Systematics of the parasitic wasp genus Oxyscelio Kieffer (Hymenoptera, Platygastridae s.l.), part III: African fauna

Abstract African species of Oxyscelio (Hymenoptera: Platygastridae s.l.) are revised. A total of 14 species are recognized, 13 of which are described as new: Oxyscelio absentiae Burks, sp. n., Oxyscelio galeri Burks, sp. n., Oxyscelio gyri Burks, sp. n., Oxyscelio idoli Burks, sp. n., Oxyscelio intensionis Burks, sp. n., Oxyscelio io Burks, sp. n., Oxyscelio kylix Burks, sp. n., Oxyscelio lunae Burks, sp. n., Oxyscelio nemesis Burks, sp. n., Oxyscelio pulveris Burks, sp. n., Oxyscelio quassus Burks, sp. n., Oxyscelio teli Burks, sp. n. and Oxyscelio xenii Burks, sp. n. The genus Freniger Szabó, syn. n. is recognized as part of an endemic African species group of Oxyscelio with incomplete hind wing venation, and Oxyscelio bicolor (Szabó), comb. n. is therefore recognized as the only previously described species of Oxyscelio from Africa. The Oxyscelio crateris and Oxyscelio cuculli species groups, previously known from southeast Asia, are represented in Africa by seven and one species respectively.


Introduction
Oxyscelio Kieffer was first described to contain a single species of Scelioninae from Java (Kieffer 1907). It remained in obscurity until Dodd (1931) recognized that it was the oldest generic name corresponding to a set of Australian and Indo-Malayan species that previously had been placed in several other genera. Dodd's concept of Oxyscelio has been upheld in more recent examinations of scelionine genera (Masner 1976, Galloway and Austin 1984, Austin and Field 1997. The Indo-Malayan, Palearctic (Burks et al. 2013a, Australian, and Pacific (Burks et al. 2013b) species of Oxyscelio have been recently reviewed, expanding the number of described species of the genus from 36 to 170, while retaining as valid all but one of the species that had been recognized by Dodd. Despite the diversity of Oxyscelio, very little is known of its life history. The host of Oxyscelio perpensus Kononova, an exposed orthopteran egg laid from an unknown species onto plant tissue, was photographed as part of its original description (Kononova and Fursov 2007) and is the only known host record of the genus.
In this study we recognize 14 species of Oxyscelio from the Afrotropical realm, including 13 newly described species. Eight of these species are placed in species groups previously recognized from the Indo-Malayan realm. Four of the remaining species are placed in a uniquely African species group comprising the only species of Oxyscelio known to have incomplete hind wing venation, a feature that has most notably been found in other genera of Scelioninae, including Scelio Latreille, Sparasion Latreille, and Nixonia Masner. These species are determined to belong to Oxyscelio based on a single spur on both the mid and hind tibia, the presence of a facial submedian carina, and fore wing with a punctiform marginal vein and no pseudostigma (sensu Masner 1976).

Materials and methods
Specimens examined were provided by the following collections: Australian National Insect Collection, Canberra, Australia (ANIC) 1 ; The Natural History Museum, London, United Kingdom (BMNH) 2 ; Canadian National Collection of Insects, Arachnids and Nematodes, Ottawa, Canada (CNCI) 3 ; Hungarian Natural History Museum, Budapest, Hungary (HNHM) 4 ; Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA (MCZC) 5 ; Lund Museum of Zoology, Lund University, Lund, Sweden (MZLU) 6 ; National Museum of Kenya (NMKE) 7 ; C.A. Triplehorn Insect Collection, Ohio State University, Columbus, Ohio (OSUC) 8 ; Queensland Primary Industries and Fisheries Insect Collection, Indooroopilly, Australia (QDPC) 9 ; Queensland Museum, Brisbane, Australia (QMBA) 10 ; South African Museum, Iziko Museums of Cape Town, South Africa (SAMC) 11 ; National Museum of Natural History, Washington, DC (USNM) 12 ; Waite Insect and Nematode Collection, Adelaide, Australia (WINC) 13 . This revision is a product of the Platygastroidea Planetary Biodiversity Inventory, funded by the U.S. National Science Foundation (N.F. Johnson, Ohio State University; Andy Austin, University of Adelaide; Principal Investigators). An objective of this project is to use biodiversity informatics resources to accelerate taxonomic work, making real-time collaboration possible. Data associated with specimens examined in this study can be accessed at hol.osu.edu and entering the unique specimen identifier (e.g. OSUC 359541) in the search form. Scale bars on all figures are in mm format. Morphological terminology follows Mikó et al. (2007) except as specified here. Ovipositor terminology is used as described by Austin and Field (1997). "T1 midlobe" refers to the raised antero-medial area of T1 that is flanked by depressed lateral areas. This is usually flat and only weakly elevated in Oxyscelio, and therefore is not strictly the same as a T1 horn, but a T1 midlobe can be expressed as a T1 horn. All terms except those for surface sculpture are defined in the Hymenoptera Anatomy Ontology (http://portal.hymao.org).
Surface sculpture terminology follows Eady (1968) in most cases and Burks et al. (2013aBurks et al. ( , 2013b in interpretations of major sculpture versus microsculpture, which are explained again here. Diminutive variant sculptural terms were avoided because of a lack of criteria for separating them from non-diminutive alternatives. "Major" surface sculpture refers to repeated sculptural patterns that interact with seta placement, not including non-repeated elements or those which are repeated only once due to bilateral symmetry. "Umbilicate-foveate" sculpture refers to rounded crater-like sculptural elements, each surrounding a setiferous pit (and thus interacting with a seta), with each fovea being much larger than its setiferous pit and spatially separated from that pit (see, e.g., Fig. 3). "Umbilicate-punctate" sculpture indicates that no sculptural element accompanies the setiferous pit (and therefore the setal pit is the "major" surface sculpture element here, e.g., T6 in Fig. 67). "Rugose" sculpture refers to a pattern of branching or wrinkling elevations that flank setiferous pits but do not fully surround them (e.g., Figs 6, 7). Rugose sculpture can coexist with umbilicate sculpture in the same area of the sclerite, in which case the rugae occur on spaces between umbilicate sculptural elements. Note that "rugose" refers to a distribution of sculptural elements, and therefore can be "irregular" or "regular" even though rugae (the elements themselves) are by definition wrinkle-like and therefore at least slightly irregular. Where both umbilicate-foveate and umbilicate-punctate sculpture are reported for the same sclerite, this should be interpreted as variable sculpture where some setiferous pits are surrounded by foveae while others are not. Under this scheme, "major" surface sculpture cannot occur in any part of the sclerite that lacks setae.
"Microsculpture" refers to repeated tiny sculptural elements that do not interact with seta placement. Microsculpture can occur on "major" sculptural elements, such as on rugae and on all surfaces of foveae. "Punctate" microsculpture refers to tiny round pits that do not bear setae. "Granulate" microsculpture refers to sculpture that is similar to that of leather or skin, with areas enclosed by tiny grooves (= sunken septa). Microsculpture can occur in areas that lack setae.
Sculptural terms for repeated sculpture that are not included in the above categories are 1) "carinae" which refers to elevations that are sharp and not branched or wrinkled but do not repeat in a way that forms a pattern (excluding repeating due to bilateral symmetry), 2) "striae" which refers to repeated elevations that are not sharp and not branched or wrinkled. These sculptural elements do not interact with setiferous pit placement, but major sculptural elements can occur between them. While alternative logic may suggest that rugose sculpture is better classed within this category, this choice was avoided because rugose sculptural patterns did apparently interact with umbilicate sculptural patterns. For the occipital carina, "crenulate" means that short carinae radiate from the occipital carina. Certain carinae may be described using the phrase "wrinkle-like," which replaces our previous words "as a ruga," this change being done to make the terms more clearly descriptive.
Illustrations. Photographs were taken using a Synoptics Ltd. system using a Leica Z16 APO microscope and a JVC KY-F75U 3-CCD camera. Source photos were stacked using Zerene Stacker version 1.04, or Auto-Montage Pro version 5.01.0005, and enhanced using Adobe Photoshop CS5 or CS6.
Phylogenetic analysis. A New Technology Search at initial level 95 was performed using TNT (Tree analysis using New Technology) version 1.1 (Goloboff et al. 2003(Goloboff et al. , 2008. Implied weighting was used, with a default function of K = 15. Bootstrapping was performed with 1,000 replicates using the same settings but without implied weighting. Bracalba cuneata Dodd was used as an outgroup for the analyses (specimens OSUC 238172, OSUC 238164), chosen because of morphological similarity between Oxyscelio and Bracalba. A total of 14 out of 50 characters were used from the overall dataset (see Appendix I for characters and matrix). Internal phylogenetic relationships. The phylogenetic analysis performed with a select group of characters ( Fig. 1) found the bicolor-group and African species of the crateris-group to be monophyletic, with Oxyscelio quassus as the sister group to the bicolor-group and the crateris-group species as sister group to all other African species. These results indicate that recognition of the genus Freniger (with F. bicolor as type) would make the genus Oxyscelio paraphyletic. Our understanding of relationships among all Oxyscelio species is insufficient to suggest a robust reclassification of these into monophyletic taxa. Therefore, we opt to treat Freniger as a junior synonym of Oxyscelio.

Species groups of African Oxyscelio
These groups are provided here to indicate intuitively perceived structure within the genus, and to provide an aid for identification. They are succinctly diagnosed here. Some characters are omitted situationally from species group diagnoses because those characters are variable within the group or are otherwise unhelpful for that particular group's identification. Individual species descriptions can be consulted regarding characters omitted from these diagnoses. The only uniquely African species group is the bicolor-group, which is defined by a character that is unique in Oxyscelio. Two other African species are not placed to group, and may represent important lineages as well (see below). The more lengthy species group diagnoses for the other groups in Burks et a complete hind wing vein. The Indo-Malayan and Australian dasymesos-group differs from O. intensionis in occipital sculpture and in having sharp projections from the corners of T7. The dasymesos-group differs from O. quassus in having a complete mesoscutal median carina, and in having a very different (short and stout) body shape. Male. Body length 3.25-3.65 mm (n = 3). A5 tyloid: carina-like, not expanded. A11: longer than broad. T1 midlobe: with 4 longitudinal carinae. Metasomal apex: with acuminate lateral corners.

Key to African species of Oxyscelio
Diagnosis. Both sexes: Hyperoccipital carina present and sharp, connected to occipital carina by lateral carina; median carina between hyperoccipital and occipital carinae present but sometimes indicated only posteriorly. Gena with granulate sculpture posteroventrally but not anteroventrally. Mesoscutellum without granulate sculpture.
Radicle color: same as scape. A4: longer than broad. A5: broader than long. Upper frons: not hood-like. Frontal depression sculpture: with 3 or more broadly interrupted transverse carinae. Median longitudinal elevation in frontal depression: absent.  OSUC 369391, 223802, 242799, 282894, 282896, 320854, 369393 (CNCI);OSUC 176083, 218855, 233095-233096, 320840-320841, 320845, 320847, 320849-320853, 320855, 369385, 369394 (OSUC);OSUC 176091, 218850, 223639, 223801, 225982-225985, 251694-251698, 267415-267417, 282879, 282895, 317893, 320838, 320842-320844, 320846, 320848 (SAMC). Comments. Oxyscelio lunae is by far the most commonly collected species of its genus from Africa, although nearly all known specimens are male. It is very similar to O. pulveris, but after extensive comparison of the two series we concluded that they are different species. The chief difference is the considerably more granulate sculpture of O. pulveris, which occurs in conjunction with lower and more rounded (therefore, less sharp and less distinctive) carinae, especially the hyperoccipital and mesoscutellar disc carinae. These features are accompanied by some more vague and less easily described differences in eye shape, mesosomal and metasomal sclerite shape, and metasomal sculpture. Comments. Oxyscelio nemesis strongly resembles Oxyscelio io, and they both vaguely resemble Oxyscelio teli. These three species together may form a monophyletic species complex, but such a grouping would currently be difficult to fully distinguish from similar African species. It can be roughly defined by the medially more or less flat occipital carina, but this feature in O. io is variable and sometimes not greatly different from that of some excluded African species.

Oxyscelio nemesis
The shape of the head of this species and the carinate margin of the antennal scribe make it superficially similar to the genus Baryconus Förster. The fore wing venation, however, makes it clear that this is an Oxyscelio: it lacks elongate marginal and postmarginal veins, and the stigma vein arises from the upturned apical portion of the submarginal vein.