Systematics of the parasitoid wasp subfamily Banchinae (Hymenoptera; Ichneumonidae) in the Afrotropical region

Reynolds Berry, Terry (2019-12)

Thesis (PhD)--Stellenbosch University, 2019.

Thesis

ENGLISH ABSTRACT: Parasitoid wasps play an important ecological role as natural controllers of insect populations and, as a result, are increasingly used in agricultural biological control of insect pests. They are an economically important group as they render an ecosystem service to society. The parasitoid wasp family Ichneumonidae (Hymenoptera) is arguably the largest animal family on earth. However, relatively little is known about the diversity of this group within the Afrotropical region. The present study contributes to the growing body of systematic studies of ichneumonids by providing a comprehensive systematic revision of the subfamily Banchinae occurring in the region. This study includes an investigation of evolutionary relationships, historical biogeography of Afrotropical species, description of new species, and the development of updated generic and species identification keys. A key to Banchinae genera within the Afrotropical region was last created over 40 years ago. Since then, recent advances have been made through the development of good quality high definition images which accompany dichotomous keys and allow for reliable identification of genera/species by taxonomists. The Afrotropical banchine fauna currently comprises 12 genera: Apophua Morley, Atropha Kriechbaumer, Cryptopimpla Taschenberg, Exetastes Gravenhorst, Glyptopimpla Morley, Himertosoma Schmiedeknecht, Lissonota Gravenhorst, Sjostedtiella Szépligeti, Spilopimpla Cameron, Syzeuctus Förster, Tetractenion Seyrig, and Tossinola Viktorov. One of these, Cryptopimpla is a predominately northern hemisphere genus represented by 47 described species of which only one is known from the Afrotropical region. Another genus, Tetractenion, which is restricted to the Afrotropical region, is only represented by two described species. This study provides the first species-level identification key to these two rare genera, including description of nine and four new species respectively. All Afrotropical species of Cryptopimpla are, to this date, only known from South Africa. Studies (prior and current) suggest that both genera are restricted to temperate areas, with a prediction through morphological investigation that the genus Tetractenion is possibly nocturnal. In addition, the generic key to Banchinae in the Afrotropical region is updated. Online interactive Lucid Phoenix and Lucid matrix keys are available at: http://www.waspweb.org/Ichneumonoidea/Ichneumonidae/Keys/index.htm. To investigate the phylogeny of Banchinae in the Afrotropical region, morphological data were combined with molecular sequence data obtained from two nuclear genes, 18S and 28S, and one mitochondrial gene, COI, for 76 taxa, representing all three tribes and 10 of the 12 currently recognized genera. Divergence dates and historical biogeography were estimated on the inferred phylogeny. The most important results of the study suggest that (1) the Banchus group of the tribe Banchini does not form part of the subfamily Banchinae, (2) the endemic genus Sjostedtiella, along with other “forest-associated” lineages, was found to be the oldest banchine genus within the Afrotropical region, and (3) the dating of the temperate-associated genus Cryptopimpla refutes the hypothesis that banchine lineages found within the Cape region are more derived because of their association with the Cape Floristic Region. There is some inference to suggest that Malagasy taxa show strong affinities to East African taxa, due to the close proximity of the island to the East African coast, and some inference indicating the connectedness between East and tropical West and Central Africa. However, it is important to bear in mind that molecular specimens from West and East Africa available for DNA extraction were limited and likewise suitable samples from India, which was historically connected to Madagascar, were also lacking. While many of the genera were found to be monophyletic, paraphyly was established for Himertosoma and Lissonota. There was an unresolved placement of a clade comprising two Malagasy species, which share both typical and unique morphological characteristics with the genus Himertosoma. However, this clade falls outside of the well-supported clade comprising the remaining Himertosoma species. Although genetically divergent, a lack of a true synapomorphy suggests that these two species are, for now, better placed within the genus Himertosoma. Their inclusion does, however, render Himertosoma a paraphyletic group, but analyses of further taxa is required to achieve a robustly supported decision on the affinities of the species within this genus. Paraphyly for the genus Lissonota was found both within the Afrotropical region and on a global scale, which was not surprising given the uncertainty on the validity and circumscription, as well as the worldwide distribution of species, of this very large genus.

AFRIKAANSE OPSOMMING: Parasitoïede wespe speel 'n belangrike ekologiese rol as natuurlike beheerders van insekbevolkings en word gevolglik toenemend gebruik in die biologiese beheer van landbou plae. Hulle is ekonomies 'n belangrike groep aangesien hulle 'n ekosisteemdiens aan die gemeenskap lewer. Die parasitoïede wespfamilie Ichneumonidae (Hymenoptera) is waarskynlik die grootste dierfamilie op aarde. Relatief min is egter bekend oor die diversiteit van hierdie groep binne die Afrotropiese streek. Die huidige studie dra by tot die groeiende basis van sistematiese studies van ichneumoniede deur 'n omvattende sistematiese hersiening van die subfamilie Banchinae wat in die streek voorkom te verskaf. Die studie sluit in die evolusionêre verhoudings, historiese biogeografie van Afrotropiese spesies, beskrywing van nuwe spesies en die ontwikkeling van opgedateerde generiese en spesies identifikasie sleutels. 'n Taksonomiese sleutel tot Banchinae genus in die Afrotropiese streek is 40 jaar gelede geskep. Sedertdien is onlangse vordering gemaak deur die ontwikkeling van hoë kwaliteit definisie beelde wat digotome sleutels vergesel en toelaat dat betroubare identifikasie van genera / spesies deur taksonome toegepas kan word. Die Afrotropiese banchine fauna bestaan tans uit 12 genera: Apophua Morley, Atropha Kriechbaumer, Cryptopimpla Taschenberg, Exetastes Gravenhorst, Glyptopimpla Morley, Himertosoma Schmiedeknecht, Lissonota Gravenhorst, Sjostedtiella Szepaleti, Spilopimpla Cameron, Syzeuctus Förster, Tetractenion Seyrig en Tossinola Viktorov. Een van hierdie, Cryptopimpla is 'n oorheersende noordelike halfrond genus verteenwoordig deur 47 beskryfde spesies waarvan slegs een van die Afrotropiese streek bekend is. Nog 'n genus, Tetractenion, wat beperk is tot die Afrotropiese streek, word slegs verteenwoordig deur twee beskryfte spesies. Hierdie studie bied die eerste spesievlak-identifikasietoets van hierdie twee skaars genera, met onderskeidelik nege en vier nuwe spesies wat beskryf is. Alle Afrotropiese spesies wat tot die genus Cryptopimpla behoort is tot op hierdie stadium slegs van Suid-Afrika bekend. Studies (vorige en huidige) dui daarop dat beide genera beperk is tot gematigde gebiede, met 'n voorspelling deur morfologie dat die genus Tetractenion moontlik naglewend is. Daarbenewens is die generiese sleutel tot Banchinae in die Afrotropiese streek opgedateer. Aanlyn interaktiewe Lucid Phoenix en Lucid matriks sleutels is beskikbaar by: http://www.waspweb.org/Ichneumonoidea/Ichneumonidae/Keys/index.htm. Om die filogenie van Banchinae in die Afrotropiese streek te ondersoek, is morfologiese data asook molekulêre volgorde data verkry vanaf twee nukluêre fragmente, 18S en 28S, en een mitochondriale geen, COI, vir 76 taxa, wat al drie stamme verteenwoordig en 10 van die 12 huidige erkende genera. Divergensiedatums en historiese biogeografie is op die afgeleide filogenie bereken. Die belangrikste resultate van die studie dui aan dat (1) die Banchus-groep van die stam Banchini nie deel uitmaak van die subfamilie Banchinae nie, (2) die endemiese genus Sjostedtiella, saam met ander “woudverwante” afstammelinge, is die oudste banchine-genus in die Afrotropiese streek, en (3) die datering van die gematigde-verwante genus Cryptopimpla verwerp die hipotese dat banchine afstammelinge in die Kaapse streek meer divergent is as gevolg van hul assosiasie met die Kaapse Floristiese Streek. Daar is 'n mate van bewyse wat voorstel dat die Malagasiese taxa sterk affiniteite met Oos-Afrikaanse taxa toon, waarskynlik weens die nabyheid van die eiland aan die Oos-Afrikaanse kus en daar is voorts ook 'n mate van aanduidings dat daar 'n verband is tussen Oos-en Tropiese Wes- en Sentraal-Afrika. Dit is egter belangrik om in gedagte te hou dat molekulêre monsters uit Wes- en Oos-Afrika beskikbaar vir DNA-ekstraksie beperk was en geskikte monsters uit Indië (wat histories aan Madagaskar gekoppel was) ontbreek ook. Terwyl baie van die genera monofieleties is, is parafiletiese groepe aangetoon vir Himertosoma en Lissonota. 'n Onopgeloste plasing van 'n groep wat uit twee spesies van Madagaskar bestaan, wat morfologiese eienskappe (beide atipies en unieke) deel met die genus Himertosoma, val buite die goed geondersteunde groep van die oorbylwende Himertosoma spesies. Hoewel geneties uiteenlopend, 'n gebrek aan 'n ware sinapomorfie stelvoor dat die twee spesies tans beter ooreenstem met die genus Himertosoma. Hul insluiting egter verander Himertosoma in 'n parafiletiese groep, maar analise van meer taxa is nodig om 'n sterk ondersteunde besluit aangaande op die verwantskappe van die spesies binne die genus te maak. Die genus Lissonota was parafileties gevind beide binne die Afrotropiese streek en op wêreldwye skaal. Dit was nie verbasend nie, gegee die onsekerheid oor die geldigheid en omskrywing, sowel as die wêreldwye verspreiding van spesies, van die baie groot genus.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/106917
This item appears in the following collections: