Diaclina ashantica, Schawaller, 2019

Schawaller, Wolfgang, 2019, The species of the genus Diaclina Jacquelin du Val (Coleoptera: Tenebrionidae: Alphitobiini) from Sub-Saharan Africa, Zootaxa 4609 (3), pp. 499-508 : 500

Diaclina ashantica sp. nov.

( Figs. 1 , 12)

Holotype (♂): Ghana, Ashanti Region, Abofour, Opro River , 320 m, 7.IV.1966, leg. S. Endrödy-Younga, HNHM.

Description: Body length 3.8 mm. Ovate, blackish brown, shining; borders of pronotum, lateral borders of elytra paler reddish brown. Punctures of dorsal surface without setae, punctures of head and pronotum with a few microsetae. Head outline continuous, not interrupted between clypeus and frons; apical margin of epistome straight, not emarginate in the middle; fronto-clypeal suture indistinct. Genal canthus not projecting beyond contours of eyes, with the outlines nearly continuous with the outlines of the latter. Eyes large, constricted by genal canthus, dorsal part as large as ventral part. Antennae not reaching the base of pronotum, with six distal antennomeres forming kind of club; 2 nd antennomere as wide as long; 3 rd elongate, nearly three times as long as wide; antennomeres 6–10 serrate, distal antennomere rounded. Pronotum transverse, width/length ratio 2.0, surface distinctly convex; widest shortly before posterior angles. Anterior margin shallowly emarginate, basal margin bisinuate, basal and lateral margins finely bordered, distal margin unbordered in the middle. Anterior corners rounded, posterior corners rounded. Pronotal disc with similar fine punctation as on head, subbasal longitudinal impressions distinct. Propleura with similar punctation without setae, surface wrinkled. Prosternal process prominent. Elytra ovate with rounded sides, base slightly narrower than pronotal base. Punctural rows without striae, diminishing posteriorly, scutellar striole absent, punctures of the rows larger than those on the pronotal disc; all intervals nearly flat and smooth, without punctation; lateral margins in dorsal view visible over entire length until apex; humeral angles indistinct. Scutellum large, triangular. Abdominal ventrites with fine punctation, punctures laterally larger, bare, basally and laterally slightly wrinkled. Tibiae gradually and faintly dilated towards apex, without external keels or other modifications. Aedeagus with triangular apicale and acute tip (Fig. 12).

Diagnosis: D. ashantica sp. nov. can be recognised by the combination of the following characters. Pronotum flat, width/length ratio 2.0, surface with fine and separate punctation, and lateral margins of pronotum widely separated from the convexity of the pronotal disc. The last character is present also in D. muehlei sp. nov., however in this species the pronotum is distinctly convex, width/length ratio 1.8, and the surface has a rough and nearly confluent punctation. The aedeagi of both species are similar (Figs. 12, 18), and even similar to the other small Diaclina species with the lateral margins of pronotum not widely separated from the convexity of the pronotal disc. See also identification key below.

Etymology: Named after the Ashanti Region in Ghana, where the holotype was collected.

Distribution: Known only from the type locality in Ghana.

Figures

FIGURES 1–6. Dorsal view of African species of Diaclina. 1 D. ashantica sp. nov., holotype HNHM. 2 D. brevicollis, lectotype NHMB. 3 D. gracilis, non-type South Africa SMNS. 4 D. minuta, lectotype NHMB. 5 D. muehlei sp. nov., holotype HNHM. 6 D. ovalis (holotype decellei syn. nov.) MRAC. Scale: 1 mm.