Tenthredo (Tenthredina) nigricornis Malaise, 1945
Material.― 1 ♂ (RMNH): “N. Vietnam, Vinh Phuc, Tam Dao N. P., c. 1000 m, 19.iv.2001, R. de Vries. RMNH 01”.
Undescribed male.— Body brownish ferruginous with black and yellow pattern. Black: antenna (except scape and base of pedicel), narrow mesonotal, pronotal and mesopleural sutures, longitudinal line of anterior and middle tibiae and that on hind femur, postocellar furrows and three rounded spots on head (two spots in lateral supra-antennal pits and one in middle of frontal area). Hind tarsi gradually darkened from brownish ferruginous to brownish black. Yellow: labrum (except narrow ferruginous upper margin), clypeus, most of mandibles (except brownish black apices), ridges around frontal area, supra-antennal tubercles (confluent with frontal ridges), narrow inner margin of eyes (blurred, not clearly visible), lower postorbital area (more or less blurred), narrow hind margin of pronotum, propleuron and a blurred spot on left mesopleuron (asymmetric). Wings yellowish with very slight infuscation on radial cells. Costa and stigma yellow. Venation brown. Clypeal emargination trapezoid (but more or less rounded) and about ⅓ × as deep as median length of clypeus. Gena about half as wide as diameter of front ocellus. Head shiny, irregularly and sporadically punctured with small and few large confluent and elongated punctures. Antenna short, about as long as head and thorax combined without propodeum. Ratio of antennal segments: 18 : 8 : 41 : 23 : 20 : 15 : 14 : 12 : 13. OOL : POL : OCL: 19 : 4 : 12. Head contracted behind the eyes. Supra-antennal tubercles and ridges around the frontal area elevated. Frontal area elongated. Postoccipital area present but hardly visible. Pronotum, mesonotal lobes and mesoscutellum shiny, sporadically punctured with small, moderately deep punctures. Mesoscutellar appendage and postscutellum smooth and shiny. Mesoscutellum blunt, subpyramidal. Mesosternum without thorn. Mesopleuron only slightly elevated. First abdominal tergite (propodeum) smooth and shiny. Second abdominal tergite with dense, deep and rough punctures in middle, moderately shiny. Other tergites with very rough, deep coriaceous surface sculpture, hardly shiny. Second and third abdominal segments narrowed. Penis valve in fig. 20. Claw without basal lobe but with subapical tooth. Subapical tooth about as long as apical but wider. Length: 11.8 mm.