Bethylus colligatus Lim, 2025

Lee, Kyung Min, Kim, Il-kwon & Lim, Jongok, 2025, New species and barcode analysis of Bethylus Latreille (Hymenoptera, Bethylidae) from South Korea, ZooKeys 1238, pp. 131-148 : 131-148

Bethylus colligatus Lim sp. nov.

Figs 1 , 2 , 3 , 4

Description.

Holotype (female). Colour. Head: black, mandible castaneous; antenna light castaneous, darkening apicad. Mesosoma: black; forewing hyaline and subhyaline, veins light castaneous; coxae, trochanters, femora dark castaneous; tibiae and tarsomere V light castaneous; tarsomeres I – V yellow. Metasoma: dark castaneous.

Morphology. Body length 3.7 mm.

Head (Fig. 4 D – G ): 1.1 × as long as wide (Fig. 4 D ). Lateral margin posterior to eye tapering to postero-lateral corner, postero-lateral corner forming round angle, posterior margin straight in dorsal view with long sub-erect setae, vertex crest slightly outcurved (Fig. 4 D ). Mandible with hairs and four teeth; all teeth sharpened apically, getting long to ventralmost tooth (Fig. 4 G ). Clypeus well developed, median clypeal lobe distinctly protuberant with apex rounded; lateral clypeal lobe polished and smooth; median clypeal carina developed, slightly extending posterad into frons (Fig. 4 D ). Antenna with 12 antennomeres; each antennomere longer than wide; first six antennomeres with in ratio of 2.19: 1.08: 1.00: 1.04: 1.04: 1.02 and 1.03 in length; 2.3, 1.9, 2.0, 1.8, 1.8, 1.8 and 2.2 × as long as wide, respectively (Fig. 4 F ). Frons coriaceous with sparse shallow punctures, separated each other by 1.5–4.0 × of their diameter (Fig. 4 D ). WF 1.2 × LEF (Fig. 4 D ). Mediooccipito-genal suture present. Occipital carina absent. Compound eye 0.35 mm in dorsal view (Fig. 4 D ); 0.34 mm long and 1.4 × as long a wide in lateral view (Fig. 4 E ); LEF 1.2 × VOL (Fig. 4 D ). Anterior angle of ocellar triangle acute, POL 1.2 × AOL; OOL 2.0 × WOT; DPV 1.7 × DAO (Fig. 4 D ). LEL 1.3 × LG (Fig. 4 E ). Malar space narrow; malar line between mandible and eye absent. Gena coriaceous with shallow sparse punctures (Fig. 4 E ).

Mesosoma (Fig. 4 A – C, H ): pronotal dorsal area coriaceous, 0.5 × long as wide with sparse small punctures as dorsal surface of head; posterior margin outcurved medially (Fig. 4 H ). Mesoscutum coriaceous with few punctures; notaulus absent; parapsidal signum parallel, well developed, and continued to posterior carina between mesoscutum and mesoscutellum; posterior margin of mesoscutum broadly rounded (Fig. 4 H ). LMS 0.8 × as long as LMST (Fig. 4 H ). Mesoscutellar disc coriaceous; mesoscuto-scutellar fovea elongate, oblique (Fig. 4 H ). Metanotum reduced medially; metanotal fovea present; lateral area polished and smooth (Fig. 4 H ). Metapectal-propodeal complex 1.1 × as long as wide; metapostnotum depressed and reticulate; median ridge smooth and polished; metapectal-propodeal disc rugulose, depressed and obliquely rugose near lateral marginal carina of metapectal-propodeal disc; lateral marginal carina of metapectal-propodeal disc complete; propodeal declivity coriaceous; anterior metapleural area coriaceous, metapleural line with two distinct pits and some weak pits; lateral surface of metapectal-propodeal complex strongly coriaceous (Fig. 4 H ). Propleuron coriaceous. Mesopectus coriaceous with shallow punctures; subalar impression, mesepimeral sulcus distinct. Prosternum coriaceous with weak longitudinal sulcus medially.

Forewing (Fig. 4 I ): 2.39 mm long. Rs + M 2 v extremely short. 2 r-rs & Rs 2 v with apex angled curved. R 1 2 v 1.4 × as long as Lpts. M 2 v 2.0 × as long as Rs 2 v. Rs 2 v 1.0 × as long as Cu 2 v. R 2 c, 1 Cu 2 c, and 1 M 2 c hyaline with sparse, short hairs; elsewhere with denser, short hairs. M 2 fl 0.94 mm long, straight.

Metasoma (Fig. 4 A ): metasomal terga smooth and polished, weakly coriaceous basally; longitudinal sulcus of first metasomal tergum distinctly exceeding first metasomal spiracle. Overlapping region of tergum weakly coriaceous. S 3 – S 6 with one transverse apical line of small punctures with suberect hairs along with posterior margin of each sternite.

Type locality.

South Korea • Gangwon Province: Yanggu: Haean: Mandae: DMZ Botanical Garden ; Malaise trap, 38°15'13"N, 128°6'47"E, Alt. 608 m, 30.vi.2015, H. T. Shin leg.

Type material.

Holotype: ♀, South Korea: Gangwon Province: Yanggu: Haean: Mandae: DMZ Botanical Garden ; Malaise trap, 38°15'13"N, 128°6'47"E, Alt. 608 m, 30.vi.2015, H. T. Shin leg. ( KNAE 20150630-MT-055 ) . Paratypes: 2 ♀, same data as holotype, KNAE 20150630-MT-056 , KNAE 20150630-MT-057 .

DNA barcodes.

GenBank accession numbers PQ 777353 – PQ 777356. The intraspecific divergence of the barcode region averages 1.15 %, with a maximum distance of 2.11 % (n = 4). The minimum distance to its nearest neighbour, B. berlandi , is 22.0 %.

Distribution.

Known only from the type locality.

Etymology.

The name colligatus is Latin, meaning “ unified, ” as the type specimens were collected from the DMZ area (Yanggu County, Gangwon Province), situated between the two Koreas. The species epithet is treated as an adjective in the nominative.

Remarks.

This species closely resembles B. convexus Wang, He & Chen from China in terms of body colour, the median clypeal lobe with a rounded apex, an acute anterior angle of the ocellar triangle, a distinctly protuberant eye, and being macropterous. However, it differs from B. convexus in several key features: the side of the head posterior to the eye taper towards the postero-lateral corner, all mandibular apical teeth are sharpened, the DPV is 1.7 × the DAO, the apex of 2 r-rs & Rs 2 v is distinctly angled in B. colligatus sp. nov., whereas the sides of head posterior to eye parallel, upper most one with margin truncated, the DPV is 1.0 × the DAO, and the apex of 2 r-rs & Rs 2 v is rounded in B. convexus .

Figures

Figure 1. Biometric measurements for head habitus A overall measurements of head, dorsal view B measurements related with eye and ocelli, dorsal view. See Table 1 for abbreviations.

Figure 2. Biometric measurements for antennae and head habitus A measurements of antennomeres, dorsal view B measurements of head and gena, lateral view. See Table 1 for abbreviations.

Figure 3. Biometric measurements for mesosoma and forewing A measurements of mesosoma, dorsal view B, C measurements related with veins and flexion line, dorsal view. See Table 1 for abbreviations.

Figure 4. Diagnostic characteristics of Bethylus colligatus sp. nov., female, holotype A whole body, dorsal view B whole body, lateral view C mesosoma, lateral view D head, dorsal view E head, lateral view F antennae, dorsal view G mandible, frontal view H mesosoma, dorsal view I forewing in dorsal view. Scale bars: 1 mm (A, B); 0.50 mm (C, E, H, I); 0.20 mm (D – G).