Digitonthophagus dilatatus 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 : 59-61

Digitonthophagus dilatatus Génier , new species

http://zoobank.org/urn:lsid:zoobank.org:act:28F9FCFD-2012-4B76-B546-B444 F54327 D9 ( Figs. 18 , 45–46 , 66 , 82 , 109–110, 130, 168–170; Map 13)

Type locality. Forêt de Sorobouli (11°47’44”N 02°53’25”W), 270 m, Sanguié , Burkina Faso.

Diagnosis. Male cephalic horns granulate internally at apex ( Fig. 46 ); males with pronotal anterior angles surface concave, produced anteriorly ( Fig. 45 ); FLP sclerite ventral portion with a single carina ( Fig. 170 ); SA sclerite apex interrupted much before apex of apical portion of FLP sclerite ( Figs. 168–169 ).

Description. Holotype ♂ ( Fig. 18 ). Measurements. Length 12.0 mm, width 7.0 mm. Head ( Figs. 45–46 ). Anterior clypeal edge straight on median seventh and appearing semicircular 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 long, distinctly arcuate and divergent in frontal view, parallel sided on basal four-fifths and abruptly tapering externally and narrower on apical sixth; posterointernal edge unmodified basally; apicointernal surface with few, coarse granules; genal edge slightly upturned and simply arcuate on anterior third, in line with clypeal edge. Pronotum ( Fig. 66 ). Surface with granulate punctures restricted to anterior half medially, with distinct umbilicate punctures on posterior half of disc; punctures distinct posterolaterally, with distinct minute punctures throughout. Anteromedian tubercle atrophied, forming an obtuse angle in lateral view; median longitudinal sulcus well-defined but narrow; surface behind the eyes slightly concave, surface of anterior angles concave with anterior angles produced forwardly; anterior half of lateral edge sinuous in dorsal and lateral view; posterior angles unmodified and simply arcuate in dorsal view. Anterior hypomeral ridge straight on most of its length and abruptly arcuate on anterior third, anterior hypomeral depression surface darker in color. Elytra ( Fig. 18 ). Intervals 2 and 4 lacking fine granules from base to apex. Legs. Protibial apicointernal tooth enlarged, with dorsal ridge extending to apex. Aedeagus ( Fig. 130 ). Parameres with dorsal and ventral edges slightly diverging toward apex in lateral view. Internal sac sclerites ( Figs. 168–170 ). Axial sclerite short, angular and extending into a point apically. Subaxial sclerite, large basally and abruptly reduced, extending straight and approximately in line with apex of right lateral fold of frontolateral peripheral sclerite, with fine and scattered villi. Frontolateral peripheral sclerite basoventral apophysis well developed; a single rather large medioventral carina present; right lateral fold produced into a rather small everted and open apically conical process with irregular apical edge located behind oblique right lateral edge of apical lobe; left lateral lobe membranous, slightly developed; subapicodorsal lobe membranous, not reaching anterior edge, apex set on left side in dorsal view; apical lobe truncate apically and directed obliquely on left side, apical villi regular in shape; subapicoventral lobe small, acute apically, short not reaching apical edge of apical lobe.

Variation. Measurements (42 ♂♂, 83 ♀♀). Length: male 8.5–12.0 mm (10.5 ± 0.9 mm), female 7.5–12.0 mm (10.1 ± 0.8 mm). Female allotype. Cephalic outline in dorsal view as in Fig. 82 ; vertex with a broadly arcuate transverse carina, dorsal edge broadly arcuate in frontal view, lateral portion gradually sloping down posteriorly; anterior pronotal tubercles well developed, external lateral edges slightly widening toward apex in dorsal view, anterolateral surface simply convex, anterosuperior edge slightly arcuate in dorsal view (Fig. 109), lateral portion of anterosuperior edge slightly upturned (Fig. 110). Protibia short, with external teeth more robust.

Primary type data. Holotype ♂ ( CMNC): [ BURKINA FASO: SANGUIÉ / Forêt de Sorobouli , 270m / 11̊47’44”N 0 0 2̊53’25”O / 13.VIII.2005, F. Génier / zone soudanienne sud / piège excr. humain, 2005-14]; [COLÉOPTÈRES / DU / BURKINA FASO / BF015361] barcode label; [HOLOTYPE ♂ / Digitonthophagus / dilatatus n.sp. / des. F. Génier, 2016] red card.

MAP 13. Distribution of Digitonthophagus dilatatus .

Material examined (57 ♂♂, 93 ♀♀), distribution (Map 13): BURKINA FASO : CENTRE-OUEST, Forêt de Sorobouli [= Forêt Classée de Baporo ], 270 m (11°47'44''N, 2°53'25''W), 10–15.viii.2005, P. Moretto— 78 ♀♀, 30 ♂♂ (108 paratypes) ( FGIC, PMOC) ; BALÉ, Boromo, 250 m (11°45'6''N, 2°51'58''W), 10.viii.2005, F. Génier (2005-10)—1 ♀, 1 ♂ (paratypes) (FGIC); KOMPIENGA, Pama, 230 m (11°17'N, 0°42'59''E), 24.viii.2005, F. Génier (2005-44)—3 ♂♂ (3 paratypes) (FGIC); SANGUIÉ, Forêt de Sorobouli, 270 m (11°47'44''N, 2°53'25''W), 13.viii.2005, F. Génier (2005-14)—1 ♀, 1 ♂ (holotype, allotype) (CMNC); Forêt de Sorobouli, 270 m (11°47'44''N, 2°53'25''W), 13.viii.2005, F. Génier (2005-15)—2 ♀♀, 1 ♂ (paratypes) (FGIC); Forêt de Sorobouli, 270 m (11°47'44''N, 2°53'25''W), 28.vii.2006, F. & S. Génier (2006-83)—1 ♂ (paratype) (FGIC). ; CAMEROON: EXTREME NORTH, Maroua (10°35'N, 14°19'E), 4.vii.1978, [anonymous] —1 ♂ (paratype) (MNHN); Waza (11°24'N, 14°34'E), 18.viii.2006, C. Vanderbergh— 2 ♂♂ (2 paratypes) ( FGIC, PMOC) ; Waza National Park (11°15'N, 14°39'E), 18.viii.2006, C. Vanderbergh— 5 ♀♀, 5 ♂♂ (10 paratypes) ( FGIC, PMOC) ; CHAD: N’DJAMENA, Farcha (12°7'N, 14°59'E), vi.1968, [anonymous]— 1 ♀, 1 ♂ (paratypes) ( MNHN) ; Farcha (12°7'N, 14°59'E), 28.vi.1967, [anonymous]— 1 ♀, 2 ♂♂ (3 paratypes) ( MNHN) ; Fort Lamy [= N’Djamena ] (12°7'N, 15°3'E), 17.vii.1958, J. Mateu— 1 ♂ (paratype) ( FETC); CÔTE D’IVOIRE : SAVANES, M’banto, Boundiali , 395 m (9°34'10.4''N, 6°40'56.5''W), 13–15.vii.2013, P. Moretto— 2 ♀♀, 5 ♂♂ (7 paratypes) ( FGIC, PMOC) ; GHANA: UPPER EAST, Bolgatanga (10°47'N, 0°5'W), 20.xi.2002, Bowku— 2 ♀♀, 2 ♂♂ (4 paratypes) ( OMOC) ; NIGERIA: KWARA, Bussa (8°51'24''N, 5°13'9''E), 4.v.1962, D.C. Eidt— 1 ♂ (paratype) ( CNC) .

Etymology. Dilatatus is a Latin adjective pertaining to the development of the anterior pronotal angles of welldeveloped males of this species. This development is unique in the genus.

Natural history. The known distribution pattern of this species suggests that it is endemic to the Sudanese savanna. Interestingly, all specimens with data were collected at light or in pitfall traps baited with human dung, no specimens were collected in ruminant dung. Additional observations are required to confirm that it is a nonruminant dung specialist.

Remarks. Externally, this species can be confused with D. fimator in West Africa. However, in addition to the characters given, the parameres are smaller and approximately parallel sided in lateral view as opposed to being wider and divergent in lateral view in D. fimator .

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.