Gasteruption bicoloratum Tan & van Achterberg

Tan, Jiang-Li, Achterberg, Cornelis van, Tan, Qing-Qing & Chen, Xue-Xin, 2016, Four new species of Gasteruption Latreille from NW China, with an illustrated key to the species from Palaearctic China (Hymenoptera, Gasteruptiidae), ZooKeys 612, pp. 51-112 : 84-87

Taxon classification Animalia Hymenoptera Gasteruptiidae

Gasteruption bicoloratum Tan & van Achterberg sp. n. Figs 7, 8-16, 17-22

Type material.

Holotype, ♀ (NWUX), "China: Shaanxi, Foping, Yueba, Qinling Mts, N33°32' E107°49', 27.vi1.vii.2015, 1095 m, Qingqing Tan". Paratypes: 4♀3♂ (NWUX, RMNH), same data as holotype.

Comparative diagnosis.

Runs in Zhao et al. (2012) to Gasteruption oriplanum Kieffer, 1911 (but the malar space is shorter in the new species and oblique in anterior view, not subparallel-sided below eyes in anterior view as in Gasteruption oriplanum and the mandibles are paler) or to Gasteruption assectator (Linnaeus, 1758). The pale fifth sternite of the female, the strongly narrowed head in dorsal view, the shorter ovipositor sheath (about 0.6 times hind tibia vs 0.9-1.3 times in Gasteruption assectator ) and the yellowish mandible separate it from Gasteruption assectator . The new species is close to Gasteruption flavimarginatum van Achterberg, 2014, but it has a slightly longer malar space (short in Gasteruption flavimarginatum ), the hind basitarsus slender and dorsally dark brown (rather robust and at least partly ivory dorsally) and the mesoscutum finely sculptured (coarser sculptured). The male differs by having the apex of the paramere dark brown, which is yellowish brown in Gasteruption flavimarginatum .

Description.

Holotype, female, length of body 9.9 mm, of fore wing 4.9 mm.

Head. Vertex and frons with satin sheen, finely coriaceous, moderately convex and without a depression medio-posteriorly; head directly contracted behind eyes in dorsal view and temples nearly straight (Fig. 14); temple 0.9 times as long as eye in dorsal view; fourth antennal segment 1.2 times as long as third segment and 0.7 times as long as second and third segments combined, fifth antennal segment as long as third segment, third antennal segment 1.6 times as long as second segment (Fig. 8); occipital carina narrow and non-lamelliform medio-dorsally (Fig. 8); OOL 1.3 times as long as diameter of posterior ocellus; face wide, 2.8 times as broad as high, 2.4 times as wide as eye in frontal view (Fig. 13); malar space somewhat protruding below lower level of eyes (Fig. 13), its minimum width 0.4 times as long as second antennal segment and 0.35 times basal width of mandible and area behind incision nearly square (Fig. 8); clypeus only medio-ventrally shallowly depressed (Fig. 13); eye with numerous short setae.

Mesosoma. Length of mesosoma 1.6 times its height; propleuron robust and 0.8 times as long as mesoscutum in front of tegulae; pronotal side entirely coriaceous except for crenulated grooves and sparsely setose, without acute tooth antero-ventrally (Figs 8-10); antesternal carina narrow and hardly lamelliform; mesosternal sulcus wide and deep; mesoscutum and scutellum rather matt and superficially rugulose-coriaceous (Fig. 10); propodeum reticulate-rugose and without median carina.

Wings. First discal cell parallel-sided and with outer posterior corner rounded, and with vein 3-CU1 near its apical third (Fig. 11).

Legs. Hind coxa finely granulate-coriaceous; length of hind femur, tibia and basitarsus 3.9, 3.6 and 4.6 times their width, respectively; hind tibia strongly inflated (Fig. 15); middle tarsus 1.1 times as long as middle tibia; middle femur subparallel-sided and slimmer than fore femur.

Metasoma. Ovipositor sheath 1.2 mm, 0.1 times as long as body, 0.2 times as long as metasoma and 0.6 times as long as hind tibia; ovipositor sheath with dense cover of fine brownish and adpressed setae, its apical half slender; hypopygium shallowly emarginate medio-posteriorly.

Colour. Black; apical half of antenna largely brown ventrally; mandible pale brownish yellow (except narrow dark borders); clypeus latero-ventrally and humeral plate dark brown; tegulum, second-seventh metasomal tergites narrowly apically and widely laterally, sixth sternite widely apically and other sternites narrowly, trochantelli, hind femur apico-ventrally and hind tibial spurs yellowish brown; fore and middle tibiae basally and hind tibia baso-ventrally widely ivory; remainder of legs, veins and pterostigma dark brown; wing membrane subhyaline.

Male. Similar to female (including fine sculpture of mesoscutum: Fig. 18); third antennal segment 1.3-1.6 times as long as second segment; fourth antennal segment 1.3-1.5 times as long as third segment and 0.8 times as long as second and third segments combined, fifth antennal segment 1.3-1.4 times as long as third segment (Fig. 21); apical sternite entirely dark brown; paramere densely whitish setose and its apex dark brown (Fig. 22).

Variation. Body length of ♀ 8.7-10.3 mm, of ♂ 8.2-9.9 mm; length of ovipositor sheath 0.6-0.7 times hind tibia; minimum width of malar space 0.3-0.4 times as long as second antennal segment; tibiae and tarsi more or less yellowish brown ventrally; apical antennal segment more or less obliquely depressed.

Distribution.

China (Shaanxi). Montane: 1095 m.

Biology.

Unknown. Collected JuneAugust.

Etymology.

Named after the bicoloured hind tibia in both sexes ( “bi” is Latin for “two”).