Elasmosomites arkadyleleji Belokobylskij, 2021

Belokobylskij, Sergey A., Dubovikoff, Dmitry A., Manukyan, Andranik R. & Zharkov, Dmitry M., 2021, Braconid parasitoids of ants (Hymenoptera, Braconidae, Euphorinae, Neoneurini) from Baltic amber with a discussion of records of fossil larvae parasitizing ant workers, Journal of Hymenoptera Research 84, pp. 29-43 : 29

Elasmosomites arkadyleleji Belokobylskij sp. nov.

Fig. 1

Type material.

Holotype: female, Eocene Baltic amber, # BX 9/21.1 (KAM).

Description.

Female. Body length 2.0 mm, fore wing length 1.6 mm.

Head: Relatively short and transverse in dorsal view, about 2.5 times wider than medial length. Vertex densely transverse striate. Ocelli slightly enlarged, arranged in obtuse triangle with base 1.7 times its sides. POL about 1.6 times OD. Eye oval, approximately 1.4 times as high as broad, below slightly converging to each other. Transverse diameter of eye about 2.5 times length of temple. Malar suture invisible. Malar space short, about 0.3 times eye height. Face slightly convex, without facial tubercles and spines, its minimum width 0.8 times medial height with clypeus, 0.7 times eye height. Clypeus distinctly curvedly emarginated on lower margin, short, its width about 6.0 times maximum height medially, almost equal to width of face. Mandible and palps not visible. Face seemingly entirely smooth.

Antenna: Slightly thickened, 14-segmented, with short and rather sparse dark setosity, about 0.7 times as long as body. Scape 1.8 times longer than maximum width, about 2.2 times longer than pedicel. Length of first flagellar segment 3.7 times its maximum apical width, 1.3 times length of scape, 1.3 times length of second segment. Length of penultimate segment 1.9 times its width, 0.7 times length of acuminate apical segment.

Mesosoma: Length of mesosoma 1.6 times its maximum width. Mesoscutum 1.4 times wider than its median length, seemingly densely punctate with submedian longitudinal carina in posterior third. Prescutellar depression (scutal sulcus) relatively short, with at least two distinct submedian carinae and slightly sparsely and finely crenulate. Scutellum slightly convex, about as long as wide anteriorly, seemingly slightly punctate. Mesopleuron not visible. Prepectal carina seemingly absent. Mesosoma densely and finely granulate below.

Wings: Fore wing 2.7 times longer than its maximum width, its membrane entirely and densely setose. Costal vein (C+SC+R) distinctly thickened, clearly widened towards apex. Short and vestigial costal cell present distally. Pterostigma wide and relatively short, triangular, 2.3 times longer than its maximum width. Metacarp (1-R1) distinctly and entirely sclerotised, 0.8 times as long as pterostigma. Radial vein (r) arising from basal 0.3 of pterostigma. Radial (marginal) cell distinctly shortened, 3.7 times longer than its maximum width, without additional transverse vein. First radial abscissa (r) long and vertical to pterostigma, 0.6 times as long as maximum width of pterostigma. Second radial abscissa (3-SR) short, 0.8 times as long as first abscissa (r), 0.12 times as long as almost straight third abscissa (SR1), 0.7 times as long as first radiomedial vein (2-SR). Third radial abscissa (SR1) almost complete, but well sclerotised only in basal 0.5 and desclerotised in remaining apical part. Second radiomedial (submarginal) cell rather small, completely delineated by almost entirely sclerotised veins, 1.4 times longer than wide. Second radiomedial vein (r-m) straight, subvertical, desclerotised medially, 0.9 times as long as first radiomedial vein (2-SR). Discoidal (discal) cell with relatively long petiole (1-SR) anteriorly, 1.4 times longer than maximum height; petiole (1-SR) not thickened; parastigma enlarged. First medial abscissa (1-SR+M) almost straight. Recurrent vein (m-cu) short, strongly postfurcal, about 1.5 times longer than second medial abscissa (2-SR+M), 0.9 times as long as first radiomedial vein (2-SR) and second radial abscissa (3-SR). Nervulus (cu-a) strongly postfurcal, distance (1-CU1) between nervulus (cu-a) and basal vein (1-M) equal to nervulus (cu-a) length. Parallel vein (CU1a) distinctly broken basally. Hind wing not visible.

Legs: Fore coxa subglobular. Trochantelli short and distinctly separated from femora on all legs. Fore femur rather wide, almost 3.0 times longer than wide, without tooth. Fore tibia without protuberances or processes, distinctly widened towards apex, its length 4.7 times maximum width. Fore tarsus slightly longer than fore tibia. Fore tibial spur almost straight, about 0.8 times as long as fore basitarsus. Tarsal segments of middle leg elongate. Hind femur wide, elongate-oval, about 2.8 times longer than its maximum width. Hind tibia distinctly widened towards apex, about 6.0 times longer than maximum width, 1.1 times longer than femur, 0.9 times as long as hind tarsus. Both spurs of hind tibia acute apically, longest spur about as long as hind basitarsus. Hind tarsus relatively slender, all its segments of similar width and not narrowed towards apex.

Metasoma: Almost twice longer than maximum width, 1.3 times longer than mesosoma; its sculpture and pubescence not visible (dorsally covered by wings). First tergite distinctly widened towards apex; its median length about 0.8 times maximum distal width. Segments behind third one distinctly projected; any sutures, if present, not visible. Sternites with distinct median keel. Ovipositor relatively short, its sheath with dense short setae, 0.4 times as long as hind tibia, about 0.2 times as long as metasoma.

Colour: Body reddish brown, with a few dark spots, metasoma in posterior half pale brown. Fore and middle legs yellowish brown, hind leg reddish brown. Wings faintly and evenly infuscate; pterostigma dark brown medially and paler basally and apically.

Male. Unknown.

Comparative diagnosis.

The new species differs from the type species E. primordialis Brues, 1933, by having the body mainly reddish brown and metasoma in posterior half pale brown (entirely black in E. primordialis ), antenna basally distinctly pale (entirely black in E. primordialis ), fore and middle legs yellowish brown (almost black or dark brown in E. primordialis ), length of first flagellar segment 3.7 times its maximum width (2.8 times in E. primordialis ), recurrent vein (m-cu) of fore wing longer, about 1.5 times longer than second medial abscissa (2-SR+M) (shorter, not longer than second medial abscissa (2-SR+M) in E. primordialis ).

Etymology.

This species is named in honour of Professor Arkady Stepanovich Lelej, the well-known Russian hymenopterist, dedicated in celebration of his 75th birthday.

Remarks.

Most extant species of the tribe Neoneurini are predominantly black in colour, only sometimes legs entirely pale or with a contrasting black and white pattern. Elasmosomites arkadyleleji sp. nov. is the first species of the Neoneurini with mainly reddish brown body.

Figures

Figure 1. Elasmosomites arkadyleleji sp. nov. (female, holotype, Baltic amber, # BX 9 / 21.1) A habitus, dorsal view B habitus, ventral view C antenna D head and mesosoma, dorsal view E head, mesosoma and legs, ventral view F metasoma and distal part of fore wing, dorsal view J metasoma, middle and hind legs, ventral view H fore wing.