Anterhynchium (Anterhynchium) mephisto ( Gribodo, 1892 )

Selis, Marco & Carpenter, James M., 2023, Revision of the Afrotropical species of the genus Anterhynchium de Saussure (Hymenoptera: Vespidae: Eumeninae), Zootaxa 5233 (1), pp. 1-102 : 59-62

Anterhynchium (Anterhynchium) mephisto ( Gribodo, 1892)

( Figs. 13–14 )

Rygchium mephisto Gribodo 1892: 283 , ♀ —“ Sierra Leona ” (holotype MSNG).

Synagris uncata Tullgren 1904: 449 , pl. 25 figs. 11a–b, ♀ —“Kitta” (holotype NHRS). Syn. nov.

Odynerus (Rygchium) rufoniger Bequaert 1918: 133 (key), 164, 310 (catalogue), figs.174–177, ♀ —“ Belgian Congo Stanleyville ” (holotype AMNH). Syn. nov.

Anterhynchium beninum Gusenleitner 2018: 300 , figs. 21–24, 26, ♀, ♁—“ Bénin, Pénéssoulou, Forêt de Pénólan , 392m ” (holotype BGOF). Syn. nov.

Diagnosis. This species can be recognized by: smaller size, coloration black with abundant red markings and sometimes yellowish spots on T2, wings fuscous with purplish reflections, pubescence of head and mesosoma dark brown to black, posterior lobe of tegula blunt, parategula curved and inclined towards middle, dorsal faces of propodeum entirely punctured, propodeum rounded with curved tooth above valvula, male clypeus with narrow apical margin, male F11 elongate and weakly curved in lateral view, mid femur of male simple, vertex of female with foveae placed in circular depression.

Typical material examined. Holotype of Rygchium mephisto : “ Coll.Gribodo / Sierr. Leona / D // Rygchium / Mephisto / ♀ Grib. / Tipo / D. Gribodo ”, ♀ ( MSNG) . Holotype of Odynerus rufoniger : “Stanleyville, Cgo. / 25°10’ E; 0°30’N. // TYPE [red label] // Am. Mus. Nat. Hist. / Dept. Invert. Zool. / No. 244450 // Odynerus / rufoniger / type J. Beq. // [barcode] / AMNH_IZC 00331883”, ♀ ( AMNH) .

Description. MALE. Fore wing length 8.0– 11.5 mm.

Head 1.25 × as wide as long in frontal view. Clypeus in lateral view convex in basal half, then flattened to the apex; in frontal view 1.1 × as long as wide, apical margin truncate and very narrow, about 0.2 × as wide as clypeus width, apical teeth dull and shortly carinate. Interantennal space carinate. Distance from posterior ocellus to occipital carina 2.1 × as long as the distance from posterior ocellus to inner eye margin. Gena 0.75 × as wide as eye at bottom of ocular sinus; occipital carina strong ventrally, becoming finer toward vertex. Scape 3.6 × as long as apically wide; F1 2.2 × as long as wide, F2–F5 and F9 longer than wide, F6–F8 subquadrate, F10 very small and subquadrate, F11 bacilliform, apically rounded and nearly straight in lateral view, weakly curved in dorsal view, reaching apex of F8; F6–F10 with indistinct tyloids. Pronotal carina complete, elevated into a very short lamella; pretegular carina indistinct dorsally. Mesoscutum 0.95 × as long as wide between tegulae, evenly convex in lateral view. Scutellum weakly convex, with a barely visible median longitudinal furrow. Metanotum in lateral view weakly angled, horizontal and vertical faces not distinctly separated by a transverse carina, vertical face transversely convex. Tegulae elongate, outer margin evenly convex, posterior lobe triangular and short, not reaching apex of parategulae. Parategulae large and straight, with rounded apex. Mesepisternum weakly convex, epicnemial carina sharp and reaching transverse furrow, becoming lamellate ventrally. Propodeum in lateral view almost vertical; sides of posterior face flat and angularly meeting on median line, therefore posterior face large and weakly depressed; dorsal faces convex; lateral faces flat with weak apical depression; dorsal carinae absent, therefore dorsal and posterior faces are not clearly separated; lateral carinae absent; inferior carina weak with a curved tooth above propodeal valvula. T 1 in dorsal view 0.75 × as long as wide, almost parallel-sided, in lateral view with a flat vertical face which continues in a flattened horizontal face, transition broadly rounded; T 2 in dorsal view wider than long, in lateral view regularly convex from base to apex; S 2 in lateral view weakly and evenly convex basally, then flattened to apex, with a large triangular depression that runs from basal margin to posterior third of sternum.

Head with shallow flat-bottomed punctures, interspaces shorter than punctures diameter on frons, becoming wider on vertex and gena; interantennal space and most of ocular sinus smooth. Clypeus micropunctate with scattered barely visible punctures on basal half, densely microstriate in apical half. Pronotum, mesoscutum and scutellum with dense deep punctures, interspaces at most equal to punctures diameter. Metanotum coarsely punctured on horizontal face, interspaces forming irregular carinae; vertical face punctured in dorsal half, impunctate ventrally. Mesepisternum, except epicnemium and posterior margin, with large flat-bottomed punctures, interspaces equal to punctures diameter dorsally, becoming wider ventrally. Dorsal plate of metaepisternum smooth and shiny, with some weak striae on dorsal third; ventral plate dull and microreticulate. Dorsal face of propodeum with coarse irregular punctures, interspaces irregular and ridge-like; posterior face finely and obliquely striate in the middle, largely smooth on sides; lateral faces with sparse transverse fine striae. T1 with fine punctures, nearly absent on vertical face, denser on disc of horizontal face, interspaces much larger than puncture diameter. T2 with oblique punctures, becoming larger and denser apically, forming a preapical band of dense deep punctures, leaving an impunctate apical margin. T3–T7 with small punctures, becoming progressively finer and sparser. S1 with transverse irregular striae on apical expanded part, basal narrow part smooth. S2–S7 punctured like respective terga, but punctures deeper and sparser, interspaces shiny. Head and mesosoma with short ferruginous-goldish pubescence, longer on frons, mesepisternum and propodeum; metasoma with dust-like pale pubescence; sternites with pale bristles, apex of S2–S6 and whole S7 with black bristles.

Black; following parts red:part of clypeus, antenna,mandible,upper part of gena, pronotum,sides of mesoscutum, scutellum, metanotum, tegula, most of mesepisternum and metaepisternum, propodeum except median line, legs, sides of T1; following parts pale yellow: clypeus, interantennal space and triangular mark above it, underside of scape, elongate spot on upper part of gena, anterior third of pronotum, parategula, upper part of mesepisternum, posterolateral angles of propodeum, apical marking on fore and mid femora, outer face of fore tibia, paired lateral spots on T1–T5. Most specimens present only the above described red markings, but in some cases they can be more extensive and cover most of mesoscutum and T1 too, while the yellow markings can be completely absent to all present, with all intermediate combinations. Wings strongly fuscous with purplish to brassy effulgence.

FEMALE. Fore wing length 13.0– 15.5 mm.

Like male, except: head 1.25 × as wide as long in frontal view; clypeus pyriforme and coarsely punctured, 1.2 × as long as wide, apical margin narrow and shallowly emarginate, apical teeth short and rounded and carinate, carinae delimiting a median shallow furrow; gena 0.95 × as wide as eye at bottom of ocular sinus; cephalic foveae placed in a circular deep depression near occipital margin; scape 3.7 × as long as apically wide; F1 1.8 × as long as wide, F2–F9 becoming proportionally shorter towards apex, F2–F3 longer than wide, F4–F9 subquadrate, F10 bullet shaped; T 1 in dorsal view 0.7 × as long as wide and more densely punctate. Yellow markings, when present, usually reduced to basal band on clypeus, bilobate spot above interantennal space and lateral spots on T1–T2.

Distribution. Benin, Cameroon, Democratic Republic of Congo, Equatorial Guinea *, Gabon, Guinea *, Ivory Coast, Liberia *, Nigeria, Republic of Congo *, Senegal *, Sierra Leone, Togo * ( Bequaert 1918; Carpenter et al. 2009; Gribodo 1892; Gusenleitner 2018; Schouteden 1919; von Schulthess 1928b) ( Fig. 10 ).

Remarks. Anterhynchium beninum , Anterhynchium rufonigrum and Anterhynchium uncatum are here synonymized under Anterhynchium mephisto after examination of the holotypes of Rygchium mephisto and Odynerus rufoniger , and a paratype of Anterhynchium beninum . No appreciable differences were found comparing them with the description of Synagris uncata . The holotype of the latter was not available for the study, as it was sent by NHRS to Giordani Soika in 1973, but the specimen cannot be found in MSNVE (cf. Dal Pos et al. 2022). However, Giordani Soika (1987: 196) stated that he considered uncatum and rufonigrum synonyms, and wrote this synonymy on labels pinned under various specimens in his collection, probably after direct examination of the holotype of Synagris uncata .

This species is quite variable in the shape of the propodeal teeth and in coloration. The propodeal teeth range from short and thin weakly curved spines near propodeal valvulae, to large and thick strongly curved spines on posterolateral angles of propodeum, while coloration ranges from specimen with red markings reduced on head, mesosoma and T1, to specimens with head and mesosoma almost entirely red and T1 red with apical black line, also the light lateral spots on T2 described for Rygchium mephisto are very variable and can be present as undefined reddish markings to defined circular yellow spots, accompanied by yellowish markings on mesosoma, legs and other tergites. The great variability in the shape of propodeal teeth could lead to thinking that these forms represent distinct species, but the presence of many different intermediate forms and the absence of other morphological differences do not support a separation.

Figures

FIGURE 10. Distributional map of mephisto species-group.

FIGURE 13. Anterhynchium mephisto (Gribodo, 1892).A, habitus of female. B, head of male in frontal view. C, head of female in frontal view. D, head of female in dorsal view. E, flagellum of male in lateral view. F, propodeum in lateral view. G, T2 in dorsal view.

FIGURE 14. Anterhynchium mephisto (Gribodo, 1892). A–B, variability of propodeal teeth.