Stenarella Szépligeti, 1916

Stenarella Szépligeti, 1916 View in CoL View at ENA

Stenarella Szépligeti, 1916: 307. Description. Type species: Ichneumon gladiator Scopoli, 1763 (= Ichneumon domator Poda 1761), by subsequent designation by Roman (1943). View in CoL

Orientostenaraeus Uchida, 1930: 321. Type species: Orientostenaraeus chinensis Uchida, 1930 (= Mesostenus insidiator Smith 1859), by original designation.

Parasilsila Cheesman, 1936: 368 . Type species: Parasilsila trilineata Cheesman, 1936 (= Mesostenus victoriae Cameron ), by original designation.

Diagnosis.

Ovipositor very long, OST > 2.7 (Fig. 1 View Figure 1 ), its apex distinctly sinuate, dorsal valve with distinct teeth or hooks; mandible long, MLW 1.85–2.6, dorsal tooth much longer than ventral one; areolet very small; T 1 0.85–1.25 as long as T 2, slender and not widened posteriorly, its spiracle placed on posterior 0.42.

Description.

FEMALE. Fore wing 5–16.5 mm long. — Head: Mandible long to very long, MLW 1.85–2.6, distinctly tapered towards apex; dorsal tooth distinctly longer than ventral one. Malar space moderately long, MSM 0.3–0.7. Clypeus wide, CWL 2.45–3.3 trapezoidal in front view, almost flat in lateral view; apical margin sharp, distinctly raised, inflexed, medially concave, without median teeth. Flagellum of uniform width, not distinctly enlarged towards apex; apical flagellomere uniformly tapered. Supra-antennal area ventrally slightly to distinctly concave, with distinct longitudinal carina. Occipital carina complete, meeting hypostomal carina far from mandible base. — Thorax. Dorsal margin of pronotum regular, not swollen; epomia indistinct to strong and long. Mesoscutum moderately convex; notaulus long, reaching 0.55–0.9 of mesoscutum length, moderately impressed, inside with weak to distinct striae. Epicnemial carina weak, sometimes almost indistinct from mesopleuron sculpturing, reaching 0.4–1.0 of distance to subtegular ridge. Sternaulus sinuous or evenly up curved, deep or shallow, reaching or not the posterior rim of mesopleuron, anteriorly placed somewhat ventrally on mesothorax, facing downwards, inside with very short to distinct vertical striae. Median portion of postpectal carina short, straight. Posterior margin of metanotum without lateral teeth – like projections. Propodeal furrow moderately deep, medially smooth. Juxtacoxal carina as short ridge or absent. Pleural carina absent. Fore tibia not distinctly swollen. Fourth tarsomeres not distinctly bilobed. — Propodeum. Propodeum moderately long, dorsal profile in lateral view evenly convex and sloped, in S. domator propodeum short with dorsal profile broken into a short anterodorsal face and a longer sloped posterodorsal face. Anterior margin medially slightly concave. Spiracle elongate, SLW 1.4–5.25. Longitudinal carinae absent, except sometimes anterior section of median longitudinal carina (area basalis defined). Anterior transverse carina complete, sharp, medially distinctly arched. Posterior transverse carina absent to complete, never forming distinct sublateral crests. Longitudinal carinae absent. — Wings: Nearly hyaline to strongly infuscate, dark brown. Forewing vein 1 - Rs + M with bulla placed centrally to apically; ramellus absent; crossvein 1 cu-a arising far from 1 M + Rs, basad by 0.2–0.4 of its own length; vein 2 Cua 1.05–1.80 × as long as crossvein 2 cu-a; crossvein 2 m-cu uniformly arched, bulla moderately short, placed medially to anteriorly; cell 1 + 2 Rs large, APH 0.25–0.55, about as long as wide or slightly longer, AWH 0.80–1.20, pentagonal; crossveins 2 r-m and 3 r-m subparallel, to distinctly convergent, both veins usually about the same length. Hind wing vein 1 - M + Cu apically almost straight to slightly convex; vein Cua slightly to much longer than crossvein cu-a, HW 1 C 1.74–3.0; vein Cub distinct, its apical 0.5 almost straight to distinctly convex; vein 2-1 A reaching at least 0.9 of distance to wing margin. — Metasoma: T 1 moderately long, about 0.51–0.58 × as long as mesosoma (from base of T 1 to apex of mesoscutum, measured laterally), slender, T 1 LW 2.15–3.55, apex distinctly wider than base, T 1 WW 1.70–2.85, approximately cylindrical, without sharp anterolateral tooth, but sometimes with weak anterolateral flange; spiracle of T 1 placed distinctly posteriorly to midlength, not distinctly prominent; median dorsal and dorsolateral carina absent or vestigial; ventrolateral carina usually distinct. Setae on T 2–8 always associated with small punctures. T 2 slender, T 2 LW 0.95–1.6, T 2 WW 1.75–2.7; thyridium subcircular or longer than wide. T 7–8 about as long as T 5–6. Ovipositor very long, OST 2.8–5.4, slender, distinctly upcurved (often contorted), scarcely punctate, basally cylindric, apically distinctly depressed; apex of ovipositor blunt, without nodus or notch; dorsal valve with 4–9 small teeth; ventral valve apically dilated and overlapping dorsal valve as a sheath, with 7–11 distinct teeth. — MALE. Known only for S. domator , S. lissonota , S. insidiator , S. tripartita , S. victoriae and S vannoorti sp. nov. Generally similar to the respective females, but not as readily recognizable as members of the genus due to the lack of the most conspicuous diagnostic trait, the long ovipositor. Morphological secondary sexual differences are usually more or less uniform within Cryptini , as noted by Santos and Aguiar (2013), and apply to the males of Stenarella as follows. General body size usually smaller than respective females. Head with extensive whitish marks on mandible, clypeus, supra – clypeal area and scape, even when the female is almost entirely black. Flagellomeres usually shorter and wider than in females; white band on flagellum starting more apically than in females of the same species. Propodeal furrow usually slightly longer than in female. Propodeum smaller, less strongly convex. Spiracle of propodeum from short and elliptic to distinctly elongate, SLW 1.45–6.0. First metasomal segment slenderer, with T 1 LW 2.9–5.3, and less widened apically, with T 1 WW 1.4–2.35. T 2–7 much slenderer than in females.

Comments.

Females of Stenarella are readily distinguishable from all other cryptine taxa by the very long ovipositor, at least 2.8 × as long as the hind tibia, and the characteristic shape of the ovipositor tip, distinctly twisted and with the dorsal valve showing distinct teeth or hooks. Other Old World taxa with very long ovipositors are the Malagasy genus Rambites and some species of Tolonus , but these can be differentiated from Stenarella by the shape of the ovipositor tip and the other characters in the diagnosis.

Males of Stenarella , however, are harder to recognize due to the absence of the ovipositor. By following the remaining characters in the diagnosis, males would be most similar to males of Picardiella , which also have a long mandible with the dorsal tooth much longer than ventral one, and a rather small areolet. Males of Stenarella can be separated from those of Picardiella by having the spiracle placed approximately at posterior 0.42 of its length (versus 0.47) and the areolet smaller ( APH 0.25–0.55, versus 0.8–1.25 in Picardiella ). In addition, many species of Stenarella have the posterior transverse carina of propodeum absent or almost indistinct from propodeal striation, while in Picardiella this carina is always complete and distinct.

Distribution.

Widely distributed in the Old World, Australia, and introduced into North America. The known distribution records are expanded from 47 countries ( Yu et al. 2016 and additions by Wahl & Green 2020 and Pham et al. 2024) to 75 after this study, in all continents except South America and Antarctica.