Kenyacus gusarovi, Kataev, 2019

Kataev, Boris M., 2019, A review of the Afrotropical genus Kenyacus (Coleoptera: Carabidae: Harpalini) from the Rwenzori Mountains, with description of seven new species, Zootaxa 4679 (3), pp. 463-498 : 472-475

Kenyacus gusarovi sp. n.

( Figs 4 , 15, 19 , 22–26 , 27b )

Type material. Holotype: ♂, “ UGANDA, Western Region, Kasese District, 13.5 km NWW Nyakalengija, Rwen- zori Mts. National Park, env. of John Matte hut, 0°23.001’N 29°55.774’E, accuracy 6 m, extent 20 m, h = 3421 m, Erica forest with mixed vegetation below, sifting leaf litter [3553] [Garmin 60CSx; WGS84] V.I. Gusarov 10.viii.2008 U121” ( ZMUN).

Paratypes: 1 ♀, same data as holotype ( ZMUN) ; 1 ♀, “ UGANDA, Western Region, Kasese District, 13.5 km NWW Nyakalengija, Rwenzori Mts. National Park, env. of John Matte Hut , 0°22.993’N 29°55.749’E, accuracy 8 m, extent 3 m, h = 3406 m, Bujuku River banks, in moss on stones [3554] [Garmin 60CSx; WGS84] V.I. Gusarov 10.viii.2008 U122” ( ZMUN) ; 1 ♂, “ UGANDA, Western Region , Kasese District, 13.5 km NWW Nyakalengija, Rwenzori Mts. National Park , John Matte hut, campsite, 0°22.991’N 29°55.774’E, accuracy 7 m, extent 3 m, h = 3428 m, meadow with Poaceae on small ridge [3560] [Garmin 60CSx; WGS84] V.I. Gusarov 11.viii.2008 U128” ( ZIN)

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Description (2 males and 1 female measured). Habitus as in Fig. 4 . Body length 4.5–4.6 mm, width 1.9–2.0 mm.

Colour: Body blackish brown, dorsal surface slightly shiny; base of mandibles, labrum, clypeus, margins of pronotum and elytra, as well as elytral suture, mentum, epipleura of pronotum and two last abdominal sternites usually paler, reddish brown or brownish yellow; palpi, antennae and legs brownish yellow; antennae more or less infuscate from antennomere 2.

Head: Large, in males HWmax/PWmax 0.77, HWmin/PWmax 0.67; in female these indices respectively 0.78 and 0.70. Eyes with large facets, only slightly convex, separated from buccal fissure at distance of width of antennomere 1, HWmax/HWmin 1.15–1.16 in males and 1.12 in female. Tempora short and flat. Frons and vertex convex. Fronto-clypeal suture distinct, superficial. Supraorbital setigerous pore located just behind level of posterior margin of eye, removed from supraorbital furrow at a distance of length of antennomere 2. Labrum slightly concave anteriorly. Clypeus with slightly prominent apical angles and almost straight apical margin between them. Mentum and submentum fused, submentum with two setae on each side. Mandibles medium-sized; left mandible slightly bent apically, with subtruncate or distinctly blunt apex. Dorsal microsculpture in both sexes distinct throughout, consisting of somewhat large isodiametric meshes, almost granulate on clypeus and behind eyes and much finer on frons. Antennae in male extending to basal edge of pronotum, with antennomeres 7–9 only slightly longer than wide; in female antennae slightly shorter, with shorter antennomeres.

Pronotum: Markedly transverse, PWmax/PL 1.52–1.56 (m = 1.54), widest at the end of anterior third, moder- ately narrowed posteriorly, PWmax/PWmin 1.19–1.23 (m = 1.21); lateral seta inserted in widest point or just before it. Sides rounded in anterior two-thirds, slightly sinuate or almost straightly converging in posterior third, without distinct border. Apical margin arcuately emarginate, apical angles projecting ahead, acute, very narrowly rounded at tip. Basal margin almost equal to apical margin and slightly narrower than elytral base, deeply emarginate, slightly concave or almost straight medially and rounded laterally; both apical and basal margins not bordered. Basal angles obtuse or almost right, at most slightly blunted at tip, not or only slightly projecting posteriorly and at most only slightly covering elytral base. Disc moderately convex, strongly sloped to apical angles, depressed basally between basal foveae. Lateral depressions beginning from apical angles as a narrow lateral gutter, slightly and evenly widened basally, reaching basal margin and then prolonged along basal margin to basal foveae; basal foveae elongate, deepened, reaching basal pronotal edge and separated anteriorly from lateral depression by a convexity. Surface of pronotum impunctate. Anterior transverse depression distinct, but shallow. Median line thin, superficial, usually reaching apical and basal margins of pronotum. Microsculpture distinct throughout, consisting of large isodiametric meshes along basal and apical margins and of slightly transverse meshes on remaining surface ( Fig. 15 ).

Elytra: Oval, widest at middle, rather short, in males EL/EW 1.32–1.40 (m = 1.36), EL/PL 2.53–2.66 (m = 2.60), EW/PWmax 1.22–1.25 (m = 1.24); in female these indices respectively 1.34, 2.53, and 1.30. Humeri slightly prominent, angularly rounded at tip. Preapical sinuation very shallow. Sutural angle in both sexes narrowly rounded at tip. Basal edge evenly sinuate, forming a very obtuse angle with lateral margin or almost arcuately connected with it. Lateral gutter distinct, slightly widened at humerus. Elytral disc convex in lateral and caudal views. Striae thin, impunctate, slightly crenulate, faintly impressed along entire length, their bases removed from basal elytral border. Parascutellar setigerous pore present, large. Parascutellar striole very short, usually more or less highly reduced, occasionally with apex connected with stria 1. Intervals somewhat flat, at most slightly convex apically, not or only weakly narrowed posteriorly; intervals 2 and 3 almost parallel-sided or slightly widened at apex; interval 3 without discal pore. Microsculpture visible throughout, consisting of large transverse meshes ( Fig. 19 ).

Ventral surface of thorax and abdomen: Prosternum with 3–5 moderately long erect setae medially and with a row of similar setae just along anterior margin. Metepisternum slightly wider than long, narrowed posteriorly. Basal abdominal sternites glabrous, two last visible (VI and VII) sternites pubescent, VI more sparsely than VII; apex of last visible sternite with two pairs of marginal setae in both sexes, subtruncate or with very shallow, indistinct incision at middle.

Legs: Metacoxae without any additional setae. Tarsi glabrous dorsally. Tarsomere 5 without setae ventrally. Meso- and metatarsomeres 1 about as long as meso- and metatarsomeres 2+3, respectively. In male, protarsomeres 2–4 slightly dilated and with biseriately arranged long adhesive scales ventrally, mesotarsomeres very faintly, indistinctly dilated, with long adhesive scales only on tarsomere 4; latter rather deeply emarginate but not bilobed.

Male genitalia: Median lobe ( Figs 23, 24 ) elongate, arcuate in lateral view, with comparatively small basal bulb, in dorsal view evenly narrowed in apical half to apex. Terminal lamella extremely short, slightly curved dorsally, without apical capitulum; in dorso-caudal view narrowly rounded at apex ( Fig. 22 ). Internal sac without any sclerotic elements.

Female genitalia: Comparatively large ( Figs 25, 26 ); laterotergite (hemisternite) elongate, asymmetrical, with posterior portion bent laterally, not membranous, without setae and spines. Basal stylomere moderately elongate, with several short setae apically.Apical stylomere elongate, rather long, markedly curved, slightly shorter than basal stylomere, with short thick seta at ventral edge of outer margin and with comparatively narrow base in ventral view; in lateral view narrow, almost parallel-sided in apical half and rounded at apex ( Fig. 25 ).

Etymology. The species is named after my friend and colleague Vladimir I. Gusarov (Oslo), an excellent specialist on Staphylinidae , who collected all new species described in this paper.

Distribution ( Fig. 27b ). This new species is known from the Bujuku Valley in vicinity of John Matte Hut at altitudes of 3406–3428 m in the south-eastern part of the Rwenzori Mountains, where it occurs sympatrically with K. parvus sp. n., K. pusillus sp. n. and K. berndi sp. n.

Bionomics. According to the label data, specimens were collected on meadow with Poaceae , in moss on stones as well as by sifting leaf litter in Erica forest with mixed vegetation in the herbaceous layer ( Figs 93 , 94 ).

Comparison. This new species is much smaller than K. ruwenzorii (5.3–6.0 mm), but larger and stouter than most other species of Kenyacus known from the Rwenzori Mountains. It is also differing from K. ruwenzorii in: head relatively larger; left mandible with subtruncate or distinctly blunt apex; dorsal microsculpture on head almost granulate on clypeus and behind eyes and much finer on frons; pronotum much wider, less strongly narrowed basally, its basal angles not or only slightly projecting posteriorly and at most only slightly covering elytral base ( Fig. 4 ); pronotal microsculpture slightly transverse on disc ( Fig. 15 ); sutural angle in both sexes narrowly rounded at tip; elytral microsculpture finer, transverse ( Fig. 19 ); prosternum with a row of long erect setae just along anterior margin; and mesotarsomeres very faintly, indistinctly dilated, with long adhesive scales only on tarsomere 4. In the body size (4.5–4.6 mm) and having a row of moderately long erect setae along apical margin of prosternum, K. gusarovi sp. n. is similar to K. parvus sp. n., but distinctly differs from it in stouter body and in wider pronotum (PWmax/PL 1.52–1.56 versus 1.30–1.45); basal angles are less obtuse, occasionally almost right, with sharper, at most only slightly blunted tip. In addition, K. gusarovi sp. n. differs from K. parvus sp. n. as well as from all other species of Kenyacus known from the Rwenzori Mountains in having left mandible with subtruncate or distinctly blunt apex (in other examined species, apex of left mandible is acute). In pronotum with somewhat deeply emarginate basal margin, K. gusarovi sp. n. is similar to K. ruwenzorii , K. parvus sp. n. and K. berndi sp. n., but differing in this feature from other species which all have pronotal basal margin more or less straight. K. gusarovi sp. n. also distinctly differs from most other congeners from the Rwenzori Mountains in median lobe of aedeagus ( Figs 23, 24 ) with relatively small basal bulb (similar only to that of K. ruwenzoricus ) and in relatively much larger female genitalia ( Figs 25, 26 ) with more elongate laterotergite.

Figures

FIGURE 27. Kenyacus, distribution. a, K. ruwenzorii (Alluaud, 1917); b, K. gusarovi sp. n.

FIGURE 93. Trail across the Bujuku river in vicinity of John Matte Hut (ca. 3400 m). Patches of Erica forest, edge of the Lower Bigo bog with tussocks of Carex runssoroensis, boulders covered with moss. Habitats of K. parvus sp. n. and K. gusarovi sp. n. Photo: Vladimir Gusarov.

FIGURE 94. Erica belt in vicinity of John Matte Hut (ca. 3400 m) near the type localities of K. gusarovi sp. n. and K. parvus sp. n. Habitat of K. gusarovi sp. n., K. parvus sp. n. and K. berndi sp. n. Photo: Vladimir Gusarov.

FIGURES 3, 4. Kenyacus, habitus (males). 3, K. ruwenzorii (Alluaud, 1917) (loc. U166); 4, K. gusarovi sp. n. (holotype). Scale bar = 1.0 mm.

FIGURES 14–21. Kenyacus, microsculpture (14–17, male pronotal; 18–21, male elytral). 14, 18, K. ruwenzorii (Alluaud, 1917); 15, 19, K. gusarovi sp. n.; 16, 20, K. parvus sp. n.; 17, 21, K. angustatus sp. n. Scale bar = 0.2 mm.

FIGURES 22–26. Kenyacus gusarovi sp. n. (holotype and female paratype). 22, apex of median lobe, dorso-caudal view; 23, median lobe, lateral view; 24, same, dorsal view; 25, stylus, lateral view; 26, laterotergite and stylus, ventral view. Scale bar = 0.5 mm.