Tetractenion pseudolutea 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 pseudolutea Reynolds Berry & van Noort sp. nov. Fig. 5

Type material.

Holotype ♀: Angola (A11), Bruco, 26.ii-2.iii.1972, Southern African Exp. B.M. 1972-1 (NHMUK). Paratypes 2♀: Angola (A11), Bruco, 26.ii-2.iii.1972, Southern African Exp. B.M. 1972-1 (NHMUK). ♀: Umbilo, Durban, Natal, 26.10.19, A.L. Bevis, Imp. Inst. Ent. Brit. Mus., 1933-190 (NHMUK). ♂: Cameroon, Ahal, 28.ix.1953. C.I.E. Coll. 15098. Pres. by Com. Inst. Ent. B.M. 1962-1. Exetastes sp. det. J.F. Perkins (NHMUK). ♀: Namibia, near Windhoek, between Mandume Ndemufayo Avenue and Western Bypass, 23.xii.2011 [collector not named], SAM-HYM-P047486 (SAMC).

Differential diagnosis.

While the color pattern of Tetractenion pseudolutea is identical to T. luteum , it is distinguishable from T. luteum by having pectinate tarsal claw on the hind leg. The head is rounded behind the eyes, separating the species from T. acaule and T. pascali . The pronotal collar with no more than a wrinkle present distinguishes the species from T. acaule and T. rosei . Pectinate tarsal claws on the hind leg separates T. pseudolutea from T. acaule and T. luteum . Metasomal tergites II and III are longer than wide distinguishing T. pseudolutea from T. ibayaensis ; and T. acaule , T. luteum , and T. ibayaensis , respectively. Sparse microtrichia on the wings distinguishes the species from T. luteum and T. pascali ; yellowish-brown venation separates the species from T. acaule , T. luteum , T. ibayaensis and T. pascali ; and a yellow pterostigma distinguishes the species from T. acaule and T. ibayaensis .

Description.

The body color is the same as in Tetractenion luteum , except for density of microtrichia on the wings. Tetractenion pseudolutea has sparse microtrichia on the wings with yellow-brown venation, and the pterostigma is yellow.

Head is rounded behind eyes; occiput deeply and angularly excavated, occipital carina strong, extending to lower gena at base of mandible; eyes very large, malar space more than half as long as wide as base of mandible; face and clypeus finely and evenly punctate, background hardly shining; face with three lobes, tentorial pits deep; clypeus small, laterally convex with declivity, apically invaginated, clypeal edge convex; mandibular teeth triangular, lower tooth longer than upper tooth; antennae long, slender and apically tapered.

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

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

Fore wing with ramellus rarely present on Rs-M vein; areolet large, quadrate, with a short stalk receiving 2m-cu at the 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.

CT 2.3; ML 0.6; IO 0.9-1.0; OO 1.7; Fl1 4.6-5.6; OT 0.1; B 9.1-10.7 mm; A 11.3-11.8 mm; F 8.6-9.8 mm.

Etymology.

This species at first glance appears to be identical in coloration to T. luteum but has morphological differences.

Distribution.

Angola, Cameroon, Namibia, and South Africa.

Figures

Figure 5. Tetractenion pseudolutea sp. nov. Holotype A habitus, lateral view B habitus, dorsal view C head, anterior view D wings (inset: data labels).