Stethantyx tenoriosa 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 : 263-265

Stethantyx tenoriosa Khalaim et Broad , sp. nov.

( Figs 64, 65 )

Comparison. Differs from other species of Stethantyx by the brownish yellow mesosoma with black mesoscutum, scutellum and propodeum ( Fig. 64 ). It is most similar to S. mesoscutator sp. nov. as both have a black mesoscutum and scutellum, but S. tenoriosa has the propodeum and head also black (brownish yellow in S. mesoscutator ), a slenderer antennal flagellum, and the propodeum with a clearly delimited basal area ( Fig. 65 ). Although this species is known only from the male, it is a very distinct species and is immediately distinguished from congeners by the characteristic colour pattern of the mesosoma.

Description. Male. Body length 5.8 mm. Fore wing length 4.2 mm.

Head strongly and roundly narrowed behind eyes in dorsal view; temple half as long as eye width. Mandible very weakly narrowed towards apex, upper tooth longer than lower tooth. Clypeus broad, lenticular, slightly convex in lateral view, mostly smooth, distinctly punctate on its upper 0.6. Malar space 0.4× as long as basal width of mandible. Flagellum of antenna distinctly narrowed towards apex, with 30–32 flagellomeres (31 flagellomeres in holotype); subbasal flagellomeres about 1.5, mid flagellomeres 1.2–1.3× as long as broad, and subapical flagellomeres slightly elongate. Inner eye orbits weakly convergent ventrally. Face with very weak central prominence, with small median tubercle in upper part. Face and frons granulate, dull, mostly without distinct punctures. Vertex and temple with fine shallow punctures; vertex very finely granulate, dull; temple smooth and shining between punctures.

Notaulus as weakly rugulose area or absent. Mesoscutum with dense and shallow punctures, very finely granulate between punctures, dull. Scutellum with lateral longitudinal carinae extending from its base to posterior 0.5–0.6. Epicnemial carina not reaching anterior margin of mesopleuron, continuing above and reaching subtegular ridge. Foveate groove of mesopleuron situated in anterior 0.7 of mesopleuron, strongly oblique, moderately broad and deep, crenulate, not reaching anterior margin of mesopleuron. Mesopleuron finely punctate, smooth and shining between punctures, with smooth impunctate area above anterior part of foveate groove. Propodeum finely granulate, dull, dorsolateral area finely (sometimes indistinctly) punctate, without wrinkles adjacent to carinae. Basal area of propodeum clearly delimited, narrow, distinctly widened anteriorly (1.5–2.0× broader anteriorly than posteriorly), about half as long as apical area ( Fig. 65 ). Propodeal spiracle separated from pleural carina by ≤0.5× diameter of spiracle. Apical area flat, anteriorly rounded or truncated.

Fore wing with veins Rs +2 r and Rs angled about 105–110°. Vein 2 rs-m about twice as long as abscissa of M between 2 rs-m and 2 m-cu. Hind wing with cu 1& cu-a distinctly inclivous. Hind femur 5.0× as long as broad, 0.86× as long as tibia.

First tergite slender, 4.7× as long as posteriorly broad, mostly smooth, petiole laterally partly striate. Glymma situated slightly behind middle of tergite 1, small and inconspicuous, joining by very shallow indistinct furrow to ventral part of postpetiole or isolated. Second tergite 2.8× as long as anteriorly broad. Thyridial depression about 4.0× as long as broad.

Head black; clypeus reddish brown in lower half, palpi and mandible (teeth reddish black) brownish yellow. Antenna black, scape ventrally yellowish. Mesosoma reddish orange, mesoscutum, scutellum, tegula and propodeum brownish black to black. Pterostigma dark brown. Legs brownish yellow; fore and mid coxae and all trochanters whitish; hind femur reddish, basal 0.7 of tibia and tarsus fuscous. First metasomal segment black. Metasoma behind first tergite brownish yellow ventrally to brown and dark brown dorsally, tergite 2 dorsally with posterior brownish yellow band.

Female. Unknown.

Variation. All males are rather uniform in colour pattern and structure.

Etymology. Named after the type locality, Tenorio.

Material examined. Holotype Male (INBio), Alajuela Prov., National Park Volcán Tenorio, N of volcano Tenorio, Guatuso, 1600 m, VII–VIII.2005, coll. J.A. Azofeifa.

Paratypes. Alajuela Prov.: 3 3 (2 3 INBio, 1 3 ZISP) same data as holotype. Distribution. Costa Rica ( Alajuela ).

Figures

FIGURES 60 – 65. Stethantyx nigrofemorata sp. nov., Ƥ: 60 — head, frontal; 61 — head and mesosoma, left; 62 — propodeum, dorsal; 63 — metasoma and legs, left. Stethantyx tenoriosa sp. nov., Ƥ: 64 — head and mesosoma, left; 65 — propodeum and base of metasoma, dorsolateral.