Leiobracon vietnamicus Long & van Achterberg, 2024

Leiobracon vietnamicus Long & van Achterberg , sp. nov.

Type material. Holotype, ♀, “Bracn. 1018 ” ( IEBR), NW Vietnam: Ha Tinh, Huong Son , Vu Quang NP, forest, sweep [net], 23.ix.2009, KD Long . Paratypes, 2♀, “Bracn. 068 ” ( IEBR), NE Vietnam: Vinh Phuc, Tam Dao NP, forest, 900m, sweep [net], 04.vii.2003, NTP LIEN ; “Bracn. 1255 ” ( IEBR), NE Vietnam: Cao Bang, Tinh Tuc, Phia OacPhia Den NP, forest, MT , 8–18.v.2013, PT NHI .

Description. Holotype, female, body 8.6 mm, fore wing 9.0 mm, ovipositor sheath 2.3 mm.

Head. Antenna incomplete, with 57 antennomeres remaining, [in paratype apical flagellomere with spine and 1.75 × longer than its maximum width (without spine) Figs 3A, B View FIGURE 3 ]; scape nearly globose, in lateral aspect longer dorsally than ventrally ( Fig. 2C View FIGURE 2 ); length of scape 1.2 × longer than width apically; flagellomeres short, nearly quadrate; first flagellomere 1.1 × longer than second; first and second flagellomeres 1.1 and 1.0 × longer than wide, respectively; length of maxillary palp 0.7 × as long as height of head; clypeus height: inter-tentorial distance: tentorio-ocular distance = 9: 17: 6; clypeus separated from face by a fine carina ( Fig. 2B View FIGURE 2 ); face coriaceous and with fine punctures, in lateral view densely setose ( Fig. 2C View FIGURE 2 ); eye height: shortest distance between eyes: head width = 33: 26: 57; face 1.2 × wider than long; width of hypoclypeal depression 1.3 × longer than distance from it to eye margin; malar suture absent, malar space 0.7 × basal width of mandible; frons flat and smooth ( Fig. 2A View FIGURE 2 ); vertex smooth, with rather short setae; OOL: OD: POL = 14: 5: 6; temples roundly narrowed behind eyes and eye 1.85 × as long as temple ( Fig. 2A View FIGURE 2 ); in lateral view transverse width of eye 1.9 × as long as temple.

Mesosoma. Length of mesosoma 1.8 × its height; pronotum smooth, densely setose; mesopleuron slightly convex and smooth ( Fig. 1A View FIGURE 1 ); metapleuron flat and smooth, fused with propodeum dorsally (without suture between metapleuron and propodeum); notauli absent ( Fig. 2D View FIGURE 2 ); mesoscutum smooth, scutellar sulcus shallow, narrow and smooth ( Fig. 2D View FIGURE 2 ); scutellum slightly convex and smooth; propodeum smooth; propodeal spiracle small, situated behind far from middle of propodeum; mesonotum and propodeum sparsely setose.

Wings. Fore wing with pterostigma 3.5 × as long as its maximum width; angle between 1-SR and C+SC+ R about 75° ( Fig. 2H View FIGURE 2 ); r: 3-SR: 2-SR: SR1= 15: 28: 22: 42; strongly bent posteriorly after arising from vein 1-SR ( Fig. 2H View FIGURE 2 ); vein r nearly as long as vein 2-SR; vein 1-M 1.7 × longer than m-cu; vein 1-CU1 short and thick, nearly quadrate; vein cu-a distinctly reclivous, slightly postfurcal ( Fig 2H View FIGURE 2 ). Hind wing with vein 2-SC+ R vertical; vein cu-a reclivous ( Fig. 2I View FIGURE 2 ), SC+ R 1: 1r-m = 15: 27.

Legs. Length of fore femur: tibia: tarsus = 20: 23: 28; length of hind femur, tibia and basitarsus, 3.55, 5.75 and 4.0 × longer than their maximum width, respectively; hind basitarsus 0.4 × as long as hind tibia and 0.7 × second-fifth tarsal segments combined; inner and outer hind tibial spurs 0.40 and 0.35 × as long as hind basitarsus, respectively, inner side of hind tarsal claw with a separate tooth ( Fig. 2E View FIGURE 2 ).

Metasoma. Metasoma 1.1 × as long as mesosoma and head combined; first tergite 2.9 × its apical width, surface smooth; lateral grooves of first tergite smooth ( Fig. 2F View FIGURE 2 ); second suture indistinct; second–sixth tergites smooth; setose part of ovipositor sheath 0.25 × as long as fore wing; hypopygium medium-sized, sclerotized throughout, apically acute, and sparsely setose ( Fig. 1C View FIGURE 1 ); ovipositor sheath densely setose, subequal to hind tibia; ovipositor with pre-apical dorsal nodus and apico-ventral serrations ( Fig. 2G View FIGURE 2 ).

In addition, the type species of Pseudoshirakia van Achterberg and Pseudospinaria Enderlein were previously reported from Vietnam.

Colour. Reddish yellow; scape and pedicel yellow, contrasting with brown flagellum; fore and middle legs yellow; hind leg yellowish brown to dark brown; spurs yellow; wings yellow, parastigma dark brown, large dark brown spot of fore wing extending to middle of vein 1-SR+M ( Fig. 2H View FIGURE 2 ); ovipositor sheath brownish black, ovipositor yellow.

Variation. Paratypes, females, body 8.6–9.0 mm, fore wing 9.8–10.5 mm, ovipositor sheath 2.5–2.6 mm, antennal segments 66.

Biology. Unknown.

Male. Unknown.

Distribution. Northeast Vietnam ( Cao Bang and Vinh Phuc provinces) and North Central Vietnam ( Ha Tinh province).