Syzeuctus flavocephalus Zardouei & Riedel, 2022

Heydari, Maryam Zardouei, Riedel, Matthias & Rakhshani, Ehsan, 2022, Review of Syzeuctus Förster, 1869 (Hymenoptera: Ichneumonidae: Banchinae) in Iran, with description of a new species, Zootaxa 5100 (2), pp. 259-268 : 261-263

Syzeuctus flavocephalus Zardouei & Riedel sp. nov.

Holotype ♀ ( DPPZ), IRAN, Sistan-o Baluchestan province , Kousheh (31°02’12.81”N, 61°32’13.66”E, 485 m), Malaise trap mounted, 24–30.VI.2015, M. Ghafouri Moghaddam leg.

Distribution: Iran, Sistan-o Baluchestan province.

Description—(Female): Body length 16.0 mm, length of fore wing 9.5 mm, length of ovipositor sheath 12.8 mm.

Head. Antenna with 39 flagellomeres. First flagellomere 4.8× longer than wide and 1.8× longer than second flagellomere and 0.55× as long as eye. Preapical flagellomere as long as wide. Face not elongate, width between eyes across clypeal sulcus 2.4× its height from antennal socket to the apex of clypeal margin medially. Face ( Fig. 1A ) mainly punctate medially, distance between punctures usually as long as their diameter. Clypeus width 2.2× its height, weakly separated from face by the impression of transverse groove, curved apically, rather sparsely punctate, with very long sparse setae apically. Inner orbits slightly divergent below. Malar space 0.8× as long as basal width of mandible. Upper tooth of mandible longer than the lower tooth. Occipital carina complete dorsomedially ( Fig. 1B ), its lower part reaching the base of mandible. Ocelli small, OOL 1.68× and POL 1.92× OD. Frons weakly swollen laterally, weakly concave medially. Temple constricted behind eyes, 0.5× as wide as the eye in lateral view, and distinctly narrowed apically ( Fig. 1C ).

Mesosoma . Pronotum punctate ( Fig. 1D ), with a large smooth and impunctate area in the lower part. Frontoventral edge of pronotum strongly curved. Epomia distinct. Epicnemial carina not reaching mid-height of the hind edge of pronotum, and at the level of sternaulus (with a distinct notch at the lower anterior corner of mesopleuron). Mesopleuron smooth medially. Sternaulus indistinct. Speculum sparsely punctate. Mesosternum densely punctate. Metapleuron punctate ( Fig. 1D ). Notaulus absent. Mesoscutum medially smooth and shining, sparsely punctate anteriorly. Scutellum smooth ( Fig. 1E ). Propodeum punctate, posterior transverse carina complete ( Fig. 1F ). Hind femur 6.3× longer than wide.

Wing. Fore wing with dark spot apically, with a long-stalked areolet ( Fig. 1G ). Second discal cell shorter than the first subdiscal cell. Vein 1cu-a interstitial. Hind wing without vein 2/CU ( Fig. 1H ).

Metasoma. First metasomal tergite weakly widened to its apex, smooth medially and punctate laterally. Length of first metasomal tergite 1.2× of its width and 1.2× the second metasomal tergite. Latero-median carinae of first tergite absent. Sclerotized part of the first sternite not extending the middle of the tergite. Second and third metasomal tergites subquadrate, their length 0.9× and 0.8× of their width, respectively; both segments densely punctured laterally and with scattered punctures in median parts ( Fig. 1I ). Ovipositor sheath narrow. Ovipositor 3.0× as long as the hind tibia, with a distinct subapical notch ( Fig. 2 ).

Colour. General body color pale yellow, head shiny yellowish. Hind legs reddish ventrally. Ovipositor reddishbrown. Metasomal tergites red with pale yellow apical bands. Flagellum, stemmaticum, apical of mandibular teeth, lateral lobes of mesoscutum apically, two small spots on propodeum and ovipositor sheaths black.

Diagnosis. According to the key and descriptions of Riedel (2021), S. flavocephalus Zardouei & Riedel sp. nov. is morphologically closely related to S. brunneomaculatus Riedel 2021 , as they share a complete posterior transverse carina of propodeum ( Fig. 1F ) and fore wing ( Fig. 1G ) with apical brown spot. It can be readily distinguished by the following characters: The ratio of POL/OD in S. flavocephalus Zardouei & Riedel sp. nov. ( Fig. 1B ) is 1.92, while it is 1.5 in S. brunneomaculatus . Temple in lateral view strongly narrowed apically in S. flavocephalus Zardouei & Riedel sp. nov. ( Fig. 1C ), while it is slightly narrowed apically in S. brunneomaculatus . Speculum sparsely punctate in S. flavocephalus Zardouei & Riedel sp. nov. ( Fig. 1D ), and densely punctate in S. brunneomaculatus . Epicnemial carina at the level of sternaulus is broken (with a distinct notch at the lower anterior corner of mesopleuron) in S. flavocephalus Zardouei & Riedel sp. nov. ( Fig. 1D ), while it is not broken (without a distinct notch at the lower anterior corner of mesopleuron) in S. brunneomaculatus . Fore wing vein 1cu-a interstitial in S. flavocephalus Zardouei & Riedel sp. nov. ( Fig. 1G ), but it is postfurcal by 1.0× its width in S. brunneomaculatus ; First metasomal tergite 1.2× its width in S. flavocephalus Zardouei & Riedel sp. nov. ( Fig. 1I ), while it is 1.6× in S. brunneomaculatus . Hind femur 6.3× longer than wide in S. flavocephalus Zardouei & Riedel sp. nov. ( Fig. 2 ), while it is 5.3× longer than wide in S. brunneomaculatus .

Etymology. The species name is derived from the characteristic yellowish coloration of the head (cephalus) of specimen referring to Latin word flavus meaning blonde. Other main parts of the body including mesosoma and posterior margin of the metasomal tergites are generally pale yellow to ivory.

Figures

FIGURE 1. External morphological characters of Syzeuctus flavocephalus Zardouei & Riedel sp. nov. – Female: A. Head, frontal view; B. Head, dorsal view; C. Head, lateral view; D. Mesosoma, lateral view, arrow indicating mesopleuroal notch; E. Mesoscotum, dorsal view; F. Propodeum, dorsal view; G. Forewing; H. Hindwing; I. Metasoma, dorsal view.

FIGURE 2. Syzeuctus flavocephalus Zardouei & Riedel sp. nov. Female, general habitus.