Sulcomesitius angustifrons, Wang & He & Chen, 2024

Wang, Chunhong, He, Junhua & Chen, Xuexin, 2024, Revision of subfamily Mesitiinae (Hymenoptera, Bethylidae) from China, European Journal of Taxonomy 960 (1), pp. 1-61 : 29-32

Sulcomesitius angustifrons sp. nov.

urn:lsid:zoobank.org:act:1E90D2B8-2938-4D0B-BEAA-5CE53006645D

Fig. 10

Diagnosis

This new species can be recognized by having the median pronotal sulcus developed, the PPP distinctly longer than its width at the base, the apical margin of the PPP distinctly acute in dorsal view and the hind wing with four distal hamuli. This species is similar to S. impressus Xu, He & Terayama, 2003 . However, the new species can be distinguished by having the following characteristics: length of eye equal to width of frons (WF 1.33× LE in S. impressus ), legs partly dark brown (reddish brown in S. impressus ), and T4–5 dark brown (brown or reddish brown in S. impressus ), punctures on lateral surface of T2 as dense as on dorsal surface (denser on lateral surface than on dorsal surface in S. impressus ).

Etymology

The specific epithet is a combination of ‘ angustus ’ (Latin for ‘narrow’) and ‘ frons ’, referring to the comparatively narrow frons.

Material examined

Holotype

CHINA – Yunnan • ♀; Xishuangbanna, Naban River Watershed National Nature Reserve ; [22.12961˚ N, 100.66612˚ E]; alt. 746 m; 6 Jun. 2008; A. Weigel leg.; IZCAS IOZ(E) 2059138.

Description

Female

MEASUREMENTS (holotype, Fig. 10A ). Body length 7.06 mm. Fore wing length 3.16 mm.

COLOURATION. Body black. Mandible brown; maxillary palp and labial palp brown. Antenna black, yellowish brown ventrally; scape, pedicel, and flagellomeres I–II brown. Fore wing bi-banded, veins brown or yellowish brown, pterostigma yellowish brown. Legs dark brown; trochanters, tibiae and tarsi yellowish brown. T1–3 with posterior margin yellowish brown, metasomal segments 3–5 dark brown with posterior margin yellowish brown, metasomal segments 6–7 yellowish brown.

PUBESCENCE. Body with short setae; maxillary palp, labial palp and antenna with dense appressed setae ( Fig. 10C ). Metasomal segments with setae longer than setae of head and mesosoma; T1 with sparse setae posterolaterally; T2 densely setose posteriorly and laterally with basal triangular area glabrous. Wings with dense, short yellowish-brown setae.

HEAD. Longer than wide, LH 1.07 × WH. Mandible with 4 apical teeth, ventralmost one sharp and largest. Clypeus trilobite; medio-clypeal lobe with anterior margin acute medially ( Fig. 10B ); medio-clypeal carina not extending into frons, arched in lateral view. Antenna distinctly thickened, at least flagellomeres II–IX shorter than wide. Frons coriaceous and densely foveolate ( Fig. 10B ); WF 1.01 × LE. Contour of eye protruding in antero-dorsal view, LE 0.46 × LH, LE 2.08 × DEV. Anterior ocellus entirely anterior to imaginary top line of eyes; POL 1.33 × AOL, OOL 0.93 × WOT, DPV 2.36 × DAO. Sides of head behind eyes rounded and slightly converging posteriorly. Vertex coriaceous and densely foveolate, vertex crest slightly protruding. Malar space 1.21 × distance between posterior ocelli and vertex crest. Gena coriaceous, densely foveolate, with shallow foveolae ventrally. Occipital carina complete, occiput coriaceous with shallow punctures. Medioccipito-genal suture present. Hypostomal sulcus present.

MESOSOMA. Dorsal pronotal area coriaceous and densely foveolate, median length 0.51 × width of posterior pronotal margin ( Fig. 10D ); median pronotal sulcus present; lateral pronotal area obliquely strigate; cervical pronotal area coarse. Mesoscutum with notauli complete, parapsidal signum shallow but complete; lateral area of mesoscutum coriaceous with shallow punctures and depressed anteriorly. Mesoscutellum coriaceous with punctures, densely foveolate; mesoscutum-mesoscutellar sulcus present, laterally dilated. Median length of dorsal surface of MPC 1.04 × its half-width; metapostnotum strongly areolate, metapostnotal median carina complete, metapostnotal-propodeal carina complete and converging posteriorly; dorsal propodeal area transversely striate; paraspiracular and lateral marginal carinae of MPC complete and parallel ( Fig. 10E ); length of PPP 0.32 × median length of dorsal surface of MPC ( Fig. 10E ); propodeal declivity areolate, median and lateral carinae complete; lateral surface of MPC areolate, anterior metapleural area transversely striate. Propleuron coriaceous and shallowly foveolate. Mesopleuron coriaceous and densely foveolate; subalar impression weak; posterior oblique sulcus of mesopleuron present and foveolate.

WINGS. Fore wing with 2r-rs&Rs 2 v slightly curved apically, 0.80 × Sc+R 2 v; posterior margin of pterostigma straight, prestigma absent ( Fig. 10G ); Cu 2 v present as yellowish-brown trace. Hind wing with four distal hamuli.

METASOMA. Metasomal terga shiny with punctures; T1 with tiny, sparse punctures; T2 with dense punctures separated by 1–5 × their diameter, posterior margin without punctures ( Fig. 10F ); T3–5 with three semi-circular impressions on posterior margin. Metasomal sterna shiny with punctures; S1 irregularly striate, metapostnotal median carina weak; S2–3 with dense punctures separated by less than 2.0× their diameter.

Male

Unknown.

Distribution

China (Yunnan) ( Fig. 20 ).

Figures

Fig. 10. Sulcomesitius angustifrons sp. nov., holotype, ♀ (IZCAS IOZ(E) 2059138). A. Habitus, lateral view. B. Head, antero-dorsal view. C. Antenna. D. Pronotum, dorsal view. E. MPC, dorsal view. F. T2, dorsal view. G. Fore wing. Scale bars: A, C–G = 0.20 mm; B = 0.25 mm.

Fig. 20. Distribution map of species of Mestiinae from China.