Afroprinus cavicola, Lackner, Tomas, 2013

Lackner, Tomas, 2013, Afroprinus cavicola gen. et sp. n. from the Afrotropical region with notes on cave-dwelling Saprininae (Coleoptera, Histeridae), ZooKeys 294, pp. 57-73 : 59-67

Afroprinus cavicola sp. n. Figs 121

Type locality.

Kenya, Chyulu Hills.

Type specimens examined.

Holotype, ♂, side-mounted on a triangular mounting card with male genitalia glued to the same card; "KENYA: / Chyulu Hills / Univ. of Nairobi" [written]; "bat droppings / in cave" [written]; "Brit. Mus. / 1972-215" [printed-written]; " Gnathoncus sp. / P.M. Hammond / det. 1972" [written-printed]; “09-071” [yellow label, pencil-written, added during the present study]; " Afroprinus / cavicola / n. gen. & sp. / HOLOTYPE / det. T. Lackner 2010 " [red label, written] (NMH). Paratypes, 4 ♂♂ and 2 ♀♀, idem, but without the identification label by P.M. Hammond (NMH; 1 ♂ PT in TLAN).

Description.

Male and female.Body length: PEL: 2.125-2.375 mm; APW: 0.75-0.875 mm; PPW: 1.625-1.75 mm; EL: 1.375-1.50 mm; EW: 1.875-2.00 mm.

Body (Figs 1, 2) ovoid, convex, ventral surface slightly flattened, cuticle matte, dark brown; legs, mouthparts and antennomeres I and II rufous; remaining part of antenna somewhat lighter.

Antennal scape (Fig. 4) with several short setae; antennal club (Figs 3, 14) round, without visible articulation, somewhat flattened dorso-ventrally; approximately distal half of its surface with thick short sensilla; proximal half with imbricate microsculpture, sensilla absent; sensory structures of antennal club (Fig. 14) with tiny sensory area accompanied by a tiny stipe-shaped vesicle on internal distal margin of antennal club.

Mouthparts. Mandibles (Fig. 12) with rounded outer margin strongly curved inwardly, apically pointed; sub-apical tooth on inner margin of left mandible large, al most perpendicular; disc of labrum (Fig. 13) convex, labral pits each with two setae; terminal labial palpomere elongate, four times as long as broad; cardo of maxilla with several short setae, stipes triangular, with three long setae; mentum quadrate, anterior margin with deep median notch, anterior and lateral margins with a row of sparse short ramose setae, disc of mentum with several short setae; terminal maxillary palpomere (Fig. 5) elongate, five times as long as broad, approximately 2.5 times as long as penultimate palpomere.

Anterior margin of clypeus (Fig. 4) slightly elevated, surface punctate, slightly depressed medially; frontal stria well impressed, curved outwardly, carinate, complete; continued as carinate supraorbital stria; disc of frons (Fig. 4) entirely densely and coarsely punctate, punctures separated by spaces shorter than half of their diameter, sparser near margins; eyes flattened, visible in dorsal view.

Pronotal sides (Fig. 1) moderately narrowing anteriorly, anterior angles blunt; marginal pronotal stria complete, slightly carinate, visible along its entire length in dorsal view; pronotal disc entirely punctate, punctures separated by spaces 1-2 times as wide as puncture diameter; pronotal hypomeron setose; scutellum small, inconspicuous.

Elytra: epipleuron with fine scattered punctures; marginal epipleural stria complete; marginal stria straight, well impressed, carinate, continued as intermittent apical stria. Humeral stria well impressed on basal third, somewhat obliterated by coarse punctuation; inner subhumeral stria well developed, visible as long median fragment posteriorly nearly reaching first dorsal stria; with carinate dorsal striae 1-4 (some specimens with a vague fragment of fifth stria on fourth elytral interval); striae 1-3 sub-equal in length, posteriorly reaching approximately five-sixths of elytral length, fourth dorsal stria slightly shorter, anteriorly well-connected with carinate sutural stria; sutural stria straight, well impressed, posteriorly connected with fragmented apical stria; between sutural stria and suture with row of microscopic punctures. Entire surface coarsely and densely punctate, punctures separated by spaces sub-equal to their diameter or shorter, periscutellar area with slightly sparser punctuation; interspaces with isodiametric microsculpture.

Propygidium (Fig. 7) completely exposed, its punctuation similar to that on elytra and pygidium.

Antero-median margin of prosternum (Fig. 8) straight, rounded laterally; pre-apical foveae deep, connected by marginal prosternal stria; prosternal process apically convex, rounded; carinal prosternal striae (Fig. 8) almost parallel-sided, apically reaching approximately half-length of prosternal process; lateral prosternal striae carinate, terminating in large pre-apical foveae; entire prosternal process with scattered punctures.

Antero-median margin of mesoventrite straight; discal marginal mesoventral stria well impressed, emarginate anteriorly, complete; disc of mesoventrite with scattered round punctuation; meso-metaventral sutural stria undulate.

Intercoxal disc of metaventrite slightly convex, entirely covered with scattered fine punctures separated by spaces 2-3 times as wide as their diameter, anteriorly punctures becoming coarser and denser, in male more so; lateral metaventral stria (Fig. 10) straight, carinate, almost reaching metacoxa; lateral disc of metaventrite slightly impressed, with deep round punctures; metepisternum + fused metepimeron with distinctly denser punctures; marginal metepisternal stria complete, deeply impressed.

Intercoxal disc of first abdominal sternite with complete lateral striae, disc with scattered fine punctures, separated spaces as wide as 3 times puncture diameter.

Protibia (Fig. 11) slightly dilated; outer margin with 6 short teeth, each topped by short rounded denticle gradually reducing in size towards base of tibia, followed by a minute denticle; setae of outer row sparse, short; setae of median row even shorter; pro tarsal groove deep; anterior protibial stria carinate, shortened apically; protibial spur minuscule, approximate to tarsal insertion; outer part of posterior surface of protibia smooth, demarcated from median part by distinct straight line; posterior protibial stria complete, terminating in two inner posterior denticles, separating median part of posterior surface from smooth inner part of posterior surface; inner margin of protibia with dense row of lamellate setae that gradually increase in size towards tibial apex.

Mesotibia (Fig. 6) slender, outer margin with a single row of short denticles gradually increasing in size towards tibial apex; setae of outer row moderately long, sparse, lightly sclerotized; setae of median row much thinner and sparser; posterior stria almost complete and only slightly shortened distally; anterior surface with a row of short denticles on outer margin, surface otherwise smooth; anterior stria complete; apical spur short; apical margin of with several stout denticles; claws of terminal tarsomere slightly bent, shorter than half tarsomere length.

Metatibia (Fig. 9) more slender than mesotibia, its denticles sparser than those of mesotibia, otherwise similar to it.

Male genitalia: Eighth sternite (Figs 15-16) divided longitudinally; vela present, with dense brush of long setae; apex of eighth sternite with one or two short setae (Fig. 15); eighth tergite and eighth sternite fused laterally (Fig. 17). Ninth tergite (Fig. 18) not longitudinally divided medially; spiculum gastrale (Fig. 18) almost parallel-sided, abruptly dilated apically; basal end broadly rounded, spatulate. Aedeagus (Figs 20-21) almost parallel-sided, slightly broadening apically, in apical third curved ventrad; basal piece short, ratio of its length to length of parameres 1: 4; parameres fused almost along their basal two-thirds.

Etymology.

The specific epithet was derived using a compounding method of word formation, by stringing together Latin word ‘caverna’ meaning cave and combining element of Latin origin ‘-cola’ (orig. colo, ere to inhabit) meaning inhabitant, referring to the cavernicolous habitat of this new species. ‘Cavicola’ is a noun in apposition, which is in accordance with ICZN rules; Article 11.9.1.2

Key to identification of Afrotropical genera of Saprininae

This key is preliminary and in future will be revised, especially in regard to the ill-defined and heterogeneous genera Saprinus , Hypocacculus , Chalcionellus and Pholioxenus . Pholioxenus shows a discontinuous distribution, with about two-thirds of its species living nidiculously inside burrows and faecal chambers of small ground mammals in the Palaearctic region and one-third found free-living in South Africa, Namibia etc., with a single species of unknown biology ( Pholioxenus trichoides Kapler, 1992) described from north Sudan ( Mazur 2011). Revision of the genus Pholioxenus is in preparation (Lackner, manuscript). Subgenera, with exceptions of Hesperosaprinus and Neosaprinus of the Nearctic and mainly Neotropical genus Euspilotus which are pertinent to this key, are excluded, since they fall within the limits of their respective genera. Limits of the Afrotropical region are according to Löbl and Smetana (2004) and encompass the entire continent of Africa south of Sahara, the island of Madagascar, along with Cape Verde Archipelago, São Tomé & Príncipe, Seychelles, Réunion, Comoros, island of Saint Helena and other smaller islands.