Diolcogaster pluriminitida Zeng & Chen

Zeng, Jie, He, Jun-hua & Chen, Xue-xin, 2011, The genus Diolcogaster Ashmead, 1900 (Hymenoptera, Braconidae, Microgastrinae) from China, ZooKeys 129, pp. 49-87 : 71-74

Diolcogaster pluriminitida Zeng & Chen sp. n. Figs 49-56

Description.

Female. Body length 3.0 mm, fore wing length 2.9 mm.

Head. Oval in anterior view, with antennal sockets high above middle level of eyes; transverse in dorsal view, 1.5 × as wide as long and almost as long as mesoscutum, with very dense short fine setae except for the sharply constricted and highly polished area behind lateral ocelli. Ocelli small, in a low and wide triangle, the transverse, posterior tangent to the anterior ocellus deeply cutting the posterior pair. POL:OD:OOL=6.2:4.0:6.7. Vertex vey shiny, strongly convex, finely transversely striate; frons polished and without setae in large part but densely rugulose and setose adjacent to eye margin; face slightly convex, also very shiny, densely strigose-punctate, transversely striate just below antennal sockets, without any trace of median keel, width of face 0.8 × as high as eye and clypeus combined (17.8:23.7); eyes of moderate size, inner margin of eyes parallel, 1.8 × as high as wide (22.3:12.7); temple and gena very shiny, sparsely transversely striate, with appressed long setae. Clypeus slightly convex, densely rugulose, with ventral margin slightly excavated medially; tentorial pits small, distance between tentorial pits 2.5 × as long as distance from pit to eye margin; malar space very short, 0.2 × as long as eye height. Antennae long and thin, with the preapical segment about 1.3 × as long as wide; flagellomeres not thickened apically, with bristly setosity, with placodes arranged regularly in 2 ranks; apical segment also as long as preapical one. Flagellomere proportion: 2 L/W=3.2, 8 L/W=3.7, 14 L/W=2.2; L 2/14=1.6; W 2/14=0.6.

Mesosoma. Pronotum shiny, with a broad and shallowly foveate ventral furrows laterally. Mesoscutum shiny, with dense but discrete punctures that denser and so that duller in the middle, with dense short fine setae all over; notauli not impressed. Disc of scutellum also shiny, as densely and discretely punctate as mesoscutum; its rugose tip at middle widely interrupting the posterior, polished band of scutellum. Lateral part of the polished band distinctly convex anteriorly. Anterior margin of the postscutellum closely applied to the posterior margin of the scutellum so that, laterally, the phragma of scutellum is completely hidden. Scutellar sulcus shallow, with few longitudinal cari nae, its width 1.3 × as long as scutellum (21.0:16.3). Propodeum very shiny, with a strong complete median keel, smooth with very few discrete large punctures, with very short transverse carina each side along the median keel and dense rugulosity around spiracles. Mesopleuron polished in large part, setigerous-punctate anteriorly and below precoxal sulcus; precoxal sulcus shallow, indistinct, setigerous-punctate.

Wings. Forewing with the very small slit-like areolet, 3-sided; vein r-m united with vein 2-SR at a considerable distance from the junction of vein 2-SR and the vein r+3-SR; vein r arising from distal 1/2 of pterostigma, far behind the middle, very obliquely placed on the pterostigma; meeting vein 2-SR at a right angle. Vein 1-R1 (metacarp) with distal end sharply defined, 4.4 × as long as its distance from the apex of the marginal cell and as long as pterostigma; pterostigma broad, 2.7 × as long as wide; r:2-SR:length of pterostigma=11.5:10.0:32.0. Width of 1st discal cell:height of 1st discal cell =25.0:22.0; 1-CU1:2-CU1:m-cu=11.0:10.0:9.5. Hind wing with vannal lobe evenly convex, fringed with long setae throughout.

Legs. Long and thin. Hind coxa with outer surface densely and discretely punctate with interspaces very shiny, dorsal surface densely rugulose and striate-rugulose, reaching to the middle of T3, setose all over. Hind tibia swollen apically and only 0.8 × as long as hind tarsus (48.5:63.8), outer surface without spines. Inner hind tibial spur longer than outer one, 0.7 × as long as hind basitarsus (20.0:28.0); fourth tarsal segment almost as long as fifth tarsal segment (7.8:8.0); apical segment of the front tarsus without a spine. Tarsal claws simple.

Metasoma. Longer than mesosoma. T1 strongly sclerotised, narrow, parallel-sided but slightly narrowed distally on posterior half, with few long setae laterally; surface with anterior 3/4 polished and posterior 1/4 rugulose with fine setae, the distinct median groove reduced on posterior 1/4; 2.4 × as long as its width and 2.4 × as long as T2. T2 polished and without setae, with a slightly swollen median field, ill-defined, 0.4 × as long as wide and 0.7 × as long as T3. Tergites posterior to T2 membranous, highly polished with a row of short fine setae before posterior margin, except the last segment scattered with short fine setae. Ovipositor sheath with even width, slightly decurved, with 2 blackened setae at apex. Hypopygium of moderate size, evenly sclerotised, polished, with dense short setae all over, apex not surpassing the last tergite.

Colour. Body black, metasoma mostly bright yellow. Antennae evenly brown except scape and pedicel yellow. Mouthparts yellow with palpi whitish. Tegula bright yellow. Fore and middle legs virtually bright yellow. Hind coxa wholly black; trochanter yellow, base of femur and basal 3/4 of tibia also yellow but gradually darkened to brown apically; tarsi and tibial spurs whitish brown. T1 dark brown, the indistinct median field of T2 also brown but lightened outwards to bright yellow, apical 3 segments and ovipositor sheaths also brown, T5, T6 and lateral part of hypopygium brownish. Wings hyaline; veins and pterostigma light brown, somewhat pale.

Variation. Some individuals from Zhejiang and Guizhou have ovipositor sheath only finely setose, without apical modified seta; metasoma mostly yellow, but size of brownish part of dorsal surface and hypopygium variable; the ill-defined median field of T2 hardly impressed in some specimens.

Male.

Unknown.

Host.

Unknown.

Material examined.

Holotype: ♀, Wanjia, Mayanghe (108°13'E, 28°35'N ~ 108°21'E, 28°41'N), Guizhou, 2007. IX. 27-30, legs. Liu Jingxian, No. 200708869. Paratype: 1♀, Mt. Huping (110°45'E, 30°02'N ~ 110°55'E, 30°07'N), Shimen, Hunan, 2009. VII. 12, legs. Ma Li, No. 200901491; 1♀, Mt. Huping (110°45'E, 30°02'N ~ 110°55'E, 30°07'N), Shimen, Hunan, 2009. VII. 12, legs. Zeng Jie, No. 200900730; 1♀, Mt. Tongledashan (111°20'E, 23°07'N ~ 111°29'E, 23°14'N), Yunan, Guangdong, 2003. VIII. 12-13, legs. Xu Zaifu, No. 20054555; 1♀, Mt. Leigong (118°03'E, 26°21'N ~ 118°15'E, 26°25'N), Fangxiang, Guizhou, 2005. VI. 2-3, legs. Liu Jingxian, No. 200605872; 1♀, West Mt. Tianmu (119°23'E, 30°20'N ~ 119°24'E, 30°20'N), Linan, Zhejiang (Malaise trap), 1998. IX. 26, legs. Zhao Mingshui, No. 20002719.

Etymology.

The specific name “pluriminitida” derives from the Latin adjective “plurimus” and adjective “nitidus”, referring to large part of T1 polished.

Distribution.

China (Zhejiang, Hunan, Guangdong, Guizhou).

Remarks.

This species is similar to Diolcogaster xanthaspis (Ashmead, 1900), but can be distinguished by the T2 with only ill-defined slightly swollen median field that with even width (the latter T2+3 with distinct but rather poorly defined median field that is slightly wider in front than behind); and propodeum smooth with very few discrete large punctures except very short transverse carina each side along the median keel and dense rugulosity around spiracles (the latter with propodeum coarsely rugose).