Colastomion citrum Long, 2021

Colastomion citrum Long , sp. n.

Figs 27–36 View FIGURES 27–36

Material examined. Holotype, ♂ ( IEBR), “ Rog.691 ”, NC Vietnam: Ha Tinh, Vu Quang NP, forest, 06.x.2009, KDLong.

Morphology. Holotype, ♂, body length 4.0 mm, fore wing length 2.8 mm, antenna 4.0 mm ( Fig. 27 View FIGURES 27–36 ).

Head. Antenna with 32 flagellomeres remaining; terminal flagellomere acuminate; middle flagellomere 3.0 × longer than wide (6: 2); 3 rd antennomere 1.2 × fourth (7: 6); 3 rd segment of maxillary palp 2.0 × longer than maximally wide (12: 6); 5 th segment 0.8 × length of 6 th (4: 5); width of face as long as face length and clypeus combined (12: 12); width of face: height of eye = 1.2: 1.5; malar space 0.6 × as long as basal width of mandible (3: 5); basal width of mandible 0.7 × as long as hypoclypeal depression (5: 7); distance between tentorial pits 2.0 × distance between pit and eye (8: 2); in dorsal view, height of eye 3.0 × as long as temple (12: 4); in lateral view; width of eye 3.0 × as long as temple (12: 4); occipital carina slightly wavy ( Fig. 35 View FIGURES 27–36 ); ocelli large, POL: OD: OOL = 3: 4: 3; distance between front and hind ocelli as long as OOL (2: 3) ( Fig. 29 View FIGURES 27–36 ); occipital carina narrowly obliterated mediodorsally ( Fig. 29 View FIGURES 27–36 ); between posterior ocellus with distinct groove; vertex and temple smooth; face narrowly smooth medially, transversely rugulose laterally ( Fig. 28 View FIGURES 27–36 ); frons smooth with divergent striae laterally ( Fig. 29 View FIGURES 27–36 ).

Mesosoma. Length of mesosoma 1.6 × as long as high (46: 28); propleuron largely smooth, sparsely crenulate anteriorly; precoxal sulcus wide, smooth posteriorly, punctate anteriorly; mesopleuron and metapleuron smooth; mesoscutum largely smooth with a deep smooth medial depression posteriorly between notauli; notauli narrow and deep anteriorly, deeply depressed posteriorly ( Fig. 30 View FIGURES 27–36 ); scutellar sulcus deep, 2.7 × as long as scutellum (8: 3) with one medial carina; scutellum smooth; propodeum widely depressed medially, almost smooth ( Fig. 31 View FIGURES 27–36 ).

Fore wing. Pterostigma 5.4 × as long as wide (27: 5); vein r arising before middle of pterostigma; vein M+CU1 straight; vein 1-SR+M slightly curved apically; vein cu-a postfurcal, nearly perpendicular ( Fig. 33 View FIGURES 27–36 ); 2-CU1 8.5 × longer than 1-CU1 (17: 2); SR1: 3-SR: r = 26: 16: 4; vein 2-SR 2.25 × 2-SR+M (9: 4); 1-CU1: cu-a: 2-CU1: 3-CU1= 2:3:17:4; basal length of second submarginal cell 2.9 × as long as its apical width (20: 7).

Hind wing. Vein M+CU 1.1 × length of vein 1-M; vein M+CU: 1-M: 1r-m = 14: 15: 6; vein 2-SC+ R thickened, subquadrate; vein SR curving subbasally and getting closer to anterior margin towards wing tip ( Fig. 34 View FIGURES 27–36 ).

Legs. Hind coxa smooth dorsally; length of hind femur: tibia: basitarsus: tarsus 1–5 = 35: 41: 23: 54; length of hind femur, tibia and basitarsus 5.0, 8.2 and 11.5 × as long as their width respectively.

Metasoma. First tergite 1.6 × as long as apical width (24: 15) ( Fig. 32 View FIGURES 27–36 ) posteriorly wide; first tergite with interrupted carina, surface rugo-punctate medially, sparsely striate laterally; 2 nd metasomal tergite 1.3 × wider than medially long (23: 18), with wide midbasal triangular area giving rise to short midlongitudinal carina, rather sparsely irregularly longitudinally striate; medial length of 2 nd tergite 1.2 × than third (17: 14); median length of 3 rd metasomal tergite 0.6 × its basal width (14: 25) ( Fig. 32 View FIGURES 27–36 ); 3 rd metasomal tergite 1.2 × wider than long; longitudinally striate; fourth-fifth tergites coriaceous basally, smooth apically; sixth tergite smooth.

Coloration. Head yellow; stemmaticum blackish brown; antenna creamwhite basally, brownish yellow apically; palpi creamwhite; propleuron yellow; mesopleuron yellow anteriorly, whitish yellow posteriorly; fore leg whitish yellow, except coxa creamwhite; middle legs whitish yellow, except coxa yellow; hind leg whitish yellow, except yellow medio-apically; wings hyaline with yellow veins; first metasomal tergite yellow; second-sixth tergites mainly pale yellow, brownish yellow laterally ( Fig. 32 View FIGURES 27–36 ).

Female: Unknown.

Etymology. From “citer” (Latin for lying near, near, close), because hind wing vein SR curving basally and getting closer to anterior margin towards wing tip.

Biology. Unknown.

Distribution. NC Vietnam ( Ha Tinh).