Spilothyrateles arabicus, Riedel, 2022

Riedel, Matthias, 2022, Contribution to the knowledge of the Ichneumoninae (Hymenoptera, Ichneumonidae) of Yemen, Linzer biologische Beiträge 54 (1), pp. 275-286 : 282-284

Spilothyrateles arabicus nov.sp. ( figs 1 , 9 , 10, 11)

M a t e r i a l e x a m i n e d: Holotype:(♀) Yemen (5554) ArRujum , 15.I.-9.IV.2001, Mal. trap, leg. A. v. Harten, RMNH ´02 [Leiden] . Paratypes: (1♀ 3♁♁) Yemen (5554) Ar Rujum , 15.I.- 9.IV.2001, Mal. trap, leg. A. v. Harten, RMNH ´02 [Leiden and coll. RIEDEL]; (1♀ 1♁) Yemen (5700) Ar Rujum , 9.IV.-5. VI.2001, Mal. trap, leg. A. v. Harten, RMNH ´02 [ RMNH]; (1♀) Yemen (7551) Sana´a, I.- V.2003, Mal. trap, A. v. Harten, RMNH´03 [Leiden] .

D e s c r i p t i o n: ♀. Body length 9-10 mm. Flagellum slender, with 36-38 flagellomeres; 1 st flagellomere 2.0-2.2× and 2 nd flagellomere 1.7-2.0× longer than wide, combined length 0.45-0.52× length of compound eye; flagellomeres behind middle slightly attenuated, widest flagellomeres almost square. Temple strongly narrowed behind eye. Ocelli large, distance between lateral ocellus and compound eye 0.8× ocellar diameter. Frons coarsely rugose-punctate. Face punctate, partly rugose. Clypeus moderately convex, with scattered punctures, strongly shining. Malar space 1.0× as long as width of mandibular base. Genal carina reaching hypostomal carina far from mandibular base. Mesosoma covered with short whitish setae. Notaulus indistinctly impressed at frontal margin of mesoscutum. Mesoscutum with coarse punctures, shining. Mesopleuron and metapleuron coarsely punctate, partly with longitudinal rugosity. Scutellum flat, about as long as wide, without lateral carina. Propodeum rounded in profile, but with differentiated horizontal and vertical areas. Area superomedia hexagonal, as wide as or slightly wider than long; anterior transverse carina (costula) frontal to its middle. Area petiolaris with longitudinal carina. Mid and hind coxae with scattered punctures in apical halves, strongly shining. Hind coxa without scopa. Hind femura 3.8× longer than wide, almost smooth and without punctures in ventral half. Areolet pentagonal, frontal distance between veins 2rsm and 3rs-m 3-4× their width; vein 2m-cu reaching areolet distad to its middle. Vein 1cu-a postfurcal by 0.3-0.4× its length. Nervellus of hind wing reclivous, intercepted in its apical 0.8.

Metasoma semi-amblypygous ( fig. 1 ). Lateral field of postpetiolus punctate, wider than median field, the latter finely aciculate. Gastrocoelus triangularly impressed, with longitudinal ridges. Thyridium slightly impressed, 0.8× as wide as the interval between thyridia. 2 nd and 3 rd tergites coarsely and densely punctate, polished between punctures. 2 nd tergite longitudinally rugose-striate centrally and 3 rd tergite only basally. 4 th tergite with very scattered punctures, 5 th tergite almost impunctate. Ovipositor sheath not reaching behind metasomal apex.

Color: black. Stripes or rings on flagellomeres 8/9-13/14, frontal orbit, usually facial orbit, collar and hind edge or upper border of pronotum, usually spots on tegula and subtegular ridge, scutellum ±, and usually fore and mid coxae frontally yellow. Metasoma red, 5 th or 6 th to 7 th tergites ± darkened or black; 6 th and 7 th tergites with large ivory median spots (rarely 5 th tergite with very small ivory spot medially). Coxae and trochanters black; legs otherwise reddish; hind tarsus ± black. Pterostigma brownish, paler at base.

♁. Body length 10-11 mm. Flagellum with 36-38 flagellomeres; 1 st flagellomere 3.2× and 2 nd flagellomere 2.0× longer than wide, combined length 0.55× eye lengt. Linear tyloids on flagellomeres 8-16/18, extending over entire length of flagellomeres. Malar space 0.5× as long as width of mandibular base. Area superomedia hexagonal, slightly longer than wide. Hind femur 3.9-4.0× longer than wide. Lateral field of postpetiolus about as wide as median field. 2 nd to 6 th tergites with coarse, rather dense punctures, strongly shining between punctures. 2 nd and 3 rd tergites with longitudinal rugose-striation medially. Hypopygium triangular, hind margin pointed medially. Structure otherwise as in ♀.

Color: black. Distal flagellomeres pale brownish ventrally. Mandible except teeth, palps, clypeus and face except median longitudinal black stripe, scape ventrally, frontal orbit, collar and upper border of pronotum, tegula and subtegular ridge, two paramedian spots on mesoscutum, entire scutellum, fore and mid coxae and trochanters frontally, and sometimes dorsal spot on hind coxa yellowish. Metasoma red, 6 th tergite apically and 7 th tergite mainly blackish; 5 th tergite with narrow ivory stripe apically; 6 th tergite with a large triangular ivory mark and 7 th tergite largely ivory. Coxae and trochanters black; legs otherwise reddish, hind femur in apical 0.1 and hind tibia at apical 0.3 infuscate; hind tarsus ± black. Pterostigma brownish, paler at base.

R e m a r k: This species is closely related to Spilothyrateles tibialis (CAMERON, 1906) from South Africa and differs slightly by the color pattern, especially in the ♁ (e.g. yellow mesoscutal spots and ivory spot on 6 th tergite absent in Spilothyrateles tibialis ). Probably, the new species is an Arabian subspecies of S. tibialis , but more material from the Afrotropical area is necessary to clarify the relationship of these species.

Figures

Fig. 1: Habitus of Spilothyrateles arabicus nov.sp. ♀ from lateral. Fig. 2: Habitus of Stenaoplus harteni nov.sp. ♀ from lateral.

Figs 8-9: Face of: (8) Stenaoplus harteni nov.sp. ♀ and (9) Spilothyrateles arabicus nov.sp. ♀. Figs 10-11: Spilothyrateles arabicus nov.sp.: (10) basal tergites of ♁, (11) propodeum of ♀.