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Extant genera and species of Microgastrinae
Miropotes Nixon 1965
Nomenclature
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Subfamily: Microgastrinae
SUMMARY
The following discussion about Miropotes, its morphological features and relationships with other genera of Microgastrinae is taken from Fernandez-Triana et al. (2014). Additionally, an unpublished paper from Fernandez-Triana and van Achterberg has found the genus in the Afrotropical region -once that paper is published, complete details will be posted here.
Mason (1981) considered Miropotes to be taxonomically isolated, but likely related to the South African genus I, and placed both relatively basally in the tribe Apantelini, as part of his proposed intuitive phylogeny of Microgastrinae. Austin (1990) discussed several shortcomings of Mason’s system of tribes, but found support (based on a reassessment of characters of the female hypopygium and ovipositor) for a clade comprising most of the genera included by Mason in his tribes Apantelini and Microgastrini. Austin also mentioned that the position of Miropotes within Microgastrinae was unclear, but considered that, for the time being, it was better to leave it within Apantelini (e.g., Fig. 5 in Austin 1990). A taxonomically and morphologically less detailed but phylogenetically more rigorous study by Walker et al. (1990) found two competing hypothesis of relationships within genera of microgastrines, with one of those hypotheses having Miropotes (and Exulonyx) as the sister group of all other Microgastrinae. However, Walker et al. (1990) emphasized that Mason’s tribes were (at least on the basis of his presented characters) unsupported and should not be used, an advice that has since been followed by most taxonomists. While studying the male genitalia of Microgastrinae, Maetô (1996) also found support for most of the Apantelini + Microgastrini clade, but stated that Miropotes (and a few other genera) lacked the defining autapomorphy. Whitfield et al. (2002) included not only a more explicit and realistically coded version of Mason’s (1981) morphological data, but also data from three genes (COI, 16S, and 28S) to study phylogenetic relationships among genera of Microgastrinae. Datasets were analyzed independently and combined. The results recovered Miropotes as the sister group of all other genera of Microgastrinae in both the morphological analysis only (bootstrap value: 100, Bremer support 10), and in the combined analysis of the three gene markers plus morphology (bootstrap value: 99). The analysis of only the 28S dataset recovered Miropotes as the sister group of all Microgastrinae (bootstrap value: 100, Bremer support 1) minus the Microplitini clade – which includes the genera Alloplitis, Microplitis, Philoplitis and Snellenius. However, the molecular analysis of the 16S or COI datasets independently, and the analysis of the three genes combined did not provide any clear support for Miropotes as an independent lineage. Later studies incorporating more genes (Banks & Whitfield 2006, Murphy et al. 2008) were not able to include additional data from Miropotes. In a paper about DNA barcoding of microgastrine wasps, Smith et al. (2012, Appendix S2, page 160) provided a Neighbor Joining Tree (K2P) of over 17 500 sequences with more than 500 base pairs from specimens worldwide. The only available sequence of Miropotes (then only identified as “Microgastrinae”, with voucher code CNCH2114, later described as Miropotes orientalis) was 15% different (i.e., almost 100 base pairs of difference) than the closest Microgastrinae sequence available. This provides additional support to the uniqueness of the genus as discussed by previous authors, although data from one relatively fast-evolving gene such as COI does not necessarily reflect deeper phylogenetic relationships among genera. Miropotes does seem to possess a number of unique morphological characters which have not yet been evaluated when studying the relationships between genera of Microgastrinae. Examples include the shape of the ovipositor sheaths and ovipositor (which, in most species of Miropotes is strongly bent); the enlarged and strongly convergent eyes (with totally to almost totally obliterated malar space); the small size of the metacoxa; and the short length of the metatibial spurs (the last two features shared by the putatively distantly related Microplitini clade). Another interesting feature, apparently overlooked by previous authors, is the presence of a light (white or yellow) spot on the gena, next to the mandible base and lower margin of eye. White spots on the lower part of the gena are rather uncommon in Microgastrinae. They are present in all known species of the genus Alphomelon, and have been occasionally found in very few species of other genera such as Apanteles, Cotesia, Dolichogenidea and an undescribed genus from New Zealand (e.g., Mason 1981, Deans et al. 2003, Ward and Fernández-Triana unpublished data). The combination of the characters mentioned above, altogether with the data discussed by Austin (1990), Walker et al. (1990), Maetô (1996) and Whitfield et al. (2002), seems to suggest that Miropotes diverged early from the rest of Microgastrinae. More phylogenetic research will be needed, especially incorporating more genes, morphological data, and some recently described new genera, before the relationships within Microgastrinae, and the position of Miropotes within it, can be better resolved.
,The following discussion about Miropotes, its morphological features and relationships with other genera of Microgastrinae is taken from Fernandez-Triana et al. (2014). Additionally, an unpublished paper from Fernandez-Triana and van Achterberg has found the genus in the Afrotropical region -once that paper is published, complete details will be posted here.
Mason (1981) considered Miropotes to be taxonomically isolated, but likely related to the South African genus I, and placed both relatively basally in the tribe Apantelini, as part of his proposed intuitive phylogeny of Microgastrinae. Austin (1990) discussed several shortcomings of Mason’s system of tribes, but found support (based on a reassessment of characters of the female hypopygium and ovipositor) for a clade comprising most of the genera included by Mason in his tribes Apantelini and Microgastrini. Austin also mentioned that the position of Miropotes within Microgastrinae was unclear, but considered that, for the time being, it was better to leave it within Apantelini (e.g., Fig. 5 in Austin 1990). A taxonomically and morphologically less detailed but phylogenetically more rigorous study by Walker et al. (1990) found two competing hypothesis of relationships within genera of microgastrines, with one of those hypotheses having Miropotes (and Exulonyx) as the sister group of all other Microgastrinae. However, Walker et al. (1990) emphasized that Mason’s tribes were (at least on the basis of his presented characters) unsupported and should not be used, an advice that has since been followed by most taxonomists. While studying the male genitalia of Microgastrinae, Maetô (1996) also found support for most of the Apantelini + Microgastrini clade, but stated that Miropotes (and a few other genera) lacked the defining autapomorphy. Whitfield et al. (2002) included not only a more explicit and realistically coded version of Mason’s (1981) morphological data, but also data from three genes (COI, 16S, and 28S) to study phylogenetic relationships among genera of Microgastrinae. Datasets were analyzed independently and combined. The results recovered Miropotes as the sister group of all other genera of Microgastrinae in both the morphological analysis only (bootstrap value: 100, Bremer support 10), and in the combined analysis of the three gene markers plus morphology (bootstrap value: 99). The analysis of only the 28S dataset recovered Miropotes as the sister group of all Microgastrinae (bootstrap value: 100, Bremer support 1) minus the Microplitini clade – which includes the genera Alloplitis, Microplitis, Philoplitis and Snellenius. However, the molecular analysis of the 16S or COI datasets independently, and the analysis of the three genes combined did not provide any clear support for Miropotes as an independent lineage. Later studies incorporating more genes (Banks & Whitfield 2006, Murphy et al. 2008) were not able to include additional data from Miropotes. In a paper about DNA barcoding of microgastrine wasps, Smith et al. (2012, Appendix S2, page 160) provided a Neighbor Joining Tree (K2P) of over 17 500 sequences with more than 500 base pairs from specimens worldwide. The only available sequence of Miropotes (then only identified as “Microgastrinae”, with voucher code CNCH2114, later described as Miropotes orientalis) was 15% different (i.e., almost 100 base pairs of difference) than the closest Microgastrinae sequence available. This provides additional support to the uniqueness of the genus as discussed by previous authors, although data from one relatively fast-evolving gene such as COI does not necessarily reflect deeper phylogenetic relationships among genera. Miropotes does seem to possess a number of unique morphological characters which have not yet been evaluated when studying the relationships between genera of Microgastrinae. Examples include the shape of the ovipositor sheaths and ovipositor (which, in most species of Miropotes is strongly bent); the enlarged and strongly convergent eyes (with totally to almost totally obliterated malar space); the small size of the metacoxa; and the short length of the metatibial spurs (the last two features shared by the putatively distantly related Microplitini clade). Another interesting feature, apparently overlooked by previous authors, is the presence of a light (white or yellow) spot on the gena, next to the mandible base and lower margin of eye. White spots on the lower part of the gena are rather uncommon in Microgastrinae. They are present in all known species of the genus Alphomelon, and have been occasionally found in very few species of other genera such as Apanteles, Cotesia, Dolichogenidea and an undescribed genus from New Zealand (e.g., Mason 1981, Deans et al. 2003, Ward and Fernández-Triana unpublished data). The combination of the characters mentioned above, altogether with the data discussed by Austin (1990), Walker et al. (1990), Maetô (1996) and Whitfield et al. (2002), seems to suggest that Miropotes diverged early from the rest of Microgastrinae. More phylogenetic research will be needed, especially incorporating more genes, morphological data, and some recently described new genera, before the relationships within Microgastrinae, and the position of Miropotes within it, can be better resolved.