Kenyacus trechoides, 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 : 482-484

Kenyacus trechoides sp. n.

( Figs 31 , 47–49 , 51a )

Type material. Holotype: ♂, “ UGANDA, Western Region, Kasese District, 10 km NWW Nyakalengija, Rwenzori Mts. National Park, main trail from John Matte Hut to Nyabitaba Hut , 0°22.071’N 29°57.378’E, accuracy 15 m, extent 15 m, h = 2999 m, Hagenia , Hypericum , Rubus , Impatiens , big gaps with bushes and grass, sifting leaf litter [3595] [Garmin 60CSx; WGS84] V.I. Gusarov 17.viii.2008 U161” ( ZMUN).

Description (male). Habitus as in Fig. 31 . Body length 4.0 mm, width 1.7 mm.

Colour: Body brown, dorsal surface slightly shiny, four basal abdominal sternites clearly infuscate; base of mandibles, labrum, clypeus, lateral margins of pronotum and elytra, as well as elytral suture slightly paler; palpi, antennae and legs brownish yellow; antennomeres 3–5 slightly infuscate.

Head: Comparatively large, HWmax/PWmax 0.81, HWmin/PWmax 0.67. Eyes with large facets, slightly con- vex, HWmax/HWmin 1.20, separated from buccal fissure at distance of width of antennomere 1. Tempora short, about quarter as long as eye, slightly convex. 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 almost straight 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 evenly bent in apical portion, with apex acute, only slightly blunted just at tip. Dorsal microsculpture in both sexes distinct throughout, similar to that of K. berndi sp. n. and K. parvus sp. n., consisting of isodiametric meshes. Antennae slightly surpassing basal edge of pronotum, with antennomeres 7–9 slightly longer than wide.

Pronotum: Slightly transverse, PWmax/PL 1.32, widest at the end of anterior third, markedly narrowed posteriorly, PWmax/PWmin 1.32; lateral seta inserted slightly before widest point. Sides rounded anteriorly, almost straightly converging from widest point to basal angles, without distinct border. Apical margin very shallowly emarginate; apical angles slightly projecting ahead, acute, blunted at tip. Basal margin slightly narrower than apical margin and noticeably narrower than elytral base, very shallowly concave medially and rounded laterally; both apical and basal margins not bordered. Basal angles obtuse, narrowly rounded at tip, not projecting posteriorly. Disc moderately convex, more strongly sloped to apical angles, slightly depressed basally and flattened at basal angles, forming latero-basal depressions not distinctly delimited from other parts of disc. Lateral depressions beginning from apical angles as narrow furrows, markedly widened in basal half, reaching basal margin and fused with laterobasal depressions. Basal fovea shallow, rather wide, reaching basal pronotal edge, fused with lateral depression at pronotal base and separated from it by small and narrow convexity anteriorly. Surface of pronotum impunctate. Anterior transverse depression distinct and long. Median line thin, superficial, situated between anterior transverse depression and basal margins of pronotum. Microsculpture distinct throughout, similar to that of K. berndi sp. n. and K. parvus sp. n. ( Fig. 16 ), consisting of large isodiametric meshes along basal and apical margins and of slightly transverse meshes on remaining surface.

Elytra: Oval, slightly widened posteriorly, widest just behind middle, EL/EW 1.38, EL/PL 2.57, and EW/ PWmax 1.41. Humeri prominent, evenly rounded at tip. Sides in apical fifth rather sharply curved inside and then almost straightly converging to apex. Sutural angle very narrowly rounded at tip. Basal edge oblique, widely arcuately curving inside humerus up to lateral margin. Lateral gutter distinct, narrow along entire length. Elytral disc convex in lateral and caudal views. Striae thin, impunctate, slightly crenulate, impressed along entire length, shallowly basally and slightly more deeply apically, their bases removed from basal elytral border. Parascutellar setigerous pore present, large. Parascutellar striole present, very short. Intervals almost flat, only very slightly convex, almost not narrowed posteriorly; intervals 2 and 3 almost parallel-sided at apex; interval 3 without discal pore. Microsculpture distinct throughout, similar to that of K. berndi sp. n. and K. parvus sp. n. ( Fig. 20 ), consisting of transverse meshes.

Ventral surface of thorax and abdomen: Prosternum with several moderately long erect setae medio-apically. Metepisternum slightly wider than long, narrowed posteriorly. Basal abdominal sternites glabrous, three last visible (V, VI and VII) sternites very sparsely pubescent; apex of last visible sternite evenly rounded, with two pairs of marginal setae.

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. Male protarsomeres 2–4 only scarcely dilated, with biseriately arranged long adhesive scales ventrally; mesotarsomeres not dilated, with a pair of scales present only on tarsomere 4; mesotarsomere 4 rather deeply emarginate.

Male genitalia: Median lobe ( Figs 47, 49 ) stout, strongly arcuate in lateral view, with large basal bulb; in dorsal view rather evenly narrowed distally in apical third. Terminal lamella in lateral view short, straight, without apical capitulum; in dorso-caudal view comparatively narrow, narrowly rounded at apex and with evenly rounded sides ( Fig. 48 ). Internal sac without any sclerotic elements; apical folding spiny patch, as in K. berndi sp. n., comparatively short, not reaching basal bulb.

Etymology. This specific name is derived from the name of the carabid genus Trechus , the members of which are somewhat similar in appearance to this and many other species of Kenyacus .

Distribution ( Fig. 51a ). This new species is known from one locality in the Bujuku Valley at altitude of 2999 m in the south-eastern part of the Rwenzori Mountains, where it was found together with K. angustatus sp. n. and K. similis sp. n.

Bionomics. According to the label data, the specimen was collected by sifting leaf litter in forest with Hagenia and Hypericum , with large gaps between trees and pronounced bush and herbaceous layer with Rubus and Impatiens ( Fig. 92 ).

Comparison. In size and general appearance with rather short oval elytra, K. trechoides sp. n. is most similar to K. berndi sp. n., but distinctly differs from it in the shape of the pronotum with more widely rounded basal angles and more shallowly emarginate apical and basal margins ( Fig. 31 ). Additionally, K. trechoides sp. n. markedly differs from K. berndi sp. n. in having supraorbital setigerous pore located more posteriorly; abdominal sternite V sparsely pubescent; male protarsus less dilated; mesotarsus almost not dilated, with adhesive scales present only on tarsomere 4; and median lobe of aedeagus ( Figs 47, 49 ) more strongly curved in lateral view and with narrower apical portion in dorsal view. In shape of pronotum and many other characters, K. trechoides sp. n. is somewhat similar to K. parvus sp. n., but smaller (body length 4.0 mm versus 4.1–4.7 mm), its elytra are relatively shorter (EL/PL 2.57 versus 2.59–2.87), abdominal sternite V is sparsely pubescent, male pro- and mesotarsi are less dilated, and median lobe of aedeagus is more strongly curved, with narrower terminal lamella and with shorter apical folding spiny patch in internal sac.

Figures

FIGURE 51. Kenyacus, distribution. a, K. trechoides sp. n.; b, K. berndi sp. n.; c, Kenyacus sp.

FIGURE 92. Bujuku valley between Nyabitaba Hut and John Matte Hut (ca. 2800–2900 m) near the type localities of K. trechoides sp. n., K. angustatus sp. n. and K. pusillus sp. n. Forest patches with Podocarpus, Hagenia and Hypericum separated by large gaps with bushes and herbaceous vegetation. Photo: Vladimir Gusarov.

FIGURES 30, 31. Kenyacus, habitus. 30, K. berndi sp. n. (holotype); 31, K. trechoides sp. n. (holotype). Scale bar = 1.0 mm.

FIGURES 32–49. Kenyacus. 32–39, K. parvus sp. n. (32–34, holotype; 35–37, paratype, loc. U160; 38, 39, paratype, loc. U121); 40–46, K. berndi sp. n. (40–42, holotype; 43, 44, paratype, loc. U121; 45, 46, same, loc. U123); 47–49, K. trechoides sp. n. (holotype). 32, 35, 40, 47, median lobe, dorsal view; 34, 37, 42, 49, same, lateral view; 33, 36, 41, 48, apex of median lobe, dorso-caudal view; 38, 43, 45, stylus, lateral view; 39, 44, 46, laterotergite and stylus, ventral view. Scale bar = 0.5 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.