Brachycyrtus antoninoi Di Giovanni, 2021

Giovanni, Filippo Di & Varga, Oleksandr, 2021, First record of the subfamily Brachycyrtinae (Hymenoptera, Ichneumonidae) from continental Africa, with description of three new species, Zootaxa 4985 (2), pp. 203-218 : 205-208

Brachycyrtus antoninoi Di Giovanni , sp. n.

( Figs 1A–C , 2A–D )

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Examined material. Holotype: ♀, “ UGANDA - Kibale N. P./ Kanyawara Biol. Station / 00°33’54,1”N – 30°21’28,1”E / 22-29.VIII.2010 / 1504m — Malaise trap / S. Katusabe & Co. leg.” ( TUZ) . Paratypes: ♀, “ Kakamega Forest / 18.xii.1970 // KENYA / A. E. Stubbs / N. M. 1972-211” ( NHM) . ♀, “[ KENYA] van Someren / Meru, 7/43 // V. G. L. van Someren / Collection / Brit. Mus. 1959-468” ( NHM) .

Description. Body length about 5.3 mm. Fore wing length 3.7 mm. Body with a moderately dense covering of short, fine, white setae.

Head ( Figs 1B–C , 2A ). Face about 0.8× as high as maximum wide; face polished, with just few discernible but shallow punctures; clypeus smooth, shining and without punctures, apical margin subtruncate; malar space about 0.5–0.6× as basal width of mandible; mandible with few small longitudinal striae near teeth; eye strongly emarginate opposite antennal socket; vertex, temple and gena polished, with inconspicuous punctures; temple narrowed behind eye (in dorsal view), gena about 0.5× as transverse diameter of eye (in lateral view); occipital carina slightly marked ventrally, joining hypostomal carina above mandible base, hypostomal carina slightly elevated; ocular-ocellar distance about 0.8× the maximum diameter of posterior ocellus, about 0.7× the distance between posterior ocelli; flagellum with 26 flagellomeres, subclavate, with last nine flagellomeres clearly enlarged; first flagellomere about 4.3–4.5× as apically wide, second flagellomere 2.6–2.7× as apically wide.

Mesosoma ( Figs 1C , 2A, 2C ). Pronotum polished, with inconspicuous punctures on posterior upper hind corner; epomia straight, flange-like and extending to dorsal edge; pronotum with few small wrinkles on ventral corner between epomia and posterior margin. Mesoscutum subpolished, strongly punctate to rugose-punctate medially, densely punctate on lateral sides; notauli absent; scuto-scutellar groove with small longitudinal ridges; scutellum subpolished, with dense but shallow punctures; scutellum with carinae extending to about 0.75× of its length. Mesopleuron polished, with dense punctures on anterior and on ventral half, on posterior half with fine longitudinal striae, some of which connected to the mesopleural furrow; sternaulus small, extending approximately to half of mesopleuron, straight and crenulate; epicnemial carina present, ending opposite to ventral angle of pronotum, epicnemial carina strongly elevated ventrally in the middle, between fore coxae; posterior transverse carina of mesosternum absent at level of mid coxae, present medially. Metapleuron subpolished, with dense but shallow punctures all over its surface, and with small longitudinal striae ventrally just above hind coxa. Propodeum subpolished; anterior transverse carina complete; area basalis obliterated, with a short longitudinal carina joining anterior transversa carina and anterior margin of propodeum; posterior transverse carina complete laterally but absent medially, thus area superomedia and area petiolaris joined; area superomedia subpolished and impunctate, area petiolaris with small transverse striae; area externa with dense but shallow punctures; area dentipara with few inconspicuous punctures on subpolished surface; area lateralis with dense but shallow punctures; pleural carina complete; propodeal spiracle sub-oval.

Wings ( Fig. 1A ). Fore wing with 1cu-a distal to M&RS by about 0.7× the length of 1cu-a; 2rs-m about 0.6× as the section of 1m-cu&M between 2rs-m and 2m-cu. Hind wing with abscissa of CU present but spectral, CU about as long as cu-a (i.e., nervellus intercepted in the middle in Townes’ morphological nomenclature).

Metasoma ( Figs 1A , 2B, 2D ). Polished with fine setiferous punctures on postpetiole and all metasomal tergites; metasomal tergite II with thyridia present, oblique; tergite II about 1.8× as apically wide, and about as long as tergite I. Ovipositor sheath about as long as hind tibia; ovipositor straight.

Colour. Face, clypeus, gena, mandible except teeth, palpi, outer side of scape light yellow; area behind antennal base, vertex, occiput black (black areas connected); teeth and inner side of scape brown; antenna yellowish basally, yellowish–brown medially, reddish–brown apically, last segments brown. Mesosoma yellow and black; a large central band and two lateral small bands on mesoscutum, scuto-scutellar groove and suture between scutellum and postscutellum, scutellum basally and medially, front margin of mesopleuron, a small band running from the center of mesopleuron to the mesopleural suture, a relatively large longitudinal band on ventral half of mesopleuron, anterior margin of metapleuron, and area of propodeum anterior to anterior transverse carina black; tegula dark brown. Fore and mid coxae, trochanters and trochantelli pale yellow; fore and mid femurs, tibiae and tarsi yellow; hind coxa black marked at the base and on outer side; hind trochantellus and hind femur yellow, hind trochanter and longitudinal stripes along inner and outer sides of hind femur dark brown; hind tibia slightly darkened basally, pale yellow subbasally and on outer side, darkened on ventral side and apically; hind tarsi reddish–brown, slightly darker apically. Metasomal tergite I black with two pale yellow spots apically, almost touching; metasomal tergite II and III black medially, reddish–brown laterally, with two yellow spots apically; metasomal tergites IV–VI black medially and reddish–brown laterally or entirely reddish–brown, with two yellow spots apically, apical margin reddish–brown; metasomal tergite VII reddish–brown with yellow marks slightly visible laterally at the apex, apical margin with narrow lighter line. Veins and pterostigma dark brown. Ovipositor sheaths reddish–brown.

Male. Unknown.

Variation. Black area on vertex reduced and not connected to black area on occiput in the specimen from Meru, Kenya; black longitudinal band on ventral half of mesopleuron reduced to two small patches in the specimen from Meru, Kenya, while it is extended ventrally on mesosternum in the specimen from Kakamega, Kenya.

Biology. Unknown.

Differential diagnosis. Brachycyrtus antoninoi sp. n. can be distinguished from all the other species of the genus by the combination of the following characters: eye strongly emarginate opposite antennal socket; flagellum with 26 flagellomeres, subclavate, with last nine flagellomeres clearly enlarged; gena about 0.35× as transverse diameter of eye (in lateral view); occipital carina joining hypostomal carina above mandible base; scuto-scutellar groove with small longitudinal ridges; mesopleuron with dense punctures anteriorly and on ventral half, posteriorly with fine longitudinal striae; epicnemial carina strongly elevated ventrally in the middle, between fore coxae; metapleuron subpolished, with dense but shallow punctures all over its surface, and with small longitudinal striae ventrally just above hind coxa; propodeum with area superomedia and area petiolaris joined, area superomedia coriaceous and area petiolaris with small transverse striae; fore wing with 1cu-a distal to M&RS and 2rs-m about 0.6× as the section of 1m-cu&M between 2rs-m and 2m-cu; hind wing with nervellus intercepted in the middle; metasomal tergite II with thyridia present; ovipositor straight; metasomal tergite I black with two pale yellow spots apically, almost touching; metasomal tergite II and III black medially, reddish–brown laterally, with two yellow spots apically; metasomal tergites IV–VI black medially and reddish–brown laterally or entirely reddish–brown.

Distribution. Kenya and Uganda.

Etymology. The new species is named after the first author’s father, Antonino Di Giovanni, who spent more than 30 years working in Kenya.

Figures

FIGURE 1. Brachycyrtus antoninoi Di Giovanni, sp. n., female, holotype. A: habitus, lateral view. B: face, frontal view. C: temple and mesoscutum, dorsal view.

FIGURE 2. Brachycyrtus antoninoi Di Giovanni, sp. n., female, holotype. A: mesopleuron and metapleuron, lateral view. B: ovipositor, lateral view. C: propodeum, dorsal view. D: metasomal tergites I–III, dorsal view.