A new species of Megischus Brullé (Hymenoptera, Stephanidae) from China, with a key to the Chinese species

Abstract A new species of Megischus Brullé from China, Megischus aplicatus sp. n.,is described and illustrated. A key to the Chinese species of Megischus is added. The holotype is deposited in the Parasitic Hymenoptera Collection of Zhejiang University, Hangzhou.

Th e genus Megischus is characterized mainly as follows: body medium sized to large; temple without conspicuous ivory stripe along outer orbit; forewing with four or more closed cells; fi rst subdiscal cell of fore wing comparatively slender and vein 2-1A completely pigmented; vein 1-M of fore wing 2.2-8.0 times as long as vein 1-SR; hind femur with two large ventral teeth; hind tarsus of female 3-segmented and of male 5-segmented; ovipositor sheath with an ivory subapical band ( van Achterberg 2002).

Material and methods
Th e specimen was collected in Hubei Province, China, and is deposited in the Parasitic Hymenoptera Collection of Zhejiang University, Hangzhou (ZJUH).
Morphological terminology, including the wing venation system, follows van Achterberg (2002). Descriptions were made under an Olympus SZ61 stereoscope, in combination with a 40W LED lamp. Photographic images were processed with both Image-Pro Plus and AnalySIS Extended Focal Imaging software, and fi gures were fi nished with ACDSee10.0 and Photoshop CS 8.0.1, mostly to adjust the size and background. Temple medially roundly convex behind eye in dorsal view ( Fig. 25 in Van Achterberg and Yang 2004); neck at lower level than middle part of pronotum postero-dorsally (Fig. 29, l.c.); vein cu-a of fore wing weakly reclivous or subvertical (Fig. 26, l.c.; 7); hind basitarsus 3.0-3.5 times as long as wide ..2 2

Genus
Temple slightly convex behind eye (Fig. 25 (Fig. 3); pronotal fold absent ( Fig. 4-5); vein 1-M of fore wing about 2.2 times as long as vein 1-SR and 0.9 times vein m-cu (Fig. 8); fi rst tergite largely smooth and shiny dorsally (Fig. 9); head largely orange brown; widened part of hind tibia of male nearly straight ventrally (Fig. 10)  Male. Length of body 25.7 mm, and of fore wing 13.9 mm. Head. Antenna with 41 segments; fi rst antennal segment 1.6 times as long as wide and twice as long as second segment, third segment 2.4 times as long as wide and 0.8 times as fourth segment; frons ( Fig. 1) strongly rugose, rugae laterally curved upwards; three anterior coronal teeth large, two posterior ones connected and somewhat sinuate; vertex ( Fig. 2) with 4 strongly curved carinae, followed by irregularly transversely striate area, striae coarser laterally and largely interrupted medio-dorsally, resulting in a more or less longitudinal impression, sculpture disappearing near occipital carina, leaving a narrow smooth area; area along inner orbit with one distinct longitudinal carina on each side; temple (Fig. 3) largely smooth and shiny, roundly convex occipital carina strongly developed.
Wings. Fore wing (Fig. 8): vein 1-M distinctly curved, 2.2 times as long as vein 1-SR and 0.9 times vein m-cu; vein 2-SR 1.1 times as long as vein r; vein r ends 0.5 times length of pterostigma behind level of apex of pterostigma; vein 1-SR 0.95 times as long as parastigmal vein; vein cu-a postfurcal and subvertical; vein 3-CU1 largely nebulous.
Legs. Hind coxa rather strong, annular, coarsely punctate and setose; hind femur ( Fig. 10) sparsely punctate and with whitish setae, area in between smooth and shiny, ventrally with two large teeth and some denticles in between; hind tibia robust, ventrally mostly straight and 1.3 times as long as hind femur, basal narrow part about 0.6 times as long as widened part, outer side obliquely carinate, inner side apically densely setose; hind basitarsus ( Fig. 11) subparallel-sided, 3.5 times as long as its apical width and 4.7 times as long as second tarsus.
Metasoma. First tergite largely smooth and shiny (Fig. 9), 5.2 times as long as its maximum width, 1.4 times as long as second tergite and 0.5 times as long as remainder of tergites; remainder of tergites smooth; pygidial process ( Fig. 12) distinct and tubular apically.
Colour. Head orange brown; pronotum, mesosoma, fi rst tergite and hind legs largely dark brown or black; metasoma except fi rst tergite brown to blackish; wing membrane light brownish, wing venation and pterostigma dark brown.
Material examined: Holotype male, China: Hubei, Shennongjia National Nature Reserve, viii.1982, Coll. Shi Shang-bo, No. 870112 (ZJUH). Female. Unknown. Host. Unknown. Distribution: China (Hubei). Comments: Th e new species runs in the key by van Achterberg (2002) combined with the revision by van Achterberg and Yang (2004) to M. ptosimae Chao. It diff ers as indicated in the included key to Chinese species.
Etymology: Th e name of this species derives from the Latin "a-" and "plicatus" which means without fold, because this species has no pronotal fold on the pronotum.