Revision of Dvivarnus ( Scelionidae , Teleasinae )

Two new species, Dvivarnus elektrolythron Talamas & Mikó, sp. n. and D. mikuki Talamas & Mikó, sp. n. are described. The genus is redescribed and a key is provided to separate Dvivarnus from other groups in Teleasinae with mesoscutellar spines.


Introduction
The subfamily Teleasinae is well defined morphologically by wing venation (elongate marginal vein, short stigmal and postmarginal veins), the anterior pronotal process and, in most cases, a compact ocellar triangle.Generic classification within the subfamily is another matter and a thorough phylogenetic analysis is needed.The vast majority of species are found in Trimorus Förster, a genus whose limits are poorly defined with respect to many of the smaller genera.Dvivarnus Rajmohana & Veenakumari is a well defined teleasine genus that morphologically falls well outside of Trimorus and until now was monotypic.
We here expand knowledge about the species-level diversity in Dvivarnus with the addition of two new species.We also provide additional characters to those of Veenakumari et al (2011) for its diagnosis relative to two lineages in Teleasinae that also have mesoscutellar spines, Gryonoides Dodd and the Trimorus carus Nixon species group.The analysis of Gryonoides follows the examination of 12 species conducted as part of an active revision of this genus by the second author.Our treatment of the Trimorus carus species group is based on examination of the holotype of T. carus Nixon and two undescribed species from the Central African Republic that share the presence of a distally bifurcating metascutellar spine.

Materials and methods
The numbers prefixed with "USNMENT" or "OSUC " are unique identifiers for the individual specimens (note the blank space after some acronyms).Details on the data associated with these specimens may be accessed at the following link: purl.oclc.org/NET/hymenoptera/hol, and entering the identifier in the form.Persistent URIs for each taxonomic concept were minted by xBio:D in accordance with best practices recommended by Hagedorn et al (2013).Morphological terms were matched to concepts in the Hymenoptera Anatomy Ontology (Yoder et al 2010) using the text analyzer function.A table of morphological terms and URI links is provided in Suppl.material 1.
Taxonomic synopses and matrix-based descriptions were generated from the Hymenoptera Online Database (hol.osu.edu) and the online program vSysLab (vsyslab.osu.edu) (matrix title: Revision of Dvivarnus) in the format of character: state.Multiple states for a character are separated by a semicolon.Characters shared among the three species of Dvivarnus were exported as the generic description (OTU for generic characters: Dvivarnus), those that were not shared among all species were exported as species descriptions.
Photographs were captured with a Z16 Leica lens with a JVC KY-F75U digital camera using Cartograph software.Single montage images were produced from image stacks with the program CombineZP.In some cases, multiple montage images were stitched together in Photoshop to produce larger images at high resolution and magnification.Full resolution images are archived at the image database at The Ohio State University (http://purl.oclc.org/NET/hymenoptera/specimage).
Scanning electron micrographs were produced with a Hitachi TM300 Tabletop Microscope.The specimen was disarticulated with a minuten probe and forceps and mounted to 12 mm slotted aluminum mounting stub (EMS Cat.#75220) using carbon adhesive tabs  by means of a fine paint brush and sputter coated with approximately 70 nm of gold/palladium.

Specimens
This study is based on specimens from the following collections:    Veenakumari et al (2011), Dvivarnus can be differentiated from other teleasines by the combination of the dense punctation found throughout T3 and S3, the presence of paired mesoscutellar spines, the absence of lateral propodeal carina and the presence of an inverted U-shaped carina dorsally surrounding the metasomal depression.Punctation on T3 can be found in some species of Trimorus (Fig. 20), but the punctation is surrounded by rugulae of varying intensity.In Dvivarnus, the punctation is uniform throughout most of the tergite and is not accompanied by additional sculptural elements.Specimen USNMENT01109195 (Fig. 20) also has spines derived from the metapleural carina, which are not present in Dvivarnus.Additional characters for the identification of Dvivarnus are presented in the key to teleasines with mesoscutellar spines.
Comments.The species of Dvivarnus are extremely similar in most pleural characters and differ primarily by features of the head, pronotum, and metasoma.Sexual dimorphism is exhibited mostly in the pattern of setation and striation of the frons.In males, the glabrous area above the interantennal process is less distinct and the density of setation throughout the frons varies greatly.The facial striae in males extend dorsally throughout the frons whereas in females the striation is absent from the center portion of the frons.
We examined two morphospecies of males that we were unable to unambiguously associate with the female of D. elektrolythron.One morphospecies (USN-MENT01109164, Figs 46-50) shares with D. elektrolythron the pattern of striation on the lateral pronotum (Fig. 50) and the longitudinal furrow on the metanotal trough (Fig. 48).However, it has distinct notauli (Fig. 46) and D. elektrolythron has none, and the posterior margin of the mesoscutellum between the mesoscutellar spines is concave in USNMENT01109164, and medially pointed in D. elektrolythron.The other morphospecies (USNMENT01109212, Figs 40-45) has the opposite arrangement of characters: it shares with D. elektrolythron the absence of notauli and the presence of a pointed posterior margin of the mesoscutellum (Figs 40,43) but it has a foveolate metanotal trough (Fig. 43) and the lateral pronotum is predominantly smooth (Fig. 45).In the absence of additional specimens that would allow us to thoroughly assess intraspecific variability in males, or molecular or biological data, we consider it best to document the morphology of these males and present them as undetermined at the species-level.

Key to teleasines with
Frons with central keel separate from carinae of torular triangle (Fig. 15); mesoscutellum with posterior margin between mesoscutellar spines medially convex in dorsal view (Fig. 28, 31); pronotum with posterior portion transversely striate (Fig. 30); lateral patch on T4 present as a dense tuft of setae (Fig. 22); T5 with lateral patch present (Fig. 22 Description.Whorl of setae on flagellomeres in male: absent.Shape of A3-A11 in male: cylindrical.Epomial carina: indistinguishable from dorsoventral striation.Netrion in lateral view: extending dorsally to proximity of mesothoracic spiracle.Netrion sulcus: complete, extending dorsally to posterior margin of pronotum.Sculpture of vertical face of pronotum: dorsoventrally strigose anteriorly, longitudinal striate posteriorly.Sculpture of mesoscutum: finely punctate.Density of setation on medial mesoscutum: dense.Notaulus: absent.Sculpture of scutoscutellar sulcus: smooth.Orientation of transaxillar carina: projecting posterolaterally.Sculpture of mesoscutellum: finely areolate.Density of setae on lateral margin of mesoscutellum: sparse.Posterior margin of mesoscutellum: convex between mesoscutellar spines.Median mesoscutellar spine: present.Lateral extreme of posterior scutoscutellar sulcus: foveae terminating below mesoscutellar spine.Sculpture of metanotal trough: smooth with elongate furrow in ventral half.Lateral propodeal carina: absent.Forewing pattern in female: wing membrane and setae brown posterior to marginal vein and in distal third, separated by a band of hyaline membrane and white setae.Sculpture of metapleural sulcus: smooth.Sculpture of dorsal metapleural area: transversely rugose.Sculpture of ventral metapleural area: transversely rugose.Number of setae on lateral T1: 3. Sculpture of T4: punctate.Lateral patch on T5: present.Number of apical setae on T7: 2. Diagnosis.Dvivarnus elektrolythron may be separated from females of D. mikuki and D. agamades by the incomplete central keel on the frons (Fig. 15), the form of the lateral patch on T4 (Figs 22,29), and by the medially convex posterior margin of the mesoscutellum.
Etymology.The epithet for this species refers to the bright red color on the mesosoma of this species.It is derived from the words elektron which in Classical Greek means "amber" and, by extension in modern times, "electricity", and lythron, meaning "gore".The name is treated as a noun in apposition.
Link to distribution map.http://hol.osu.edu/map-large.html?id=403212Material examined.Holotype, female: IVORY COAST: Savanes Rég., Korhogo Dept., Konborodougou, 18.III-21.III.1984, M. Matthews, USNMENT01109168 (deposited in CNCI).6, 18-19, 21, 32-39 Description.Whorl of setae on flagellomeres in male: absent.Shape of A3-A11 in male: cylindrical.Color of antenna in male: brown.Color of antennae in female:  Diagnosis.Dvivarnus mikuki can be separated from D. agamades and D. elektrolythron by the glabrous torular triangle and by the color of the mesosoma, which is entirely black except for the metascutellar spine.Additionally, D. mikuki can be separated from D. agamades by the absence of an epomial carina, the form of the metanotal trough, which is non-foveolate and is dorsoventrally divided by a transverse furrow, and by the banding pattern on the wings of females.From D. elektrolythron it can be separated by the broad lateral patch on T4 and the convex posterior margin of the mesoscutellum between the mesoscutellar spines.
Etymology.The word "mikuki" means "spears" in Swahili, the language of Kenya where the holotype specimen originates, and refers to the many spines found on the mesosoma.The name is treated as noun in apposition.