Xynobius brevifemora Han & van Achterberg, 2024

Han, Yunjong, van Achterberg, Cornelis & Kim, Hyojoong, 2024, Four new species of the genus Xynobius Foerster (Hymenoptera, Braconidae, Opiinae) from South Korea, ZooKeys 1193, pp. 219-243 : 219

Xynobius brevifemora Han & van Achterberg sp. nov.

Figs 13 , 14-24 , 25-28

Type material.

Holotype. ♀ (KSNU), "South Korea: 290-2 Singwan-dong, Gunsan, Jeonbuk prov., 35°56'34"N, 126°40'45"E, 14.-30.v.2016, MT [= Malaise trap], Hyojoong Kim leg., KSNU".

Diagnosis.

Apical third of antenna dark brown or black (Fig. 23 ); eye 2.4-2.7 × longer than temple in dorsal view; middle lobe of mesoscutum largely glabrous and strongly shiny (Fig. 16 ); scutellum slightly convex; fore wing at most slightly infuscated (Fig. 14 ); pterostigma gradually narrowed apically, triangular; hind tarsus largely dark brown or brown (Fig. 28 ); first tergite approximately as long as wide apically (Fig. 26 ); second metasomal tergite smooth; setose part of ovipositor sheath 0.3 × as long as fore wing, 2.2 × first tergite and 1.4 × hind tibia; all femora robust (Fig. 13 ); mesosoma except metapleuron and propodeum orange brown.

Description.

Female; length of body 4.0 mm, of fore wing 3.9 mm.

Head. Antenna with 40 segments and 1.1 × as long as body; third segment of antenna 1.9 × longer than its width (Fig. 23 ); area between antennal sockets rugose; eye 2.7 × longer than temple in dorsal view (Fig. 21 ); vertex and stemmaticum shiny, smooth and moderately setose; frons finely punctate and densely setose (Fig. 20 ); face punctate and densely short setose; clypeus 2.8 × wider its maximum height (Fig. 20 ); ventral margin of clypeus slightly concave and sparsely setose; hypoclypeal depression present; length of maxillary palp nearly as long as height of head; malar sulcus absent; occipital carina absent dorsally; mandible triangular in lateral view, hardly twisted and gradually widened basally (Fig. 27 ).

Mesosoma. Mesosoma 1.3 × longer than its height; pronope absent (Fig. 21 ); pronotum with indistinctly crenulated groove posteriorly; mesopleuron largely shiny and smooth, but precoxal sulcus oblique and moderately crenulate; epicnemial area crenulate ventrally, remaining area smooth (Fig. 15 ); pronotal side largely smooth except crenulated groove anteriorly and posteriorly; mesopleural sulcus smooth; anterior groove of metapleuron crenulate; metapleuron coarsely punctate and sparsely setose posteriorly (Fig. 15 ); notauli absent on disc of mesoscutum but as a pair of short and deep impressions present anteriorly; mesoscutum shiny, smooth and with few setae, middle lobe largely glabrous (Fig. 16 ); medio-posterior depression of mesoscutum absent; scutellar sulcus narrow and crenulate (Fig. 16 ); scutellum largely shiny and smooth, rather flat in lateral view; propodeum sparsely setose with long medio-longitudinal carina connected to two longitudinal carinae posteriorly forming reversed Y posteriorly, no transverse carina and remaining area coarsely rugose (Figs 16-18 ).

Wings. Fore wing (Fig. 14 ): pterostigma wide, triangular and narrowed apically ending before level of vein r-m; vein r nearly 0.6 × longer than vein 2-SR; vein 1-SR+M sinuate; vein 3-SR sublinear with vein r, parallel with vein 2-M and 1.8 × longer than vein 2-SR; vein 2-SR almost straight; vein SR1 curved upward, ~ 2.0 × longer than vein 3-SR; vein 1-M curved; second submarginal cell narrow; r: 3-SR: SR1 = 5: 13: 25; vein m-cu distinctly antefurcal, converging to vein 1-M posteriorly; first subdiscal cell transverse; vein CU1b short. Hind wing (Fig. 14 ): vein m-cu absent; vein 1r-m 0.5 × as long as vein 1-M; vein 2-M only pigmented.

Legs. Hind femur 3.4 × longer than its maximum width (Fig. 28 ).

Metasoma. Length of first metasomal tergite 1.1 × its apical width; first tergite gradually widened apically and its surface with longitudinal striae medially, and remaining area shiny and smooth (Figs 22 , 25 , 26 ); dorsope present and surrounded by strongly curved dorsal carinae (Figs 22 , 25 , 26 ); second metasomal suture indistinctly indicated dorsally (Fig. 22 ); second tergite shiny and smooth except a pair of droplet-shaped impressions anteriorly; second tergite 0.6 × as long as third tergite in dorsal view; following tergites shiny, smooth and moderately setose posteriorly (Fig. 17 ); hypopygium 0.4 × as long as metasoma, rather acute apically and reaching apex of metasoma (Fig. 19 ); setose part of ovipositor sheath ~ 2.2 × longer than first tergite and 0.3 × as long as fore wing (Figs 13 , 24 ).

Colour. Body generally blackish to dark brown (Fig. 13 ); face and temple ventrally, mesoscutum, scutellum, metanotum, pronotum, mesopleuron, and ovipositor yellowish brown to orange (Figs 15 , 16 ); palp, tegulae, legs (except hind tibia dorsally and tarsus) pale brown; narrowed band on fourth-sixth tergites anteriorly (Fig. 17 ) and apical segments of antenna brown; pterostigma and veins of wings dark brown.

Distribution.

South Korea.

Biology.

Unknown.

Etymology.

Named after the robust and comparatively short femora of the new species (Figs 13 , 28 ); brevis is Latin for short.

Remarks.

The new species has a rather shallow dorsope bordered with strongly curved dorsal carinae basally, vein r much shorter than vein 2-SR and a large hypoclypeal depression; therefore, it belongs to the genus Xynobius . It has the reduced notauli (absent on mesoscutal disc and only distinctly impressed anteriorly), glabrous middle lobe of mesoscutum, a long medio-longitudinal carina on propodeum with two diverging longitudinal carinae posteriorly and remainder coarsely rugose, the short second submarginal cell of fore wing, median keel present between antennal sockets, second metasomal tergite relatively shorter than third tergite and relatively long setose part of ovipositor sheath. In the key by Tobias (1998), it runs to the subgenus Xynobius Psyttalia Walker sensu Tobias by having two diverging medio-longitudinal carinae posteriorly on propodeum, short second metasomal tergite (0.7 × as long as third metasomal tergite) and indistinctly indicated second metasomal suture. This new species is superficially similar to P. spectabilis van Achterberg, 2016, because they share the reduced medio-posterior depression of mesoscutum, vein r of fore wing sublinear with vein 3-SR, mesosoma yellowish brown to orange (except propodeum and metapleuron blackish to dark brown), pterostigma of fore wing distinctly triangular and reduced vein m-cu of hind wing. The new species has the dorsope present and dorsal carinae on first metasomal tergite not united (dorsope absent but dorsal carinae strong in its basal half and with depressed area below in P. spectabilis ), ventral margin of clypeus strongly convex (slightly convex in P. spectabilis ), median keel on frons between antennal sockets present (keel absent and frons behind antennal sockets rugose in P. spectabilis ), with two longitudinal carinae on propodeum and partly coarsely rugose (smooth in P. spectabilis ) and obtuse apex of hypopygium (acute apex in P. spectabilis ). In the key by Fischer (1972), it runs to the subgenus Xynobius Phlebosema Fischer, and to Opius fischeri Papp, 1981. However, O. fischeri has no medio-longitudinal carinae on the propodeum (medio-longitudinal carina present in the new species), reduced median keel between antennal sockets (present), third segment of antenna more than 3.0 × longer than its width (1.9 × longer than its width), first metasomal tergite smooth (striate medially) and relatively short setose part of ovipositor sheath (~ 2.7 × longer than first tergite).

Among the described Korean and Chinese species of Xynobius , the new species is similar to X. gracilitergum (Fischer, 1990) and X. sulciferus (Papp, 1967) because of sharing the slightly convex scutellum, length of eye 1.6-2.7 × temple in dorsal view, vein m-cu of fore wing antefurcal (but slightly so in X. sulciferus ), wing membrane at most slightly infuscated and second metasomal tergite smooth. Xynobius brevifemora differs from both by having no medio-posterior depression of mesoscutum (present in both species), first tergite approximately as long as its apical width (1.7-2.2 × in both species), setose part of ovipositor sheath ~ 1.4 × longer than hind tibia (shorter than length of hind tibia in both species), femora robust (femora more slender in both species) and mesosoma (except metapleuron and propodeum) orange-brown (black in both species).

Figures

Figure 13. Xynobius brevifemora Han & van Achterberg, sp. nov., holotype, ♀, habitus, lateral.

Figures 14 - 24. Xynobius brevifemora Han & van Achterberg, sp. nov., holotype, ♀ 14 wings 15 mesosoma, lateral view 16 mesosoma, dorsal view 17 metasoma, dorsal view 18 propodeum, dorsal view 19 hypopygium, ventral view 20 head, anterior view 21 head, dorsal view 22 1 st- 3 rd metasomal tergites, dorsal view 23 antenna 24 ovipositor and its sheath, lateral view.

Figures 25 - 28. Xynobius brevifemora Han & van Achterberg, sp. nov., holotype, ♀ 25 1 st metasomal tergite, dorsal view 26 1 st metasomal tergite, dorso-posterior view 27 mandible, lateral view 28 hind leg, lateral view.