Heterocoelia curtisulcus, 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 : 6-9

Heterocoelia curtisulcus sp. nov.

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Fig. 2

Diagnosis

This new species can be recognized by its having flagellomeres with dense setae shorter than one-third of width of flagellomere; median pronotal sulcus present and not foveolate; median mesonotal sulcus present near posterior margin of mesoscutum; PPP equal to or slightly longer than its width at base; hypopygium longer than wide with anterior margin broad and posterior branches short; genitalia with dorsal harpe narrower than ventral harpe.

This new species is similar to H. neomoczari (Barbosa & Azevedo, 2018) in having flagellomere I less than 2.0× length of flagellomere II. However, it can be distinguished by having median pronotal sulcus not foveolate (distinctly foveolate in H. neomoczari ); median mesonotal sulcus present (absent in H. neomoczari ); PPP with apical margin rounded in lateral view (acute in H. neomoczari ).

Etymology

The specific epithet ‘ curtisulcus ’ is a combination of the Latin words ‘ curtus ’ (‘short’) and ‘ sulcus ’(‘groove’) referring to the median mesonotal sulcus of this species present on the posterior third of the mesoscutum.

Material examined

Holotype

CHINA – Shandong • ♂; Laoshan ; 3 Aug. 1995; Ping Cai leg.; ZJUH 958281 .

Paratype (1 ♂)

CHINA – Shandong • 1 ♂; Laoshan ; 4 Aug. 1995; Junhua He leg.; ZJUH 955913 .

Description

Male

MEASUREMENTS (n = 2). Body length 4.66–5.02 mm; fore wing length 2.65–3.15 mm; LH 1.07–1.09 × WH; WF 1.67–1.74× LE; LE 0.99–1.02 × DEV; POL 1.62–1.70× AOL; OOL 0.95–1.01× WOT; DPV 1.90–2.14× DAO; median length of pronotum 0.53–0.54× its width along posterior margin; length of hypopygium 1.73–1.79× its width; length of posterior branches of hypopygium 0.13–0.16× length of hypopygium.

COLOURATION. Black. Mandible dark brown, teeth brown; maxillary and labial palpi brown. Antenna brown, scape blackish brown. Legs brown, coxae and femora dark brown, tarsi yellowish brown. Fore wing hyaline, light brown; veins and pterostigma brown. Trochanters, tibiae apically and tarsi yellowish brown. Mesosoma blackish brown. Metasomal segments brown apically.

PUBESCENCE. Body with short setae, denser on ventral surface.Antenna with short appressed setae, 0.25 × width of flagellomere ( Fig. 2C ). Eye with sparse short setae, nearly 4.0 × diameter of an ommatidium. Wings with short, dense brown setae. Legs with dense, short setae. Metasoma with setae longer than setae on head and mesosoma; T1 with setae laterally, T2 with basal glabrous triangular area dorsally.

HEAD. Longer than wide, LH 1.07 × WH. Mandible with four apical teeth, ventralmost one longest. Clypeus trilobite, medio-clypeal lobe with anterior margin rounded ( Fig. 2B ); medio-clypeal carina present, not extending into frons, arched in lateral view. Antenna thin, flagellomeres cylindrical, length of flagellomere III 1.48 × length of flagellomere II. Frons coriaceous and densely foveolate ( Fig. 2B ); WF 1.74 × LE. Contour of eye distinctly protruding in antero-dorsal view ( Fig. 2B ); LE 1.02 × DEV. Anterior ocellus partly anterior to imaginary top line of eyes in antero-dorsal view; POL 1.62× AOL, OOL 1.01× WOT, DPV 1.90 × DAO. Vertex coriaceous and densely foveolate, sides of head behind eyes rounded, vertex crest protruding. Gena coriaceous and densely foveolate, ventral surface with shallower and sparser foveae, medioccipito-genal suture present. Occipital carina present, occiput coriaceous.

MESOSOMA. Dorsal pronotal area coriaceous and densely foveolate, median length 0.54 × width along posterior pronotal margin; anterolateral corner rounded; median pronotal sulcus complete, not foveolate ( Fig. 2D ); lateral pronotal area areolate; cervical pronotal area coarse. Mesoscutum coriaceous with dense punctures, elevated posteriorly; median mesonotal sulcus present on posterior third of mesonotum ( Fig. 2D ); notauli complete and converging posteriorly ( Fig. 2D ); parapsidal signum shallow and absent near anterior margin. Mesoscutellum coriaceous and foveolate; mesoscutum-mesoscutellar sulcus present, laterally dilated ( Fig. 2D ); medio-longitudinal sulcus absent. Dorsal surface of MPC elevated; median length of dorsal surface of MPC equal to its half-width; metapostnotum strongly areolate, metapostnotal median carina complete; metapostnotal-propodeal carina complete, distinctly oblique anteriorly and converging posteriorly; dorsal propodeal area striate; paraspiracular and lateral marginal carinae of MPC complete; PPP present, 0.21× median length of dorsal surface of MPC, apical margin of PPP rounded in lateral view; transverse posterior carina of MPC complete; propodeal declivity areolate, median and lateral carinae complete; lateral surface of MPC areolate, sublateral carina of MPC not extending to PPP. Propleuron coriaceous and densely foveolate. Mesopleuron coriaceous, densely foveolate; subalar impression present; posterior oblique sulcus of mesopleuron foveolate; postepicnemial sulcus present; ventral surface foveolate, with short carina near mesocoxa, medio-longitudinal sulcus present on apical half.

WINGS. Fore wing with 2r-rs&Rs 2 v slightly curved apically; posterior margin of pterostigma straight, prestigma absent ( Fig. 2F ); Cu 2 v nebulous. Hind wing with three distal hamuli, distance between 1 st and 2 nd hamuli 1.43 × distance between 2 nd and 3 rd hamuli.

METASOMA. Metasomal terga shiny, with punctures; T1 with tiny sparse punctures, medio-longitudinal sulcus present at basal third of T1; T2 with dense punctures, coriaceous basally ( Fig. 2E ); basal half of T3–4 coriaceous. Metasomal sterna shiny, with variably sized punctures; S1 with dense punctures. Length of hypopygium 1.79× its width; anterior margin incurved ( Fig. 2G ); posterior margin incurved, posterior branches broad and short, with long setae, length of branches 0.16 × length of hypopygium.

MALE GENITALIA. Harpe bilobate, dorsal harpe S-shaped ( Fig. 2H ); ventral harpe broader than dorsal harpe, with long setae apically ( Fig. 2I ). Cuspis bilobate, with long setae; digitus bent and papillate apically, with setae basally; aedeagus bottle-shaped ( Fig. 2H ).

Female

Unknown.

Distribution

China (Shandong) ( Fig. 20 ).

Remarks

The type specimens of this species were identified as Sulcomesitius borneoensis Móczár, 1976 by Xu et al. (2003) because of the presence of a median mesonotal impression on the mesoscutum near the posterior margin. However, some males of the genus Heterocoelia also have a median mesonotal sulcus on the mesoscutum ( Azevedo et al. 2018; Barbosa et al. 2022), and the shape of hypopygium is now used as an important character for the generic identification of the males. After an examination of the male hypopygium, we included these specimens in the genus Heterocoelia rather than Sulcomesitius because of the longer than wide hypopygium with posterior branches broad and short. In Heterocoelia they cannot be associated with a named species; therefore, the species is here described as H. curtisulcus sp. nov.

Figures

Fig. 2. Heterocoelia curtisulcus sp. nov., holotype, ♂ (ZJUH 958281). A. Habitus, lateral view. B. Head, antero-dorsal view. C. Antenna. D. Pronotum and mesonotum, dorsal view. E. T2, dorsal view. F. Fore wing. G. Hypopygium. H. Genitalia, dorsal view. I. Genitalia, ventral view. Scale bars: 0.20 mm.

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