Revision of the endemic Afrotropical genus Tetractenion (Hymenoptera, Ichneumonidae) with an identification key to genera of Banchinae for the region

Terry Reynolds Berry; Simon van Noort

doi:10.3897/zookeys.1007.55543

Abstract

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 1, 2 LIF3 files to this paper for inter-exchange with other key production software.

Keywords

Atrophini, Banchini, Glyptini, Ichneumonoidea, Lucid identification keys, taxonomy

Introduction

Banchinae is a cosmopolitan group of moderately small to large-sized parasitoid wasps (Gauld et al. 2002). The group is usually well represented in all faunas and amongst the most commonly collected of all ichneumonids (Gauld et al. 2002; Broad et al. 2011). There are roughly 1800 described species and 66 genera of Banchinae currently recognized (Khalaim and Ruíz-Cancino 2012; Watanabe and Maeto 2012, 2014; Broad 2014; Choi et al. 2015; Reynolds Berry and van Noort 2016; Herrera-Florez 2017; Vas 2017; Watanabe 2017, 2018, 2020; Kasparyan and Kulitzky 2018; Li et al. 2018; Sheng et al. 2018; Watanabe and Sheng 2018; Kang et al. 2019, 2020; Yu et al. 2020). With the banchine fauna poorly known for many areas of the world, and a number of undescribed genera and species from tropical regions preserved in museum collections, the number of species is certainly far greater (Broad et al. 2011).

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 (Wahl and Sharkey 1993; Broad et al. 2011). “However, some or all of these characters do not apply to aberrant genera and species” (Broad et al. 2011) and therefore these morphological characters cannot be classified as synapomorphies for the Banchinae. An additional two apomorphies were later proposed (Gauld and Wahl 2000; Broad et al. 2011): firstly, the subapical flagellomeres of female antennae possess elongate placoid sensilla only on the dorsal surface, with smaller, rounded sensilla on the ventral surface; and secondly, the posterior corner of the pronotum is rounded, slightly twisted and flattened. While within the Ophioniformes group (Ophioninae, Ctenopelmatinae, Banchinae, Mesochorinae, Nesomesochorinae, Metopiinae, Campopleginae, Tatogastrinae, Cremastinae, Tersilochinae, Anomaloninae, Neorhacodinae, Oxytorinae, Stilbopinae, Sisyrostolinae, and Lycorinae; Gauld 1985; Wahl 1991, 1993; Quicke et al. 2009) these two characters are phylogenetically informative, it has been established that they are not synapomorphic for the subfamily Banchinae (Broad et al. 2011).

Morphologically, Banchinae can be subdivided into three tribes namely Banchini, Glyptini, and Atrophini (Townes and Townes 1973; Yu et al. 2020). In addition to having very short ovipositors, Banchini differs from the other tribes by having eight or more sensilla on the larval prelabium (Quicke 2015). Atrophini possess a reduced hypostoma (Quicke 2015) and Glyptini share similar modifications on the metasoma with Lycorina and some Pimplinae taxa, in that taxa within Glyptini typically possess triangular areas on tergites II–IV, delimited by paired, lateromedian grooves (Shimizu 2019), though the precise pattern of grooves differs in the former taxa. Given that Pimplinae and Lycorininae are distantly related subfamilies to Banchinae (Bennett et al. 2019), the similarity of these structures is likely to be the result of analogous character states that appear similar as a result of convergence.

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 Townes and Townes (1973), providing the most comprehensive taxonomic treatment to date. Nevertheless, the generic key is outdated and not supported with applicable illustrations of character states. Subsequent to this treatment, the genus Glyptopimpla was removed from synonymy with Teleutaea Förster and re-instated as a valid genus and as a senior synonym of Zygoglypta Momoi and Orientoglypta Kuslitzky (Gupta 2002).

Tetractenion, placed in the tribe Banchini, is a very rare genus restricted to the Afrotropical region (Townes 1969; Yu et al. 2020). Until now, Tetractenion included only two species, T. luteum Seyrig, recorded from continental central Africa (Democratic Republic of Congo and Kenya) and T. acaule Seyrig, recorded from Madagascar (Seyrig 1932, 1935). The purpose of this paper is to revise the genus Tetractenion, and to provide well-illustrated updated keys to the genera of Banchinae in the Afrotropical region, and to the species of Tetractenion. Online Lucid keys are available on www.waspweb.org and the associated underlying data is made available as Suppl. materials 1, 2: LIF3 files to this paper for inter-exchange with other key production software.

Materials and methods

Photographs

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 (RMCA) were kindly made available by Stéphane Hanot and Arnaud Henrard and those in the Muséum national d’Historie naturelle, Paris (MNHN) were kindly made available by Agnièle Touret-Alby. All images presented in this paper are available at www.waspweb.org (van Noort 2020).

Depositories

Codens follow Arnett et al. (1993), and updated according to the online version http://hbs.bishopmuseum.org/codens/

NHMUK The Natural History Museum, London, England (Gavin Broad);

MNHN Muséum national d’Historie naturelle, Paris (Agnièle Touret-Alby);

RMCA Musée Royal de l’Afrique Centrale, Tervuren (Stéphane Hanot);

SAMC Iziko South African Museum, Cape Town, South Africa (Simon van Noort);

CASC California Academy of Sciences, San Francisco, United States of America (Robert Zuparko).

Nomenclature and abbreviations

The morphological terminology follows Wahl and Sharkey (1993), but the wing venation nomenclature follows Gauld (1991). Most morphological terms are also defined on the HymAToL website (http://www.hymatol.org) and HAO website (http://portal.hymao.org/projects/32/public/ontology/). The following morphometric abbreviations are used (in order of appearance in the descriptions):

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);

Fl_n (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

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 (Penev et al. 2009; Sharkey et al. 2009): 1. Traditional dichotomous keys these are published below and also made available as interactive keys supported by links to species pages on www.waspweb.org; 2. Online interactive Lucid matrix keys were produced, hosted on www.waspweb.org, and made available as Suppl. materials 1, 2: LIF3 files to this paper for import to, and inter-exchange with other key production software. The LIF3 file is an XML-based file that stores all the Lucid4 key data, allowing exchange of the key with other key developers (Penev et al. 2009; Sharkey et al. 2009). In contrast to dichotomous keys where a choice needs to be made at each key couplet to continue, Lucid matrix keys use a different approach where relevant states from multiple character features can be selected independently until identification is achieved (www.lucidcentral.org). All keys were produced using high quality annotated images, highlighting diagnostic characters that are integrated into the key above each couplet. This is a user-friendly output making the keys readily accessible to a wide range of users with diverse expertise. This key format circumvents the requirement of familiarity with morphological terminology associated with the particular group, because the characters are visually illustrated making the keys usable by the lay person (van Noort et al. 2015).

Results

Key to Banchinae genera of the Afrotropical region


1	Tergites II–IV with a median pair of (usually) deep oblique grooves that converge anteriorly and diverge posteriorly (A); Cu1 longer than cu-a, such that Cu2 arises below middle of these combined veins (nervellus of Townes) (B)	2

–	Tergites II–IV without a median pair of oblique grooves (a); Cu1 often longer than cu-a, but may be shorter (b)	4

2	Occipital carina strongly curved before junction with hypostomal carina (A); areolet open, i.e., vein 3rs-m absent (B)	*Apophua*

–	Occipital carina without a strong curve before junction with hypostomal carina (a); areolet closed (b)	3

3	Malar space 0.5–0.8× as long as basal width of mandible (A); epomia long and strong (B)	*Glyptopimpla*

–	Malar space 1.4–2.5× as long as basal width of mandible (a); epomia usually absent or indistinct, only represented as a short wrinkle (b)	*Sjostedtiella*

4	Hind wing with Cu1 longer than cu-a such that Cu2 arises below the middle of these combined veins (nervellus of Townes), Cu2 rarely absent (A); fore wing with 3rs-m sometimes lacking, shape of areolet when closed various (A); mesopleuron usually wider than high (B)	5

–	Hind wing with Cu1 shorter than cu-a such that Cu2 arises above the middle of these combined veins (nervellus of Townes) (a); fore wing with 3rs-m always present, areolet rhomboidal (a); mesopleuron usually higher than wide (b)	11

5	Occipital carina joining hypostomal carina at base of mandible (A); epomia usually present (B); propodeal spiracle elliptic (C)	*Syzeuctus*

–	Occipital carina joining hypostomal carina distant from base of mandible (a); epomia usually absent (b); propodeal spiracle circular to elongate (c)	6

6	Tergite I with anterior half slender, less than half as wide as posterior margin (A); glymma absent (B); with its spiracle at or behind middle (A, B); propodeum lacking carinae (C); propodeal spiracle elongate (C)	*Atropha*

–	Tergite I with anterior half about or more than half as wide as posterior margin (a); glymma present (a); with its spiracle in front of middle (a, b); propodeum usually with either an apical transverse carina or pleural carina, or both (c); propodeal spiracle usually circular to elongate (c)	7

7	Apex of submetapleural lobe tooth-like (A); tarsal claws simple with a single basal tooth above (B); areolet open (C); occipital carina broadly interrupted above.	*Tossinola*

–	Apex of submetapleural lobe rounded (a); tarsal claws simple or pectinate (b); areolet open or closed (c); occipital carina complete.	8

8	Apical 0.3–0.4 of flagellum tapered to a slender apex (A); ovipositor sheath 0.6–1.2× as long as hind tibia (B)	9

–	Flagellum not tapered at the apex (a); ovipositor sheath usually more than 1.4× as long as hind tibia (b)	10

9	First tergite evenly and rather strongly narrowed anteriorly , about half as wide as posterior margin (A); areolet always truncate-shaped (B); ovipositor 0.6× as long as hind tibia (C)	*Cryptopimpla*

–	First tergite stout, only moderately narrowed anteriorly, more than half as wide as posterior margin (a); areolet always open (b); ovipositor 0.8–1.2× as long as hind tibia (c).	*Spilopimpla*

10	First tergite nearly always with longitudinal striae (A); areolet open (B)	*Himertosoma*

–	First tergite rarely covered with longitudinal striae (a); areolet closed or sometimes lacking (b)	*Lissonota*

11	Occipital carina joining hypostomal carina above base of mandible (A); ovipositor sheath short to long, 0.14–1.8× as long as hind tibia (B); mandibular teeth usually subequal in length (C); apical clypeal margin normal (C)	*Exetastes*

–	Occipital carina joining hypostomal carina at base of mandible (a); ovipositor sheath always short, 0.1–0.2× as long as hind tibia (b); lower tooth of mandible always longer than upper tooth (c); clypeus apically invaginated (c)	*Tetractenion*

Details of morphological characters that were used to update the key to Afrotropical banchine genera

Occipital carina with strong curve prior to meeting hypostomal carina: this character (couplet 1A), although noted in the global generic key by Townes (1969), was not included in the previously published generic key to Afrotropical Banchinae (Townes and Townes 1973). This is a strong and reliable character distinguishing Apophua from the remaining Glyptini genera, Sjostedtiella and Glyptopimpla.
Shape of the areolet when closed: the shape of the areolet has been found to be a useful character to separate the tribes/genera. When distinguishing the tribes Atrophini and Banchini, the areolet in Exetastes and Tetractenion is always large and rhomboidal with a very short stalk, whereas in those Atrophini that possess an areolet it is always small, but variably shaped (couplet 4A, a). An anteriorly truncate areolet (couplet 9B, veins 2rs-m and 3rs-m meeting RS separately) present in many Cryptopimpla species has been reported (Townes 1969; Sheng 2011; Takasuka et al. 2011) to be a character state that is constant for all Afrotropical Cryptopimpla species (Reynolds Berry and van Noort 2016). In Syzeuctus and Atropha, the areolet is triangular with a long stalk and in Lissonota the areolet, when closed, is nearly always petiolate (i.e., dorsal aspect pointed, veins 2rs-m and 3rs-m meet before RS, couplet 10c; Townes 1969).
Mesopleuron compressed in Exetastes Group: Tetractenion and Exetastes species have stocky bodies with the mesopleuron laterally compressed (higher than wide) and often flat whereas in Atrophini the mesopleuron is usually wider than high (dorso-ventrally compressed, couplet 4B, b).
Distinguishing Tossinola: the length of the ovipositor sheath relative to the hind tibia has previously been used as an additional character to separate Tossinola from the other Afrotropical genera in the tribe Atrophini where the areolet is open (Townes and Townes 1973). However, the relative lengths overlap across Lissonota, Cryptopimpla and Tossinola species, making it an unreliable character to separate these genera. While a medially, broadly interrupted occipital carina is still the most diagnostic character for the genus Tossinola, another useful character is the state of the apex of the submetapleural carinae: tooth-like in Tossinola (Townes 1969) but rounded in the other Afrotropical banchine genera.
Flagellum apically tapered: as observed by Townes (1969), the flagella of the genera Lissonota and Himertosoma are not, or may only be weakly, apically tapered. For Cryptopimpla and Spilopimpla species, the flagella are tapered to a slender apex (couplet 8 A, a; Townes 1969; Reynolds Berry and van Noort 2016).
Distinguishing Cryptopimpla: аll Afrotropical Cryptopimpla possess a first tergite that is evenly and rather strongly narrowed toward the base (couplet 9A; Reynolds Berry and van Noort 2016). In addition, the ovipositor sheath ca. 0.6× as long as the hind tibia is diagnostic of Cryptopimpla species (couplet 9C; Reynolds Berry and van Noort 2016).
Distinguishing Himertosoma from Lissonota: the absence of a crease separating the fifth laterotergite from the fifth metasomal tergite has been suggested as the single defining character that separates Himertosoma from Lissonota (couplet 10A, a; Watanabe and Maeto 2012). However, this does not appear to be a defining character for Afrotropical Lissonota species as the absence/presence of the crease varies within and among species. Given that the areolet can also sometimes be open in Lissonota species, assessment of the sculpture of the first metasomal tergite is required to separate Lissonota from Himertosoma. Himertosoma species nearly always have longitudinal striae present whereas Lissonota species rarely possess either strong punctures or longitudinal striae (couplet 10B, b; Townes 1969).
Length of the mandibular teeth: in the global description of the genus Exetastes by Townes (1969), he noted that the length of the lower mandibular tooth relative to the upper could be either equal or slightly longer/shorter. “Slightly” is a poor character description, especially concerning mandibular teeth, which wear out throughout the wasp’s life. In the description of the genus, based on Costa Rican species, by Gauld et al. (2002), all species had equal mandibular teeth. Relative length of the mandibular teeth is a more reliable character, if one of the teeth is markedly longer or shorter. For example, in Afrotropical Cryptopimpla the upper tooth is distinctly longer than the lower tooth (Reynolds Berry and van Noort 2016). Similarly, it has been previously noted (Townes 1969), and further corroborated during this revision of Tetractenion, that the upper mandibular tooth is distinctly shorter in all species, making it a diagnostic feature for the genus. While most Afrotropical Exetastes have equal mandibular teeth, Exetastes discretus (Morley 1917) and an undescribed species in SAMC has mandibles with the lower tooth distinctly longer than the upper. This warrants further investigation, because these two genera are closely related, as they both form part of the Exetastes group. This character may represent a transition between the two genera.
Clypeus apically invaginated: this is a diagnostic feature of Tetractenion, while in Afrotropical Exetastes, as has been observed in other species, the clypeal edge is convex or straight, without a median indentation (Gauld et al. 2002).

Tetractenion Seyrig, 1932

Tetractenion Seyrig, 1932, Mém. Acad. Malgache 11: 167. Type: Tetractenion acaule Seyrig. Monobasic.

Diagnosis

(updated from Townes 1969). Fore wing 6.4–10 mm long. Body of moderate proportions, the hind legs long. Frons unarmed. Head with three lobes on the face, tentorial pits deep; clypeus small, laterally convex with declivity, apically invaginated, with clypeal edge convex. Antennae long and slender, apically tapered. Teeth of mandible both triangular, the lower tooth longer than the upper tooth. Labium not elongate. Occipital carina joining hypostomal carina at the base of mandible. Epicnemial carina present and ending at anterior edge of mesopleuron. Apex of scutellum rounded, notauli present. Propodeum weakly convex, often with transverse wrinkling and with a posterior transverse carina and lateral longitudinal carinae present, but faint or reduced. Pro-and meso-tarsal claws pectinate to apex, meta-tarsal claws pectinate or simple. Areolet is often large and rhomboidal with a short stalk, receiving 2m-cu at center. Fore wing with cu-a opposite 1A or a little distad, ramellus present or absent on 1m-cu. Hind wing with Cu1 shorter than cu-a such that Cu2 arises above the middle of these combined veins. Metasomal tergite I without dorsolateral carinae. Epipleura of tergites II and III ca. 0.15× as wide as long. Posterior third of metasoma moderately laterally compressed. Ovipositor sheath ca. 0.1–0.2× as long as hind tibia.

Biology

Unknown.

Distribution

Angola, Cameroon, Democratic Republic of Congo, Kenya, Madagascar, Namibia, Nigeria, South Africa.

Species richness

T. acaule Seyrig, 1932

T. ibayaensis sp. nov.

T. luteum Seyrig, 1932

T. pascali sp. nov.

T. pseudolutea sp. nov.

T. rosei sp. nov.

Key to Afrotropical species of the genus Tetractenion


1	Metasomal tergite I distinctly dorso-medially compressed, tergites IV–VIII white where weakly sclerotized (A); keels distinctly raised on mesoscutal lobes (B); notauli abbreviated, not reaching the scutellum	*T. acaule*

–	Metasomal tergite I with dorso-medial compression weak or absent, tergites IV–VIII strongly sclerotized (a); keels only slightly raised on mesoscutal lobes (b); notauli present, posteriorly meeting before reaching the scutellum	2

2	Metasomal tergite I stout, ca. as long as wide in dorsal view (A); pits on the mesopleuron and propodeum are large and deep (B)	T. ibayaensis sp. nov.

–	Metasomal tergite I elongate, ca. 2× as long as wide in dorsal view (a); pits on the mesopleuron and propodeum shallow (b)	3

3	Hind tarsal claw simple (A); wings with dense microtrichia, venation dark (B)	*T. luteum*

–	Hind tarsal claw pectinate (a); wings usually with sparser microtrichia, venation usually yellowish-brown (b)	4

4	ML 0.6 (A); head yellow, congruent with yellow body (B)	T. pseudolutea sp. nov.

–	ML 0.7–0.9 (a); head dark purplish-brown or reddish, contrasting with yellow body (b)	5

5	Pronotal collar with strong carina present (A); head reddish and less robust, face weakly three lobed (B)	T. rosei sp. nov.

–	Pronotal collar weakly wrinkled (a); head dark purplish-brown and more robust, face strongly three-lobed	T. pascali sp. nov.

Species descriptions

Tetractenion acaule Seyrig, 1932

Fig. 1

Type material

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 Townes and Townes (1973), labeled by T. Yoshida, 2011 (MNHN) (photos of Lectotype examined: http://coldb.mnhn.fr/catalognumber/mnhn/ey/ey9333). Non-type ♀ (examined): Madagascar, Bekily, Reg. Sud. de L’ile, Feb 1930 and Jan–Feb 1931, Coll. Mus. Congo, Col. P.L.G. Benoit, Tectractenion acuale, det. P.L.G. Benoit, 1953 (RMNH). Additional material. ♀: Madagascar: Majunga Prov., Besalampy District, Marofototra dry forest, 17 km W of Besalampy, 4–11 February 2008, 16°43.30'S, 44°25.42'E, coll. M. Irwin, R. Harin’Hala, Malaise, dry wash in forest, elev. 170 ft MG-42A-20 (CASC).

Differential diagnosis

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.

Description

(updated from Seyrig 1932). Size 9–11 mm. Color: head white with a large black central area on occiput, reaching eyes on vertex and pointed on frons; antenna black, without pale ring; mesosoma red; metasomal tergites I and II red, though tergite II sometimes brownish, following tergites black with large membranous white areas from tergite IV; legs red, hind femur, tibia and tarsus infuscate; wings with sparse microtrichia, venation brown, pterostigma brown and centrally translucent reddish.

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.