Ichneumonidae

Source: Wikipedia, the free encyclopedia.

Ichneumon wasps
Temporal range:
Recent[1]
Diphyus sp., Rhône (France)
Anomaloninae, (Tanzania)
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Suborder: Apocrita
Superfamily: Ichneumonoidea
Family: Ichneumonidae
Latreille
, 1802
Subfamilies

See below

The Ichneumonidae, also known as ichneumon wasps, ichneumonid wasps, ichneumonids, or Darwin wasps, are a

parasitoid wasps of the insect order Hymenoptera. They are one of the most diverse groups within the Hymenoptera with roughly 25,000 species described as of 2016.[2] However, this likely represents less than a quarter of their true richness as reliable estimates are lacking, along with much of the most basic knowledge about their ecology, distribution, and evolution.[1] It is estimated that there are more species in this family than there are species of birds and mammals combined.[3] Ichneumonid wasps, with very few exceptions, attack the immature stages of holometabolous insects and spiders, eventually killing their hosts.[4] They thus fulfill an important role as regulators of insect populations, both in natural and semi-natural systems, making them promising agents for biological control.[5]

Yellow and black flying insect lacking an ovipositor... male Ichneumonid Wasp
Male ichneumonid wasp

The distribution of the ichneumonids was traditionally considered an exception to the common latitudinal gradient in species diversity, since the family was thought to be at its most species-rich in the temperate zone instead of the tropics, but numerous new tropical species have now been discovered.

Etymology and history

true flies) and scorpion wasps due to the extreme lengthening and curving of the abdomen (scorpions
are arachnids, not insects).

The name is derived from Latin 'ichneumon', from Ancient Greek ἰχνεύμων (ikhneúmōn, "tracker"), from ἴχνος (íkhnos, "track, footstep"). The name first appeared in Aristotle's "History of Animals", c. 343 BC. Aristotle noted that the ichneumon preys upon spiders, is a wasp smaller than ordinary wasps, and carries its prey to a hole which they lay their larvae inside, and that they seal the hole with mud.[6] Aristotle's writing, however, more accurately describes the mud daubers than the true ichneumon wasps, which do not construct mud nests and do not sting.

Description

Adult ichneumonids superficially resemble other

wasps. They have a slender waist, two pairs of wings, a pair of large compound eyes on the side of the head and three ocelli
on top of the head. Their size varies considerably from a few millimetres to seven or more centimetres.

The ichneumonids have more antennal segments than typical, aculeate wasps (

stinger, ichneumonid females have an unmodified ovipositor which they use to lay eggs inside or on their host. Ichneumonids generally inject venom along with the egg, but only larger species (some in the genera Netelia and Ophion
) with relatively short ovipositors use the ovipositor in defense. Males do not possess stingers or ovipositors in either lineage.

  • Head (Ichneumon xanthorius). Antennae with many segments
    Head (Ichneumon xanthorius). Antennae with many segments
  • Female Xanthopimpla punctata. Ovipositor longer and more slender than stingers of aculeate wasps
    Female Xanthopimpla punctata. Ovipositor longer and more slender than stingers of aculeate wasps
  • Lissonota sp., female Oxfordshire
    Lissonota sp., female
    Oxfordshire

Ichneumonids are distinguished from their sister group Braconidae mainly on the basis of wing venation. The fore wing of 95% of ichneumonids has vein 2m-cu (in the Comstock–Needham system), which is absent in braconids. Vein 1rs-m of the fore wing is absent in all ichneumonids, but is present in 85% of braconids. In the hind wing of ichneumonids, vein rs-m joins Rs apical to (or rarely opposite) the split between veins Rs and R1. In braconids, vein rs-m joins basal to this split. The taxa also differ in the structure of the metasoma: about 90% of ichneumonids have a flexible suture between tergites 2 and 3, whereas these tergites are fused in braconids (though the suture is secondarily flexible in Aphidiinae).[7]

Ichneumonid fore wing (Syzecteus sp.). The presence of vein 2m-cu and absence of vein 1Rs+M distinguish the wing from that of braconids.
Ichneumonid hind wing. Vein rs-m joins Rs after the split between veins Rs and R1.
Braconid hind wing. Vein rs-m joins Rs before the split between veins Rs and R1.

Distribution

Ichneumonids are found on all continents with the exception of Antarctica. They inhabit virtually all terrestrial habitats, wherever there are suitable invertebrate hosts.

The distribution of ichneumonid species richness is subject to ongoing debate. Long believed to be rare in the tropics, and at its most species rich in the temperate region, the family became a classic textbook example of an 'exceptional' latitudinal diversity gradient.[8] Recently this belief has been questioned, after the discovery of numerous new tropical species.[9][10][11]

Reproduction and diet

A very few ichneumonid species lay their eggs in the ground, but the vast majority inject eggs either directly into their

Coleoptera and Hymenoptera. Some species in the subfamily Pimplinae also parasitise spiders. Hyperparasitoids such as Mesochorinae oviposit inside the larvae of other ichneumonoids. The hosts of some species are agricultural pests, therefore ichneumons are sometimes valuable for biological pest control, but the hosts of most species are unknown; host information has been reviewed and summarized by various researchers, e.g. Aubert,[12][13][14] Perkins.[15][16] and Townes.[17]

Ichneumonids use both idiobiont and koinobiont strategies. Idiobionts paralyze their host and prevent it from moving or growing. Koinobionts allow their host to continue to grow and develop. In both strategies, the host typically dies after some weeks, after which the ichneumonid larva emerges and pupates.[18]

See also: Parasitoid § Basic concepts

Adult ichneumonids feed on a diversity of foods, including plant sap and nectar; females of some species also feed on their hosts by sipping body fluids released during oviposition, or even stabbing host and non-host insects to imbibe their body fluids. They spend much of their active time searching, either for hosts (female ichneumonids) or for emerging females (male ichneumonids).[19] The parasitism pressure exerted by ichneumonids can be tremendous, and they are often one of the major regulators of invertebrate populations.[20][21] It is quite common for 10-20% or more of a host's population to be parasitised (though reported parasitism rates often include non-ichneumonid parasitoids).[22][23]

Taxonomy and systematics

An ichneumonid caught in amber 15-20 million years ago.

The taxonomy of the ichneumonids is still poorly known. The family is highly diverse, containing 24,000 described species. Approximately 60,000 species are estimated to exist worldwide, though some estimates place this number at over 100,000. They are severely undersampled, and studies of their diversity typically produce very high numbers of species which are represented by only a single individual.

cladistic
studies require major computing capacity.

Extensive catalogues of the ichneumonids include those by Aubert,[12][13][14] Gauld,[26] Perkins,[15][16] and Townes.[17][27][28][29][30] Due to the taxonomic difficulties involved, however, their classifications and terminology are often confusingly contradictory. Several prominent authors have gone as far as to publish major reviews that defy the International Code of Zoological Nomenclature.[27][28][29][30][31][32]

The large number of species in Ichneumonidae may be due to the evolution of parasitoidism in Hymenoptera, which occurred approximately 247 million years ago.

Ectoparasitoid woodwasp that parasitized wood-boring beetle larvae in trees.[35] The family has existed since at least the Early Cretaceous (c. 125 mya),[36][37] but probably appeared already in the Jurassic (c. 181 mya), soon after the appearance of its major host groups.[38]
It diversified during the Oligocene.

Subfamilies

In 1999, the extant ichneumonids were divided into 39 subfamilies,[39][40] whose names and definitions have varied considerably. In 2019, combined morphological and molecular phylogenetic analysis of the family resulted in the following 41 subfamilies being recognized, in addition to the extinct Labenopimplinae.[41]

Famous ichneumonologists

Famous ichneumonologists include:

Darwin and the Ichneumonidae

The perceived cruelty of the ichneumonids troubled philosophers, naturalists, and theologians in the 19th century, who found the parasitoid life cycle inconsistent with the notion of a world created by a loving and benevolent God.[42] Charles Darwin found the example of the Ichneumonidae so troubling that it contributed to his increasing doubts about the nature and existence of a Creator. In an 1860 letter to the American naturalist Asa Gray, Darwin wrote:

I own that I cannot see as plainly as others do, and as I should wish to do, evidence of design and beneficence on all sides of us. There seems to me too much misery in the world. I cannot persuade myself that a beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of Caterpillars, or that a cat should play with mice.[43]

Morphology

  • Megarhyssa greenei female
    Megarhyssa greenei female
  • Morphology of the head and its processes: (А) head capsule; (В) antenna; (С) mandible[44]
    Morphology of the head and its processes: (А) head capsule; (В) antenna; (С) mandible[44]
  • Morphology of the thorax (D)[44]
    Morphology of the thorax (D)[44]
  • Morphology of the abdomen and processes of the thorax: (E) front wing; (F) leg III; (G) abdomen of female[44]
    Morphology of the abdomen and processes of the thorax: (E) front wing; (F) leg III; (G) abdomen of female[44]

See also

References

  1. ^ a b Quicke, D. L. J. (2015). The braconid and ichneumonid parasitoid wasps: biology, systematics, evolution and ecology. Chichester: John Wiley & Sons, Ltd.
  2. ^ Yu, D. S.; van Achterberg, C.; Horstmann, K. (2016). Taxapad 2016. Ichneumonoidea 2015 (Biological and taxonomical information), Taxapad Interactive Catalogue Database on flash-drive. Nepean, Ottawa, Canada.
  3. OCLC 28576921
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  4. ^ Broad, G. R.; Shaw, M. R.; Fitton, M. G. (2018). "Ichneumonid wasps (Hymenoptera: Ichneumonidae): their classification and biology". Handbooks for the Identification of British Insects, 7(12): 1-418.
  5. ^
    hdl:10141/622809
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  6. ISBN 978-963-525-370-8
    . The wasps that are nicknamed 'the ichneumons' (or hunters), less in size, by the way, than the ordinary wasp, kill spiders and carry off the dead bodies to a wall or some such place with a hole in it; this hole they smear over with mud and lay their grubs inside it, and from the grubs come the hunter-wasps. ... The eagle and the snake are enemies, for the eagle lives on snakes; so are the ichneumon and the venom-spider, for the ichneumon preys upon the latter.
  7. ^ Sharkey, M.J. (1993), Family Braconidae, pp. 362-394. In: Goulet, H. and J. Huber (eds.). Hymenoptera of the World, an Identification Guide to Families, Agriculture Canada Research Branch Monograph No. 1894E.
  8. JSTOR 1937717
    .
  9. JSTOR 2647379
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  10. PMID 23034706
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  11. PMID 22355411
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  12. ^
    OCLC 773541612.[page needed
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  13. ^
    OCLC 461814920.[page needed
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  14. ^
    OCLC 716442080.[page needed
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  15. ^
    OCLC 704042974.[page needed
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  16. ^
    OCLC 316445110.[page needed
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  17. ^
    OCLC 669390657.[page needed
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  18. ISSN 0024-4066
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  19. ISBN 9780521819411
    .
  20. JSTOR 3547182
    .
  21. JSTOR 2265951
    .
  22. JSTOR 5219. INIST 4125431
    .
  23. S2CID 86014193
    .
  24. PMID 29632746
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  25. ISSN 1752-4598
    .
  26. ^ Gauld, I. D. (1976). "The classification of the Anomaloninae (Hymenoptera: Ichneumonidae)". Bulletin of the British Museum (Natural History) Entomology. 33: 1–135.
  27. ^ a b Townes, H. K. (1969a). "Genera of Ichneumonidae, Part 1 (Ephialtinae, Tryphoninae, Labiinae, Adelognathinae, Xoridinae, Agriotypinae)". Memoirs of the American Entomological Institute. 11: 1–300.
  28. ^ a b Townes, H. K. (1969b). "Genera of Ichneumonidae, Part 2 (Gelinae)". Memoirs of the American Entomological Institute. 12: 1–537.
  29. ^ a b Townes, H. K. (1969c). "Genera of Ichneumonidae, Part 3 (Lycorininae, Banchinae, Scolobatinae, Porizontinae)". Memoirs of the American Entomological Institute. 13: 1–307.
  30. ^ a b Townes, H. K. (1971). "Genera of Ichneumonidae, Part 4 (Cremastinae, Phrudinae, Tersilochinae, Ophioninae, Mesochorinae, Metopiinae, Anomalinae, Acaenitinae, Microleptinae, Orthopelmatinae, Collyriinae, Orthocentrinae, Diplazontinae)". Memoirs of the American Entomological Institute. 17: 1–372.
  31. ^ Oehlke, J (1966). "Die westpaläarktische Arte der Tribus Poemeniini (Hymenoptera, Ichneumonidae) ["The Western Palearctic species of the tribe Poemeniini"]". Beiträge zur Entomologie. 15: 881–892.
  32. ^ Oehlke, J (1967). "Westpaläarktische Ichneumonidae 1, Ephialtinae". Hymenopterorum Catalogus. 2 (new ed.): 1–49.
  33. PMID 28343967
    .
  34. PMID 21540117
    .
  35. PMID 16332211
    .
  36. S2CID 83827172
    .
  37. S2CID 83902440
    .
  38. PMID 33057674
    .
  39. ^ Wahl, David (1999): Classification and Systematics of the Ichneumonidae (Hymenoptera) Archived 2008-07-25 at the Wayback Machine. Version of 1999-JUL-19. Retrieved 2008-JUN-18.
  40. ^ Wahl, David; Gauld, Ian. "American Entomological Institute". Genera Ichneumonorum Nearcticae. The American Entomological Institute. Retrieved 9 August 2017.
  41. ^ Bennett, A.M.R.; Cardinal, S.; Gauld, I.D.; Wahl, D.B. (2021). "Phylogeny of the subfamilies of Ichneumonidae (Hymenoptera)". Journal of Hymenoptera Research. 71: 1–156.
    doi:10.3897/jhr.71.32375
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  42. ^ "Nonmoral Nature". Archived from the original on 2015-11-17. Retrieved 2011-04-05.
  43. ^ "Letter 2814 — Darwin, C. R. to Gray, Asa, 22 May [1860]". Retrieved 2011-04-05.
  44. ^ a b c Tereshkin, A. (2009): Illustrated key to the tribes of subfamilia Ichneumoninae and genera of the tribe Platylabini of world fauna (Hymenoptera, Ichneumonidae). Linzer biol. Beitr. 41/2: 1317-1608. PDF

External links

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