Rugosimirax Ranjith & van Achterberg, gen. nov.

(Figures 1–2)

urn:lsid:zoobank.org:act: 222F607C-EE1E-498D-8126-67A7A9725937

Type species: Rugosimirax expectata Ranjith & van Achterberg, sp. nov.

Diagnosis

Head. Head wider than long in anterior (Fig. 1B) and dorsal (Fig. 1C) views. Eyes sparsely setose, slightly diverging posteriorly (Fig. 1B). Face smooth, setose (Fig. 1B), moderately convex in lateral view (Fig. 1E). Clypeus smooth, smooth (Fig. 1B) convex in lateral view (Fig. 1E), apical margin of clypeus straight (Fig. 1B). Malar suture distinct, complete (Fig. 1B, E). Tentorial pit deep (Fig. 1B). Mandible bidentate, upper tooth longer than lower tooth. Maxillary palp with four segments (Fig. 1E). Labial palp with three segments (Fig. 1E). Frons smooth, convex medially, depressed laterally (Fig. 1C). Vertex and occiput smooth, sparsely setose (Fig. 1C). Ocelli arranged in equilateral triangle (Fig. 1C). Temple moderately rounded in dorsal view (Fig. 1C). Occipital carina absent (Fig. 1C). Antenna with 14 antennomeres, basal four flagellomeres elongate, fourth flagellomere with acute spine apico-ventrally (absent in R. fereta (Papp & Chou, 1996) comb. nov.), flagellomeres 5–11 shortened, transverse, terminal flagellomere longer than wide (Fig. 1D).

Mesosoma. Mesosoma longer than high (Figs 1A, E). Sides of pronotum and propleuron smooth (Fig. 1E). Pronotum without pronope dorsally (Fig. 1F). Mesoscutum smooth, with carinated margin postero-laterally (Fig. 1F). Notauli long, crenulated (Fig. 1F). Scutellar sulcus indistinct (Fig. 1F). Scutellum smooth and with a pair of circular depressions posteriorly, separated by diameter of a depression (Fig. 2A). Sides of scutellum irregularly sculptured (Fig. 2A). Metanotum medially protruding (Fig. 1E), laterally irregularly rugose (Fig. 2A). Mesopleuron smooth, glabrous medially, sparsely setose posteriorly (Fig. 1E). Metapleuron smooth with an oval pit medially (Fig. 1E). Propodeum rugose, or with longitudinal or oblique carinae (Figs 2A–B). Propodeal spiracle round (Fig. 2B).

Wings. Fore wing: Vein r distinct (Fig. 2F). Vein R1 often long (short in R. fereta (Papp & Chou, 1996) comb. nov.) (Fig. 2F). Vein (RS+M)a unpigmented (Fig. 2F). Vein 1CUa thickened (Fig. 2F). Vein 2RS less than 2.0 less than 2.0 × (RS+M)b. Hind wing: Vein cu-a reclivous (Fig. 2F). Vein M+CU shorter than 1M (Fig. 2F). Vein R longitudinal (Fig. 2F).

Legs. Hind coxa smooth (Fig. 1E). Tarsal claws with rounded basal lobe.

Metasoma. First tergite smooth, distinctly widened after basal constriction, parallel-sided in posterior 1/3 rd (Fig. 2D). Second tergite striate antero-laterally (Figs 2D, E). Second suture faintly impressed (Fig. 2E). Ovipositor sheath roundly widened posteriorly and with tuft of setae apically (Fig. 2C).

Etymology. The genus is named after the combination of the remarkable rugose or carinate sculpture of the propodeum and ‘ Mirax ’, the type genus of the subfamily.

Distribution. Oriental region (India and Taiwan).

Comparative diagnosis. Propodeal sculpture within the Miracinae subfamily is a taxonomically stable character. The new genus Rugosimirax exhibit an intermediate condition of the propodeum i.e., propodeum without transverse carinae and more or less longitudinally or obliquely (rugose-) carinate. Based on this character state, Rugosimirax gen. nov. could be placed near Centistidea as the propodeum is more or less carinate. Similarly, the new genus exhibits well developed and long fore wing vein R1 (longer than length of pterostigma, but short in R. fereta comb. nov.), which is a plesiomorphy. However, Rugosimirax gen. nov. is unique within the subfamily in having the ovipositor sheath with tuft of setae apically, the apical antennomeres quadrate in shape and (in two species) the fourth flagellomere bearing an acute apical tooth. This character state is unknown in the other two genera, Mirax and Centistidea . The propodeal sculpture and the shortening of the apical antennomeres are putative apomorphic character states of Rugosimirax gen. nov. Apart for these characters Rugosimirax gen. nov. exhibits plesiomorphic characters shared with Centistidea, viz., partial development of notauli and the state of posterior circular pits on the scutellum. The distance between posterior pits on the scutellum is probably of subgeneric importance as shown by the subgenus Paracentistidea of Centistidea has well separated posterior pits (van Achterberg & Mehrnejad 2002). The shape of the posterior pits is important to distinguish the new genus from both other genera. In conclusion, the new genus is similar to the genus Centistidea, but has several apomorphic characters to warrant a separate status.

Considering the listed apomorphic character states exhibited by the new genus we transfer two species previously placed in the genus Centistidea to the new genus. Centistidea fereta (Papp & Chou 1996) comb. nov. and Centistidea glabrator (Ranjith & van Achterberg 2019) comb. nov.

Key to species of Rugosimirax Ranjith & van Achterberg gen. nov.

1. Fore wing vein R1 shorter than pterostigma; apical antennomeres brown; posterior depressions of scutellum separated by less than diameter of a depression; fourth flagellomere without acute tooth ventrally; fore wing vein 2-M absent or indistinct............................................................ Rugosimirax fereta (Papp & Chou, 1996) comb. nov.

- Fore wing vein R1 distinctly longer than pterostigma (Fig. 2F); apical antennomeres yellow (Fig. 1D); posterior depressions of scutellum separated by distance of diameter of a depression (Fig. 2A); fourth flagellomere with acute tooth ventrally (Fig. 1D); fore wing vein 2-M present, pigmented (Fig. 2F)............................................................ 2

2. Propodeum with a longitudinal carina antero-medially; pterostigma brown; ninth flagellomere yellowish; first flagellomere 5.2 × as long as wide; hind coxa similarly yellowish as its femur.............................................................................................. Rugosimirax glabrator (Ranjith & van Achterberg, 2019) comb. nov.

- Propodeum smooth medially (Fig. 2A); pterostigma yellow (Fig. 2F); ninth flagellomere dark brown (Fig. 1D); first flagellomere 6.0 × as long as wide; hind coxa ivory, paler than its femur.... Rugosimirax expectata Ranjith & van Achterberg, sp. nov.