Diolcogaster praritas 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 : 74-76

Diolcogaster praritas Zeng & Chen sp. n. Figs 57-64

Description.

Female. Body length 3.2 mm, fore wing length 3.5 mm.

Head. Oval in anterior view, with antennal sockets high above middle level of eyes; transverse in dorsal view, 1.6 × as wide as long and slightly narrower than mesoscutum, with sparse and short setae except the sharply constricted and highly polished area behind lateral ocelli. Ocelli of moderate size, in a low, very wide triangle, the transverse, posterior tangent to the anterior ocellus just cutting the posterior pair. POL:OD:OOL=6.0:3.4:7.0. Vertex and frons smooth and shiny, only between the ocelli and the eye-margin very sparsely punctate; vertex strongly convex; face slightly convex, feebly and transversely striate-punctate, without any trace of median keel, width of face 0.9 × as high as eye and clypeus combined (20.0:23.2); eyes small, inner margin of eyes adjacent to face parallel, 1.6 × as high as wide (20.5:13.0); temple and gena feebly rugose-punctate and shiny, densely setose. Clypeus slightly swollen, feebly rugose; tentorial pits of moderate size, distance between tentorial pits 2.6 × as long as distance from pit to eye margin (10.4:4.0); malar space short, 0.3 × as long as eye height. Antennae a little shorter than the body, with the preapical segment about 1.5 × longer than wide; scape short; flagellomeres long, thick, without bristly setosity, with placodes arranged regularly in 2 ranks except the distal 6 or 7 segments; apical segment slightly longer than preapical one. Flagellomere proportion: 2 L/W=3.6, 8 L/W=2.5, 14 L/W=2.1; L 2/14=1.4; W 2/14=0.8.

Mesosoma. Pronotum with a very indistinct ventral furrow laterally. Mesoscutum with dense rugose-puctures but interspaces shiny, with short setae all over; notauli not impressed, but indicated by a band of broad depression posteriorly. Disc of scutellum finely, discretely punctate, very shiny, with normal setosity, polished at tip, so the posterior, polished band of scutellum continuous. Lateral part of the polished band at least 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 carinae, its width almost as long as scutellum (15.0:15.5). Propodeum short, shiny, finely reticulate-rugose all over, with a well-defined median keel. Mesopleuron in large part polished. Precoxal sulcus very short, indicated by a shallow depression with dense but shallow punctures.

Wings. Forewing with rather large 4-sided areolet; vein r(1st abscissa of the radius) much longer than 3-SR(2nd abscissa of the radius), arising from distal 1/2 of pterostigma, far behind the middle, placed at right angles to the pterostigma, meeting vein 2-SR at a 150 degree angle. Vein 1-R1 (metacap) with distal end sharply defined, 3.5 × as long as its distance from the apex of the marginal cell and 1.2 × as long as pterostigma; pterostigma 2.7 × as long as wide; r:2-SR:length of pterostigma=9.0:10.0:31.0. Width of 1st discal cell:height of 1st discal cell =26.5:23.0, 1-CU1:2-CU1:m-cu=9.0:13.6:10.0. Hind wing with vannal lobe convex, fringed with long setae throughout.

Legs. Long and thin. Hind coxa very feebly punctate, almost polished. Hind tibia swollen apically and about 0.8 × as long as hind tarsus (55.0:68.2), outer surface without distinct spines. Inner hind tibial spur much longer than outer one, 0.6 × as long as hind basitarsus (17.0:30.0); fourth tarsal segment shorter than fifth tarsal segment (7.2:10.0); apical segment of the front tarsus without a spine Tarsal claws simple.

Metasoma. T1 almost parallel-sided, with a shallow median groove over basal 2/3 that with ill-defined sides; dull and coarsely rugose, with long setae laterally and sparse short setae dorsally, 1.4 × as long as its width and 1.5 × as long as T2. T2 trapezoidal, with a shiny and feebly longitudinally striated raised median field, irregularly shaped but distinctly narrowed behind; the lateral fields striate-rugose, but sculptures reduce toward lateral margin, 1.5 × times as wide as long and 1.1 × as long as T3. Tergites posterior to T2 highly polished and smooth, more membranous, with short fine setae posterolaterally; setae of metasoma very sparse, almost absent on T3. Ovipositor sheath with 2-3 blackened setae at apex. Hypopygium large, evenly sclerotised, smooth and shiny, with fine setae subapically, with apex a little surpassing the last tergite.

Colour. Body almost black, metasoma yellow on anterior half ventrally and brown dorsally. Antennae light brown at base and darkened toward apex to brown. Clypeus brownish, mouthparts brownish yellow, with ventral margin of mandible brown; palpi whitish yellow. Tegula light brown. Legs almost virtually yellow, except hind coxa brown at extreme base and hind tibia and tarsuli slightly brownish. Tergites dark brown, except lateral margin of T2 and posterolateral corner of T3 yellowish. Tergites posterior to T2 somewhat transparent. Wings hyaline; veins and pterostigma brown, somewhat transparent.

Variation. Paratype distinctly smaller than holotype; T3 yellowish on posterior half and pterostigma broader.

Male.

Unknown.

Host.

Unknown.

Material examined.

Holotype: ♀, Tongbiguan (97°38'E, 24°37'N), Yingjiang, Yunnan, 2009. V. 17, legs. Zeng Jie, No. 200904237. Paratype: 1♀, Mt. Fengyang (119°12'E, 27°55'N ~ 119°14'E, 27°56'N), Longquan, Zhejiang, 2007. VII. 28, legs. Liu Jingxian, No. 200802854.

Etymology.

The specific name “praritas” derives from the Latin noun “praritas”, referring to the irregular median field of T2.

Distribution.

China (Zhejiang, Yunnan).

Remarks.

This species is similar to Diolcogaster austrina (Wilkinsonellus, 1929), but can be distinguished by the disc of scutellum finely, discretely punctate (the latter with disc of scutellum smooth and highly polished); pterostigma shorter than 1-R1 vein (the latter with pterostigma just longer than 1-R1 vein); and TII with surface of the lateral fields besides median field striate-rugose, but reduced toward lateral margin (the latter with the lateral fields besides median field unsculptured).