Enneadesmus forficula socotrensis Borowski, 2017

Borowski, Jerzy & Sławski, Marek, 2017, Bostrichidae (Coleoptera) of Socotra with description of two new subspecies, Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 57, pp. 101-111 : 108-109

Enneadesmus forficula socotrensis Borowski subsp. nov.

( Figs 12–13 )

Type material. HOLOTYPE: J, labelled:‘ YEMEN, SOCOTRA ISLAND, Delisha vill.env., Jatropha unicostata shrubland, at light, 8.VI.2012, 12°41.2′N, 54°07.7′E, 36m, Socotra expedition 2012, J. Bezděk, J. Hájek, V. Hula, P. Kment, I. Malenovský, J. Niedobová & L. Purchart leg.’ ( NMPC) . PARATYPES: 7 spec. ( NMPC, JBCW): same data as in holotype ; 1 spec., labelled: ‘ YEMEN, SOCOTRA ISLAND, Halla area , Arher, freshwater spring in sand dune, 9.–10. + 15. VI.2012, 12°33.0′N, 54°27.6′E, 5m, Socotra expedition 2012, J. Bezděk, J. Hájek, V. Hula, P.Kment, I. Malenovský, J. Niedobová & L. Purchart leg.’ ( NMPC) .

Description. Body length 3.2–4.2 mm. Body cylindrical, slightly lustrous, yellowish- to reddish-brown.

Head. Antennae with nine antennomeres; club formed with three terminal antennomeres. Antennomeres III–VI very short, strongly compressed, together ca. equal in length to subtriangular (widest apically) first antennomere of club (i.e. antennomere VII); second antennomere of club (i.e. antennomere VIII) much narrower, of length subequal to width; terminal antennomere elongate, subparallel-sided, ca. 2.5 times longer than wide. Labrum transverse, yellowish-brown, densely covered with yellowish-golden setulae. Epistome narrow, anteriorly blackish-posteriorly reddish-brown, almost entire surface finely punctulated and setulose. Front blackish- or (rarely) reddish-brown, finely punctulated and densely setulose, surface between punctures smooth and lustrous. Lateral and posterior margins with long, erect, yellow setae making a distinctive girdle surrounding frontal surface from three sides. Vertex distinctly separated from front, longitudinally rugose. Eyes long, protruding from head outline.

Pronotum somewhat wider than long, sides slightly rounded, anteriorly strongly convergent. No lateral carinae. Anterior margin of pronotum shallowly arcuately emarginated. Anterior and dorsal part wrinkled with six larger denticles laterally, posterior finely, sparsely granular and punctulated, surface in between smooth and lustrous. Pronotal setulation inconspicuous, recumbent, only on sides of larger denticles in anterior part longer and erect. Scutellum trapezoidal, posterior margin shallowly emarginated.

Elytra partly parallel-sided; anterior half paler, yellowish-brown, posterior dark brown. Humeral protuberances distinct. Elytral punctation conspicuous, dense, irregular. Suture on truncation swollen, distinctly elevated above surface level; setulation more distinct on posterior half, short, recumbent, yellow and yellowish-gray. Truncation above distinctly concave on sides of suture. Each side of truncation at middle with conical, arcuately bent backwards and inwards, as long as wide at base, sharply pointed dent. Surface of truncation finely punctulate, smooth and lustrous. Elytral apices swollen, somewhat divergent and turned upwards.

Legs yellowish-brown except somewhat darker protibiae. Inner edges of tibiae with numerous fine denticles and distinct setation, setae of meso- and metatibiae longer and more erect than those of protibiae.

Ventral surface of body yellowish- to reddish-brown, ventrites dark with paler lateral and posterior margins.

Male ( Fig. 12 ). Entire surface of front uniform, distinct depressions on basolateral margin lacking, the girdle of long, yellow, erect setae surrounding front broken behind posterior margin of eyes. Front inside the girdle covered with fine, recumbent, uniform setulation.

Female ( Fig. 13 ). Frontal surface not uniform: laterally near posterior margin with deep but sometimes – because of dense pilosity of margins – inconspicuous foveae. The girdle of long, yellow, erect setae continuous, surrounds front uniformly on all ocular margins, consists of dense long setae bent at tips towards middle of front. Front inside the girdle covered with fine, erect or semierect, usually uniformly distributed setulae.

Differential diagnosis. Resembling the continental E. forficula forficula (Fairmaire, 1883) ( Figs 14–15 ), but differing in smaller size (3.5–5.5 mm in E. f. forficula ), elytral index I=1.6–1.7 (as compared to I=1.9–2.0), and distinctly shorter denticles on the elytral truncation (in the nominotypical form at least twice as long as wide at base).

Etymology. The Latin adjective referring to the country of origin of the new subspecies.

Geographical element and distribution. Palaearctic element, Socotran endemic.

Apatinae

Figures

Figs 8–13. Habitus in dorsal view. 8–9 – Enneadesmus obtusidentatus obscurior subsp. nov. (8 – male, 9 – female); 10–11 – E. obtusidentatus obtusidentatus Lesne, 1899 (10 – male, 11 – female); 12–13 – E. forficula socotrensis subsp. nov. (12 – male, 13 – female).

Figs 14–19.Habitus in dorsal view. 14–15 – Enneadesmus forficula forficula (Fairmaire, 1883) (14 – male, 15 – female); 16–17 – Phonapate nitidipennis (Waterhouse, 1881) (16 – male, 17 – female); 18–19 – Xylomedes rufocoronata (Fairmaire, 1892) (18 – male, 19 – female).