Ichneumonidae and Braconidae . The group is thought to contain as many as 100,000 species, many of which have not yet been described. Like other parasitoid wasps , they were long placed in the "Parasitica", variously considered as an infraorder or an unranked clade , now known to be paraphyletic . The name

80-411: A considerable number, keeping the wings gripped together especially tightly. Hymenopteran wings have relatively few veins compared with many other insects, especially in the smaller species. In the more ancestral hymenopterans, the ovipositor is blade-like, and has evolved for slicing plant tissues. In the majority, however, it is modified for piercing, and, in some cases, is several times the length of

120-491: A host and lays an egg on, near, or inside the host's body. The ovipositor of ichneumonoids generally cannot deliver a sting as many wasps or bees do. It can be used to bore wood and lay eggs on hosts deep inside, or reach hosts hidden inside leaf shelters. Upon hatching, the larva feeds either externally or internally, killing the host when it is ready to pupate . Various ichneumonoids are used as biological control agents in controlling horticultural or forest pests. An example

160-404: A special ovipositor for inserting eggs into hosts or places that are otherwise inaccessible. This ovipositor is often modified into a stinger . The young develop through holometabolism (complete metamorphosis )—that is, they have a wormlike larval stage and an inactive pupal stage before they reach adulthood. The name Hymenoptera refers to the wings of the insects, but the original derivation

200-409: A wide range of feeding habits. The most primitive forms are typically phytophagous, feeding on flowers, pollen, foliage, or stems. Stinging wasps are predators, and will provision their larvae with immobilised prey, while bees feed on nectar and pollen . A huge number of species are parasitoids as larvae. The adults inject the eggs into a host, which they begin to consume after hatching. For example,

240-399: Is determined by the number of chromosomes an individual possesses. Fertilized eggs get two sets of chromosomes (one from each parent's respective gametes ) and develop into diploid females, while unfertilized eggs only contain one set (from the mother) and develop into haploid males. The act of fertilization is under the voluntary control of the egg-laying female, giving her control of

280-503: Is ambiguous. All references agree that the derivation involves the Ancient Greek πτερόν ( pteron ) for wing. The Ancient Greek ὑμήν ( hymen ) for membrane provides a plausible etymology for the term because species in this order have membranous wings. However, a key characteristic of this order is that the hindwings are connected to the forewings by a series of hooks . Thus, another plausible etymology involves Hymen ,

320-531: Is derived from Latin 'ichneumon', from Ancient Greek ἰχνεύμων (ikhneúmōn, "tracker"), from ἴχνος (íkhnos, "track, footstep"). The name is shared with the Egyptian mongoose, Herpestes ichneumon . The superfamily is defined by fusion of the costal and radial veins of the fore wing, and almost all species have more than 11 antennal segments. Both included families have a cosmopolitan distribution . Ichneumonoids have morphological similarities with relatives within

360-489: Is the relationship between the species Ichneumon eumerus and its host butterfly Phengaris rebeli . The butterfly larva is a parasite within Myrmica ant nests. The adult I. eumerus searches for ant nests and only enters when they contain P. rebeli caterpillars. Once inside, they oviposit within the caterpillars and escape the nest by releasing a chemical which causes the worker ants to fight each other rather than

400-521: The morphology of the organ is related to the life history. Members of the Dipteran (fly) families Tephritidae and Pyrgotidae have well-developed ovipositors that are partly retracted when not in use, with the part that sticks out being the oviscape. Oestridae , another family within Diptera, often have short hairy ovipositors, the species Cuterebra fontinella has one of the shortest within

440-693: The Hymenoptera during the Permian , leading to a single clade which contains the Apocrita and the Orussoidea , but has been secondarily lost multiple times. The Apocrita emerged from that clade during the Jurassic . Sawflies [REDACTED] Orussoidea [REDACTED] Ichneumonidae [REDACTED] Braconidae [REDACTED] Chalcidoidea and allies [REDACTED] Aculeata [REDACTED] Ichneumonoids are solitary insects, and

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480-594: The Triassic , with the oldest fossils belonging to the family Xyelidae . Social hymenopterans appeared during the Cretaceous . The evolution of this group has been intensively studied by Alex Rasnitsyn , Michael S. Engel , and others. Phylogenetic relationships within the Hymenoptera, based on both morphology and molecular data, have been intensively studied since 2000. In 2023, a molecular study based on

520-457: The basal part that sticks out is known as the scape , or more specifically oviscape , the word scape deriving from the Latin word scāpus , meaning "stalk" or "shaft". Grasshoppers use their ovipositors to force a burrow into the earth to receive the eggs. Cicadas pierce the wood of twigs with their ovipositors to insert the eggs. Sawflies slit the tissues of plants by means of

560-402: The genetic load of deleterious genes is purged relatively quickly. Some hymenopterans take advantage of parthenogenesis , the creation of embryos without fertilization . Thelytoky is a particular form of parthenogenesis in which female embryos are created (without fertilisation). The form of thelytoky in hymenopterans is a kind of automixis in which two haploid products (proto-eggs) from

600-927: The Ancient Greek god of marriage, as these insects have married wings in flight. Another suggestion for the inclusion of Hymen is the myth of Melissa , a nymph with a prominent role at the wedding of Zeus. Molecular analysis finds that Hymenoptera is the earliest branching group of Holometabola . Hymenoptera (sawflies, wasps) [REDACTED] Coleoptera (beetles) [REDACTED] Strepsiptera (twisted-wing parasites) [REDACTED] Raphidioptera (snakeflies) [REDACTED] Megaloptera (alderflies and allies) [REDACTED] Neuroptera (Lacewings and allies) [REDACTED] Lepidoptera (butterflies, moths) [REDACTED] Trichoptera (caddisflies) [REDACTED] Diptera [REDACTED] Mecoptera (scorpionflies) [REDACTED] Siphonaptera (fleas) [REDACTED] Hymenoptera originated in

640-497: The Cape honey bee Apis mellifera capensis . Oocytes that undergo automixis with central fusion often have a reduced rate of crossover recombination , which helps to maintain heterozygosity and avoid inbreeding depression . Species that display central fusion with reduced recombination include the ants Platythyrea punctata and Wasmannia auropunctata and the Cape honey bee Apis mellifera capensis . In A. m. capensis ,

680-826: The analysis of ultra-conserved elements confirmed many previous findings and produced a relatively robust phylogeny of the whole Order. Basal superfamilies are shown in the cladogram below. Tenthredinoidea [REDACTED] Xyeloidea ( Triassic -present) [REDACTED] Pamphilioidea [REDACTED] Siricoidea (horntails or wood wasps) [REDACTED] Xiphydrioidea (wood wasps) [REDACTED] Cephoidea (stem sawflies) [REDACTED] Orussoidea ( parasitic wood wasps) [REDACTED] Apocrita ( ants , bees , wasps ) [REDACTED] Hymenopterans range in size from very small to large insects, and usually have two pairs of wings. Their mouthparts are adapted for chewing, with well-developed mandibles (ectognathous mouthparts). Many species have further developed

720-429: The body. In some species, the ovipositor has become modified as a stinger , and the eggs are laid from the base of the structure, rather than from the tip, which is used only to inject venom . The sting is typically used to immobilize prey, but in some wasps and bees may be used in defense. Hymenopteran larvae typically have a distinct head region, three thoracic segments, and usually nine or 10 abdominal segments. In

760-420: The eggs of the endangered Papilio homerus are parasitized at a rate of 77%, mainly by Hymenoptera species. Some species are even hyperparasitoid , with the host itself being another parasitoid insect. Habits intermediate between those of the herbivorous and parasitoid forms are shown in some hymenopterans, which inhabit the galls or nests of other insects, stealing their food, and eventually killing and eating

800-466: The exception of some bee larvae where the larval anus has reappeared through developmental reversion. In general, the anus only opens at the completion of larval growth. Hymenoptera as a group are highly susceptible to habitat loss, which can lead to substantial decreases in species richness and have major ecological implications due to their pivotal role as plant pollinators. Oviposition Some ovipositors only retract partly when not in use, and

840-503: The family. Ovipositors exist not only in winged insects , but also in Apterygota , where the ovipositor has an additional function in gathering the spermatophore during mating. Little is known about the egg-laying habits of these insects in the wild. Female bitterlings in the genus Rhodeus have an ovipositor in the form of a tubular extension of the genital orifice. During breeding season, they use it when depositing eggs in

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880-505: The host's immune system and prevent it from destroying the eggs. However, in virtually all stinging Hymenoptera , the ovipositor is no longer used for egg-laying. An exception is the family Chrysididae , members of the Hymenoptera, in which species such as Chrysis ignita have reduced stinging apparatus and a functional ovipositor. Fig wasp ovipositors have specialized serrated teeth to penetrate fruits, but gall wasps have either uniform teeth or no teeth on their ovipositors, meaning

920-405: The intruding wasp. The wasp eggs then hatch inside the caterpillar and eventually consume and kill the host. Hymenoptera Hymenoptera is a large order of insects , comprising the sawflies , wasps , bees , and ants . Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are parasitic . Females typically have

960-488: The longest egg-laying organs (relative to body size) known. The stingers of the Aculeata (wasps, hornets, bees, and ants) are ovipositors, highly modified and with associated venom glands . They are used to paralyze prey, or as defensive weapons. The penetrating sting plus venom allows the wasp to lay eggs with less risk of injury from the host. In some cases, the injection also introduces virus particles that suppress

1000-439: The mantle cavity of freshwater mussels , where their eggs develop in reasonable security. Seahorses have an ovipositor for introducing eggs into the brood pouch of the male, who carries them until it is time to release the fry into a suitable situation in the open water. The marbled newt , or Triturus marmoratus, females participate in parental investment by ovipositing their eggs. They carefully wrap them in aquatic leaves as

1040-417: The mouthparts into a lengthy proboscis , with which they can drink liquids, such as nectar . They have large compound eyes , and typically three simple eyes, ocelli . The forward margin of the hind wing bears a number of hooked bristles, or " hamuli ", which lock onto the fore wing, keeping them held together. The smaller species may have only two or three hamuli on each side, but the largest wasps may have

1080-473: The multiple origins of eusociality within this order. In many colonies of bees, ants, and wasps, worker females will remove eggs laid by other workers due to increased relatedness to direct siblings, a phenomenon known as worker policing . Another consequence is that hymenopterans may be more resistant to the deleterious effects of inbreeding . As males are haploid, any recessive genes will automatically be expressed, exposing them to natural selection. Thus,

1120-471: The occupant. The Hymenoptera are divided into two groups; the Symphyta which have no waist, and the Apocrita which have a narrow waist. The suborder Symphyta includes the sawflies , horntails , and parasitic wood wasps . The group may be paraphyletic , as it has been suggested that the family Orussidae may be the group from which the Apocrita arose. They have an unconstricted junction between

1160-811: The order Hymenoptera, including ants and bees . Ichneumonoidea contains a great deal of morphological diversity, with species ranging in size from 1 to 130 mm (0.039 to 5.118 in) long. Most are slender, and the females of many species (particularly in the genus Megarhyssa ) have extremely long ovipositors for laying eggs. The ichneumonid wasps may be more familiar to non- entomologists than braconids, as they are generally larger. The two families are distinguished from each other primarily by details of wing venation. Most are brownish or black, not brightly colored. Fore wings lack vein 2m-cu. Ichneumonids vary greatly in size and their color varies from brightly colored to uniform black. Fore wing with vein 2m-cu present and tubular. Parasitoidism evolved only once in

1200-440: The ovipositor and so do some species of long-horned grasshoppers . In the ichneumon wasp genus Megarhyssa , the females have a slender ovipositor (terebra) several inches long that is used to drill into the wood of tree trunks . These wasps are parasitic in the larval stage on the larvae of horntail wasps, hence the egg must be deposited directly into the host's body as it is feeding. The ovipositors of Megarhyssa are among

1240-422: The recombination rate during meiosis is reduced more than tenfold. In W. auropunctata the reduction is 45 fold. Single queen colonies of the narrow headed ant Formica exsecta illustrate the possible deleterious effects of increased homozygosity. Colonies of this species which have more homozygous queens will age more rapidly, resulting in reduced colony survival. Different species of Hymenoptera show

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1280-413: The same meiosis fuse to form a diploid zygote. This process tends to maintain heterozygosity in the passage of the genome from mother to daughter. It is found in several ant species including the desert ant Cataglyphis cursor , the clonal raider ant Cerapachys biroi , the predaceous ant Platythyrea punctata , and the electric ant (little fire ant) Wasmannia auropunctata . It also occurs in

1320-615: The sex locus and develop as a male, instead. This is especially likely to occur in an individual whose parents were siblings or other close relatives. Diploid males are known to be produced by inbreeding in many ant, bee, and wasp species. Diploid biparental males are usually sterile but a few species that have fertile diploid males are known. One consequence of haplodiploidy is that females on average have more genes in common with their sisters than they do with their daughters. Because of this, cooperation among kindred females may be unusually advantageous and has been hypothesized to contribute to

1360-417: The sex of her offspring. This phenomenon is called haplodiploidy . However, the actual genetic mechanisms of haplodiploid sex determination may be more complex than simple chromosome number. In many Hymenoptera, sex is determined by a single gene locus with many alleles. In these species, haploids are male and diploids heterozygous at the sex locus are female, but occasionally a diploid will be homozygous at

1400-438: The suborder Symphyta , the eruciform larvae resemble caterpillars in appearance, and like them, typically feed on leaves. They have large chewing mandibles, three pairs of thoracic limbs, and, in most cases, six or eight abdominal prolegs . Unlike caterpillars, however, the prolegs have no grasping spines, and the antennae are reduced to mere stubs. Symphytan larvae that are wood borers or stem borers have no abdominal legs and

1440-399: The suborder (and clade) Apocrita , characterized by a constriction between the first and second abdominal segments called a wasp-waist ( petiole ), also involving the fusion of the first abdominal segment to the thorax . Also, the larvae of all Apocrita lack legs, prolegs, or ocelli. The hindgut of the larvae also remains closed during development, with feces being stored inside the body, with

1480-427: The thoracic legs are smaller than those of non-borers. With rare exceptions, larvae of the suborder Apocrita have no legs and are maggotlike in form, and are adapted to life in a protected environment. This may be the body of a host organism, or a cell in a nest, where the adults will care for the larva. In parasitic forms, the head is often greatly reduced and partially withdrawn into the prothorax (anterior part of

1520-520: The thorax and abdomen. The larvae are herbivorous, free-living, and eruciform , usually with three pairs of true legs, prolegs (on every segment, unlike Lepidoptera ) and ocelli . The prolegs do not have crochet hooks at the ends unlike the larvae of the Lepidoptera. The legs and prolegs tend to be reduced or absent in larvae that mine or bore plant tissue, as well as in larvae of Pamphiliidae . The wasps , bees , and ants together make up

1560-524: The thorax). Sense organs appear to be poorly developed, with no ocelli, very small or absent antennae, and toothlike, sicklelike, or spinelike mandibles. They are also unable to defecate until they reach adulthood due to having an incomplete digestive tract (a blind sac), presumably to avoid contaminating their environment. The larvae of stinging forms ( Aculeata ) generally have 10 pairs of spiracles, or breathing pores, whereas parasitic forms usually have nine pairs present. Among most or all hymenopterans, sex

1600-489: The vast majority are parasitoids ; the larvae feed on or in another insect until it finally dies. Most hosts are holometabolous insect larvae, but there are many exceptions. In general, ichneumonoids are host specific, and only attack one or a few closely related host species. Many species use polydnaviruses to suppress the immune systems of their host insects. Due to the wide variety in hosts and lifestyles, see subfamily pages for more detail. The female ichneumonoid finds

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