Systematics of Scelioninae (Hymenoptera, Platygastroidea): new synonymy, distribution, and species

Abstract The genera Doddiella Kieffer, 1913 and Aratala Dodd, 1927 are treated as junior synonyms of of Aneuroscelio Kieffer, 1913 following study of the rediscovered holotype of the type species Aneuroscelio rufipes Kieffer, 1913 (syn. nov.). The nine species previously recognized in Doddiella are all transferred to Aneuroscelio (comb. nov.). Calliscelio schlingeri (Masner & Johnson) is recognized as a junior synonym of Calliscelio vitilevuensis (Fullaway) (syn. nov.). Huddlestonium exu Polaszek & Johnson is recorded from Kenya, significantly expanding its known range from West Africa (Côte d’Ivoire, São Tomé). A new species of the genus Tyrannoscelio Masner, Johnson & Arias-Penna, T. cerradensissp. nov, is described from Paraguay and the Center-West of Brazil (Mato Grosso). The depositories of the holotypes of five recently described are corrected.


Introduction
Our knowledge of the diversity of parasitoid wasps in the superfamily Platygastroidea has grown by leaps and bounds over the past 25 years. Since the publication of the last hardcopy taxonomic catalogs for the group (Johnson 1992, Vlug 1995, the number of de-scribed genera has grown by 18.5%, from 426 to 505, and the number of species-group taxa has increased an astonishing 68.4%, from 4184 to 7045. The most current online tabulation of the diversity reports 263 valid genera and slightly over 6000 valid species.
In the course of this rapid expansion, several small discoveries and mistakes have been made, most of which would be too minor to merit separate publication. The goal of this contribution is to address these issues and formally document them in the literature.

Status of Doddiella Kieffer
In 1913 J.-J. Kieffer published the description of a new genus of scelionine from Aburi in the Gold Coast (present-day Ghana), dedicating it to the teenaged Alan P. Dodd of Queensland. The primary distinguishing characteristic for the new genus was cited as the absence of veins in the wings. This feature was thought to be shared, within the Scelionidae of the time, only with Rielia Kieffer, a genus today known as Mantibaria Kirby. Ironically, although he was the person intended to be honored, Kieffer's description was not sufficient for Dodd to recognize the genus, and he later described it anew under the name Aratala (Dodd 1927). Nine species are currently treated as valid taxa, and the genus is known from the Afrotropical, Oriental, Australian, and Neotropical regions, and also edging into the Palearctic in Egypt and Ethiopia. It is a striking and unmistakable creature, so much so that Masner erected for it the monobasic tribe Doddiellini in 1976. It has received a limited amount of taxonomic attention, having been mentioned in the literature 16 times. Identification keys have been published for the African and Palearctic species (Priesner 1951, Kononova andKozlov 2008).
In the same year in which Doddiella first appeared, Kieffer also described the new genus Aneuroscelio from Murang'a (reported as Méranga or Fort-Hall) in British East Africa, modern Kenya. This name languished in obscurity due to the inadequacy of Kieffer's description and lack of study of the single known specimen of the type species, Aneuroscelio rufipes Kieffer. The type specimen had not been examined because it was not found in the pinned and mounted collection in the Muséum national d'Histoire naturelle in Paris (see comments in Masner 1976: 56). Through the efforts and kindness of Dr. Claire Villemant of that institution, Kieffer's types from that paper have now been unearthed, preserved in vials of ethanol and kept separate from the rest of the collection. We have since mounted these specimens so that they can be studied and the taxonomic concepts of names they represent can be determined.
Aneuroscelio rufipes is a typical species of Doddiella (Fig. 1). Not only does it lack wing veins, but it possesses all of the characteristic features: a dense field of white setae on the gena, mesopleuron smooth and lacking almost all of the the typical sulci and foveae, netrion absent, metascutellum produced into a "blade-like projection," first metasomatic segment elongate, and the posterior margin of the second segment strongly raised and curved (Masner 1976). The two generic names are clearly synony-mous. Masner (1976) anticipated this but could not resolve the issue without the type. Beyond the synonymy, the question then is which name is senior?
Doddiella was described in the pages of the Bollettino del Laboratorio di Zoologia Generale e Agraria della R. Scuole Superior d'Agricoltura in Portici in volume 7. The index for that volume cites the dates of publication of each article, and Kieffer's paper is dated 20 October 1913. The description of Aneuroscelio appeared as a contribution to the Hymenoptera section in "Voyage de Ch. Alluaud et R. Jeannel en Afrique Orientale (1911)(1912)", and an insert in that book dates the article to 15 August 1913. Thus, the name Aneuroscelio has priority over the much better known Doddiella.

Corrections of holotype depositories
The collections in which the holotypes for the following species are deposited were reported incorrectly. The corrections are noted alongside the taxon name.

Huddlestonium exu Polaszek & Johnson is widespread in Africa
The genus Huddlestonium is a curious creature whose features demand an expansion of the boundaries of what is morphologically possible in the Platygastroidea ). It clearly belongs to the superfamily as it possesses the characteristic ventral papillar sensilla on the apical claval segments of the female (the male is, as yet, undiscovered). However, it has no well-developed laterotergites and laterosternites on the metasoma and the female antenna is uniquely 13-merous. It was described from two collections, a single specimen from the Côte d'Ivoire and a short series of four specimens from the island of São Tomé, both collecting localities in western Africa. Among the extant fauna, it is most similar to the Neotropical genus Plaumannion, a group that is even rarer than Huddlestonium as it is known from only 3 specimens (one of which is broken). In terms of the fossil record, Huddlestonium bears a striking resemblance to the Eocene genus Archaeoscelio Brues (see ) and perhaps even to the recently described Cretaceous species Geoscelio mckellari Engel & Huang (Engel et al. 2017).
It was, therefore, of some surprise to find new specimens of Huddlestonium collected nearly 2000 miles east of São Tomé in western Kenya. One specimen (UCRC ENT 154639) was collected in Isecheno Nature Reserve (0.24°N, 34.87°E); and two (OSUC 192430, 232305) in Ruma National Park (0.65°S, 34.33°E). The specimens differ slightly from their west African counterparts, particularly in the closer proximity of the lateral ocelli to the margins of the compound eyes. We were initially tempted to treat these specimens as a new species. Despite the great distance separating the collecting localities, the morphological differences seem too slight to warrant that course of action, particularly given the small number of specimens at hand. The new data do indicate that Huddlestonium is much more widely distributed than previously known. Unfortunately, we remain ignorant of the hosts that they parasitize.

A new species of Tyrannoscelio Masner, Johnson & Arias-Penna
The genus Tyrannoscelio is known from only two species: T. genieri Masner & Johnson from the southeastern Brazilian state of Espírito Santo, and T. crenatus Arias-Penna, known from two specimens from the opposite side of the continent, in the Colombian province of Caquetá. The genus is immediately recognizable on the basis of the expanded, crenellated frontal shelf, and the extraordinarily elongate mandibles. More subtly, though, the genus is notable for the presence of a distinct skaphion and the lack of a postmarginal vein in the forewing. Here we describe a third species of the genus, from central Paraguay and the Brazilian state of Mato Grosso. Etymology. The specific epithet refers to the cerrado habitat in which the specimens were collected and is treated as an adjective.
Comments. Since the original description of T. genieri several additional specimens have been collected in the Brazilian state of Espírito Santo in or near the Soore-tama Biological Reserve, the same area from which the species was described originally. The habitats are described on the specimen labels as semi-deciduous or primary lowland Atlantic forest. The additional species in the Center-West of Brazil, Paraguay, and Colombia suggests that the genus is very widely distributed and rare or perhaps restricted in its habitat preferences or timing of adult emergence.