Megaodynerus flavogaster Long, Chen & Li, 2025

Long, Si-Zhu, Chen, Bin & Li, Ting-Jing, 2025, Taxonomic notes on the rare genus Megaodynerus Gusenleitner, 2012 (Hymenoptera, Vespidae, Eumeninae): a new species from China, with an updated key to all known species, Journal of Hymenoptera Research 98, pp. 1031-1037 : 1031-1037

Megaodynerus flavogaster Long, Chen & Li sp. nov.

Figs 2–12

Material examined.

Holotype • ♀, China, Anhui, Lu’ an City, Jinzhai County, Tiantangzhai Town , 31°10'23"N, 115°49'29"E, alt. 703 m, 15 May 2023, Yin-Qiao Zhang leg. ( IOZCAS) . Paratypes • 2 ♂, China, Anhui, Anqing City , Yuexi County, 31°2'28"N, 116°6'22"E, alt. 716 m, 2 June 2023, Huan-Xi Cao leg. ( IOZCAS) .

Diagnosis.

This species is distinguished from the two known species M. maximus Gusenleitner, 2012 and M. bimaculus Bai, Chen & Li by the following character combination: metanotum without a median longitudinal groove (Figs 6 , 8 ), transition between dorsal and posterior surfaces of propodeum with a raised round carina (Fig. 6 ), both T 1 and T 2 almost wholly brownish yellow except anterior margin and median black spot, T 3 and T 4 with apical brownish yellow bands (Fig. 11 ).

Description.

Female: Body (Fig. 2 ) length 16.7 mm, forewing length 15.0 mm; frons with thick setae exceeding the diameter of an ocelli; mesosoma covered with strongly short and brown setae except mesopleuron and propodeum with longer and light setae, metasoma with microscopic pubescence; body black, with the following parts brownish yellow: basal half of clypeus, interantennal spot, ventral surface of antennal scape, small spot on gena, anterior quarter of pronotum, tegula except the inner margin, a pair of tiny dark spots on scutellum, small dark spot on metanotum, outside of dorsal surface of propodeum, both T 1 and T 2 almost whole excluding their anterior margins and narrow median gaps, apical bands of T 3 and T 4, lateral spots on apexes of both S 2 and S 3; wings brown, with purple luster.

Head. Head slightly wider (about 1.1 times) than long in frontal view (Fig. 4 ); clypeus about 1.1 times as wide as long, with small and sparse shallow punctures, interspaces microscopically longitudinal carinate at apex, apical emargination shallow and laterally blunt (Fig. 4 ); mandible with four prominent teeth; frons distinctly reticulo-punctate; vertex with moderate punctures and two connecting cephalic foveae (Fig. 5 ), foveae bearing dense pubescence, its lateral margin not exceeding posterior ocellus, and their posterior margin close to occipital carina; gena with denser punctures than vertex, occipital carina broaden slightly at the side.

Mesosoma. Mesosoma much longer than wide in dorsal view (Fig. 8 ); pronotum with deep punctures, these punctures slightly sparser than those on the anterior of mesoscutum; pronotal carina produced completely and lateral corner round; mesoscutum about 1.1 times as long as wide, weakly convex in lateral view, posterior area with two deep longitudinal furrows, anteriorly with dense punctures and posteriorly with slightly sparser punctures (Fig. 8 ); mesopleuron with flat-bottomed punctures, with weak epicnemial carina; scutellum with dense punctures and a medial longitudinal furrow (Fig. 8 ); metanotum reticulo-punctate, with much coarser and punctures much densely than both mesoscutum and scutellum, without a median longitudinal furrow (Figs 6 , 8 ); metapleuron smooth; propodeum dorsally with irregular punctures and coarser than mesoscutum, posterior and lateral surfaces of propodeum with transverse striations, transition between dorsal and posterior surfaces with a raised round carina (Fig. 6 ).

Metasoma. T 1 slightly wider than long in dorsal view (1.3 times), punctures larger and denser than mesoscutum with anterior area much coarser, medial longitudinal furrow on the horizontal surface gradually shallower from anterior to posterior (Fig. 11 ); punctures on T 2 smaller and sparser than those on T 1, with thin apical transparent lamella; S 2 (Fig. 12 ) concave at base, almost impunctate with scattered and fine punctures; T 3 with narrower apical transparent lamella; observable part of T 3 – T 6 with deep punctures; S 3 – S 6 with sparse punctures.

Male. Body length 10.5–11.4 mm (Fig. 3 ); sculpture, setae and coloration similar to female except as follows: clypeus wholly yellow, its apical emargination broader and deeper forming lateral acute tooth (Fig. 7 ); apex of A 13 bent back reaching the base of A 11, A 11 – A 13 ventrally brownish yellow (Fig. 9 ); vertex without cephalic foveae; epicnemial carina strongly developed; scutellum and metanotum occasionally with larger yellow spots; epicnemial carina much developed then the female; penis valve suddenly widened at the apex (Fig. 10 ).

Distribution.

China: Anhui.

Etymology.

The specific name is derived from two Latin words: flavus (= yellow) and gaster (= metasoma), referring to the species with a lot of yellow marks on metasoma.

Figures

Figures 2–12. Megaodynerus flavogaster sp. nov., holotype (♀) (2, 4, 5, 6, 8, 11, 12) paratype (♂) (3, 7, 9, 10). 2, 3. Habitus (dorsal view); 4, 7. Head (frontal view); 5. Head (dorsal view) 6 propodeum (dorsal view); 8. Mesosoma (dorsal view); 9. Antenna; 10. Genitalia (dorsal view); 11. Metasoma (dorsal view); 12. Metasoma (ventral view).