S. Mahunka szerk.: Folia Entomologica Hungarica 58. (Budapest, 1997)

coxae and outer aspects of femora, tibia, tarsi of all legs. Wings dusky hyaline, fore wing subinfumated towards apex, hind one clear, stigma and venation dark brown to black. Antenna stout, 1.8 x head width, segments 3 and 4 as 3 : 2. Clypeus (Fig. 1) semicircularly incised up to 1 /5th of its medial length. Labrum broader than long (5 : 3) with rounded anterior margin. Malar space equal to diameter of median ocellus. LID : IDMO : EL = 2 : 3 : 2.1; OOL : POL : OCL = 2.1 : 1 : 1.7. Frontal area slightly below level of eyes. Supra-antennal tubercles elevated and cut off by an inconspicuous furrow from insignificant frontal ridges. Median fovea deep in its anterior half and almost indistinct in posterior half. Circum-, inter- and postocellar furrows shaip. Lateral furrows deep, reaching hypothetical hind margin of head. Postocellar area subconvex, broader than long (4 : 2). Head indistinctly narrowing behind eyes. ITD : ICD = 3:1. Mesoscutellum gibbous; appendage carinate. Mesepisternum roundly raised; mesosternum without thorns. Apical tooth of tarsal claw (Fig. 6) longer than subapical. Metabasitarsus shorter than following three joints combined. IATS : MB : OATS = 2 : 3.2 : 1.7. Metafemur shorter than metatibia. Head distinctly wrinkled with large, shallow, confluent punctures, hind orbit with some scattered punctures. Mesonotum densely and scutellum minutely punctured. Appendage with few large punctures. Metanotum almost impunctate. Mesepisternum with minute and shallow punctures. Abdomen uniformly microstriated. Lancet as in Fig. 11, with 21 serrulae, each serrula having a single AST and 15 PST. Male - Average length: 9.5 mm. Similar to female except: clypeus more roundly incised up to 1 /4th of its medial length with broad truncate lateral teeth. Male genitalia: penis valve (Fig. 16), gonoforceps (Fig. 19). Holotype - Female, Sikkim, Lachung, 2800 m, 27. V. 1994. Paratypes - 5 females, 3 males with same data as of holotype. Population variations - None. Distribution - India: Sikkim. Remarks - Tenthredo nigricasta sp. n. is somewhat related to 77. lacheni Singh et Saini, but can be easily separated from that by its V-shaped apex of mesonotal middle lobe, mesoscutellum except narrow hind margin are pale green in T. nigricasta sp. n. (all black in T. lacheni); no thorns present in 77 nigricasta sp. n. (thorns present in between supra-antennal tubercles in 77. lacheni); metafemur shorter than metatibia in T. nigricasta sp. n. (as long as metatibia in T. lacheni). Etymology - The species is named after its body colour. Tenthredo nefaensis sp. n. (Figs 2, 7, 12) Female - Average length 10 mm. Body black, yellowish to green are clypeus, labrum, mandibles except apices, spot on hind orbit touching temples, posterolateral angles of pronotum, tegula, stripe on anterior half of mesoscutellum, appendage, anterior aspects of metanotum, anterior 3/5ths of mesepisternum except a median narrow stripe, metapleuron, narrow hind margins of first five abdominal tergites with deflexed sides of all tergites, all sternites, outer angles of pro- and mesolegs, metalegs except tibia and tarsi, posterolateral angles of pro-, meso- and metaleg except coxae and trochanters. Fore wings dusky hyaline, hind ones clear, stigma and venation dark brown to black.