Stethantyx niger 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 : 248-250

Stethantyx niger Khalaim et Broad , sp. nov.

( Figs 5 , 37, 38 , 40 )

Comparison. This is the only species of Stethantyx in Costa Rican with an almost entirely black head, antennal flagellum and mesosoma (clypeus and anterior margin of pronotum yellowish). Stethantyx niger is also characteristic by the very short malar space and ovipositor with distinct dorsal and fine ventral teeth ( Fig. 40 ).

Description. Female. Body length 6.2 mm. Fore wing length 4.5 mm.

Head strongly rounded behind eyes in dorsal view; temple half as long as eye width. Mandible very weakly narrowed towards apex, upper tooth much longer than lower tooth. Clypeus broad, lenticular, almost flat in lateral view, smooth, with distinct moderately dense punctures on its upper 0.4. Malar space very short, about 0.1× as long as basal width of mandible. Flagellum of antenna weakly but distinctly narrowed towards apex, with 26–30 flagellomeres (28 flagellomeres in holotype), all flagellomeres slightly elongate; mid and subapical flagellomeres sometimes subsquare. Inner eye orbits weakly convergent ventrally. Face with weak central prominence. Face and frons densely punctate over very finely granulate, dull surface. Vertex granulate, dull, with fine and dense punctures. Temple with moderately dense, fine, sometimes indistinct punctures, shallowly granulate.

Notaulus usually as a short longitudinal wrinkle joining to anterolateral margin of mesoscutum, with a distinct pit behind the end of wrinkle. Mesoscutum finely granulate, dull, finely and densely punctate. Scutellum with lateral longitudinal carinae extending from its base to posterior c. 0.7–0.8, not joining posteriorly. Foveate groove of mesopleuron situated in anterior 0.7 of mesopleuron, strongly oblique, coarse, with strong transverse wrinkles, not reaching anterior margin of mesopleuron ( Fig. 37 ). Mesopleuron finely granulate, with distinct, moderately dense punctures. Propodeum granulate, dorsolateral area finely and densely punctate, apical area usually with transverse wrinkles. Basal part of propodeum weakly widened anteriorly, about 1.5× as long as broad, and 0.43× as long as apical area ( Fig. 38 ). Propodeal spiracle separated from pleural carina by about one diameter of spiracle. Apical area flat, anteriorly truncate.

Fore wing ( Fig. 5 ) with veins Rs +2 r and Rs angled about 100°. 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 somewhat inclivous. Hind femur 4.6× as long as broad, 0.86× as long as tibia.

First tergite slender, 4.1× as long as posteriorly broad, mostly smooth, petiole laterally striate. Glymma situated near middle of tergite 1, deep, joining by very shallow, indistinct furrow to ventral part of postpetiole. Second tergite 1.73× as long as anteriorly broad. Thyridial depression more than 3.0× as long as broad. Ovipositor weakly upcurved, apically with two weak, rounded dorsal teeth, and two fine teeth ventrally ( Fig. 40 ); sheath 1.2× as long as first tergite and 1.27× as long as hind tibia.

Head, mesosoma and metasomal segment 1 black; scape and pedicel ventrally and legs (apex of hind femur, tibia and tarsus more or less infuscate) yellowish; lower 0.8 of clypeus, palpi, mandible (teeth black), propleuron and anterior margin of pronotum brownish yellow (sometimes upper and posterior margins of pronotum narrowly reddish brown). Tegula brown. Pterostigma black. Metasoma behind tergite 1 yellow ventrally to brown dorsally, tergites 2 and basal half of tergite 2 dorsally black.

Male. Unknown.

Variation. One female from Barra Honda National Park is conspicuously lighter than other specimens, with the pronotum and mesopleuron extensively reddish brown, flagellum yellow-brown, legs and metasoma behind tergite 1 almost entirely yellow, and metasomal segment 1 brown.

Etymology. Named after its predominantly black body.

Material examined. Holotype female (BMNH), San José Prov., San Antonio de Escazú, 1300 m, VIII.1988, coll. I.D. Gauld.

Paratypes. Alajuela Prov.: 1 Ƥ (ZISP) National Park Arenal, Sector Cerro Chato, San Carlos, 1100 m, IX– X.1999, coll. G. Carballo. Guanacaste Prov.: 1 Ƥ (ZISP) Santa Rosa National Park, VII–VIII.1985, coll. D. Janzen & I.D. Gauld. 1 Ƥ (BMNH) volcano Orosi, 800 m, V–VI.1986, coll. Mariksa & I.D.Gauld. 2 Ƥ (BMNH) Barra Honda National Park, 200 m, dry forest, VI.1988, coll. I.D. Gauld & P. Mitchell. 1 Ƥ (INBio) Guanacaste National Park, 9 km S of Santa Cecilia , Estación Pitilla, 700 m, V.1995, coll. P. Ríos. Puntarenas Prov.: 1 Ƥ (BMNH) Las Cruces, 6 km S of San Vito de Java, 1200 m, VII–VIII.1988, coll. I.D. Gauld & P. Mitchell. 1 Ƥ (BMNH) San Vito, Las Alturas, 1500 m, VII.1991, coll. K. Gaston. San José Prov.: 1 Ƥ (ZISP) same data as holotype. 2 Ƥ (BMNH) same data, but V and VI.1988.

Distribution. Costa Rica ( Alajuela , Guanacaste, Puntarenas, San José).

Figures

FIGURES 1 – 6. Wings of Stethantyx spp., Ƥ: 1 — S. ajajuela sp. nov.; 2 — S. curvator sp. nov.; 3 — S. guanacasteca sp. nov.; 4 — S. heredia sp. nov.; 5 — S. niger sp. nov.; 6 — S. notaulator sp. nov.

FIGURES 36 – 39. Stethantyx heredia sp. nov., Ƥ: 36 — propodeum, dorsal. Stethantyx niger sp. nov., Ƥ: 37 — mesosoma, left; 38 — propodeum, dorsal. Stethantyx notaulator sp. nov., Ƥ: 39 — upper part of mesosoma, left. Scale bars = 0.1 mm.

FIGURES 40 – 46. Stethantyx niger sp. nov., Ƥ: 40 — apex of ovipositor, left. Stethantyx orosia sp. nov., Ƥ: 41 — head, frontal; 42 — mesoscutum and scutellum, dorsal; 43 — mesosoma, left; 44 — propodeum, dorsal. Stethantyx osa sp. nov., Ƥ: 45 — head, frontal. Stethantyx pseudoorosia sp. nov., Ƥ: 46 — head, frontal. Scale bars = 0.1 mm.