Lycogaster nigralva, Chen, Hua-yan, van Achterberg, Cornelis, He, Jun-hua & Xu, Zai-fu, 2014

Chen, Hua-yan, van Achterberg, Cornelis, He, Jun-hua & Xu, Zai-fu, 2014, A revision of the Chinese Trigonalyidae (Hymenoptera, Trigonalyoidea), ZooKeys 385, pp. 1-207 : 36-38

Lycogaster nigralva sp. n. Figs 130-140

Type material.

Holotype, ♀ (IZCAS) "[China], Sichuan, Mt. Emei, Baoguosi, 550-750 m, 23.V.1957, Fu-xing Zhu".

Diagnosis.

Antenna of female distinctly widened medially (Fig. 133); vertex less flattened in lateral view than that of Lycogaster flavonigrata (Fig. 135); area between ocelli and eye distinctly punctate (Fig. 132); mandible and mesosoma entirely black (Figs 131, 136); lateral lobes of mesoscutum densely punctate laterally (Fig. 136); vein m-cu of fore wing comparatively far postfurcal (Fig. 134); medial third of fore wing largely dark brown (Fig. 134); second sternite black posteriorly (Fig. 140); medio-posterior lamella of second sternite convex (Fig. 140); protuberance of second metasomal sternite convexly protruding medially or truncate (Fig. 140), submedial acute teeth of second sternite comparatively far removed from each other (Fig. 140); second tergite punctate and moderately shiny (Fig. 138).

Description.

Holotype, female, length of body 8.9 mm (of fore wing 6.8 mm).

Head. Antenna with 23 segments, segments after third segment distinctly widened and after 14th segments becoming gradually slenderer (Fig. 133); frons coarsely and rather densely punctate and vertex spaced punctate (interspaces often much wider than width of punctures) and shiny (Figs 131, 132), with short greyish setae; head subparallel-sided behind eyes, distinctly narrowed posteriorly and 1.1 times wider than mesoscutum (Fig. 132); dorsal length of eye 0.7 times length of temple (Fig. 132); temple smooth, shiny and with medium-sized whitish setae; occipital carina narrow lamelliform medio-dorsally and without crenula; supra-antennal elevations hardly developed as a thin rim and smooth; clypeus weakly emarginate and comparatively thin medio-ventrally.

Mesosoma. Length of mesosoma 1.6 times its height (Fig. 137); mesopleuron below transverse mesopleural groove densely rugose anteriorly and spaced punctate and weakly shiny posteriorly, above groove densely rugose; transverse mesopleural groove narrow, deep and moderately crenulate; notauli widened, deep and coarsely crenulate; middle lobe of mesoscutum transversely rugose and weakly shiny (Fig. 138), lateral lobes densely and coarsely punctate; scutellar sulcus wide, both medially and laterally and coarsely crenulate; scutellum largely smooth (except some punctures), distinctly shiny, rather flat and anteriorly near level of mesoscutum; metanotum flat, shiny and smooth medially (Fig. 138); propodeum oblique rugulose anterio-laterally, remainder of propodeum coarsely rugose with small smooth interspaces medially and carina of foramen thick and arched (Fig. 138); foramen medially 0.8 times higher than wide basally.

Wings. Fore wing: length of vein 1-M 2.1 times as long as vein 1-SR (Fig. 134).

Metasoma. First tergite 0.4 times as long as apically wide, gradually narrowed basally, with shallow elliptical depression medially (Fig. 138) and flattened apically; second–fifth tergites spaced punctate (interspaces much wider than width of punctures) and rather shiny; second sternite coarsely and densely punctate, its medio-apical protuberance lamelliform and convex medio-apically (Fig. 140) and with pair of triangular submedial teeth, third sternite only with distinct ledge (Fig. 140); hypopygium truncate apically.

Colour. Black (including mandible); apex of all trochanters ivory, all tarsus, tegulae, pterostigma and veins dark; pair of large lateral patches on second tergite and small patches on basal third tergite and apically on second sternite yellow; fore wing largely brown but paler subbasally (Fig. 134).

Male. Unknown.

Biology.

Unknown. Collected in May at 550-750 m.

Distribution.

China (Sichuan).

Etymology.

Name derived from “niger” (Latin for “black”) and “alvus” (Latin for “belly”) because of the entirely black second sternite.