Xynobius geniculatus (Thomson, 1895)

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 geniculatus (Thomson, 1895)

Figs 54 , 55-64

Opius geniculatus Thomson, 1895: 2179.

Opius (Nosopoea) geniculatus : Fischer 1972: 282-284; Papp 1981b: 44-59.

Opius (Allotypus) geniculatus : Tobias and Jakimavičius 1986: 63.

Opius albicoxis Marshall, 1898: 236; Fischer 1967: 143 (as synonym of O. geniculatus Thomson), 1972: 282.

Material examined.

1 ♀ (KNA), " South Korea: DMZ Botanical Garden, Mandae-ri, Haean , Yanggu , Gangwon prov., 38°15'09.3"N, 128°06'40.6"E, 17.x.2017 - 17.xi.2017, MT [= Malaise trap]" .

Diagnosis.

Antennal segments of ♀ 38-44; area below pterostigma with brownish patch (Figs 54 , 55 ), rarely obsolescent; precoxal sulcus smooth; mesoscutum largely glabrous, but middle lobe sparsely setose, notauli absent on disc, only anteriorly deeply impressed and medio-posterior depression distinct; pterostigma triangular; vein M+CU1 of fore wing largely sclerotised (Fig. 55 ); second metasomal tergite bicoloured (dark brown and with a pale yellowish patch medially); hind tarsus (except telotarsus) pale yellowish or ivory; second submarginal cell of fore wing long (Fig. 55 ); area around medio-posterior depression of mesoscutum finely punctate or punctulate; at least apex of hind femur dark brown; no pronope; setose part of ovipositor sheath 0.6 × as long as first metasomal tergite.

Re-description.

Female; length of body 3.6 mm, of fore wing 4.1 mm.

Head. Antenna with 44 segments and 1.5 × as long as body (Fig. 64 ); third segment of antenna 2.6 × longer than wide, ~ 1.1 × longer than fourth segment of antenna; eye 2 × longer than temple in dorsal view (Fig. 61 ); stemmaticum shiny and smooth; vertex shiny, smooth and moderately setose posteriorly; frons with depression medially and remainder shiny and smooth; face densely punctate and setose, median keel present up to between antennal sockets (Fig. 60 ); clypeus 2.4 × wider than its maximum height; clypeus punctate and moderately setose, rather flat in lateral view; hypoclypeal depression present; malar sulcus straight; occipital carina absent medio-dorsally; mandible slightly curved apically, triangular in lateral view and gradually widened basally.

Mesosoma. Mesosoma 1.5 × longer than its height (Fig. 56 ); pronope absent (Figs 57 , 61 ); propleuron largely smooth and propleuron flange present posteriorly (Fig. 56 ); mesopleuron largely shiny and smooth, including narrow precoxal sulcus; epicnemial area distinctly crenulate; pronotal side largely smooth with crenulated groove anteriorly and posteriorly; mesopleural sulcus crenulate; anterior groove of metapleuron crenulate; metapleuron largely shiny, smooth and moderately setose along grooves; notauli absent on disc of mesoscutum (Fig. 57 ); mesoscutum shiny, smooth and densely setose medially; scutellum slightly punctate and setose; medio-posterior depression of mesoscutum round; scutellar sulcus distinctly crenulate, medium-sized and curved; propodeum moderately setose with short medio-longitudinal carina anteriorly, indistinct transverse carina and areola, remainder of propodeum shiny and largely rugose (Figs 57 , 62 ).

Wings. Fore wing (Fig. 55 ): pterostigma triangular with dark spot below pterostigma; vein 1-SR+M sinuate; vein 3-SR angled with vein r, parallel with vein 2-M and ~ 2 × longer than vein 2-SR; vein 2-SR straight and oblique; vein SR1 curved upward, nearly 1.8 × longer than vein 3-SR; r: 3-SR: SR1 = 5: 46: 84; vein m-cu postfurcal; second submarginal cell elongated; vein CU1b medium-sized. Hind wing: vein m-cu pigmented and curved basally; vein 1r-m 0.6 × as long as vein 1-M; vein 2-M pigmented.

Legs. Hind femur 4.6 × longer than its maximum width (Fig. 54 ).

Metasoma. First metasomal tergite 1.3 × longer than its apical width (Fig. 58 ); first tergite slightly widened apically and its surface with longitudinal striae medially and remaining area shiny and smooth; dorsope distinct (Figs 57 , 58 ); second metasomal suture indistinctly indicated (Fig. 59 ); second tergite shiny and smooth, with a pair of oblique depressions anteriorly; second and following tergites shiny, smooth, with transverse band of setae posteriorly; setose part of ovipositor sheath 0.6 × as long as first metasomal tergite and nearly 0.07 × as long as fore wing (Fig. 63 ).

Colour. Body black (Fig. 54 ); clypeus ventrally, mandible, and ovipositor brown; flagellar segments of antenna, femur, and tibia of hind leg and tarsal claw dark brown; scape of antenna, pterostigma, vein of wings and spot below pterostigma, tegulae, and remainder of legs brown; palpi pale yellowish; posterior band of third-sixth metasomal tergites brown or yellowish brown.

Distribution.

South Korea (new record), Europe, Eastern/Western Palearctic region.

Biology.

Parasitoid of Trypeta immaculata (Macquart, 1835) and Stemonocera cornuta (Scopoli, 1771) ( Tephritidae ) ( Yu et al. 2016).

Remarks.

This species runs in the key by Tobias (1998) to Opius geniculatus Thomson, because of having the distinct medio-posterior depression of mesoscutum, smooth precoxal sulcus, distinct hypoclypeal depression, vein m-cu of fore wing weakly postfurcal, hind femur 4.6 × longer than its width, antenna with 44 segments, pterostigma short and triangular, mesoscutum rather densely setose, vein 3-SR of fore wing twice longer than vein 2-SR, a brownish spot below pterostigma and brownish band posteriorly at third-sixth metasomal tergites.

Figures

Figure 54. Xynobius geniculatus (Thomson), ♀, habitus, lateral.

Figures 55 - 64. Xynobius geniculatus (Thomson), ♀, South Korea 55 wings 56 mesosoma, lateral view 57 mesosoma, dorsal view 58 1 st metasomal tergite, dorsal view 59 metasoma, dorsal view 60 head, anterior view 61 head and pronotum, dorsal view 62 propodeum, dorsal view 63 ovipositor and sheath, latero-ventral view 64 antenna. The red arrow indicates the dorsope.