The superfamily Ichneumonoidea contains one extinct and three extant families, including the two largest families within Hymenoptera:

Ichneumonidae The Ichneumonidae, also known as the ichneumon wasps, Darwin wasps, or ichneumonids, are a family of parasitoid wasps of the insect order Hymenoptera. They are one of the most diverse groups within the Hymenoptera with roughly 25,000 species cur ...

and

Braconidae The Braconidae are a family of parasitoid wasps. After the closely related Ichneumonidae, braconids make up the second-largest family in the order Hymenoptera, with about 17,000 recognized species and many thousands more undescribed. One analysis ...

. The group is thought to contain as many as 100,000 species, many of which have not yet been described. Like other

parasitoid wasp Parasitoid wasps are a large group of hymenopteran superfamilies, with all but the wood wasps (Orussoidea) being in the wasp-waisted Apocrita. As parasitoids, they lay their eggs on or in the bodies of other arthropods, sooner or later causin ...

s, they were long placed in the "Parasitica", variously considered as an

infraorder Order ( la, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and ...

or an unranked clade, now known to be paraphyletic.

Etymology

The name 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''.

Description

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 the order Hymenoptera, including

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of ...

s and bees. Ichneumonoidea contains a great deal of morphological diversity, with species ranging in size from long. Most are slender, and the females of many species (particularly in the genus ''

Megarhyssa ''Megarhyssa'', also known as giant ichneumonid wasps, giant ichneumons, or stump stabbers, is a genus of large ichneumon wasps, with some species known for having the longest ovipositors of any insects. They are idiobiont endoparasitoids of the ...

'') 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.

Braconidae

Most are brownish or black, not brightly colored. Fore wings lack vein 2m-cu.

Ichneumonidae

Ichneumonids vary greatly in size and their color varies from brightly colored to uniform black. Fore wing with vein 2m-cu present and tubular.

Evolution

Parasitoidism evolved only once in the Hymenoptera during the

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last ...

, leading to a single clade which contains the

Apocrita Apocrita is a suborder of insects in the order Hymenoptera. It includes wasps, bees, and ants, and consists of many families. It contains the most advanced hymenopterans and is distinguished from Symphyta by the narrow "waist" ( petiole) formed ...

and the

Orussoidea Orussoidea is a superfamily of sawflies. It contains the living family Orussidae, as well as the extinct families Burmorussidae and Paroryssidae. They are the group of sawflies closest to the Apocrita, the group containing wasps, bees and ants, w ...

, but has been secondarily lost multiple times. The Apocrita emerged from that clade during the

Jurassic The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of ...

Parasitic life cycle

Ichneumonoids are solitary insects, and the vast majority are parasitoids; the

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

e feed on or in another insect until it finally dies. Most hosts are holometabolus 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

polydnavirus A polydnavirus (PDV) is a member of the family ''Polydnaviridae'' of insect viruses. There are two genera in the family: '' Bracovirus'' and '' Ichnovirus''. Polydnaviruses form a symbiotic relationship with parasitoid wasps; ( ichnoviruses ( ...

es 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 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

pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in thei ...

te. Various ichneumonoids are used as biological control agents in controlling horticultural or forest pests. An example 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 The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typical ...

within the caterpillars and escape the nest by releasing a chemical which causes the worker ants to fight each other rather than the intruding wasp. The wasp eggs then hatch inside the caterpillar and eventually consume and kill the host. ;Life cycle of '' Hercus fontinalis'' File:Hercus fontinalis early instar larvae.jpg, Early instar larvae on caterpillar File:Hercus fontinalis later instar larvae.jpg, Later instar larvae File:Hercus_fontinalis_final_instar_larva.jpg, Final instar larvae building cocoon File:Hercus fontinalis pupa.jpg, Pupa inside cocoon File:Hercus fontinalis eclosion.jpg, Adults emerging from cocoons File:Hercus fontinalis female.jpg, Adult female

References

External links

* *
Reference large-format photos of 15 different species of Ichneumonidae
* A
interesting account
of an observer's encounter with Ichneumons.

* ttp://bugguide.net/node/view/14971 Bugguide.net. Superfamily Ichneumonoidea - Braconids and Ichneumons {{Taxonbar, from=Q957016 Apocrita superfamilies Biological pest control wasps Insects in culture de:Schlupfwespen