Digitonthophagus petilus Génier, 2017

Génier, François & Moretto, Philippe, 2017, Digitonthophagus Balthasar, 1959: taxonomy, systematics, and morphological phylogeny of the genus revealing an African species complex (Coleoptera: Scarabaeidae: Scarabaeinae), Zootaxa 4248 (1), pp. 1-110 : 52-54

Digitonthophagus petilus Génier , new species

http://zoobank.org/urn:lsid:zoobank.org:act:4B8CB6CC-46E9-49CC-9 A 3D-5C8C74 A 4F878 ( Figs. 15 , 39–40 , 63 , 79 , 103–104, 127, 159–161; Map 10)

Type locality. El Wak, North Eastern Province, Kenya.

Diagnosis. Pronotum rather opaque ( Fig. 63 ); FLP sclerite subapicodorsal lobe strongly produced anteriorly ( Figs. 159–160 ); right lateral fold produced into a longitudinal spoon-shape process with apical portion open ventrally, ventral edge with a brush of minute villi, lacking well-sclerotized projection on apicoventral edge ( Fig. 160 ); axial sclerite shorter than subaxial sclerite, acute apically ( Figs. 159–160 ); subaxial sclerite long and thin ( Fig. 160 ).

Description. Holotype ♂ ( Fig. 15 ). Measurements. Length 11.5 mm, width 6.0 mm. Head ( Figs. 39–40 ). Anterior clypeal edge straight on median fifth in dorsal view; clypeofrontal carina broadly arcuate and interrupted at gena; vertex lacking median tubercle, surface with punctures fine to small, separated by one to four diameters. Horns rather short, divergent from base to apex in frontal view, gradually tapering from base to apex; posterointernal edge with a low angular projection; apicointernal surface lacking granules, with few feebly scabrous punctures; genal edge slightly upturned and feebly angulate on anterior third, forming a broad angle with clypeal edge. Pronotum ( Fig. 63 ). Surface with granulate punctures restricted to anterior half, with moderately large punctures on posterior half of disc; punctures smaller posterolaterally, with minute punctures distinct and rather dense throughout. Anteromedian tubercle atrophied, simply round in lateral view; median longitudinal sulcus narrow and shallow; surface behind the eyes with a simple round shallow depression, surface of anterior angles convex; anterior half of lateral edge arcuate in dorsal and lateral view; posterior angles slightly upturned and simply arcuate in dorsal view. Anterior hypomeral ridge broadly arcuate anteriorly, anterior hypomeral depression surface light in color. Elytra ( Fig. 15 ). Intervals 2 and 4 with few scattered, fine granules on apical declivity. Legs. Protibial apicointernal tooth enlarged, with dorsal ridge extending to apex. Aedeagus ( Fig. 127 ). Parameres with dorsal and ventral edges slightly diverging toward apex in lateral view. Internal sac sclerites ( Figs. 159–161 ). Axial sclerite broadly arcuate, with apex acute. Subaxial sclerite, gradually tapering from base to mid-distance, fine and straight on apical half, extending straight beyond apex of right lateral fold of frontolateral peripheral sclerite apical portion, with villi on apical third. Frontolateral peripheral sclerite basoventral apophysis well developed; lacking medioventral carinae; right lateral fold produced into longitudinal spoon-shape process with apical portion open internally, ventral edge bordered with a brush of villi; left lateral lobe membranous, slightly developed; subapicodorsal lobe membranous, reaching anterior edge, apex set on right side in dorsal view; apical lobe round and directed obliquely on left side and bent ventrally, left edge emarginate, apical villi similarly shaped throughout; subapicoventral lobe apical portion acute and in line with apical lobe apically, with distinct villi on apical third.

Variation. Measurements (50 ♂♂, 40 ♀♀). Length: male 8.0–12.0 mm (10.1 ± 1.0 mm), female 8.0–11.0 mm (9.7 ± 0.7 mm). Female allotype. Cephalic outline in dorsal view as in Fig. 79 ; vertex with a straight, transverse carina, dorsal edge broadly arcuate in frontal view, lateral portion gradually sloping down; anterior pronotal tubercles atrophied, external lateral edges parallel sided, anterolateral surface simply convex, anterosuperior edge slightly arcuate in dorsal view (Fig, 103), lateral portion of anterosuperior edge slightly upturned (Fig. 104). Protibia short, with external teeth more robust.

Primary type data. Holotype ♂ ( CMNC): [ KENYA: NE PROV. / El Wak / 1-3.V.2001 / Werner & Smrz leg.]; [ WORLD / SCARAB. / DATABASE / WSD00029750] barcode label; [HOLOTYPE ♂ / Digitonthophagus / petilus n.sp. / des. F. Génier, 2016] red card.

MAP 10. Distribution of Digitonthophagus petilus .

Material examined (69 ♂♂, 63 ♀♀), distribution (Map 10): ETHIOPIA : OROMIA, Yabelo (4°53'N, 38°5'E), iv.1994, Werner— 1 ♂ (paratype) ( CMD) ; SOUTHERN NATIONS, NATIONALITIES, AND PEOPLE’S REGION, Arba Minch (6°2'N, 37°33'E), 11–17.ix.2000, P. Léonard— 23 ♀♀, 22 ♂♂ (45 paratypes) ( FGIC, PMOC) ; Dila (6°24'30''N, 38°18'30''E), ix.2000, P. Léonard— 1 ♂ (paratype) ( PMOC) ; KENYA: Tsavo National Park [=Tsavo East National Park] (2°45'S, 38°49'E), 18.x.1973, T.J. Kingston— 1 ♀, 3 ♂♂ (4 paratypes) ( OUMNH) ; Tsavo National Park [=Tsavo East National Park] (2°45'S, 38°49'E), 9.xi.1973, T.J. Kingston— 1 ♀, 1 ♂ (paratypes) ( OUMNH) ; Tsavo National Park [=Tsavo East National Park] (2°45'S, 38°49'E), 13.xi.1973, T.J. Kingston— 1 ♀ (paratype) ( OUMNH) ; Tsavo National Park [=Tsavo East National Park] (2°45'S, 38°49'E), 18.xi.1973, T.J. Kingston— 1 ♀ (paratype) ( OUMNH) ; Tsavo National Park [=Tsavo East National Park] (2°45'S, 38°49'E), 21.xi.1973, T.J. Kingston— 3 ♀♀, 1 ♂ (paratypes) ( OUMNH) ; Tsavo National Park [=Tsavo East National Park] (2°45'S, 38°49'E), 10.xii.1973, T.J. Kingston— 1 ♀ (paratype) ( OUMNH) ; Tsavo National Park [=Tsavo East National Park] (2°45'S, 38°49'E), 15.xii.1973, T.J. Kingston— 1 ♂ (paratype) ( OUMNH) ; BARINGO, Loiminange , 980 m (0°31'N, 36°7'E), 24.x.1988, M.N. Mungal & R.K. Butlin— 6 ♀♀, 5 ♂♂ (11 paratypes) ( OUMNH) ; ISIOLO, 10 km N Isiolo (0°27'14''N, 37°36'36''E), 16. xii.1 990, B.D. Gill— 7 ♀♀, 11 ♂♂ (18 paratypes) ( BDGC) ; MANDERA, El Wak (2°49'N, 40°56'E), 1–3.v.2001, Werner & Smrz— 10 ♀♀, 9 ♂♂ (holotype, allotype, 17 paratypes) ( CMD, CMNC) ; RIFT VALLEY, Samburu National Reserve (1°13'N, 36°57'E), 4.xii.1989, Moreno-Mestre— 1 ♀, 3 ♂♂ (4 paratypes) ( PMOC) ; TAITA TAVETA, Tsavo , 50 km N Voi (3°0'S, 38°27'E), 25.xii.1990, B.D. Gill— 1 ♀, 4 ♂♂ (5 paratypes) ( BDGC) ; Voi , Tsavo East National Park (3°23'S, 38°34'E), 31.xii.1990, B.D. Gill— 3 ♀♀, 2 ♂♂ (5 paratypes) ( BDGC) ; SOUTH SUDAN: CENTRAL EQUATORIA, Rejaf (4°45'N, 31°34'E), 29.xii.1911, [anonymous]— 4 ♀♀, 2 ♂♂ (6 paratypes) ( MNHN) ; SUDAN: SENNAR, Sennar (13°34'N, 33°34'E), [no date], Tritsch— 1 ♂ (paratype) ( SMF) ; UGANDA: CENTRAL, Entebbe (0°4'N, 32°28'E), [no date], H. Rolle— 2 ♂♂ (2 paratypes) ( IRSNB) .

Etymology. Petilus is a Latin adjective (frail, slight, puny) pertaining to the aspect of the apical portion of the internal sac subaxial sclerite (SA).

Natural history. Some specimens collected in buffalo, cow, and elephant dung.

Remarks. We first regarded D. petilus as a northern population of D. gazella . The very similar configuration of the right lateral fold and lacking the ventral sclerotized projection was nearly identical to typical D. gazella . But after careful observations of the FLP sclerite, several additional congruous characters were found; the much more developed subapicodorsal lobe and the much narrower subapicoventral lobe with its apex covered with distinct villi ( Figs. 159–161 ) combined with the external characters such as the overall dorsum dull aspect and smaller average size are consistent. The possibility that D. petilus could be a subspecies of D. gazella needs to be tested. However, the fact that its distribution is parapatric with D. gazella seems to preclude this possibility.

Figures

FIGURES 15 – 18. Male dorsal habitus. 15. D. petilus, holotype; 16. D. viridicollis, holotype; 17. D. aksumensis, holotype; 18. D. dilatatus, holotype.

FIGURES 39 – 46. 39, 41, 43, 45. Male head, dorsal view; 40, 42, 44, 46. Male head, frontal view. 39 – 40. Digitonthophagus petilus, holotype; 41 – 42. D. viridicollis, holotype; 43 – 44. D. aksumensis, holotype; 45 – 46. D. dilatatus, holotype.

FIGURES 63 – 70. Male pronotum, dorsal view. 63. D. petilus, holotype; 64. Digitonthophagus viridicollis, holotype; 65. D. aksumensis, holotype; 66. D. dilatatus, holotype; 67. D. fimator, holotype; 68. D. lusinganus, lectotype; 69. D. ulcerosus, holotype 70. D. namaquensis, holotype.

FIGURES 79 – 86. Female head, dorsal view. 79. Digitonthophagus petilus, allotype; 80. D. viridicollis, allotype; 81. D. aksumensis, allotype; 82. D. dilatatus, allotype; 83. D. fimator, allotype; 84. D. lusinganus, paralectotype; 85. D. ulcerosus, allotype 86. D. namaquensis, allotype.

FIGURES 159 – 170. Internal sac sclerites (FLP, A + SA). 159, 162, 165, 168. Dorsal view; 160, 163, 166, 169. Ventral view. 161, 164, 167, 170. Right lateral view. 159 – 161. Digitonthophagus petilus, holotype; 162 – 164. D. viridicollis, holotype; 165 – 167. D. aksumensis, holotype; 168 – 170. D. dilatatus, holotype.

FIGURES 119 – 134. Parameres, dorsal view. 119. D. bonasus, alloreferent (Tamil Nadu State, India); 120. Digitonthophagus uks, holotype; 121. D. sahelicus, holotype; 122. D. catta, alloreferent (West Bengal, India); 123. D. eucatta, holotype; 124. D. falciger, holotype; 125. D. biflagellatus, holotype; 126. D. gazella, non type (Antisiranana Province, Madagascar); 127. D. petillus, holotype; 128. D. viridicollis, holotype; 129. D. aksumensis, holotype; 130. D. dilatatus, holotype; 131. D. fimator, holotype; 132. D. lusinganus, lectotype; 133. D. ulcerosus, holotype 134. D. namaquensis, holotype.