Psyttalia nigristriata Long, sp. nov.

Figures 7, 8

Type material. Holotype, ♀, “Opii. 310” (IEBR), NE Vietnam: Tuyen Quang, Na Hang, Thanh Tuong, forest, 22°19’01’’N 105°24’02’’E 162m, MT, 5.xii.2016, KD Long.

Paratypes, 3 ♀, “Opii. 309” (IEBR), the same locality as holotype, but 15.i.2017, KD Long; “Opii. 026” (IEBR), NW Vietnam: Hoa Binh, Yen Thuy, Lac Thinh, sugarcane plantation, 20°23’45’’N 105°34’22’’E 100m, MT, 10.ix.2002, KD Long; Opii. 275” (IEBR), NW Vietnam: Son La, fruit orchard, 21°18’03’’N 103°55’38’’E 671m, MT, 25.v.2016, KD Long .

Comparative diagnosis. Psyttalia nigristriata, sp. nov. shares with P. hoabinhensis and P tricolorata the relatively short vein r of fore wing and the first subdiscal cell of fore wing nearly parallel-sided posteriorly, but is easily recognized as follows: 1) dark brown stripes on metasomal tergites 1–3 (Fig. 8E) [(vs entirely yellow in P. hoabinhensis, sp. nov. (Fig. 4F) or black P. tricolorata, sp. nov. (Figs 14E, H)]; 2) precoxal sulcus narrow, fused punctures and crenulae (Fig. 8F) (vs sulcus wider, distinctly crenulate in in P. hoabinhensis and P. tricolorata (Figs 4E, 14F); and 3) pterostigma narrow triangular in shape, 3.7 × as long as wide medially (vs broad triangular in shape, 3.0–3.2 × as long as wide medially).

Description. Holotype, ♀, length of body 2.8 mm, fore wing 3.0 mm, ovipositor 1.0 mm (Fig. 7).

Head. Antenna complete, 35 flagellomeres, flagellomeres bristly; first flagellomere as long as second and 3.5 × their width; length of maxillary palp subequal to height of head; in dorsal view, head 2.1 × as wide as long medially; length of eye in dorsal view 5.0 × temple (Fig. 8A); temple shiny, smooth and with sparse setae; OOL: OD: POL = 6: 3: 3; in lateral view, medially eye 1.7 × as long as wide and 4.0 × as wide as temple; in frontal view, width of clypeus 3.0 × its maximum height, as long as face height and 0.6 × width of face (Fig. 8B); ventral margin of clypeus evenly convex medially (Fig. 8B); hypoclypeal depression narrow and deep (Fig. 8B); distance between tentorial pits 2.5 × distance from pit to eye margin; malar suture absent; malar space narrow, 0.4 × basal width of mandible; clypeus punctate; face rugo-punctate with distinct raised carina medially (Fig. 8B); mandible rather robust, apically with both teeth wide, normal basally and with narrow ventral carina; occipital carina remains far removed from hypostomal carina and dorsally largely absent; frons nearly flat, depressed laterally, without round pit between antennal sockets, smooth medially (Fig. 8A); vertex and temple smooth.

Mesosoma. Laterally, length of mesosoma 1.3 × its height; pronotal side largely smooth, with deep median groove (Fig. 8F); propleuron flattened; epicnemial area smooth dorsally; precoxal sulcus narrow, crenulate medially, punctate anteriorly and posteriorly (Fig. 8F); remainder of mesopleuron smooth and shiny; pleural sulcus smooth ventrally; mesosternal sulcus narrow and finely crenulate; postpectal carina absent; mesoscutum very shiny and nearly glabrous (Fig. 8D); notauli only anteriorly as pair of smooth pit-like impressions and largely absent on disc, mesoscutum flat posteriorly; scutellar sulcus deep and narrow, nearly parallel-sided medially, 0.2 × as long as scutellum, with 3 crenulae; scutellum slightly convex and smooth, only sparsely setose apically and laterally; metanotum with short carina; surface of propodeum smooth, except for short transverse crenulae median carina medio-posteriorly, and with convergent lateral grooves above spiracle (Fig. 8G).

Wings. Vein 1-SR of fore wing as long as wide and nearly linear with 1-M; pterostigma narrow triangular in shape; length of pterostigma 3.7 × as long as its width medially (Fig. 8H); 1-R1 ending at wing apex and 1.8 × as long as pterostigma; vein exiting before middle of pterostigma, linear with antero-ventral margin of pterostigma, and not linear with vein 3-SR; 1-SR+M more or less sclerotized; vein r-m unsclerotized, r: 2-SR: 3-SR: r-m: SR1 = 5: 13: 18: 7: 41; subdiscal cell hardly narrowed anteriorly; vein r 0.4 × 2-RS; 2-SR+M 2.7 × its maximum width; 1-CU1: cu-a = 3: 4; r: 3-SR: SR1 = 5: 18: 41; 2-SR: 3-SR: r-m = 13: 18: 7; 1-M straight; m-cu far antefurcal, not linear with vein 2-SR+M and slightly curved, subparallel with 1-M (Fig. 8H); cu-a oblique, and far postfurcal; 1-CU1 widened basally; 1-CU1: 2-CU1: cu-a = 3: 13: 4; only apex of M+CU1 sclerotized, pigmented basally; vein r-m unsclerotized (Fig. 10H); vein SR1 nearly straight; subdiscal cell hardly narrowed anteriorly. Hind wing: M+CU: 1-M: 1r-m = 13: 17: 9; cu-a straight, unsclerotized apically; m-cu and SR absent (Fig. 8I).

Legs. Length of femur, tibia and basitarsus of hind leg 3.9, 8.0 and 5.0 × their width, respectively; hind basitarsus 0.4 × hind tibia, and 0.6 × second–fifth tarsus combined; inner and outer spurs and as long as basitarsus, respectively; hind tibia and tarsus with long setae.

Metasoma. Length of first tergite 1.1 × its apical width, convex medio-posteriorly, its surface largely smooth basally, rugo-striate medio-apically (Fig. 8E), dorsal carinae strong in basal half of tergite and with depressed area below; second suture not indicated; combined length of second and third metasomal tergites 0.4 × the remaining tergites posteriorly; first tergite superficially coriaceous; second and following tergites smooth, shiny and sparsely setose apically and laterally.

Colour. Yellow and dark brown; antenna brown; head yellow but stemmaticum black; palpi pale yellow; propleuron, mesopleuron and metapleuron yellow; mesonotum yellow; metanotum brown; propodeum yellow anteriorly, brown posteriorly; fore and middle legs yellow, except coxa whitish yellow and tarsus yellowish brown; hind coxa and femur yellow; hind tibia and tarsus brown; tegula pale yellow; pterostigma brown entirely; wing membrane hyaline, veins brown; first tergite brown; second tergite yellowish brown medially, yellow laterally; third and fourth tergites largely brown basally, yellow apically and ventrally; fifth tergite largely brown, yellow laterally; the remainder yellow; sternites and hypopygium yellow; ovipositor sheath brown; ovipositor brownish yellow.

Variation. Paratype, 3♀, antenna with 31–45 flagellomeres; length of body 2.3–3.3– 3.8 mm, fore wing 2.7–3.8 mm, length of visible ovipositor 1.0– 2.2 mm.

Male. Unknown.

Distribution. NE Vietnam (Tuyen Quang); NW Vietnam (Hoa Binh, Son La).

Biology. Unknown.

Etymology. From “niger” (Latin for “black, dark, dusky”), in reference to the transverse dark brown stripes basally on the third–fifth metasomal tergites.