Alystria albolineata, Riedel & Watanabe, 2025

Alystria albolineata sp. nov.

( Figs 14–18 View FIGURES 14–18 )

Holotype. ( ♂) [ Japan] Kagoshima Pref., Yakushima Isl. , Malaise trap ( AC3 ), 150 m alt., 8–28. VI. 2007, T.Yamauchi et al. leg. ( Kanagawa).

Etymology. The species name refers to the ivory bands of the tergites.

Description. Male. Body length 12.0 mm.

Head. Flagellum with 36 flagellomeres, slender and bristle-shaped; 1 st flagellomere 3.4× as long as wide, distal flagellomeres slightly nodose. Tyloids on flagellomeres 10–17, oval, maximally 0.6× as long as their flagellomere. Temple rather long, slightly and roundly narrowed behind eye, granulate and with superficial punctures. OED 1.2× and OOD 1.3× ocellar diameter. Frons and face granulate and coarsely rugose-punctate. Clypeus almost flat, slightly protruding laterally, densely punctate; apical margin blunt and with blunt median projection. Ventral mandibular tooth rather large but smaller than dorsal tooth and moderately bent inwards (by 40°). Malar space 0.3× as long as width of mandibular base. Gena densely punctate. Genal carina reaching hypostomal carina close to mandibular base, both carinae low.

Mesosoma . Side of pronotum punctate, with some coarse striae posteriorly. Notaulus impressed in frontal 0.3 of mesoscutum. Mesoscutum densely punctate and granulate, dull. Mesopleuron and metapleuron punctate; speculum smooth; juxtacoxal carina present. Epicnemial carina low ventrally. Scutellum moderately and roundly elevated, slightly wider than long, with dense punctures and lateral carina in basal 0.8. Propodeum coarsely rugose-punctate, gradually sloping from base to apex (as in Coelichneumon ), without apophysis; spiracle slit-shaped. Area superomedia heart-shaped, slightly longer than wide; costula reaching slightly posterior to its middle. Hind femur densely punctate, 3.6× as long as wide. Claws simple. Areolet quadrangular, almost pointed frontally; vein 2m-cu reaching slightly distal to its middle. Vein 1cu-a antefurcal by 2.0× its width.

Metasoma. Postpetiole moderately widened, without latero-median carina, median field slightly elevated and finely aciculate, lateral field punctate. 2 nd tergite 1.1× as long as wide. Gastrocoelus strongly impressed, with coarse ridges. Thyridium transverse, 2.0× as wide as interval between thyridia. 2 nd to 4 th tergites densely rugose-punctate, dull. 2 nd to 4 th sternites with median folds. Apical margin of hypopygium moderately and roundly elongate medially.

Color . Black. Flagellomeres 12–16 ivory dorsally. Palps, clypeus, face, complete orbits except black interruption on malar space, and scape ventrally ivory. Collar, ventral edge and upper margin of pronotum, subtegular ridge, small spot of ventral mesopleuron, scutellum except black median stripe, postscutellum, upper division of metapleuron, area posteroexterna and apical part of area dentipara of propodeum, apical stripes of all tergites (widened laterally on 2 nd and 3 rd tergites) ivory. Leg black; frontal spots of fore and mid coxae and small dorsal spot of hind coxa ivory; fore and mid femora and tibiae reddish-yellow frontally; apical spurs of hind tibia ivory. Wings slightly infuscate, pterostigma black.

Female unknown.

Distribution. Japan (Yakushima Isl.).

Remarks. Due to the Coelichneumon -like form of propodeum, globose and carinated scutellum, rhombic areolet and antefurcal vein 1cu-a, finely aciculate postpetiole and large thyridia, we include this new species in the genus Alystria Cameron here (for a description of this genus see Heinrich 1970: 96–97). It differs from A. curvilineata Cameron, 1904 by its wider temple, larger thyridia, ivory bands of all tergites and black hind tarsus.