Baloghianestes oribatidiformis Ballerio, Gill & Grebennikov

Ballerio, Alberto, Gill, Bruce D. & Grebennikov, Vasily V., 2011, Illustrated overview and identification key to Cameroonian Ceratocanthinae beetles (Coleoptera: Scarabaeoidea: Hybosoridae) with description of four new species, Zootaxa 2892, pp. 1-24 : 7-8

Baloghianestes oribatidiformis Ballerio, Gill & Grebennikov , n. sp.

( Figs. 4 , 7 A, C, E)

Material. Holotype, male: Cameroon S.-West Prov., Mt. Kupé at Nyasoso, N04°49.153’ E009°42.453’, 19– 21.V.2006, 1550m., V. Grebennikov leg. ( CNCI) [distended specimen glued on card, dissected, genitalia mounted in DMHF resin on a separate card, same pin]. Paratypes: 63 specimens [five males and two females dissected], same data as holotype ( ABCB, BDGC, CNCI, MRAC). Further material examined (not included in type series), 43 specimens [4 males and one female dissected]: Cameroon S.-West Prov., Bakingili, N04°03.35’ E009°03.823’, 24– 26.V. 2006, 250m, V. Grebennikov leg. ( ABCB, BDGC, CNCI).

Description. HL: 0.68 mm; HW: 1.30 mm; PL: 1.25 mm; PW: 2.19 mm; EL: 2.24 mm; EW: 2.22 mm. Small, flightless Ceratocanthinae . Body strongly convex; uniformly dark brown with faint brown-bronze sheen; underside and tarsi reddish brown, antennae pale yellow; head, pronotum and elytra covered by a pale yellow pubescence, visible at low magnification (45x).

Head: W/L ratio = 1.91, subpentagonal. Fore margin triangular, with angle blunt and obtuse (about 150°) and sides almost rectilinear; genae slightly produced outwards, acutely pointed; genal canthus indistinct; dorsal ocular area absent; ventral ocular area transverse, narrow. Head surface slightly convex, irregularly densely punctured; vertex with coarse, simple, deep punctures; puncture distance from each other being shorter than their diameter; disc with a longitudinal cariniform process, irregularly raised; discal surface covered by large, doubly ocellate, impressed punctures, almost adjacent to each other; ocellum bearing a simple, erect seta, interval between punctures raised.

Pronotum: short and transverse (W/L ratio = 1.75); fore angles distinctly truncate, no bead visible apart from around the truncature of fore angles; sides of fore margin, sides of pronotum and base without any visible bead. Pronotum with disc strongly raised basally, raised process inverted V-shaped, fore margin of pronotum also raised; the entire surface covered by strongly impressed large, doubly ocellate punctures; all punctures almost adjacent to each other; ocellum large and bearing a simple, erect seta.

Scutellum: slightly longer than wide (W/L ratio = 0.99); apex sharp and acute, with distal third narrow; sides of base notched by articular process of elytron; a small apical portion of mesepisternum visible from above; surface covered by small, impressed, simple punctures, basally becoming larger and distally ocellate.

Elytra: longer than wide (W/L ratio = 0.95), dorsal outline rounded; strongly convex; surface covered by impressed, doubly ocellate, large punctures; ocellum large and bearing a simple, erect seta. Humeral callus absent, replaced by a distinct irregular tubercle. Pseudoepipleura with the same microsculpturing as elytra; delimited by a lateral sharp, complete carina. Elytral suture distinctly raised; sutural stria absent; inferior sutural stria present; marginal area extremely small, almost completely replaced by the articular area, which bears about 5-7 visible ridges. Wings completely absent.

Antennae short, with nine antennomeres; scape securiform; pedicellum irregularly shaped, about as wide as the distal portion of scape; funicle short with antennomeres noticeably wider than long; club as long and almost as wide as funicle, with three small, setose antennomeres. Clypeopleuron developed. Labrum distally gently depressed; with a wide, U-shaped emargination; proximally fringed with few (about six) very long, fine setae. Mentum with ventral surface completely flat, subrectangular, emarginate in the middle of anterior edge; labial palpi (including palpiger) with four palpomeres. Mandible with pointed apical tooth, without small secondary tooth.

Procoxae subcontiguous; profemora with surface smooth, bearing fine, flying, long setae; with a slight emargination at distal third. Protibiae broadly curved outwards, with outer lateral edge finely serrate; apical spur slender with tip acute. Protarsus attached near apical third on lateroventral surface of tibia, with basal tarsomere shorter than the other four tarsomeres combined, protarsomeres 2–4 short and subequal; protarsomere 5 slightly longer, bearing two small, regularly curved claws; protarsomeres, excluding protarsomere 5, with tufts of setae on ventral surface. Mesocoxae and metacoxae close to each other; mesofemora with smooth surface bearing fine, flying, long setae; with a distinct emargination at distal third of hind edge. Mesotibiae slender; proximally with a large, smooth, depressed area; with two short, fine, straight apical spurs near inner apical angle. Metafemora abruptly narrowed at proximal third, surface microreticulated; metatibiae triangularly shaped with sinuate inner edge; apex of metatibiae with two short, fine, straight apical spurs. Ventral side of mesotarsi and metatarsi (with the exception of the last tarsomere) with tufts of short setae.

Secondary sexual dimorphism: males have the inner apical spur of mesotibiae shorter than the outer one and bent slightly inwards (this character is slightly pronounced and difficult to discern), while in females both apical spurs are straight.

Male genitalia: aedeagus with parameres short and weakly sclerotized, subrectangular, slightly asymmetrical, without dorsobasal apophysis lying along anchoring point with basal piece ( Fig. 7 E); basal piece slightly twisted and long, about three times as long as parameres; temones present; internal sac longer than the tegmen, armed with a sclerite ( Fig. 7 A, C). Genital segment with branches joining together forming a distinct manubrium, slightly longer than basal triangle.

Female genitalia: vaginal palpi elongate and setose; bursa copulatrix with echinulate, subcircular, large plates.

Diagnosis. This species can be easily recognised from all other representatives of the genus Baloghianestes by the presence of a humeral tubercle on the elytra, combined with the large, doubly ocellate punctation similar to that of pronotum and elytra, and by the raised discal area of the pronotum.

Etymology. Oribatidiformis , Latin adjective meaning having the shape of an oribatid mite, due to the appearance of these convex beetles resembling some oribatid mites.

Remarks. The Bakingili population of this species shows some differences from the Mt. Kupé population, such as the setae having expanded apices and slight differences in the shape of the sclerite of the internal sac of the aedeagus. We do not deem these differences enough to warrant a separation at the species level, nonetheless we preferred not to include the Bakingili specimens in the type series.

Figures

FIGURE 4. Baloghianestes oribatidiformis n. sp., habitus. A—distended specimen, dorsal, B – D—rolled up specimen, ventral (B), dorsal (C), lateral (D).

FIGURE 7. Male genitalia of Ceratocanthinae beetles. A— Baloghianestes oribatidiformis n. sp., Bakingili population, sclerite of internal sac, B— Baloghianestes korupensis n. sp., sclerite of internal sac; C— Baloghianestes oribatidiformis n. sp., Mt. Kupé population, sclerite of internal sac, D— Baloghianestes anceps n. sp., distal part of internal sac / median lobe, E— Baloghianestes oribatidiformis n. sp., shape of parameres, lateral, F— Baloghianestes anceps n. sp., genital segment. Scale bar: 0.2 mm.