Phylogeny of the<i>Polysphincta</i>group of genera (Hymenoptera: Ichneumonidae; Pimplinae): a taxonomic revision of spider ectoparasitoids

<jats:p><jats:bold>Abstract. </jats:bold>A cladistic analysis of the<jats:italic>Polysphincta</jats:italic>genus‐group (= the ‘Polysphinctini’ of authors), a clade of koinobiont ectoparasitoids of spiders, was undertaken using ninety‐six characters for seventy‐seven taxa (sixty‐five ingroup and twelve outgroup). The genus‐group is monophyletic, nested within the Ephialtini as (<jats:italic>Iseropus</jats:italic>(<jats:italic>Gregopimpla</jats:italic>(<jats:italic>Tromatobia</jats:italic>((<jats:italic>Zaglyptus</jats:italic> + <jats:italic>Clistopyga</jats:italic>) + (<jats:italic>Polysphincta</jats:italic>genus‐group))))). Within the<jats:italic>Polysphincta</jats:italic>genus‐group, the clade (<jats:italic>Piogaster</jats:italic> + <jats:italic>Inbioia</jats:italic>) is sister‐lineage to all other genera. The cosmopolitan genus<jats:italic>Zabrachypus</jats:italic>is nonmonophyletic, and has been subdivided into a monophyletic Nearctic/Western Palaearctic<jats:italic>Zabrachypus</jats:italic>s.str. and an Eastern Palaearctic<jats:italic>Brachyzapus</jats:italic><jats:bold>gen.n.</jats:bold>, comprising<jats:italic>B. nikkoensis</jats:italic>(Uchida)<jats:bold>comb.n.</jats:bold>,<jats:italic>B. tenuiabdominalis</jats:italic>(Uchida)<jats:bold>comb.n.</jats:bold>and<jats:italic>B. unicarinatus</jats:italic>(Uchida & Momoi)<jats:bold>comb.n.</jats:bold>An Afrotropical species placed in<jats:italic>Zabrachypus</jats:italic>,<jats:italic>Z. curvicauda</jats:italic>(Seyrig), belongs to<jats:italic>Schizopyga</jats:italic><jats:bold>comb.n.</jats:bold>The monophyly of the cosmopolitan genus<jats:italic>Dreisbachia</jats:italic>is equivocal, and we consider that species assigned to it are best placed in an expanded<jats:italic>Schizopyga</jats:italic>(<jats:bold>syn.n.</jats:bold>). The monobasic Afrotropical genus<jats:italic>Afrosphincta</jats:italic>is also a synonym of<jats:italic>Schizopyga</jats:italic>(<jats:bold>syn.n.</jats:bold>). The newly delimited<jats:italic>Schizopyga</jats:italic>is the sister‐lineage of<jats:italic>Brachyzapus</jats:italic>, and these two genera form the sister‐lineage of<jats:italic>Zabrachypus</jats:italic>s.str. as the monophyletic clade (<jats:italic>Zabrachypus</jats:italic> + (<jats:italic>Schizopyga</jats:italic> + <jats:italic>Brachyzapus</jats:italic>)). The Holarctic genus<jats:italic>Sinarachna</jats:italic>is monophyletic if the Palaearctic species<jats:italic>S. anomala</jats:italic>(Holmgren) is excluded and transferred to<jats:italic>Zatypota</jats:italic><jats:bold>comb.n.</jats:bold>The European species<jats:italic>Polysphincta nielseni</jats:italic>Roman belongs to the Palaearctic genus<jats:italic>Reclinervellus</jats:italic>, and (<jats:italic>Reclinervellus</jats:italic> + <jats:italic>Sinarachna</jats:italic>) is the sister‐lineage to a monophyletic group of undescribed Asian species herein assigned to a new genus,<jats:italic>Chablisea</jats:italic><jats:bold>gen.n.</jats:bold>All remaining polysphinctine genera form a strongly monophyletic clade, the<jats:italic>Polysphincta</jats:italic>clade, although the relationship between this clade and the<jats:italic>Chablisea</jats:italic>and<jats:italic>Zabrachypus</jats:italic>clades remains an unresolved trichotomy. The<jats:italic>Polysphincta</jats:italic>clade comprises three lineages as an unresolved trichotomy, a monophyletic<jats:italic>Oxyrrhexis</jats:italic>, a major group (‘<jats:italic>Polysphincta</jats:italic>’ (<jats:italic>Ticapimpla</jats:italic>(<jats:italic>Acrotaphus</jats:italic> + <jats:italic>Hymenoepimecis</jats:italic>))) and an<jats:italic>Acrodactyla</jats:italic>lineage. In the second group, ‘<jats:italic>Polysphincta</jats:italic>’ is paraphyletic with respect to the other three genera. However, we retain ‘<jats:italic>Polysphincta</jats:italic>’ as a genus because few species of this very large genus were included in our analysis. We suspect that, when the tropical fauna is better known, it will be possible to subdivide ‘<jats:italic>Polysphincta</jats:italic>’ into two or more monophyletic taxa. In the third lineage, the<jats:italic>Acrodactyla</jats:italic>lineage, the Holarctic genus<jats:italic>Acrodactyla</jats:italic>is monophyletic if the European species<jats:italic>A. madida</jats:italic>(Haliday) is excluded. Consequently, we erect a new genus<jats:italic>Megaetaira</jats:italic><jats:bold>gen.n.</jats:bold>for this species. The monobasic Afrotropical genus<jats:italic>Pterinopus</jats:italic>is the sister‐lineage to the cosmopolitan genus<jats:italic>Eruga.</jats:italic>The very large cosmopolitan genus<jats:italic>Zatypota</jats:italic>seems to be monophyletic if two New World species,<jats:italic>Z. parva</jats:italic>(Cresson) and<jats:italic>Z. gerardoi</jats:italic>Gauld, Ugalde & Hanson, are transferred to<jats:italic>Flacopimpla</jats:italic><jats:bold>comb.n.</jats:bold>The expanded<jats:italic>Flacopimpla</jats:italic>is the sister‐group to the Indo‐Australian g ...