Trachionus mandibularoides Cui & van Achterberg

Cui, Qian, van Achterberg, Cornelis, Tan, Jiang-Li & Chen, Xue-Xin, 2015, The genus Trachionus Haliday, 1833 (Hymenoptera, Braconidae, Alysiinae) new for China, with description of four new species, ZooKeys 512, pp. 19-37 : 28-31

Taxon classification Animalia Hymenoptera Braconidae

Trachionus mandibularoides Cui & van Achterberg sp. n. Figs 33, 34-42, 44

Type material.

Holotype, ♀ (NWUX), "NW. China: Shaanxi, Xunyangba, Ningshan, c. 1300 m, vii.2014, 33°33'N, 108°32'E, Jiangli Tan, NWUX".

Diagnosis.

Mandible with two wide lateral lobes and one smaller ventral lobe (Fig. 44); sternaulus present as flat punctate area anteriorly (Fig. 35); scutellum coarsely punctate and distinctly convex (Fig. 36); median punctate band of mesoscutum anteriorly as wide as smooth bands next to it (Fig. 36). The new species differs from the similar European Trachionus mandibularis (Nees, 1816) by having the epistomal suture narrow, the sternaulus not impressed (but indicated as a flat punctate area anteriorly) and the mandible distinctly widened ventrally.

Description.

Holotype, female; body length 2.2 mm, forewing length 2.7 mm.

Head. Width of head 2.5 × its median length; dorsally head smooth, strongly shiny and only sparsely setose; antenna incomplete, 20 segments remaining, third segment 1.6 × as long as fourth segment, length of third and fourth segments 2.3 × and 1.5 × their width, respectively; frons narrowly depressed behind antennal sockets and smooth; eye in dorsal view 2.2 × longer than temple; temple in dorsal view rounded, shiny and sparsely setose; OOL: diameter of ocellus: POL = 10:3:4; face medio-dorsally somewhat elevated, with upward pointing long setae, with satin sheen and punctulate; clypeus transverse, with some small punctures and convex; epistomal suture narrow; mandible nearly touching eye, length of malar space 0.1 × basal width of mandible; mandible 1.3 × as long as its maximum width, largely rugose medially; mandible dis tinctly widened apically, with long and acute triangular middle tooth, two wide lateral lobes and one smaller lobe ventrally; maxillary palp 0.9 × height of head.

Mesosoma. Length of mesosoma 1.4 × its height; pronotum laterally mostly punctate, but smooth medio-dorsally; sternaulus present as spaced punctate area anteriorly; precoxal sulcus complete, wide and rugose-punctate; remainder of mesopleuron largely smooth but punctate dorsally; mesosternal sulcus shallow and punctate, posteriorly transversely rugose; metapleuron coarsely punctate-reticulate; median groove of mesoscutum and notauli complete, wide and distinctly punctate, mesoscutum anteriorly rugose-punctate; lateral lobes of mesoscutum glabrous, smooth and shiny medially; remainder of mesoscutum with few setae; scutellar sulcus deep, punctate and with 3 longitudinal carinae, 0.4 × as long as scutellum; scutellum convex, coarsely punctate and with long setae; highest point of metanotal spine protruding above level of scutellum; surface of propodeum coarsely foveolate-punctate, median carina of propodeum only anteriorly present, remainder of carinae indiscernible because of surrounding sculpture; propodeum rather steeply lowered posteriorly and postero-laterally with protruding carinae.

Wings. Pterostigma nearly elliptical; marginal cell of forewing elongate; vein r issued just before middle of pterostigma (Fig. 34); r:2-SR:3-SR+SR1 = 6:11:45; SR1 curved; 1-CU1:2-CU1 = 1:20; M+CU1:1-M:m-cu = 7:4:3; CU1b present; m-cu slightly antefurcal; 1-CU1 widened. Hind wing: M+CU:1-M:1r-m = 14:8:9; cu-a straight; m-cu absent.

Legs. Hind coxa mostly smooth; tarsal claws medium-sized (Fig. 41); length of femur, tibia and basitarsus of hind leg 3.2, 6.2 and 3.5 × their width, respectively; all femora slightly widened.

Metasoma. Length of first tergite nearly equal to its apical width, its surface longitudinally coarsely striate, with dorsal carinae converging medially and united in distinct median carina (Fig. 37); second and third tergites punctate-striate, but third tergite smooth apically; combined length of second and third metasomal tergites 0.4 × total length of metasoma (Figs 37, 42); apically striae of third tergite with distinct shiny interspaces; setose part of ovipositor sheath 0.1 × as long as fore wing; hypopygium large and apically acute (Fig. 42).

Colour. Black (including mandible); palpi and legs yellow but tarsi dark brown and base of hind coxa darkened; tegulae, ovipositor sheath, pterostigma and forewing veins dark brown; veins of hind wing pale brown; forewing membrane slightly infuscate; metasoma dark brown ventrally, but hypopygium yellowish brown apico-laterally.

Distribution.

China (Shaanxi).

Etymology.

The new species is named after Trachionus mandibularis and “oides” (Latin for "similar to"), because of the similar sculpture of the mesosoma.