Tetractenion pascali Reynolds Berry & van Noort, 2020

Berry, Terry Reynolds & Noort, Simon van, 2020, Revision of the endemic Afrotropical genus Tetractenion (Hymenoptera, Ichneumonidae) with an identification key to genera of Banchinae for the region, ZooKeys 1007, pp. 49-84 : 49

Tetractenion pascali Reynolds Berry & van Noort sp. nov. Fig. 4

Type material.

Holotype ♀: Namibia, near Windhoek, between Mandume Ndemufayo Avenue and Western Bypass, 23.xii.2011, SAM-HYM-P047471 (SAMC). Paratypes ♂: South Africa, Eastern Cape, Asante Sana Game Reserve, 32°16.762'S, 24°57.309'E, 1186 m, 23 Feb-7 April 2010, S. van Noort, Malaise Trap, Southern Karoo Riviere, Riverine Woodland, ASA09-WOO1-M06, SAM-HYM-P044553 (SAMC). ♀: Namibia, near Windhoek: a bush between kleine Kuppe and Aus Born Mountains, A. Gumovsky, 23-25.xii.2011 (NHMUK).

Differential diagnosis.

Tetractenion pascali is immediately distinguishable from all other Tetractenion species by having a color combination of a largely yellow body and a dark head. The facial features are more robust compared to the other species, with the three lobes on the face prominent and the mandibles larger, and the spiracle on the second tergite of the metasoma is hardly protruding. In addition, though the posterior transverse carina may be reduced or faint in the other species, it is distinct in T. pascali . The malar space nearly as long as the width of the mandibular base separates T. pascali from T. acaule , T. pseudolutea , and T. ibayaensis . Pectinate hind tarsal claws distinguish T. pascali from T. luteum and T. acaule ; and a weakly wrinkled pronotal collar separates the species from T. acaule and T. rosei . Metasomal tergites II and III are longer than wide separating the species from T. ibayaensis and T. acaule , T. luteum , and T. ibayaensis , respectively. Tetractenion luteum is the only other species besides T. pascali that possess dense microtrichia on the wings.

Description.

Color: head brown, mandibles yellow from base to brown at apex. Antennae brown. Body yellow with red-brown areas on metanotum; tibia III with shades of infuscation, tarsus III infuscate. Wings with dense microtrichia, pterostigma yellow, venation brown.

Head narrowed straight behind eyes; occiput deeply and angularly excavated, occipital carina strong, extending to lower gena at mandibular base; malar space nearly as long as basal mandibular width; eyes very large; face and clypeus features robust, mandibles large; face three-lobed and punctate on a shiny background, punctures on second lobe and clypeus deeper than punctures on lobes flanking eyes, tentorial pits deep; clypeus small, laterally convex with declivity, apically invaginated, clypeal edge convex; mandibular teeth triangular, lower tooth longer than upper tooth; antenna long, slender and apically tapered.

Mesosoma stout and moderately punctate on a shiny background; pronotum with no more than a wrinkle on collar; mesoscutal lobes present on mesoscutum, notauli posteriorly meeting before reaching the scutellum; mesopleuron higher than wide, epicnemial carina present at ending at anterior edge of mesopleuron; shallow pits on mesopleuron and propodeum. Propodeum weakly convex, punctate and posteriorly confluently grading into transverse wrinkles, posterior transverse carina present and distinct, lateral longitudinal carinae present but faint, spiracle small and circular-elliptical.

Metasoma indistinctly punctate on a shiny background; tergite I elongate, twice as long as wide, tapered anteriorly, dorso-ventrally compressed in the medial region, glymma present, spiracle positioned in front of middle and hardly protruding; tergite II longer than wide, gastrocoeli indistinct; tergite III longer than wide; tergites IV-VIII higher than wide.

Fore wing without ramellus on Rs-M vein; areolet large and quadrate with a short stalk receiving 2m-cu at center. Hind wing with Cu1 shorter than cu-a such that Cu2 arises above the middle of these combined veins. Legs very long, hind femur reaching beyond metasomal apex, length of tibia III plus tarsus III as long as body; spurs of tibia III longer than half metatarsal length; tarsal claws pectinate.

Males: similar to females; ramellus present.

CT 2-2.4; ML 0.7-0.9; IO 1.2-1.3; OO 1.6-2.1; Fl1 4.5-4.8; OT 0.2; B 7.7-11.5 mm; A 11-14 mm; F 9.2-10 mm.

Etymology.

Named after our colleague, Pascal Rousse, who first noted this to be a new species.

Distribution.

Namibia and South Africa.

Comments.

In males, the ramellus on the fore wing is present, distinguishing the species from T. acaule and T. luteum . The wings of T. rosei are inter-locked; this character could not be compared.

Figures

Figure 4. Tetractenion pascali sp. nov. Holotype A habitus, lateral view B habitus, dorsal view (inset: data labels) C head, anterior view D wings.