﻿A taxonomic revision of the Old World genus Dichoteleas Kieffer (Hymenoptera, Scelionidae)

﻿Abstract The genus Dichoteleas Kieffer (Scelionidae: Scelioninae) is known only from the Old World: Kenya, Tanzania, Malawi, South Africa, Madagascar, southern India, the island of New Guinea, and eastern Australia. After revision, 10 species are recognized. Four species were previously recognized and are redescribed: D.ambositrae Risbec (Madagascar), D.indicus Saraswat (India: Kerala), D.rugosus Kieffer (Australia: Queensland), and D.subcoeruleus Dodd (Australia: Queensland). Six species are described as new: D.fulgidussp. nov. (Indonesia: Papua Barat), D.fuscussp. nov. (Papua New Guinea, Australia: Queensland), D.hamatussp. nov. (Kenya, Tanzania, Malawi, South Africa)., D.rubyaesp. nov. (Madagascar), D.striatussp. nov. (Madagascar), and D.umbrasp. nov. (Tanzania). Dichoteleaspappi Szabó is treated as a junior synonym of D.rugosus. An identification key to species of the genus is provided.


Introduction
The genus Dichoteleas was first described by Jean-Jacques Kieffer in 1907 on the basis of a single male specimen collected in Mackay, North Queensland, Australia.It was distinguished from Pentacantha Ashmead (a genus of the subfamily Teleasinae) by the "Thorax mit drei spitzen Zähnen" (thorax with three pointed teeth) and the presence of the postmarginal vein on the forewing (Kieffer, 1907).Kieffer did not specify in his generic description on which parts of the mesosoma these teeth occur, but in his description of the sole species, D. rugosus, he indicated that the teeth are found on the sides of the mesoscutellum and medially on the metanotum.After collecting a female of the type species, Dodd (1926) added that the antennal club had 7 segments.Later, Masner (1976) proposed that Dichoteleas could be identified by its large hairless eyes, elongate maxillary palpi, and subtridentate mandibles.
In the years since its description, five species have been described in the genus.Three were described from Australia (D. rugosus Kieffer, D. subcoeruleus Dodd, and D. pappi Szabó), one from Madagascar (D. ambositrae Risbec), and one from India (D. indicus Saraswat).Only D. subcoeruleus was described based on more than a single sex, and none of these were based on more than five specimens.In their revision of Australian Scelioninae, Galloway and Austin (1984) noted that D. pappi may be a junior synonym of D. rugosus, since the species have similar ranges, and Dichoteleas pappi was described from one female specimen, while D. rugosus was described from a male.Masner (1976) placed Dichoteleas in the tribe Calliscelionini of the subfamily Scelioninae, although he mentioned that the genus was "difficult to classify tribally."He also cited a possible relationship with Amblyscelio Kieffer or Neoscelio Dodd.Dichoteleas was grouped with Amblyscelio and Oxyteleia Kieffer In the 4-gene analysis of Chen et al. (2021), but the bootstrap support for this was relatively weak.Dichoteleas is fairly unusual among platygastroids in that some of the species are distinctly metallic in color.To the best of our knowledge, all members of the subfamily Scelioninae are egg parasitoids of spiders or other insects, but there are currently no host records for Dichoteleas and little else is known of this group.
The goals of this paper are to incorporate information from newly collected specimens, revise the circumscription of described species on the basis of these new data, document and describe hypothesized new species within the genus, and to provide a comprehensive identification key for the species of Dichoteleas.
Each specimen examined in this paper has a unique identifier consisting of a prefix (e.g., "OSUC") and a number.The associated data for each specimen may be accessed at http://mbd-db.osu.edu using this unique identifier.Morphological terminology generally follows Mikó et al. (2007).The term claval formula (Bin 1981) refers to the apical antennomeres of the female that bear papillary sensilla on their ventral surface.The claval formula is the number of papillary sensilla on each antennomere separated by a dash, starting from the distal antennomere to the most proximal antennomere.The antennomere is also designated by number (from proximal to distal segment).A 5-segmented clava with 1 sensillum on the most distal antennomere and 2 sensilla on each of the remaining antennomeres would be represented with a claval formula of A12-A8: 1-2-2-2-2.Metasomal tergites are referred to by the letter T followed by a number, e.g., T1 is the first (i.e., basalmost) metasomal tergite.
The terminology for the surface sculpture follows (Harris, 1979).Species descriptions and a taxon by data matrix were generated using vSysLab (https:// vsyslab.osu.edu).These descriptions were exported in the format of "Character: Character state(s)."The states of characters polymorphic for a species are separated by semicolons.Photographs of specimens were captured using a Leica Z16 APOA system and stacked with the Leica Application Suite software.Images of type specimens were provided by Elijah Talamas (Florida State Collection of Arthropods).
Our concept of species is based on the biological species concept as described by Mayr (1942).Species are populations whose individuals have the ability to interbreed in nature.Many morphological characters likely are the result of polygenic origin, and interbreeding populations exchange genes among themselves but not with other species.Thus, one would predict that separate species will eventually come to evolve differences in morphological character states, either randomly or through natural selection (Wild 2004).Other factors -including sexual dimorphism, under-sampling of intraspecific variability, genetically simple but discrete character states, and environmental influences -may suggest species differences.It is the task of the taxonomist in the early stages of the study of a group to tease apart such sources of variation, evaluate the evidence, and propose hypotheses of how many independent species exist and which characters can be used to distinguish them.Going forward, these hypotheses can be tested with new characters and new sources of characters.(Austin and Field 1997).

Key to species of Dichoteleas
Generic diagnosis.Dichoteleas can be identified by its elongate maxillary palpi, lateral spines on the mesoscutellum, medial spine on the metascutellum, and well-developed postmarginal vein on the forewing.This taxon can be distinguished from Neoscelio by the short (or absent) setation on the eyes and the well-developed postmarginal vein.It may be distinguished from Oxyteleia and Oreiscelio since in Dichoteleas the metascutellum only has a single median spine.The New World genus Pseudoheptascelio may also be interpreted to have a bidentate mesoscutellum.In that group the stigmal vein (r-rs) arises from the submarginal vein before it reaches the costal margin of the fore wing.In Dichoteleas, the stigma vein arises from the costal margin.
Distribution.Dichoteleas species are known from Kenya, Tanzania, Malawi, northeastern South Africa, Madagascar, southern India, New Guinea and Far North Queensland in Australia (Figs 1-8).No specimens have yet been collected in other parts of sub-Saharan Africa, southeast Asia, or regions to the east of Papua New Guinea.

Description
Etymology.The epithet comes from the Latin word for "shiny," referring to the smooth, metallic luster of the mesosoma.This epithet is treated as an adjective.
Etymology.The epithet comes from the Latin word for "dusky," referring to the darker, metallic color of the mesosoma (in comparison to D. fulgidus).This epithet is treated as an adjective.
Etymology.The name hamatus is drawn from the Latin word for hooked, referring to the hooked projections on the axillular carinae.This epithet is treated as an adjective.
Etymology.The epithet rubyae in honor of the first author's grandmother, Ruby Thomas.The name also refers to the red coloration of the mesosoma.This epithet is treated as a noun in the genitive case.
Comments.There is some variation in the visibility of the notauli.In most specimens, the notauli were obscured by the mesoscutal sculpture, but one specimen (CASENT 2137863) had clearly defined notauli.

Dichoteleas rugosus Kieffer Figs 7, 29-31
Dichoteleas rugosus Kieffer, 1907: 297 (original    Comments.In the original description, Kieffer (1907) wrote that D. rugosus was missing parapsidal lines.They are present but obscured by the sculpture of the mesoscutum.Diagnosis.This species can be distinguished from D. ambositrae by the longitudinal striations between the notauli and the black/brown pronotum and from D. rugosus by its glabrous mesosoma.
Etymology.The epithet refers to the longitudinal striations present on the mesoscutum.This epithet is treated as an adjective.
Comments.There was some variation in the length and the number of the longitudinal striations on the mesoscutum.In fewer than half of the specimens, the striations started anteriorly and terminated around the middle of the mesoscutum.In the majority of the specimens, the striations started anteriorly and terminated at the posterior margin of the mesoscutum.

Dichoteleas subcoeruleus Dodd Figs 8, 35-37
Dichoteleas subcoeruleus Dodd, 1926: 370, 371     Etymology.The name umbra is from the Latin word for shadow or shade, referring to the dark color.This epithet is treated as a noun.

Comments on undescribed specimens:
There were a few specimens that did not fit into these species descriptions.We have chosen to not formally describe them because all were male and only 1-2 specimens were available.
Diagnosis.This specimen has an anteriorly produced IAP, similar to D. indicus, but it lacks a central keel and submedian carinae on the frons.
Diagnosis.These specimens have a curved carina in the shape of an inverted "U" present on the frons.It appears to join the facial striae anteriorly.Submedian carinae are present, and there is a blunt medial projection on the mesoscutellum.The specimens were collected in southern India, Tamil Nadu state (Coimbatore and the Anaimlai Hills).