Brachyzapus striatus Humala, 2023

Humala, A. E., 2023, New for the Russian fauna Darwin wasps (Hymenoptera: Ichneumonidae) from Primorsky Krai and Sakhalin Island, Far Eastern Entomologist 484, pp. 1-8 : 5-7

Brachyzapus striatus Humala , sp. n.

https://zoobank.org/NomenclaturalActs/ 909A36FE-3BD8-4E21-A760-A419FE26114E

Figs 1– 5

TYPE MATERIAL: Holotype – ♀, Russia: Primorsky Krai, Khasanskiy District, Gamov Cape, Vityaz Bay , 42.607° N, 131.192° E, 13.IX 2019, A. Humala leg. ( ZISP).

DESCRIPTION. Female. Fore wing 6.2 mm, body length 9.2 mm ( Fig. 1 ).

Head. Head distinctly narrowed behind eyes, nearly as wide as high. Frontal orbits strongly convergent downwards, weakly excavated at the level of antennal sockets ( Fig. 3 ), facial margins subparallel. Minimum face width 0.3 × head width. Face smooth, sparsely punctured, the distance between punctures longer than their diameter; clypeus more sparsely punctured. Face and clypeus pubescent, hairs length as long as flagellum diameter. Frons shiny, without punctures, somewhat concave. Antenna as long as fore wing, with 28 elongate flagellomeres; first flagellomere 5.7 × as long as wide. Ocelli of moderate size, maximum diameter as long as distance between lateral ocellus and eye; postocellar line 0.9 × as long as maximum diameter of lateral ocellus ( Fig. 2 ). The level of posterior margins of ocelli is clearly in front of the level of posterior eyes margins. Temple moderately short, 0.6 × as long as the width of compound eye. Occipital carina complete, connected to hypostomal carina far from base of mandible. Clypeus with thin apical ridge. Mandible bidentate with teeth weakly twisted, upper tooth distinctly longer than lower tooth. Malar space 0.2 × as long as basal width of mandible.

Mesosoma . Mesosoma 1.4 × as long as maximum height. Pronotum polished with strong curved epomia, striated in front of epomia and sparsely punctured along upper margin ( Fig. 4 ). Mesoscutum punctured; notauli deep, reaching the middle of mesoscutum. Lateral margin of mesoscutum behind tegula strongly widened, lamelliform. Scutellum moderately and evenly convex, bordered by carinae in anterior half.

Mesopleuron smooth, with swelling below subtegular ridge ( Fig. 4 ). Epicnemial carina ended near middle of mesopleuron far from its front margin. Sternauli not developed. Mesosternum sparsely punctured with whitish setae. Propodeum with reduced carinae, excluding pleural carinae and posterior stubs of lateral longitudinal carinae; at the site of posterior transverse carina transversely striated ( Fig. 5 ). Propodeal spiracle oval, separated from pleural carina by its minimum diameter length. Metapleurum polished in lower half, upper part with punctures and hairs; submetapleural carina strong, angularly bent in anterior 0.4.

Legs. Legs stout, fore femur inflated. Hind femur 4.2 × as long as maximum width; fifth tarsomeres enlarged, claws simple. The ratio between the lengths of the hind tarsomeres are 63:30:18:11:28.

Wings. Fore wing without areolet, second recurrent vein (2m-cu) with two bullae. Nervulus (1cu-a) clearly postfurcal, first subdiscal cell somewhat widened posteriorly; parallel vein connects to postnervulus below the middle. Nervellus (CU+cu-a) strongly reclivous, intercepted in the middle; subbasal cell in the upper half is almost hairless.

Metasoma. First tergite subpolished, 1.9 × as long as maximum width posteriorly, with glymmae ( Fig. 4 ). Median dorsal carinae converge towards the posterior quarter of the tergite, forming a longitudinally striated area in the middle, not reaching posterior margin of tergite ( Fig. 5 ). Lateral carina extends above the spiracle, reaching posterior margin of tergite. First sternite convex in profile, ended at the level of spiracles. Second metasomal tergite 1.4 × as long as maximum width posteriorly, more coarsely sculptured; basolateral corners separated by shallow oblique grooves. Ovipositor slightly upcurved, evenly tapered to sharp point, sheath length 0.8 × as long as hind tibia ( Fig. 1 ).

Color. Body black; maxillary and labial palps, dorsoposterior corner of pronotum, tegula and base of wings yellowish. Legs yellowish; hind coxa and femur yellowish-brown; hind tibia fuscous with proximal pale band and light medial part; tibial spurs and first tarsomere in basal ¾ and basal third of second tarsomere pale. Antennae, mandibles, ovipositor and pterostigma brown. All tergites with very narrow yellowish posterior edge.

Male. Unknown.

DIAGNOSIS. Brachyzapus striatus sp. n. closely related to B. convergens Choi et Lee, 2019 , sharing with it strongly convergent downwards inner orbits and short malar space, but can be distinguished from the latter by more stout metasomal tergites without yellowish posterior margins; postfurcal nervulus; nervellus intercepted in the middle (vs. in upper third); the second tarsomere of hind leg is longer than the fifth tarsomere (vs. the fifth tarsomere is longer than the second tarsomere); propodeum with transverse striae, hind femur 4.2 × as long as wide (vs. 3.8 ×); ovipositor longer and slightly upcurved sheath 0.8 × as long as hind tibia (vs. 0.6 ×), and coloration of antenna, hind legs and tergites. From other Brachyzapus species occurring in the Palearctic and keyed by Choi et al. (2019), the new species differs: from B. atripedalis (Sheng, 2001) , B. politus Pham, Broad, Matsumoto et Wägele, 2012 , B. pyramidalis Choi et Lee, 2019 and B. tenuiabdominalis (Uchida, 1941) in more strongly convergent downwards inner orbits, shorter malar space and coloration of the body; from B. nikkoensis (Uchida, 1928) and B. nitidus (Hao et Sheng, 2002) in black scutellum, postscutellum and posterior margins of tergites; from B. nitidus and B. unicarinatus (Uchida et Momoi, 1958) in lacking posterior transverse carina of propodeum, and more stout hind femur, 4.2 × as long as wide (vs. 5.0– 6.0 ×).

DISTRIBUTION. The new species is currently known only from the type locality in the Russian Far East (south part of Primorsky Krai) .

ETYMOLOGY. The species is named after the striation on propodeum, postpetiole and anterior pronotum.

Figures

Figs 1–5. Brachyzapus striatus Humala, sp. n., ♀, holotype. 1 – habitus, lateral view, scale bar 1.0 mm; 2 – head, dorsal view, scale bar 0.2 mm; 3 – head, frontal view, scale bar 0.2 mm; 4 – head, mesosoma and first tergite, lateral view, scale bar 1.0 mm; 5 – propodeum and basal tergites, dorsal view, scale bar 0.5 mm.