Homolobus infumator, copyright Chris Johnson.

Belongs within: Apocrita.
Contains: Ichneumonidae, Urosigalphini, Doryctinae, Braconinae, Rogadinae, Opiinae, Alysiinae, Aphidiinae, Ichneutinae, Cheloninae, Macrocentrinae, Orgilinae, Agathidinae, Helconinae, Sigalphinae, Euphorinae.

The Ichneumonoidea are a hyperdiverse group of parasitoid wasps, most of which are more or less slender-bodied with multi-segmented antennae bearing a short scape. Living species are mostly divided between the two families Ichneumonidae and Braconidae, with members of the Braconidae having the second recurrent vein present in the fore wing, cell R in the hind wing shorter than the submarginal vein or absent, and metasomal tergites 3 and 4 rigidly joined.

Basal subfamilies within the Braconidae are ectoparasitic as larvae, with subfamilies from Rogadinae down in the tree below being endoparasitic. A number of basal braconid subfamilies (e.g. Rhyssalinae, Histeromerinae and Doryctinae) include parasites of beetles, and these may be the ancestral hosts for the family. However, the relatively small, little-known braconids of the Rhyssalinae may also parasitise Lepidoptera or Diptera (Achterberg 1993). Histeromerus is a small, rarely collected genus characterised by a very short face, with the head being nearly prognathous (Achterberg 1993). The Apozyginae are another small subfamily, known only from Chile, which retain certain wing veins usually absent in other braconids (2m-cu in the forewing and 2-CU in the hind wing), and have the second and third metasomal sternites fused into a single plate (Achterberg 1993). The cosmopolitan Hormiinae, which are idiobiont ectoparasites of Lepidoptera larvae, have the second and third tergites of the metasoma more or less membranous dorsally, generally less sclerotised than the flanking epipleura (Achterberg 1993). The Lysiterminae, with similar host biology, have more or less striate second and third tergites with the spiracles usually on the notum (Achterberg 1993).

The Helconinae are a group of braconid wasps endoparasitic on larval Coleoptera. Most helconines have forewings with two submarginal cells and vein r-m present, but the second submarginal cell is absent in members of the tribe Brachistini (Achterberg 1993). Members of the genera Schizoprymnus and Triaspis have the first three metasomal terga forming a carapace (Naumann 1991).

Multifarities most horrid
Published 15 June 2009
Braconid wasp of the subfamily Aphidiinae laying an egg in a hapless aphid. Photo from BioMed Central.

We all know that J. B. S. Haldane is supposed to have remarked that God seemed to have an “extraordinary fondness for beetles”. What Haldane may not have realised was the possibility that the beetles were just a means to an end. As the current rate of taxonomic description is considered, some researchers have come to the suspicion that the true objects of the Creator’s affection are not beetles, but parasitoid wasps*. Which, when you consider the natures of parasitoid wasps, kind of explains some things about life.

*Personally, I’m still taking the long odds and backing the nematodes.

Microgastrinae larvae emerging from a host caterpillar. Photo from here.

The Braconidae are just one of the stupidly diverse lineages of Hymenoptera. According to ToLWeb (in 2004), there are some 12,000 described species of braconids, with estimates of up to 50,000 in total. Braconids form the living sister group to the similarly diverse Ichneumonidae, though braconids tend to be smaller in size (still, some of them are more than big enough). Braconids include both exoparasitic and endoparasitic taxa, parasitoids of eggs, larvae or adult insects, and a small number of gall-forming plant-parasitic taxa for added variety. The usual opinion is that the exoparasitic taxa represent the ancestral lifestyle for the family, but the actual phylogeny of the family is still being hammered out (and the “usual opinion” may yet turn out to be the wrong opinion). About forty subfamilies are currently recognised, but most authors (e.g. Shi et al. 2005) divide those subfamilies between three main lineages, the cyclostomes, microgastroids and helcionoids, with some subfamilies of uncertain position relative to the three. The microgastroids and helcionoids are all koinobiont endoparasitoids (after the wasp has laid its eggs in the host, the host continues to grow and develop), while the cyclostomes include both exoparasitoids and endoparasitoids, with exoparasitoids usually paralysing the host before laying their eggs (Wharton 1993). The microgastroids are fastidious in their tastes, restricting their diet to Lepidoptera (Murphy et al. 2008), while helcionoids attack a wide variety of hosts, including hemimetabolous as well as holometabolous insects. Early phylogenetic studies suggested that the cyclostomes (which possess a distinctive mouthpart morphology) were paraphyletic with regard to the other braconids, but more recent studies support a monophyletic cyclostome clade (Shi et al. 2005). The monophyly of a microgastroid + helcionoid clade is supported by molecular data (Shi et al. 2005) but remains short on morphological support (Quicke et al. 1999).

An individual of the genus Atanycolus (subfamily Braconinae in the cyclostome group). Photo by Richard Bartz.

The Aphidiinae are the largest group of braconids to not fit comfortably within the three-way division. Aphidiinae are parasitoids of aphids. Morphological data supports a relationship between aphidiines and the cyclostome group (Quicke et al. 1999), but the molecular analysis of Shi et al. (2005) suggested a relationship between the Aphidiinae and the Euphorinae, members of the helcionoids. The intriguing feature of this result is that Aphidiinae and Euphorinae both have the unusual characteristic (for insect parasitoids) of parasitising adult hosts rather than larvae—albeit with different host ranges in the two subfamilies. Euphorinae were probably originally parasitoids of beetles but some species have since become parasitoids of hosts as diverse as grasshoppers or Psocoptera A more recent combined morphological and molecular study whose authors argued against an Aphidiinae-Euphorinae relationship in favour of an Aphidiinae-cyclostome connection (Zaldivar-Riverón et al. 2006) actually did not test anything either way, because the authors’ choice of taxa and outgroup effectively forced an a priori cyclostome position.

An adult of Microgastrinae. Photo by Scott Justis.

Finally, some would think it rather remiss of me to write about braconids without making some mention of polydnaviruses, but I don’t see why I should when a much better description of such things than I could produce has already been written by Merry Youle at Small Things Considered. After you read the main article there, though, make sure you scroll down the comments to Merry’s description of the differences between polydnaviruses in Braconidae and Ichneumonidae suggesting the independent origins of the polydnavirus system in the two families. As well as the differences described by Mary, it also turns out that polydnaviruses are not characteristic of braconids as a whole, but are in fact only found within the microgastroid clade (Wharton 1993), so an independent origin from ichneumonid polydnaviruses has phylogenetic as well as biochemical support.

Systematics of Ichneumonoidea
    |  i. s.: Cedria paradoxaA71
    |--Praeichneumon [Praeichneumonidae]GE05
    |    `--P. townesiRJ93
       `--+--Eoichneumon Jell & Duncan 1986H02 [EoichneumonidaeGE05]
          |    `--E. duncanae Jell & Duncan 1986RJ93
          `--Braconidae [Anomalidae, Branconidae]GE05
               |  i. s.: HeterospilusBM76
               |           |--H. microstigmiBM76
               |           `--H. prosopidisN57
               |         AcampsohelconinaeA02
               |           |--UrosigalphiniA02
               |           |--Afrocampsis van Achterberg & Quicke 1990 [Afrocampsini]A02
               |           |    `--A. griseosetosusA02
               |           `--Acampsohelcon Tobias 1987 [Acampsohelconini]A02
               |                `--A. rasnitzini Tobias 1987A02
               |         PambolinaeA93
               |           |--Notiopambolus depressicaudaA93
               |           `--Pambolus biglumisA93
               |         Pseudobathystomus (Atlantobathystomus Belokobylskij & Koponen 2004)F05
               |           `--P. (*A.) macaronesius Belokobylskij & Koponen 2004F05
               |         MicrodusMS01
               |           |--M. gloriatorius [=Bracon (Microdus) gloriatorius]G20
               |           `--M. tumidulusMS01
               |         Phaenocarpa jaculansMS01
               |         CoeliniusMS01
               |           |--C. gracilisMS01
               |           |--C. nigerMS01
               |           `--C. parvulus [=Bracon (Coelinius) parvulus]G20
               |         Chaenon ancepsMS01
               |         Wroughtonia ligatorHR11
               |         Diaeretus essigellaePK17
               |         Rhetinorhyssalus morticinusPK17
               |         Fushunobracon Hong 2002H02
               |           `--*F. orientalis Hong 2002H02
               |         Sinobracon Hong 1974H02
               |           `--*S. speciosus Hong 1974H02
               |         Eobraconus inopinatusRJ93
               |         PromicrogasterD96
               |         Sycosoter lavagneiRD77
               |         AnacanthobraconP92
               |         AspicolpusP92
               |         CantharoctonusP92
               |         ChelonohelconP92
               |         CoeloreuteusP92
               |         DiachasmaP92
               |         DigastrothecaP92
               |         DiodontogasterP92
               |         DiospilitesP92
               |         DoryctomorphaP92
               |         ElasmosomitesP92
               |         ElectrohelconP92
               |         EocardiochilesP92
               |         EumacrocentrusP92
               |         HormiellusP92
               |         MeteoritesP92
               |         MiracoidesP92
               |         Neoblacus facialis Brues 1937P92
               |         OnychouraP92
               |         PalaeorhyssalusP92
               |         ParasyrrhizusP92
               |         PolystenusP92
               |         ProchremylusP92
               |         PromonolexisP92
               |         SemirhytusP92
               |         SnelleniusP92
               |         TaphaeusP92
               |         Ecphylus oculatus Muesebeck 1960P92
               |         ParahormiusP92
               |    |--Oncophanes [Oncophanini]A93
               |    |    `--O. minutusA93
               |    |--Acrisis [Acrisidini]A93
               |    |    `--A. minutissimusA93
               |    `--RhyssaliniA93
               |         |--Dolopsidea indagatorA93
               |         `--RhyssalusA93
               |              |--R. clavatorA93
               |              `--R. kerzhneriA93
               `--+--Histeromerus [Histeromerinae]A93
                  |    |--H. canadensisA93
                  |    `--H. mystacinusA93
                     `--+--Apozyx [Apozygidae, Apozyginae]A93
                        |    `--A. penyaiA93
                           |  |    |--PentaterminiA93
                           |  |    `--Acanthormius [Lysitermini]A93
                           |  |         `--A. sumatrensisA93
                           |  `--Hormiinae [Hormiini]A93
                           |       |--Pseudohormius turkmenusA93
                           |       `--HormiusA93
                           |            |--H. moniliatus [=Bracon (Hormius) moniliatus]G20
                           |            `--H. romaniA93
                              |    |--Rhysipolis [Rhysipolini]A93
                              |    |    |--R. hariolatorA93
                              |    |    `--R. meditatorA93
                              |    `--ExotheciniA93
                              |         |--Xenarcha abnormisA93
                              |         `--ColastesA93
                              |              |--C. braconiusA93
                              |              `--C. hariolatorMS01
                              `--+--+--Vaepellis [Vaepellinae]A93
                                 |  |    `--V. varicaA93
                                 |  `--+--BraconinaeA93
                                 |     `--Telengaia [Telengaiinae]A93
                                 |          `--T. ventralisA93
                                    |  `--+--BetylobraconinaeA93
                                    |     |    |--Mesocentrus crassipesA93
                                    |     |    `--Betylobracon waterhouseiA93
                                    |     `--Mesostoa [Mesostoinae]A93
                                    |          |--M. compressaA93
                                    |          `--M. kerriA93
                                    `--+--+--Gnamptodon [Gnamptodontinae]A93
                                       |  |    |--G. molestusA93
                                       |  |    `--G. pumilioA93
                                       |  `--+--OpiinaeA93
                                       |     `--AlysiinaeA93
                                             |  |  `--Dirrhope [Dirrhopinae]A93
                                             |  |       `--D. rufaA93
                                             |  `--+--Ecnomios [Ecnomiinae]A93
                                             |     |    `--E. papuensisA93
                                             |     `--+--CheloninaeA93
                                             |        `--AdeliinaeA93
                                             |             |--AdeliusA93
                                             |             `--Paradelius ghesquiereiA93
                                             `--+--+--Amicrocentrum [Amicrocentrinae]A93
                                                |  |    `--A. concolorA93
                                                |  `--+--MacrocentrinaeA93
                                                |     `--Charmon [Charmontinae]A93
                                                |          `--C. cruentatusA93
                                                      |  `--Pselaphanus [Pselaphaninae]A93
                                                      |       `--P. trogoidesA93
                                                         |    |--Microtypus wesmaeliiA93
                                                         |    `--Neomicrotypus penaiA93
                                                            |  `--CenocoeliinaeA93
                                                            |       |--Capitonius bifasciatusA93
                                                            |       `--CenocoeliusPS05
                                                            |            |--C. analisA93
                                                            |            `--C. huggerti Pitz & Sharkey 2005PS05
                                                               |  |    |--Pronkia [Pronkiini]A93
                                                               |  |    |    `--P. antefurcalisA93
                                                               |  |    `--Meteoridea [Meteorideini]A93
                                                               |  |         `--M. hutsoniA93
                                                               |  `--BlacinaeA93
                                                               |       |--DyscoletiniA93
                                                               |       |    |--Dyscoletes canadensisA93
                                                               |       |    `--Hellenius semiruberA93
                                                               |       `--BlaciniA93
                                                               |            |--Blacometeorus brevicaudaA93
                                                               |            `--BlacusA93
                                                               |                 |--B. fuscitibialisA93
                                                               |                 `--B. humilis [=Bracon (Blacus) humilis]G20
                                                                  |  `--TrachypetinaeA93
                                                                  |       |--Cercobarcon [Cercobarconinae, Cercobarconini]A93
                                                                  |       |    `--C. riekiA93
                                                                  |       `--Trachypetus [Trachypetini]A93
                                                                  |            `--T. clavatusA93
                                                                     `--+--Xiphozele [Xiphozelinae]A93
                                                                        |    `--X. compressiventrisA93
                                                                             |--Westwoodiella [Westwoodiellini]A93
                                                                             |    `--W. bicolorA93
                                                                             `--Homolobus [Homolobini]A93
                                                                                  |--H. huddlestoniA93
                                                                                  `--H. infumatorA93

*Type species of generic name indicated


[A93] Achterberg, C. van. 1993. Illustrated key to the subfamilies of the Braconidae (Hymenoptera: Ichneumonoidea). Zoologische Verhandelingen 283: 1–189.

[A02] Achterberg, C. van. 2002. Revision of the genus Canalicephalus Gibson and the recognition of the Acampsohelconinae (Hymenoptera: Braconidae) as extant. Zoologische Mededelingen 76 (20): 347–370.

[A71] Askew, R. R. 1971. Parasitic Insects. Heinemann Educational Books: London.

[BM76] Bohart, R. M., & A. S. Menke. 1976. Sphecid Wasps of the World. University of California Press: Berkeley.

[D96] Davis, D. R. 1996. Neotropical Tineidae, VI: Prosetomorpha falcata, a new genus and species of Setomorphinae (Lepidoptera: Tineoidea) from Colombia associated with curculionid galleries in stems of Solanum. Proceedings of the Entomological Society of Washington 98 (2): 173–187.

[F05] Fernández, J. 2005. Noticia de nuevos táxones para la ciencia en el ámbito Íbero-Balear y Macaronésico. Nuevos táxones animales descritos en la península Ibérica y Macaronesia desde 1994 (IX). Graellsia 61 (2): 261–282.

[G20] Goldfuss, G. A. 1820. Handbuch der Naturgeschichte vol. 3. Handbuch der Zoologie pt 1. Johann Leonhard Schrag: Nürnberg.

[GE05] Grimaldi, D., & M. S. Engel. 2005. Evolution of the Insects. Cambridge University Press: New York.

[HR11] Heraty, J., F. Ronquist, J. M. Carpenter, D. Hawks, S. Schulmeister, A. P. Dowling, D. Murray, J. Munro, W. C. Wheeler, N. Schiff & M. Sharkey. 2011. Evolution of the hymenopteran megaradiation. Molecular Phylogenetics and Evolution 60: 73–88.

[H02] Hong Y. 2002. Amber Insect of China. Beijing Scientific and Technological Publishing House.

[MS01] Mocsáry, A., & V. Szépligeti. 1901. Hymenopterák [Hymenopteren]. In: Horváth, G. (ed.) Zichy Jenő Gróf Harmadik Ázsiai Utazása [Dritte Asiatische Forschungsreise des Grafen Eugen Zichy] vol. 2. Zichy Jenő Gróf Harmadik Ázsiai Utazásának Állattani Eredményei [Zoologische Ergebnisse der Dritten Asiatischen Forschungsreise des Grafen Eugen Zichy] pp. 121–169. Victor Hornyánszky: Budapest, and Karl W. Hierseman: Leipzig.

Murphy, N., J. C. Banks, J. B. Whitfield & A. D. Austin. 2008. Phylogeny of the parasitic microgastroid subfamilies (Hymenoptera: Braconidae) based on sequence data from seven genes, with an improved time estimate of the origin of the lineage. Molecular Phylogenetics and Evolution 47 (1): 378–395.

[N57] Nicholson, A. J. 1957. The self-adjustment of populations to change. Cold Spring Harbor Symposia on Quantitative Biology 22: 153–172.

[PK17] Peters, R. S., L. Krogmann, C. Mayer, A. Donath, S. Gunkel, K. Meusemann, A. Kozlov, L. Podsiadlowski, M. Petersen, R. Lanfear, P. A. Diez, J. Heraty, K. M. Kjer, S. Klopfstein, R. Meier, C. Polidori, T. Schmitt, S. Liu, X. Zhou, T. Wappler, J. Rust, B. Misof & O. Niehuis. 2017. Evolutionary history of the Hymenoptera. Current Biology 27 (7): 1013–1018.

[PS05] Pitz, K. M., & M. J. Sharkey. 2005. Cenocoelius huggerti, the first record of the subfamily Cenocoeliinae (Hymenoptera: Braconidae) from Africa. Journal of Hymenoptera Research 14 (1): 92–95.

[P92] Poinar, G. O., Jr. 1992. Life in Amber. Stanford University Press: Stanford.

Quicke, D. L. J., H. H. Basibuyuk & A. P. Rasnitsyn. 1999. Morphological, palaeontological and molecular aspects of ichneumonoid phylogeny (Hymenoptera, Insecta). Zoologica Scripta 28 (1–2): 175–202.

[RD77] Richards, O. W., & R. G. Davies. 1977. Imms’ General Textbook of Entomology 10th ed. vol. 2. Classification and Biology. Chapman and Hall: London.

[RJ93] Ross, A. J., & E. A. Jarzembowski. 1993. Arthropoda (Hexapoda; Insecta). In: Benton, M. J. (ed.) The Fossil Record 2 pp. 363–426. Chapman & Hall: London.

Shi, M., X. X. Chen & C. van Achterberg. 2005. Phylogenetic relationships among the Braconidae (Hymenoptera: Ichneumonoidea) inferred from partial 16S rDNA, 28S rDNA D2, 18S rDNA gene sequences and morphological characters. Molecular Phylogenetics and Evolution 37 (1): 104–116.

Wharton, R. A. 1993. Bionomics of the Braconidae. Annual Review of Entomology 38: 121–143.

Zaldivar-Riverón, A., M. Mori & D. L. J. Quicke. 2006. Systematics of the cyclostome subfamilies of braconid parasitic wasps (Hymenoptera: Ichneumonoidea): a simultaneous molecular and morphological Bayesian approach. Molecular Phylogenetics and Evolution 38 (1): 130–145.

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