Review of Afrotropical sceliotracheline parasitoid wasps (Hymenoptera, Platygastridae)

The platygastrid subfamily Sceliotrachelinae, while represented globally by numerous biologically important taxa, is generally poorly known for the Afrotropical region. It contains a number of species of economic significance, including some that attack hemipteran pests of citrus. Here we review the taxonomy of the subfamily for the region. We revise two enigmatic, endemic South African genera, Afrisolia Masner and Huggert and Sceliotrachelus Brues, providing illustrated identification keys to the species. Afrisolia anyskop van Noort & Lahey, sp. nov., Afrisolia quagga van Noort & Lahey, sp. nov. and Afrisolia robertsoni van Noort & Lahey, sp. nov. are described for this previously monotypic genus. Sceliotrachelus was previously known only from the two male type specimens of Sceliotrachelus braunsi Brues. Two new species, Sceliotrachelus midgleyi van Noort, sp. nov. and Sceliotrachelus karooensis van Noort, sp. nov., are described from the Eastern and Western Cape, respectively. The female of S. braunsi is described for the first time and additional distribution records for the species are documented. The putatively basal species, S. karooensis, exhibits less derived morphology than the highly apomorphic S. braunsi, necessitating reassessment of the limits of the genus. The exceptional morphology exhibited by species of Sceliotrachelus is hypothesized to be an adaptation to living in leaf-litter. We also revise the Old World species of Parabaeus Kieffer, describing a remarkable new species, Parabaeus nasutus van Noort, sp. nov., and provide an illustrated and updated key to the species. Fidiobia Ashmead is currently represented in Africa by seven described species to which we add Fidiobia celeritas van Noort & Lahey, sp. nov., a charismatic new species from South Africa. The distribution of the genus Isolia is expanded to include new country records for I. hispanica Buhl (Kenya) and an undescribed species from Madagascar. To facilitate the ongoing exploration and documentation of the African platygastrid fauna, an identification key to Afrotropical sceliotracheline genera and high resolution images of exemplar species for the remaining genera are provided. An overview of known species richness and biology is also included. All images presented here as well as additional images and interactive online Lucid identification keys are available on WaspWeb at http://www.waspweb.org.