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

• Published in: Systematic entomology Vol. 31; no. 3; pp. 529 - 564
• Main Authors: Gauld, Ian D., Dubois, Jacques
• Format: Journal Article
• Language: English
• Published: Oxford, UK; Malden, USA Blackwell Publishing Ltd 01-07-2006
• Subjects: Ichneumonidae; Polysphincta
• ISSN: 0307-6970; 1365-3113
• DOI: 10.1111/j.1365-3113.2006.00334.x

.  A cladistic analysis of the Polysphincta 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 (Iseropus (Gregopimpla (Tromatobia ((Zaglyptus + Clistopyga) + (Polysphincta genus‐group))). Within the Polysphincta genus‐group, the clade (Piogaster + Inbioia) is sister‐lineage to all other genera. The cosmopolitan genus Zabrachypus is nonmonophyletic, and has been subdivided into a monophyletic Nearctic/Western Palaearctic Zabrachypus s.str. and an Eastern Palaearctic Brachyzapusgen.n., comprising B. nikkoensis (Uchida) comb.n., B. tenuiabdominalis (Uchida) comb.n. and B. unicarinatus (Uchida & Momoi) comb.n. An Afrotropical species placed in Zabrachypus, Z. curvicauda (Seyrig), belongs to Schizopygacomb.n. The monophyly of the cosmopolitan genus Dreisbachia is equivocal, and we consider that species assigned to it are best placed in an expanded Schizopyga (syn.n.). The monobasic Afrotropical genus Afrosphincta is also a synonym of Schizopyga (syn.n.). The newly delimited Schizopyga is the sister‐lineage of Brachyzapus, and these two genera form the sister‐lineage of Zabrachypus s.str. as the monophyletic clade (Zabrachypus + (Schizopyga + Brachyzapus)). The Holarctic genus Sinarachna is monophyletic if the Palaearctic species S. anomala (Holmgren) is excluded and transferred to Zatypotacomb.n. The European species Polysphincta nielseni Roman belongs to the Palaearctic genus Reclinervellus, and (Reclinervellus + Sinarachna) is the sister‐lineage to a monophyletic group of undescribed Asian species herein assigned to a new genus, Chabliseagen.n. All remaining polysphinctine genera form a strongly monophyletic clade, the Polysphincta clade, although the relationship between this clade and the Chablisea and Zabrachypus clades remains an unresolved trichotomy. The Polysphincta clade comprises three lineages as an unresolved trichotomy, a monophyletic Oxyrrhexis, a major group (‘Polysphincta’ (Ticapimpla (Acrotaphus + Hymenoepimecis))) and an Acrodactyla lineage. In the second group, ‘Polysphincta’ is paraphyletic with respect to the other three genera. However, we retain ‘Polysphincta’ 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 ‘Polysphincta’ into two or more monophyletic taxa. In the third lineage, the Acrodactyla lineage, the Holarctic genus Acrodactyla is monophyletic if the European species A. madida (Haliday) is excluded. Consequently, we erect a new genus Megaetairagen.n. for this species. The monobasic Afrotropical genus Pterinopus is the sister‐lineage to the cosmopolitan genus Eruga. The very large cosmopolitan genus Zatypota seems to be monophyletic if two New World species, Z. parva (Cresson) and Z. gerardoi Gauld, Ugalde & Hanson, are transferred to Flacopimplacomb.n. The expanded Flacopimpla is the sister‐group to the Indo‐Australian genus Eriostethus, and these two in turn form the sister‐group to (Zatypota + Longitibia). This complex forms an unresolved tetrachotomy with (Pterinopus + Eruga), Acropimpla and Megaetaira. Formal descriptions of all genera are included, together with an illustrated key to the genera. Brief notes are given about the recorded hosts of each genus.