Asthenopholis rex, Harrison, James G., 2009

Harrison, James G., 2009, A taxonomic revision of the African leaf chafer genus Asthenopholis Brenske, 1898 (Coleoptera: Scarabaeidae: Melolonthinae): a SEM study, Zootaxa 2225, pp. 1-48 : 12

Asthenopholis rex sp. nov.

(Figs. 2, 21, 26–27, 42–43, 59–63, 96–97, 113–115, 136–137, 153–155, 175).

Diagnosis. Large (about 24–25 mm long) brown to black species; cuticular scales are straw coloured rather than white as in A. adspersa . Scutellum smooth and lacking any punctation or setae (Fig. 96). Within Asthenopholis this species is easily identified by its large size and distribution in northern coastal KwaZulu- Natal, which together make the species unmistakable (Fig. 21).

Description. Holotype. Male: Length 24.0 mm, width 15.0 mm. Colour. Black to brown, with straw coloured cuticular scales (Fig. 2). Head (Figs. 26–27, 42–43): Head uniformly covered with pointed scales (except posterior edge), scaliferous punctures coarse, with scales directed posteriorly. Clypeus with anterior margin reflexed, dorsal section of clypeus at reflex is scaleless, corners rounded and sides almost parallel. Clypeal suture fine, distinct and medially reflexed posteriorly. Raised protuberance situated laterally near eye. Pronotum (Figs. 27): Pronotum ratio 1.6:1. Posterior edge of prothorax with single row of fine, long setae (Fig. 27). Lateral edges with an obtuse rounded angle in the middle; anterior and posterior margins smooth, lateral margins incised by setiferous punctures (setae finer than on disc), forming an irregularly, flattened serrated edge. Disc covered by tan coloured pointed scales, directed posteriorly, and absent on median posterior section of pronotal disc. Scutellum (Figs. 96–97): Triangular, sides equilateral, posterior apex rounded, surface smooth and without setae, punctation or prominent sculpture (at 400X) to light microscope, substrigulate under SEM. Elytra (Figs. 113–115): Elytral striae very weak, almost absent, about two per elytron. Elytra covered with fine, white scales; uniformly dispersed except scale-less circular patches situated posterior-laterally (ranging from 3–4 per elytron). Individual scales under SEM shorter and blunter than A. adspersa (compare Fig. 114 with 111); elytron microsculpture under SEM at 2000X with sharper points than A. adspersa (compare Fig. 115 with 112). Pygidium (Figs. 136–137): Completely covered with fine, white setae; medial, vertically orientated raised area in females, flatter in males; puncture rims almost contiguous under SEM and setae longer and sharper than A. adspersa (compare Fig. 137 with 135). Male genitalia illustrated in Figs. 153–155; anterior view of parameres wider in A. rex than in A. adspersa ; distal portion of parameres viewed laterally broader in A. rex than in A. adspersa .

Morphological variability. Size. (n = 2Ƥ): Mean length 24.5 mm, (range 24–25 mm). Mean width 14 mm. Pronotum ratio 1.5:1 (n = 2Ƥ). The only known specimens are the male holotype and two female paratypes, which are all similar in appearance.

Etymology. Together with large species of Macrophylla Hope and Sparrmannia Laporte , this species is one of the largest South African chafers, and within Asthenopholis is one of the most spectacular species. Consequently it is named “ rex ”, which is Latin for king.

Distribution. Currently only known from two localities on the coast of KwaZulu– Natal, i.e. Sodwana Bay National Park and St Lucia Estuary (Fig. 21). The St Lucia record overlaps with the northern range of A. adspersa , but no A. adspersa have been collected north of the St Lucia wetland system. It is suspected that A. rex would occur northwards along the South African coastline and into Mozambique, so the known records are probably from the southern most range of A. rex .

Conservation status. Being what appears to be a narrow range coastal dune endemic, this species would be threatened by dune mining, but is probably conserved within the Greater St Lucia World Heritage Site.

Natural history and pest status. Not known to be a pest and its natural history is unknown. Phenology indicated in Fig. 175.

Type material ( Asthenopholis rex sp. nov.): (Holotype 3, 2Ƥ paratypes). “ SOUTH AFRICA, NTL, [KwaZulu– Natal], Sodwana Bay Nat[ional] Park, 27.32S 32.41E, 07–14.xi.1987, L. S. Evans / male genitalia point mounted / Asthenopholis sp. Det. A.V. Evans [19]’88 / National Coll. of Insects, Pretoria, S. Afr / Holotype 3, Asthenopholis rex sp. nov. Harrison, J. du G. 2009” [specimen condition: right hand side metatarsi missing] (13 SANC), idem but Paratype Ƥ, Asthenopholis rex sp. nov. Harrison, J. du G. 2009 (1Ƥ SANC); “ South Africa, NTL, St Lucia Estuary, 28.17S 32.25E, 13.ii.1989, R. Oberprieler / National Coll. of Insects, Pretoria, S. Afr / Paratype Ƥ, Asthenopholis rex sp. nov. Harrison, J. du G. 2009” (1Ƥ SEM SANC).