Episyron immaculatus Song & Ma sp. nov.

Fig. 3 A – F

Material examined.

Holotype: CHINA • ♀; Inner Mongolia, Helan Mountain, Xiangchizi; 38°49'N, 105°52'E; 7. VIII. 2010; coll. Fangzhou Ma; sweep net (YNAU) ; Paratypes: CHINA • 1 ♀; Inner Mongolia, Helan Mountain, Xiazigou; 39°12'N, 105°42'E; 9. VIII. 2010; coll. Fangzhou Ma; sweep net (YNAU) ; CHINA • 1 ♀; Inner Mongolia, Helan Mountain National Nature Reserve; 38°21'N, 105°44'E; 26. VII. 2010; coll. Dingji Zhang, sweep net (YNAU) .

Description.

Female. Length: body 10.5–12.5 mm; fore wing 8.1–9.8 mm.

Colour. Body black, yellow marks as follows: narrow stripes along inner orbit in median part of face in frontal view, stripes along posterior margin of eyes (Fig. 3 B, C). Mid, hind femora (apical black) and tibiae reddish, spur brown (Fig. 3 A). Fore wings slightly dark, with brownish apical band (Fig. 3 E).

Pubescence. Mandible, scape, vertex, gena, pronotum, propodeum and apical metasoma with sparse black setae; pronotum, scutellum, metanotum, metapleura, metapostnotum, propodeum, dorsal surface of hind coxa and T 1 with unevenly distributed, brown squamiform pubescence (Fig. 3 A – D).

Head. In frontal view, head width 1.17–1.20 times its height (Fig. 3 B). Mandible slender, with two subapical teeth. Clypeus slightly convex medially, anterior margin rounded, its width 1.95–2.11 times length (Fig. 3 B). Malar space short. Area between antennal sockets convex. Frons flat, with long and conspicuous median line, extending to anterior ocellus (Fig. 3 B). Inner orbits nearly parallel below and slightly convergent above; MID width 1.85–1.89 times eyes; LID: MID: UID = 68: 69: 50 (Fig. 3 B). In dorsal view, ocelli approximately in obtuse triangle, ocellar area slightly raised; POD: OOD = 1.34–1.67 (Fig. 3 C). Head with developed occipital angles, occipital carina conspicuous (Fig. 3 C). In lateral view, gena 0.26–0.28 times eye width. Flagellum filiform, F 1 slender, length 5.25–5.78 times its maximum width, and 1.62–1.73 times scape; SL: PL: F 1: F 2: F 3: F 4: F 5 = 31: 10: 52: 37: 33: 30: 26.

Mesosoma. Pronotum length in dorsal view 0.43–0.58 times its maximum width, slightly converging toward base, posterior margin arcuate and slightly angulate medially. Mesoscutum with evident parapsidal line, from apical to 3 / 4 metanotum (Fig. 3 A). Mesoscutellum and metanotum conspicuously convex medially. Metapostnotum narrow medially, and posterior margin arcuately expanded, and its length nearly 0.33–0.45 times metanotum (Fig. 3 D). Propodeum slightly convex in profile, with uniform arcuate transition, length 0.74–0.80 of its maximum width (Fig. 3 D).

Wings. Marginal cell of fore wing nearly as long as its length from the wing tip (Fig. 3 E). Pterostigma short, its posterior margin rounded (Fig. 3 E). Fore wing with three submarginal cells, SMC 3 apparently greater than SMC 2 (Fig. 3 E). SMC 2 receiving crossvein 1 m-cu at basal 0.61–0.63, SMC 3 receiving crossvein 2 m-cu at basal 0.54–0.60 (Fig. 3 E). Hind wing crossvein cu-a arc-like, M + CuA vein fork before intersection of cu-a and M + CuA (Fig. 3 E).

Legs. Fore tarsus with flattened spines, slightly widening or almost parallel-sided toward subapex (Fig. 3 F). Tarsomere 1 outside with four outer spines, first spine shorter; tarsomere 2, 3 with two outer spines; tarsomere 4 with one outer spine; tarsomere 5 without spine; three spines on ventral surface of tarsomere 1; apical spine of tarsomere 1 exceeding apex of tarsomere 2; tarsomere 2 apical spine extended beyond apex of tarsomere 3, a row of small spines on ventral surface of tarsomeres 1–4 (Fig. 3 F). Long spur of hind tibia 0.80–0.82 times of metatarsus. Tarsal claws symmetrical and bifid, inner tooth broad and obliquely truncated (Fig. 3 F).

Metasoma. Metasoma without petiole, apex of T 6 slightly compressed (Fig. 3 A).

Male. Unknown.

Distribution.

China: Inner Mongolia (Alashan).

Etymology.

The specific epithet immaculatus originates from the prefix “ im - ” and the Latin word “ maculatus ”, and refers to the black metasoma, without any spots or bands.

Remarks.

The new species clearly differs from Episyron rufipes (Linnaeus, 1758) and other congeners by the following characteristics:

Female of E. immaculatus: F 1 length 5.25–5.78 times its maximum width; POD: OOD = 1.34–1.67 (Fig. 3 A); mid, hind femora (apical black) and tibia reddish (Fig. 3 A); pterostigma short, its posterior margin rounded (Fig. 3 E); pronotum, mesonotum and metasoma black, without any spots or bands (Fig. 3 A, D).

In Episyron rufipes (Linnaeus, 1758) (female): F 1 length 5.78–6.5 times its maximum width; POD: OOD = 1.18–1.33 (Fig. 9 C); apical 2 / 3 of mid femora, hind femora (basal black), mid and hind tibia reddish (Fig. 9 A); pterostigma elongated, its posterior margin parallel to anterior one (Fig. 9 E); a yellow spot on tegulae, paired basolateral roundish spots on T 2, paired basal transverse large spots on T 3 (sometimes connected), spots on T 4-5 usually hidden, and roundish light yellow spot on T 6 basally (Fig. 9 A, D).