Small to medium size. Temple always with pale yellowish streak behind eye. Neck emarginate anteriorly, finely striate, pronotal fold absent; reduced venation with vein 2-CU1 of fore wing always less developed, but sometimes complete; veins 2-SR and 2-SR+M of fore wing absent; vein 1-SR absent or faintly developed; hind tibia distinctly narrowed and compressed basally, outer side usually without fine oblique striae; hind tarsus with three tarsomeres in the female, while five in the male.

Afrotropical, Neotropical, Palaearctic and Oriental.

Holotype, ♀ (BFU), Vietnam: Binh Thuan, Huyen Thuan Bac, Dong Tien, 108°2.382’E, 11°12.912’N, VI.2020, leg. Local collector; Paratypes, 3♂ (BFU), Vietnam: Binh Thuan, Huyen Thuan Bac, Dong Tien, 108°2.382’E, 11°12.912’N, VI.2020, leg. Local collector.

Head transverse in dorsal view and slightly elliptical in lateral view; frons completely yellowish-brown without streaks; vertex coarsely transversely carinate rugose with three distinct carinae between ocelli; propodeum shallowly circularo-foveolate with a relatively smooth coriaceous area anteriorly (the anterior coriaceous area concave more deeply in the male than in the female); pterostigma translucent with dark brown margins, long and narrow, subparallel-sided; vein 2-CU1 extremely short; hind femur with 2 ivory large teeth venrtally and with a blackish tooth obtusely developed basally; ovipositor sheath without sub-apical band.

Holotype. Female. The length of body (except ovipositor sheath) 10.5 mm; forewing 6.4 mm long, 1.4 mm wide; the length of ovipositor sheath 9.6 mm.

Head. Antenna with 28 flagellomeres; frons finely and transversely rugose (Fig. 1); three anterior coronal teeth large and lobe-shaped, while the posterior two relatively small and wide; the ocular triangular area with three coarse transverse rugae; vertex finely transversely rugose anteriorly, with coarse and slightly curved rugae reaching occipital carina; temple smooth and shiny, roundly contracts behind eyes (Fig. 2).

Mesosoma. Pronotum moderately robust and largely coriaceous; neck anteriorly deeply emarginated, with several transverse ridges (Fig. 4), neck at about the same level of the middle part of pronotum postero-dorsally; pronotal fold absent; middle part of pronotum finely coarsely striate; posterior pronotum distinctly elevated and transversely rugose; mesoscutum with finely reticulate striate anteriorly and posterior half coarsely; scutellum smooth and with foveolae laterally (Fig. 5); propodeum completely with shallow, circular foveolae, with a relatively smooth coriaceous area anteriorly (Fig. 6).

Wings. Fore wing: hyaline (Fig. 7); vein 2-CU1 weakly developed, 0.25 × as long as vein cu-a; pterostigma subparallel-sided, elongate and acute apically, 2.5 × as long as vein r and 11.0 × as wide as its maximum width; vein SR1 2.1 × as long as vein r; vein SR1 and vein r obtusely angled; vein r ends 0.13 × length of pterostigma behind level of apex of pterostigma.

Legs. Hind coxa transversely striate, dilated sub-apically (Fig. 8); hind femur densely reticulate, with two ivory large ventral teeth and with a blackish tooth rather obtuse developed basally (Fig. 9); hind tibia coriaceous, 1.25 × as long as hind femur; basal narrow part of hind tibia 1.1 × as long as widened part, inner side of widened part basally distinctly V-shaped depressed, apically setose (Fig. 10); basitarsus 4.7 × as long as wide, with dense and bristle setae ventrally (Fig. 11).

Metasoma. Tergite I (TI) finely transversely striate (Fig. 12), ca 7.4 × as long as its maximum width, 2.25 × as long as TII; basal one fifth of TII striate, and the remaining tergites largely shiny, smooth or weakly aciculate (Fig. 13); pygidial area indistinctly differentiated in color, and truncate apically (Fig. 14); ovipositor sheath completely black, and ca 0.9 × as long as body length (Fig. 15).

Colour. Brownish to blackish; frons completely yellowish-brown without streaks (Fig. 1), temple ventrally yellowish-brown along compound eye; wing membrane hyaline (Fig. 7), wing veins brownish; pterostigma translucent with dark brown margins; pronotum, mesoscutum and propodeum blackish; prosternum brownish; hind femur, hind tibia and metasoma largely blackish to blackish-brown; large ventral tooth of hind femur ivory (Fig. 9); ovipositor sheath complelely blackish without whitish subapical band (Fig. 15).

Paratypes. Male. The length of body 9.5–11.4 mm; the length of forewing 4.9–5.7 mm.

Resemble to female but differs as follows: fore legs and mid legs brown; a large reddish-brown spot developed in the middle part of hind femur; the blackish tooth on the basal part of hind femur comparatively more developed; tergite I ca 3.2–3.37 × as tergite II and 0.92–1.05 × as remainder of metasoma; tergite III reddish-brown in dorsal view, and tergite II to tergite IV brownish to reddish-brown in ventral view; forewing 4.9–5.7 mm; vein 2-CU1 weakly developed, 0.21–0.3 × as long as vein cu-a; pterostigma subparallel-sided, elongate and acute apically, 1.74–2.35 × as long as vein r and 8.6-9.6 × as wide as its maximum width; vein SR1 1.74–2.06 × as long as vein r; vein SR1 and vein r obtusely angled; vein r ends 0.24–0.26× length of pterostigma behind level of apex of pterostigma.

We name the new species as “meridionalis” (Latin for south) for the type locality is in the southern part of Vietnam.

Vietnam.

Collected in June. Host is unknown.

The new species runs to F. flavidentatus in the key to Chinese species by Hong et al. (2011) in having the base of anterior tooth of corona yellowish brown; teeth of hind femur ivory and a less developed vein r on fore wing. However, the new species differs from F. flavidentatus in lacking the ivory sub-apical band of ovipositor sheath; propodeum with a relatively smooth coriaceous area anteriorly and an indistinctly differentiated pygidial area (pygidial impression in F. flavidentatus deep and reverse V-shaped). This new species runs to F. sudhae (Narendran & Sureshan, 2003) in the key to Indian species by Binoy et al. (2020) but it differs from F. sudhae in having 3 carinae between ocelli of the vertex and a distinct median longitudinal grove on posterior half of mesoscutum. The new species is also similar to F. quadridens, a species from Luang Prabang, Laos, in having posterior half of the pronotum distinctly striate, the ovipositor sheath completely blackish and a coarsely sculptured frons, but it can be easily distinguished by the two robust and ivory teeth on the hind femur (F. quadridens has 4 medium to large blackish teeth) and a slightly curved vein SR1 on the fore wing (more straight in F. quadridens).