Microchelonus bidentulus sp. nov.

The species differs from majority of species of the genus Microchelonus in the presence of two teeth in the middle of outer margin of clypeus - similar to the genus Ascogasler. 1t is closely related to Microchelonus flagellaris TOBIAS, 1989 from Russian Far East, because of its small 2nd radiomedial cell very narrowed anteriorly, the structure of antennae, deep notauli and colouration. It differs from this species by teeth on clypeus, short temple, mesosoma and metasoma, and small lateral teeth of propodeum.

The closest European species is Microchelonus temporalis TOBIAS, 1986. The new species differs from it in the small 2nd radiomedial cell very narrowed anteriorly, deep notauli, convex temple, the presence of yellow spots at base of metasoma, and larger body size.

Female. Body length 3,5 - 4,85 mm (holotype 4,85 mm, paratypes 3,5 - 4 mm). Head behind eyes roundly narrowed, 1,2 times width of mesonotum, its width 1,6 times length, twice medial length. Tempora dorsally 1,2 times longer and laterally 2 times longer than eye. The base of ocellar triangle slightly longer than ocular-ocellar line (13:12, 12:10). Distance between ocelli 2 - 2,5 times ocellus diameter (fig. 2). Longitudinal diameter of eye 1,8 -1,9 times the transversal one, 1,8 times height of cheek. Face in upper part with longitudinal medial carina, its width 1,8 times height, 1,4 times longitudinal diameter of eye. Inter-tentorial line slightly longer than line between tentorial pit and eye. Clypeus in the middle of outer margin with two teeth which are in small specimens fine (fig. 1). Antennae slightly shorter than body, robust behind middle, very slender apically. Length of first and second segment of flagellum 4 and 3,5 times their width, respectively; other segments up to 7th or 8th gradually shorter, 7-9th or 8-10th segments 2 times longer than their width; length of the two subapical segments 3 times their width. Apical segment of antenna sometimes flattened. Mesosoma with very convex mesonotum anteriorly, with deep notauli, its length 1,3 times height. Mesonotum lateroposteriorly with processes which are larger than lateral teeth of propodeum. Propodeum with distinct transverse carina and small flattened and rounded lateral teeth.

Radial cell of wing 3 times 2nd radiomedial cell, its anterior margin equal to length of pterostigma; 3rd abscissa of radial vein S-shaped, 2,5 times longer than Ist radio-medial vein; 2nd abscissa of radial vein short, approximately 2 times shorter than Ist one (fig. 3). Distance from nervulus to basal vein 0,6 - 0,8 nervulus length. Length of hind femur 3 times width. Inner spur of hind tibia slightly shorter than 0,5 length of Ist segment of hind tarsus; 5th segment of hind tarsus longer than 3rd, but shorter than the 2nd. Carapace of metasoma more narrowed anteriorly than posteriorly, apically incurved in 0,1 of its length, in basal third with two convergent posterior carinae, its length 1,8-2 times width (fig. 4), 3,5 times maximum height (in apical part - fig. 5). Ovipositor hidden.

Head finely and densely rugose-punctulate, dull. Vertex behind ocelli and temple slightly transversally striate. Face with thick numerous twisting rugae, inclined from its upper lateral corners like a fan. Clypeus finely punctulate, shiny. Mesosoma predominantly roughly rugose. Mesonotum with medial longitudinal carina, areolate-rugose posteriorly and along back part of notauli, upper part of propodeum areolate-rugose. Scutellum rugose-punctulate, slightly shining. Sternauli roughly crenulate, more fine in small specimens. Carapace of metasoma in basal part with few twisting and anastomosed longitudinal rugae which gradually disappear behind its middle. Sometimes these rugae reach only the middle of metasoma. Apex of metasoma unclearly areolate-rugose.

Body black. Apex of fore and middle femora, fore and middle tibiae, tarsi and trochanters of middle and hind legs yellowish-brown. Palpi and hind tarsi dirty brown. Hind tibiae in apical half dark brown, in basal part brown, before middle slightly yellowish. Fore and middle tibiae and tarsi sometimes brown. Trochanters of all legs sometimes brownish-yellow. Metasoma with two yellow spots baso-laterally. Wings infuscate. Pterostigma and veins of wing brown, in its basal half yellowish.

Holotype: ♀, Slovakia occ, Biele Karpaty Mountains, Chocholnianska dolina Valley - Gregorova, July 9, 1992, J. LUKAS Igt.
Paratypes: The same data, 2 ♀♀ 9 July 9, 1992; 3 ♀♀, July 20, 1992; 1 ♀, August 1, 1992; 3 ♀♀, July 15, 1993; J. LUKAS Igt. - 1 ♀, July 3, 1934, Nizky Jesenik Mountains, GREGOR Igt.
Holotype and part of paratypes are deposited in Zoological Institute of Comenius University in Bratislava, part of paratypes in Zoological Institute of Russian Academy of Sciences in Saint Petersburg, paratype from Nizky Jesenik Mountains in the MoravianMuseum, Brno.