Orthocentrus flavescens Humala & Lee, 2020

Humala, Andrei E., Lee, Jong-Wook & Choi, Jin-Kyung, 2020, A review of the genus Orthocentrus Gravenhorst (Hymenoptera, Ichneumonidae, Orthocentrinae) from South Korea, Journal of Hymenoptera Research 75, pp. 15-65 : 15

6. Orthocentrus flavescens Humala & Lee sp. nov.

Fig. 5

Description.

Female. Fore wing length 3.1 mm.

Face at level of antennal sockets 1.4 times as wide as high; face smooth, polished, sparsely punctate, eyes not setose, dorsal ridge of face in between antennal sockets with a median blunt low prominence; face profile straight except dorsally very slightly impressed, inner orbits slightly divergent ventrally; edge of clypeus straight, antennal sockets not on a distinct high shelf; subocular sulcus well developed, nearly straight; maxillary palp reaching beyond fore coxa. In dorsal view, head posteriorly slightly concave, temples very short, lateral ocellus separated from eye by a distance 1.4 times longer than its maximum diameter, POL 1.6 times as long as diameter of lateral ocellus; ocellar-ocular grooves present. Minimum distance between antennal sockets about 0.4 × diameter of socket; antenna with 20 flagellomeres elongate, first flagellomere about 3.0 times as long as wide and about 0.9 times as long as scape; scape slightly convex on inner surface, slightly concave on outer surface.

Mesosoma smooth and polished; mesoscutum anteriorly with distinct notauli; in profile, scutellum particularly high, metapleuron slightly convex; propodeum with posterior transverse carina complete, strong and raised between lateral longitudinal carinae, lateromedian longitudinal carinae complete, lateral longitudinal carinae distinct, spiracle small.

Legs robust; coxae polished, femora with coriaceous microsculpture, tibiae and tarsi coriaceous-granulate; hind femur 2.9 times as long as high, hind tibia 3.5 times as long as apically wide; tibiae with spine-like setae.

Wings not particularly narrow; fore wing without areolet; vein Rs nearly straight, fore wing with vein Rs+2r meeting middle of pterostigma; vein cu-a nearly interstitial (opposite Rs&M); nervellus straight, intercepted below.

First tergite stout, widening posteriorly, 1.2 times as long as posteriorly wide; coriaceous, with two lateromedian longitudinal carinae and longitudinal striae, with transverse impressions originating at about middle of tergite, sloping posteriorly, meeting centrally.

Second tergite 0.8 times as long as posteriorly wide; coriaceous and longitudinally striate, with developed lateromedian longitudinal carinae, anterior corners impressed and transverse groove near posterior margin bending anteriorly near lateral margins, forming a somewhat uplifted striated area medially; small thyridia contrastingly coloured. Third tergite longitudinally striate with transverse impressions originating at about middle of tergite, sloping posteriorly, not meeting centrally. Remainder of metasoma unsculptured, polished. Ovipositor thin, comparatively short, weakly upcurved, without subapical dorsal notch; ovipositor sheath narrow, with sparse setae.

Body setose except eyes, pronotum, mesopleuron and metapleuron, setae scattered on metasoma and posterior sides of coxae.

Yellowish brown; face dusky orange, inner orbits broadly yellow up to occiput; antenna yellowish-brown; malar area yellow posterior to subocular sulcus and up to level of eye middle; mouthparts, legs yellow; propleuron, pronotum, mesopleuron in lower 2/3, mesoscutum anteriorly and longitudinal bars along notauli, scutellum, central part of metapleuron, reddish brown; posterior margins of tergites 1-3 and tergite 4 light-brown.

Male. flagellum with 21 flagellomeres; basic coloration - yellow, frons reddish-yellow. Otherwise as in female.

Biology.

Hosts unknown.

Etymology.

Named from the Latin flavesco (turn yellow) after the yellowish general body colouration.

Comparison.

This is a distinctive species on account of the metasomal tergites 2-3 with strong transverse-diagonal furrows separating contrastingly coloured creamy latero-posterior corners. From the closely allied O. castellanus it differs in the absence of the fore wing areolet and fewer antennal flagellomeres.

Material examined.

Holotype: female; South Korea, GW: Chuncheon-si , Sanong-dong, Gwangwon Provincial Arboretum, 1-14.VIII.2013, I.G. Kim leg. (DNUE).

Paratype: South Korea, GB: 1 ♂, Bongjeongsa 10-11.VII.1998, J.W. Lee leg. (DNUE-0135) .

Distribution.

South Korea (GB, GW).

Figures

Figure 5. Orthocentrus flavescens sp. nov. Holotype. A Habitus in lateral view B head in frontal view C head in dorsal view D head and mesosoma in lateral view E mesosoma in dorsal view F areolet G first to third tergites in dorsal view.