Research Article |
Corresponding author: Simon van Noort ( svannoort@iziko.org.za ) Academic editor: Bernardo Santos
© 2020 Terry Reynolds Berry, Simon van Noort.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Berry TR, van Noort S (2020) Revision of the endemic Afrotropical genus Tetractenion (Hymenoptera, Ichneumonidae) with an identification key to genera of Banchinae for the region. ZooKeys 1007: 49-84. https://doi.org/10.3897/zookeys.1007.55543
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The Afrotropical banchine fauna comprises 12 genera: Apophua Morley, Atropha Kriechbaumer, Cryptopimpla Taschenberg, Exetastes Gravenhorst, Glyptopimpla Morley, Himertosoma Schmiedeknecht, Lissonota Gravenhorst, Sjostedtiella Szépligeti, Spilopimpla Cameron, Syzeuctus Förster, Tetractenion Seyrig, and Tossinola Viktorov. A well-illustrated revised key to the genera using high definition images is provided, and the endemic Afrotropical genus Tetractenion is revised, previously represented by two described species. Four new species are described: T. ibayaensis sp. nov., T. pascali sp. nov., T. pseudolutea sp. nov., and T. rosei sp. nov. The first species-level identification key is provided for this rare genus. Based on morphological attributes the hypothesis is presented that the species in this genus are probably nocturnal. All images and online interactive Lucid keys are available at: www.waspweb.org and the associated underlying data is made available as Suppl. materials
Atrophini, Banchini, Glyptini, Ichneumonoidea, Lucid identification keys, taxonomy
Banchinae is a cosmopolitan group of moderately small to large-sized parasitoid wasps (
Most Banchinae can be readily diagnosed by the following characters: 1) a submetapleural carina anteriorly generally expanded into a lobe; 2) an arched posterior transverse carina of the propodeum; and 3) a dorsal apical notch on the ovipositor (
Morphologically, Banchinae can be subdivided into three tribes namely Banchini, Glyptini, and Atrophini (
Within the Afrotropical region, the subfamily comprises 12 genera and 187 described species: Apophua Morley, Atropha Kriechbaumer, Cryptopimpla Taschenberg, Exetastes Gravenhorst, Glyptopimpla Morley, Himertosoma Schmiedeknecht, Lissonota Gravenhorst, Sjostedtiella Szépligeti, Syzeuctus Förster, Spilopimpla Cameron, Tetractenion Seyrig, and Tossinola Viktorov. A dichotomous identification key to banchine genera within the Afrotropical region was last produced by
Tetractenion, placed in the tribe Banchini, is a very rare genus restricted to the Afrotropical region (
Specimens were either pinned or point mounted on black, acid-free cards for examination (using a Leica M205C stereomicroscope with LED light source), photography, and long-term preservation. Images were taken using the Leica LAS 4.4 system which comprised a Leica Z16 microscope with a Leica DFC450 Camera with a 0.63× video objective attached. The imaging process, using an automated Z-stepper, was managed using the Leica Application Suite V 4.4 software installed on a desktop computer. Diffused lighting was achieved using a Leica Dome. Images of the types held in Musée Royal de l’Afrique Centrale, Tervuren (
Codens follow
The morphological terminology follows
A antenna length, from base of scape to flagellar apex (mm);
B body length, from toruli to metasomal apex (mm);
CT (clypeus transversality index): maximum width of clypeus: median height;
F fore wing length, from tegula to wing apex (mm);
Fln (length index of flagellomere n): length: width of flagellomere n;
IO (inter-ocellar index): shortest distance between posterior ocelli: ocellus diameter;
ML (malar space length index): malar space (shortest distance between mandible base and compound eye): basal mandibular width;
OO (oculo-ocellar index): shortest distance between eye and posterior ocellus: ocellus diameter;
OT (ovipositor sheath-tibia index): length of ovipositor sheath: length of hind tibia.
The first three measurements (absolute measures) were measured on all specimens in the type series, with measurements from the primary type reported separately in brackets if necessary.
Identification keys were produced in two formats to facilitate accessibility by a range of end-users and to meet the requirements of publishing both static and dynamic interactive keys under an open access model (
Tetractenion Seyrig, 1932, Mém. Acad. Malgache 11: 167. Type: Tetractenion acaule Seyrig. Monobasic.
(updated from
Unknown.
Angola, Cameroon, Democratic Republic of Congo, Kenya, Madagascar, Namibia, Nigeria, South Africa.
T. acaule Seyrig, 1932
T. ibayaensis sp. nov.
T. luteum Seyrig, 1932
T. pascali sp. nov.
T. pseudolutea sp. nov.
T. rosei sp. nov.
Lectotype
♀: Madagascar, Rogez, Forêt Cote Est, Muséum Paris, 1.31. A. Seyrig, EY9333, [White label with TYPE written in red] [Red type label]: Lectotype ♀ Tectractenion acuale, Seyrig, 1932, designated by
Tetractenion acaule is immediately distinguishable from all other Tetractenion species by its unique color combination of a red mesosoma and a mostly black metasoma; distinct keels are present on outer mesoscutal lobes, the notauli do not reach the scutellum; metasomal tergite I has a distinct medial compression in the dorso-ventral view, tergite II have distinct gastrocoeli, and tergites IV–VIII are dorso-posteriorly weakly sclerotized, appearing as large membranous white areas on the dorsal surface. Tetractenion acaule closely resembles T. ibayaensis as both species are similar in color, having largely fulvous bodies with a white face and the hind femur infuscate, whereas the remaining Tetractenion species are largely yellow in color with yellow hind femora. Tetractenion acaule can easily be distinguished from T. ibayaensis by having a white gena and weakly sclerotized metasomal tergites IV–VIII; the head is narrow, straight behind the eyes; a distinct carina is present on the pronotal collar; distinct keels are present on the outer mesoscutal lobes, with the notauli not reaching the scutellum; pits on the mesopleuron and propodeum are shallow; metasomal tergite I is distinctly dorso-medially compressed; gastrocoeli on tergite II are distinct; tergites IV–VIII are postero-dorsally weakly sclerotized and white; and tarsal claws on the hind leg are simple. In T. ibayaensis the gena is brown and tergites IV–VIII are strongly sclerotized; the head is rounded behind the eyes; with no more than a wrinkle present on the pronotal collar; the mesoscutal lobes are hardly present, the notauli reach the scutellum; pits on the mesopleuron and propodeum are deep; metasomal tergite I is stout and indistinctly dorso-ventrally compressed in the medial region; gastrocoeli on tergite II are indistinct; and tarsal claws on the hind legs are pectinate.
(updated from
Head narrow, straight behind eyes; occiput deeply and angularly excavated, occipital carina strong, extending to lower gena at base of mandible; eyes very large; malar space almost half as long as mandibular basal width; face and clypeus finely, evenly and rather sparsely punctate on a shiny background; face with three lobes, tentorial pits deep; clypeus small, laterally convex with declivity, apically invaginated, with clypeal edge convex; mandibular teeth triangular, lower tooth longer than upper tooth; antenna long, slender and apically tapered.
Mesosoma stout; mesonotum deeply punctate, inter-punctuate spaces about as wide as punctures, rather matt, but not coriaceous; keels distinctly raised on outer mesoscutal lobes of mesoscutum, notauli abbreviated, not reaching the scutellum; apex of scutellum rounded; pronotum shining with a distinct thickened carina on collar, sparsely and very finely punctate; mesopleuron higher than wide, sparsely but more deeply punctate, speculum similarly punctate, background hardly shining, epicnemial carina ending at anterior edge of mesopleuron; shallow pits on mesopleuron and propodeum; metapleuron matt and deeply punctate; propodeum weakly convex, roughly punctate dorsally, punctate posteriorly confluently grading into transverse wrinkles, posterior transverse carina reduced, lateral longitudinal carinae present but faint, spiracle roundish-elliptic and small.
Metasoma hardly punctate at base of tergite II, indistinctly punctate beyond base; tergite I elongate, more than twice as long as wide, tapered anteriorly, glymma present, spiracle positioned slightly in front of middle and protruding, especially dorsally, with a distinct medial depression dorso-ventrally; tergite II longer than wide or subquadrate with gastrocoeli distinct; tergite III quadrate to transverse; metasomal tergites IV–VIII moderately laterally compressed; ovipositor sheath concealed or hardly protruding.
Fore wing without ramellus on Rs-M vein; Rs hardly sinuate; 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 on hind leg simple.
Male hardly different: temples a bit less narrowed behind eyes, metasomal tergite II entirely black.
Madagascar.
Tetractenion acaule Lectotype (
Holotype
♀: Tanzania, Mkomazi Game Reserve, Ibaya Camp, north west side, 3°57.91'S, 37°48.09'E, 22–24 April 1996, S. van Noort, Acacia/Commiphora/Combretum bushland, Yellow P. Trap, SAM-HYM-P019172 (
Tetractenion ibayaensis is immediately distinguishable from other Tetractenion species by having a largely fulvous body and a white face, with the occiput, gena and metasomal tergites IV–VIII dark brown to black, and the hind tibia and tarsus infuscate. The clypeal and mandibular setae are long. The metasoma is hardly laterally compressed with metasomal tergite I stout, being about as long as wide. Pits on the mesopleuron and propodeum are visibly large and deep. In addition, the clypeus is hardly apically invaginated and the propodeal spiracle is distinctly circular and not circular-elliptical as in the other species.
The head is rounded behind the eyes distinguishing the species from T. acaule and T. pascali. The pronotal collar is no more than a wrinkle, separating the species from T. acaule and T. rosei. Pectinate tarsal claws on the hind legs separates the species from T. acaule and T. luteum. Metasomal tergites II and III are quadrate separating the species from all other Tetractenion species except T. acaule where tergites II and III are sometimes subquadrate and quadrate, respectively; and T. luteum where tergite III is quadrate. Sparse microtrichia on the wings distinguishes T. ibayaensis from T. luteum and T. pascali, and the pterostigma is brown separating the species from T. luteum, T. pascali, T. rosei, and T. pseudolutea.
Body mostly fulvous; tibia and tarsus III brown; metasomal tergites IV–VIII brown to nearly black; head with face and area around eyes white; frons and occiput dark brown to near black; mandibles yellow with base and tips brown. Sparse microtrichia on wings, venation and pterostigma brown.
Head rounded behind eyes; occiput deeply and angularly excavated, occipital carina strong, extending to lower gena at mandibular base; malar space half as long as mandibular basal width; eyes very large; face and clypeus finely and evenly punctate on a shiny background; 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; clypeal and mandibular setae long; antenna long, slender and apically tapered.
Mesosoma stout and deeply punctate on a shiny background; mesopleuron higher than wide, epicnemial carina ending at anterior edge of mesopleuron; deep pits on the mesopleuron and propodeum; pronotum moderately punctate on a shiny background with no more than a wrinkle on collar; mesososcutal lobes hardly present on mesoscutum, notauli posteriorly meeting before reaching the scutellum; propodeum weakly convex, posteriorly confluently grading into weak transverse wrinkles, posterior transverse carina indistinct, lateral longitudinal carinae reduced, spiracle small and circular.
Metasoma with tergite I stout, tapered anteriorly, not distinctly dorso-ventrally compressed in medial region, glymma present, spiracle positioned in front of middle and protruding, especially dorsally, hardly punctate dorso-laterally, metasoma indistinctly punctate beyond and shining; gastrocoeli on tergite II indistinct; tergites II and III quadrate, tergites IV–VIII only slightly 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.
CT 2.1; ML 0.5; IO 1.6; OO 1.6; Fl1 4.3; OT 0.2; B 8.1 mm; A 8.1 mm; F 6.4 mm.
Named after the type locality. Noun in apposition.
Holotype
♂: Nyeri, Kenya, June 1932 (
Tetractenion luteum is immediately distinguishable from the other species in the genus as this species is the only yellow-colored Tetractenion species to possess simple hind tarsal claws, and this character is consistent in both sexes. The head is rounded behind the eyes, distinguishing the species from T. acaule and T. pascali. The malar space nearly as long as the width of the base of the mandible separates T. luteum from T. acaule, T. pseudolutea, and T. ibayaensis. The pronotal collar is weakly wrinkled, separating the species from T. acaule and T. rosei. Metasomal tergite II is longer than wide and distinguishes the species from T. ibayaensis; and a quadrate tergite III separates T. luteum from T. pseudolutea, T. pascali, and T. rosei. Furthermore, T. pascali is the only other species that possess dense microtrichia on the wings.
(updated from
Head with temple short, rounded behind eyes; occiput deeply and angularly excavated, occipital carina strong, extending to lower gena at base of mandible; eyes very large, malar space a bit shorter than width of mandibular base; face and clypeus finely, evenly and rather sparsely punctate on a matt background; face with three lobes, tentorial pits deep; clypeus small, laterally convex with declivity, apically invaginated, with clypeus edge convex; mandibular teeth triangular, lower tooth longer than upper tooth; antenna about as long as body, slender and apically tapered.
Mesosoma stout, matt to sub-polished; pronotum finely punctate on a sub-polished background, no more than a wrinkle present on pronotal collar; mesoscutum moderately punctate, mesoscutal lobes hardly present, notauli posteriorly meeting before reaching the scutellum; mesonotum and mesopleuron finely punctate; mesopleuron higher than wide, epicnemial carina ending at anterior edge of mesopleuron; shallow pits on mesopleuron and propodeum; propodeum weakly convex, matt to sub-polished, moderately punctate posteriorly confluently grading into transverse wrinkles, posterior transverse carina reduced, lateral longitudinal carinae present but faint, spiracle small and circular-elliptical.
Metasoma with a sub-polished background, anterior half of tergite I and dorso-lateral region of tergite II hardly punctate, indistinctly punctate beyond base; tergite I twice as long as wide, glymma present, tapered anteriorly, weak to indistinctly dorso-ventrally depressed in the medial region, spiracle positioned in front of middle and protruding, especially dorsally; tergite II longer than wide, gastrocoeli indistinct; tergite III quadrate.
Fore wing with ramellus absent 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; fore and mid tarsal claws pectinate, hind tarsal claws simple.
Democratic Republic of Congo, Kenya, Namibia, Nigeria, and South Africa.
Tetractenion luteum Holotype (
Holotype
♀: Namibia, near Windhoek, between Mandume Ndemufayo Avenue and Western Bypass, 23.xii.2011, SAM-HYM-P047471 (
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.
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.
Named after our colleague, Pascal Rousse, who first noted this to be a new species.
Namibia and South Africa.
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.
Holotype
♀: Angola (A11), Bruco, 26.ii–2.iii.1972, Southern African Exp. B.M. 1972-1 (
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.
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.
This species at first glance appears to be identical in coloration to T. luteum but has morphological differences.
Holotype
♂: Cameroon, Yaoundé, 1953, C.I.E. Coll. 15098. Pres. by Com. Inst. Ent., B. M. 1962-1. Exetastes sp. ♀ det. J. F. Perkins (
Tetractenion rosei is immediately distinguishable from other Tetractenion species by the reddish color of the head and pronotum in combination with a yellow body, completely yellow legs with venation on the wings also yellow. The head is not narrowed straight behind the eyes but rather rounded, distinguishing the species from T. acaule and T. pascali. The malar space nearly as long as the basal mandible width separates T. rosei from T. acaule, T. pseudolutea, and T. ibayaensis. Tetractenion acaule is the only other species besides T. rosei possessing a thickened and well-defined carina on the pronotal collar.
Pectinate hind tarsal claws separate the species from T. acaule and T. luteum. Sparse microtrichia on the wings distinguishes the species from T. luteum and T. pascali, and the pterostigma is yellow distinguishing the species from T. acaule and T. ibayaensis. Metasomal tergites II and III are longer than wide separating T. rosei from T. ibayaensis; and T. acaule, T. luteum, and T. ibayaensis, respectively.
Color : head and pronotum reddish, black area restricted to region of ocelli. Body, legs, antennae yellow. Wings with sparse microtrichia, venation yellow, pterostigma yellow.
Head rounded 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 moderately and evenly punctate on a shiny background; 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; antenna long, slender and apically tapered.
Mesosoma stout with a shiny background; mesopleuron moderately punctate, epicnemial carina ending at anterior edge of mesopleuron; pits on the mesopleuron and propodeum shallow; mesonotum moderately punctate; pronotum sparsely and finely punctate on a shiny background with a well-defined carina on collar; mesoscutum deeply punctate, mesoscutal lobes hardly present, notauli posteriorly meeting before reaching the scutellum; propodeum weakly convex, deeply punctate posteriorly confluently grading into transverse wrinkles, posterior transverse carina indistinct, lateral longitudinal carinae present, spiracle small and round.
Metasoma indistinctly punctate on a shiny background; tergite I more than twice as long as wide, tapered anteriorly, slight dorso-ventral depression in medial region, glymma present, spiracle in front of middle and protruding; tergites II and III longer than wide; gastrocoeli on tergite II indistinct; tergites IV–VIII higher than wide.
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 1.6; ML 0.9; IO 1.4; OO 2.2; Fl1 3.5; B 9.3 mm; F 8.6 mm.
Named because of the reddish color of the head and pronotal collar. Noun in apposition.
Cameroon.
This is a rare species known only from one female specimen. Sampling in other areas of the Afrotropical region has so far not produced any further specimens. The wings are inter-locked in such a way that a useful diagnostic character of the wings cannot be seen, i.e., whether the ramellus is present or not.
Since publication of the first key to genera of Banchinae in the Afrotropical region (
The general habitus and coloration of Tetractenion species suggest that this is possibly a nocturnal genus. A list of characters associated with being nocturnal or crepuscular includes a general brown-yellow color; long antennae; large eyes and large ocelli (
Although there have been recent comprehensive long-term inventory surveys conducted across many parts of Africa with many rich, recently collected bulk samples that still need to be sorted, in reality, comprehensive sampling of Ichneumonidae in the region has been relatively limited to specific areas (
Most of the species have the pro-, meso-, and meta-tarsal claws pectinate to the apex. Tetractenion luteum and T. acaule (a Madagascan endemic) are the only two species that possess simple tarsal claws on the hind leg. While the overall color patterns of T. pseudolutea are identical to T. luteum, it is readily distinguishable from T. luteum by having a pectinate tarsal claw on the hind leg. With most Tetractenion species having pectinate tarsal claws on the hind leg, it is plausible that this character state is the plesiomorphic condition. Based on the assumption that it is more parsimonious for evolutionary trajectories to proceed via the reduction of morphological characters, rather than evolution of more complex character states, T. luteum and T. acaule are most probably the more derived species within the genus, but this hypothesis requires corroboration with the addition of genetic evidence, and a thorough phylogenetic analyses based on both morphological and molecular characters.
The current revision has increased the species richness of the genus threefold. Further comprehensive sampling will undoubtedly uncover additional Tetractenion species in the Afrotropical region.
TRB received financial assistance provided by the South African National Research Foundation (NRF) through the Professional Development Program (PDP) and funding from the City of Cape Town. SvN was funded by South African NRF (National Research Foundation) grants: GUN 2068865; GUN 61497; GUN 79004; GUN 79211; GUN 81139; GUN 98115. Part of the South African field work conducted by SvN was funded by the National Science Foundation under PlatyPBI grant no. DEB-0614764 to N.F. Johnson and A.D. Austin. Cape Nature; the Eastern Cape Department of Environmental Affairs and the Northern Cape Department of Nature and Environmental Conservation provided collecting permits for South Africa. This study also benefited from generous contributions of banchine material from the following sources:
Lucid Interchange Format version 3 (LIF3) for the key to the genera of Afrotropical Banchinae (Hymenoptera, Ichneumonidae)
Data type: Lucid Interchange Format version 3
Explanation note: The LIF3 file is an XML-based file that stores all the Lucid4 key data, allowing exchange of the key with other key developers.
Lucid Interchange Format version 3 (LIF3) and Lucid SDD files for the key to Tetractenion species (Hymenoptera, Ichneumonidae, Banchinae)
Data type: Lucid Interchange Format version 3 (LIF3) and Lucid SDD files
Explanation note: The LIF3 file is an XML-based file that stores all the Lucid4 key data, allowing exchange of the key with other key developers.