Stethantyx mesoscutator Khalaim et Broad

Khalaim, Andrey I. & Broad, Gavin R., 2013, Tersilochinae (Hymenoptera: Ichneumonidae) of Costa Rica, part 2. Genera Megalochus gen. nov. and Stethantyx Townes, Zootaxa 3693 (2), pp. 221-266 : 247-248

Stethantyx mesoscutator Khalaim et Broad , sp. nov.

( Figs 58, 59 )

Comparison. Differs from other species of Stethantyx by the brownish yellow mesosoma with only the mesoscutum and scutellum black ( Fig. 58 ). This species is also characterized by the head black dorsally and brownish yellow ventrally, entirely brownish yellow legs and metasoma, 44-segmented antennal flagellum and the short ovipositor. The new species is most similar to S. tenoriosa sp. nov. as both species have a black mesoscutum and scutellum, but S. mesoscutator has the propodeum and lower part of the head brownish yellow (both are black in S. tenoriosa ), antenna with 44 shorter flagellomeres (30–32 flagellomeres in S. tenoriosa ), and the propodeum without a delimited basal area, with some longitudinal wrinkles dorsally ( Fig. 59 ).

Description. Female. Body length 7.5 mm. Fore wing length 5.7 mm.

Head strongly rounded behind eyes in dorsal view; temple 0.42× as long as eye width. Mandible very slender, very weakly narrowed towards apex, upper tooth much longer than lower tooth. Clypeus broad, lenticular, convex in lateral view, mostly smooth, finely granulate and with sparse punctures on its upper 0.3. Malar space half as long as basal width of mandible. Flagellum of antenna distinctly narrowed towards apex, with 44 short flagellomeres; subbasal flagellomeres distinctly transverse, mid flagellomeres about as long as broad, subapical flagellomeres slightly elongate. Inner eye orbits very weakly convergent ventrally. Face with central prominence. Face, frons and vertex densely punctate, very finely granulate between punctures. Temple finely and moderately densely punctate, finely granulate to almost smooth between punctures.

Notaulus as weakly impressed wrinkled area near anterolateral margin of mesoscutum. Mesoscutum densely punctate, weakly granulate and dull between punctures. Scutellum with lateral longitudinal carinae strong in anterior half of scutellum, vanishing in its posterior half and not joining posteriorly. Epicnemial carina not reaching anterior margin of mesopleuron, continuing above and reaching subtegular ridge. Foveate groove of mesopleuron situated more or less in centre of mesopleuron, oblique, shallow but sharp and crenulate, reaching neither anterior nor posterior margin of mesopleuron. Mesopleuron finely and shallowly punctate, mostly smooth and shining between punctures, finely granulate peripherally. Propodeum finely granulate, dorsolateral area finely punctate, and apical area very finely, indistinctly punctate. Basal part of propodeum very short, 0.23× as long as apical area, with many longitudinal wrinkles dorsally ( Fig. 59 ). Propodeal spiracle separated from pleural carina by about one diameter of spiracle. Apical area flat, anteriorly rounded ( Fig. 59 ).

Fore wing with veins Rs +2 r and Rs angled 130°. Vein 2 rs-m almost twice as long as abscissa of M between 2 rs-m and 2 m-cu. Hind wing with cu 1& cu-a slightly inclivous. Hind femur 4.8× as long as broad, 0.83× as long as tibia.

First tergite moderately slender, 3.3× as long as posteriorly broad, mostly smooth, petiole laterally striate. Glymma situated near middle of tergite 1, shallow, not joining by furrow to ventral part of postpetiole. Second tergite 1.8× as long as anteriorly broad. Thyridial depression about 4.0× as long as broad. Ovipositor short, strongly upcurved at apex, with very shallow dorsal subapical depression; sheath 1.15× as long as first tergite and about as long as hind tibia.

Head with clypeus (black on lower 0.3), palpi, mandible (teeth blackish) and lower part of temple brownish yellow, the rest black. Antenna with scape brownish yellow, pedicel ventrally brownish yellow and dorsally black, flagellum entirely black. Mesosoma brownish yellow with mesoscutum, scutellum and tegula black. Legs and metasoma entirely brownish yellow. Pterostigma brown.

Male. Very similar to female. Flagellum with 39–43 segments. Notaulus sometimes absent or with single short carina. Frontal orbits sometimes also brownish yellow.

Etymology. Named after its characteristic black mesoscutum.

Material examined. Holotype female (INBio), Puntarenas Prov., Buenos Aires, Estación Altamira , Cerro Biolley, 1766 m, V–VI.2000, coll. D. Rubí.

Paratypes. Alajuela Prov.: 1 3 (ZISP) Sector Colonia Palmareña, 9 km SE of Bajo Rodriguez, 700 m, VI– VII.1996, coll. G. Carballo. Heredia Prov.: 1 3 (INBio) La Selva Biological Station, 3 km S of Puerto Viejo, 10º26ʹ N, 84º01ʹ W, VII.1993, coll. H.A. Hespenheide. Puntarenas Prov.: 1 3 (INBio) National Park Corcovado, Golfo Dulce Forest Reserve, Cerro Rincón, Estación Aguijas, 645–745 m, IV–V.2000, coll. J.A. Azofeifa.

Distribution. Costa Rica ( Alajuela , Heredia , Puntarenas).

Figures

FIGURES 56 – 59. Stethantyx cacaoensis sp. nov., Ƥ: 56 — habitus, left (holotype). Stethantyx cartagoa sp. nov., Ƥ: 57 — antenna, left. Stethantyx mesoscutator sp. nov., 3: 58 — head and mesosoma, left; 59 — propodeum and base of metasoma, dorsolateral.