Mesoceration concavum Perkins 2008, new species
Creators: name: Perkins, Philip D.
Publisher: name: Zenodo
Year: 2008
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Hydraenidae
Mesoceration
Mesoceration concavum

description: Mesoceration concavum new species   
(Figs. 61, 65, 101)  
 Type Material. Holotype (male): South Africa: Mpumalanga Province, E. Transvaal, Blyderiver Canyon, water stones, 24° 35' S, 30° 49' E, 2 May 1981, Endrödy­Younga (#1764). Deposited in the TMSA. Paratypes (280): Mpumalanga Province, E. Transvaal, Berlin, river stones, elev. 1200 m, 25° 33' S, 30° 43' E, 11 December 1986, Endrödy­Younga (#2376) (6 TMSA); E. Transvaal, Blyderiver Canyon, water stones, 24° 35' S, 30° 49' E, 2 May 1981, Endrödy­Younga (#1764) (52 TMSA); E. Transvaal, Mariepskop, shore washing, 24° 35' S, 30° 50' E, 2 May 1981, Endrödy­Younga (#1761) (2 TMSA); E. Transvaal, Mariepskop, water stones, 24° 35' S, 30° 50' E, 2 May 1981, Endrödy­Younga (#1760) (2 TMSA); Fanie Botha Trail, Maritzbos Hut area, SW Sabie, afromontane forest in ravine; FMHD #2004­058, berl., stream­edge debris, & direct collecting, elev. 1270 m, 25° 5' S, 30° 40' E, 11 February 2004, Solodovnikov, Clarke, Newton (1093) (1 FMNH); Mt. Sheeba, under river stones, 24° 51' S, 30° 45' E, 27 November 1986, Endrödy­Younga (#2322) (6 TMSA); N. Transvaal, Soutpansberg Entabeni, from river bed, 22° 58' S, 30° 15' E, 15 March 1973, Endrödy­Younga (#55) (1 TMSA); N. Transvaal, Soutpansberg, Entabeni, river stones, 22° 59' S, 30° 15' E, 21 April 1976, Endrödy­Younga (#1135) (40 TMSA); Soutpansberg, Entabeni Forest St., river stones, 22° 58' S, 30° 16' E, 21 January 1989, Endrödy­Younga (#2606) (11 TMSA); same locality, 22° 59' S, 30° 17' E, 21 January 1989, Endrödy­Younga (#2607) (135 TMSA); same locality, 22° 59' S, 30° 10' E, 21 January 1989, Endrödy­Younga (#2609) (21 TMSA); Uitsoek, Grootkloof ind. for., intercept trap, 28 days, 25° 15' S, 30° 33' E, 28 September 1986, Endrödy­Younga (#2294) (3 TMSA).   
 Differential Diagnosis. Among concavum group members, M. concavum individuals are recognized by the small body size (ca. 1.42 mm), the deeply concave metaventral disc, and the short elytra compared to the pronotal width (ca. 0.80/0.44). This species is similar to M. natalensis in having coarse elytral punctures and small body size, but otherwise the two species are very different in habitus (Figs. 61, 68). The aedeagi of the two species are also quite distinct (Figs. 65, 74).   
 Description. Size (length/width, mm) holotype: body (length to elytral apices) 1.42/0.56; head 0.28/ 0.36; pronotum 0.34/0.44; elytra 0.80/0.56. Dorsum of head and pronotal disc piceous, pronotum laterally and elytra dark brown, maxillary palpi and legs rufotestaceous, venter dark brown to piceous. Eyes rather small, in dorsal aspect about 5 facets in longest series.   
Head with labrum effacedly microreticulate, weakly shining. Clypeus shining, finely punctulate. Frons microreticulate only at sides, disc shining, finely sparsely punctulate, punctures separated by about 3xpd; anteocellar sulci deep. Ocelli distinct. Mentum and submentum microreticulate, dull.  
Pronotum cordate, widest in front of middle; anterior angles rounded, posterior rectangular; sides finely margined, crenulate; anterior margin shallowly arcuate over median 3/4, without hyaline border; discal reliefs shining, very finely, very sparsely punctate; anteriorly and posteriorly very coarsely and densely punctate, punctures ca. 2xef, interstices less than 1xpd; with 10 distinct foveae as follows: two median, an anterior elongate and round posterior, well separated; a small round anterior and larger oval posterior admedian; and a moderately large anterior and slightly smaller posterior adlateral on each side; foveae microreticulate and punctate, dull; each puncture with a fine short seta.  
Elytra with sides weakly rounded, apices subtruncate; sutural apices rectangular; humeral angles weak; sides weakly explanate; quite convex at summit of posterior declivity, only slightly past midlength. Serial punctures quite large in anterior 1/2, larger than largest pronotal punctures, interstices ca. 1xpd, progressively finer apically; series 1 weakly striate­impressed in basal 1/3; seven series between suture and carina, 6th interval discrete to near base; punctures on disc each with minute granule at anterior margin. Intervals, except 8th, flat or very weakly rounded, very finely unilinearly punctulate, non­granulate, width on disc about 1xpd; 8th distinctly carinate. All punctures bearing a short fine seta.  
Thoracic ventrites and abdominal ventrites 1–4 densely clothed with short setae, except glabrous proventral midlongitudinal area, mesoventrite plaques, and glabrous strongly shining posterior margin of metaventral disc. Metaventral disc deeply concave. Abdominal ventrites as follow: 1st with sublateral basal carina on each side; 5th similarly clothed basally and laterally, leaving semilunulate posterior area effacedly microreticulate, dull; 6th glabrous and effacedly microreticulate, with transverse band of piliferous punctures.  
Legs of male with two spiniform setae on apical protarsomere. Femora and tibiae effacedly microreticulate.  
Females with elytral explanate margin slightly wider, elytral apices more distinctly obliquely truncate; pronotal anterior angles not distinctly more produced than in males.  
Wings reduced, about 3/4 length of elytra.  
Aedeagus length ca. 0.34 mm; main­piece markedly sinuate in ventral view, narrowest at midlength, in lateral view sinuate, basal ring large; distal piece short, apex markedly arcuate subapically in lateral view; parameres shorter than main­piece, curvature similar to that of main­piece (Fig. 65).  
 Etymology. Named in reference to the concave metaventral disc.   
 Distribution. Currently known from several localities in Mpumalanga Province (Fig. 101).
description: Published as part of Perkins, Philip D., 2008, Facial affect recognition in individuals at clinical high risk for psychosis, pp. 1-124 in Zootaxa 1864 on pages 45-46, DOI: 10.17615/mqt8-8z21, http://zenodo.org/record/5133132