Xylomedes bidasi Borowski & Lasoń, 2021

Jerzy, Borowski, Andrzej, Lasoń & Marek, Sławski, 2021, Remarks on Xylomedes Lesne, 1902 with description of a new species from Iran (Coleoptera: Bostrichidae, Apatinae), Zootaxa 4941 (2), pp. 291-300 : 292-298

Xylomedes bidasi Borowski & Lasoń n. sp.

( Figs 1–2 , 14 , 17 )

Type material. Holotype: Iran occ., VI 2010, Fars prov., Zagros Mts., Malashoreh pass, 1900m, 30km S of Yasui, J. Simandl lgt., female, ( DFP).

Paratypes: Iran, Fārs, 29°11’N / 53°23’E, 1830m, Kuhhā-ye Zagros, Mïān Jangal, 36km NW of Fasā, 8 V 2017, Acer and Pistacia forest, Pistacia sp., ex. cult. (imago 06 VI 2017), female, ( DFB); Iran, Fārs, 29°11’N / 53°23’E, 1830m, Kuhhā-ye Zagros, Mïān Jangal, 36km NW of Fasā, 8 V 2017, Acer and Pistacia forest, Pistacia sp., ex. cult. (imago 06 VI 2017), female, ( AL); Iran, Lorestan, 33°28’N / 49°4’E, 1490m, Kuhhā-ye Zagros, 2km SSE of Dorud, 24 IV 2016, leg. Andrzej Lasoń, mountain meadow, Pistacia sp., ex. cult. (imago 19 VI 2016), female, ( AL); Iran, Lorestan, 33°28’N / 49°4’E, 1490m, Kuhhā-ye Zagros, 2km SSE of Dorud, 24 IV 2016, leg. Andrzej Lasoń, mountain meadow, Pistacia sp., ex. cult. (imago 06 VIII 2016), female, ( AL); Iran occ., VI 2010, Fars prov., Zagros Mts., Malashoreh pass, 1900m, 30km S of Yasui, J. Simandl lgt., male, ( DFP); Iran, Fars prov., 80km SE Darab, N 28°25’23”, E 55°09’09”, 24 V 2014, 1512m, Walter Grosser lgt., female, ( DFP).

Descriptions. Female. Body cylindrically elongated, 11.5-13.8 mm in length, brownish-red to dark brown ( Fig. 1 ). Labrum with dense brush of golden setae on the sides and anterior margin. Epistome deeply arcuately emarginated, posteriorly covered with short, fine erect setulae, golden setae on lateral parts much longer and denser. Frontoclypeal suture indistinct, in the form of fine striola. Front markedly convex, with two elevated outgrowths near posteromedian margins of eyes. Frontal surface finely transversely wrinkled and indistinctly granulated. Sides with brushes of dense erect golden setae disappearing before the tips of outgrowths; median part with fine, erect, much sparser setulae. Short but conspicuous furrow runs between outgrowths. Occipital part of head indistinctly pubescent, covered with fine lustrous papillae. Eyes large, semiglobular, distinctly protruding from head outline. Antennae 10-jointed, with 3-jointed club whose two basal joints ca 1.5 times wider than long, and elongated terminal joint somewhat shorter than basal two together. Pronotum slightly wider than long, usually darker than elytra. Anterior third of surface finely rugose with some larger denticles localized mainly near anterior angles; median part covered with fine, shining, moderately dense papillae, progressively larger and denser sideward. Pronotal pubescence twofold: long and erect on sides, much shorter, finer, semierect, forward directed at middle. Scutellum distinct, elongated, apically slightly rounded or transversely truncated. Elytra elongated, partly parallelsided, apices sharply angular, somewhat divergent. Ventral side of apical margins without distinct notches or denticles, suture on truncation swollen and slightly elevated. Puncturation dense, irregular, fine, here and there arranged into longitudinal rows. Pubescence conspicuous, consisting of yellowish-brown setae of unequal length: short, erect, backward directed dominate, but between them sparser, long, vertically erect ones also occur; on truncation and sides setae are somewhat denser than on dorsal surface. Legs brownish-red with long (especially on tibiae) erect setae. Outer side of protibiae with fine denticles and one large terminal dent bent outwards at nearly right angle. Inner edges of protibiae denser pubescent with one large hooked terminal dent. Tarsi longer than tibiae, 4-jointed, joints flattened laterally; tarsomere 1 extremely small, barely discernible, closely attached to normally long tarsomere 2; terminal joints of all tarsi with pairs of large claws. Abdomen paler than sternum, hind margins of sternites paler still. Ventral side covered with long, recumbent or semierect setae. Anal sternite with dense brush of golden setulae on apical margin.

Male. Length 11 mm. Body cylindrically elongated, blackish-brown ( Fig. 2 ). Labrum brownish-red; anterior margin with dense brush of golden setae.Anterior margin of epistome deeply triangularly emarginated in the middle, emargination almost reaching the hind margin ( Fig. 17 ); frontoclypeal suture in the form of furrow, deepest and most conspicuous at middle. Sides of epistome with golden erect setae. Front finely sparsely granulated with, also fine and sparse, erect setae. Occipital part of head with denser, more lustrous and distinctly larger granules. Eyes not large, moderately convex. Antennae 10-jointed with 3-jointed club, whose basal two joints somewhat wider than long and terminal joint elongated, equal in length to sum of basal two. Antennal pubescence very short, setulae sparsely distributed. Pronotum square in dorsal aspect, anterior margin slightly arcuately emarginated, anterior angles prolonged into downward directed process adorned with two large denticles, the second of them forming a hooked apex of process. Anteriorly pronotum covered with tubercles and denticles of various size, largest near apical angles and smallest medially; at middle of basal part granulae are sparse and fine. Pronotal pubescence sparse, more conspicuous on sides and apical part; the anterior half—especially on the sides—covered with fine, sparse, erect setulae; those on middle and basal parts are almost exclusively fine and recumbent. Scutellum clearly visible, elongated, apex broadly rounded. Elytra partly parallelsided, humeri prominent, truncation gently sloping. Surface densely covered with deep, irregularly spaced punctures (only on the sides partly arranged into longitudinal rows). Suture on truncation swollen and elevated. Elytral apices jointly rounded, not spiniform. Ventral side of apical margins finely denticulate. Elytral pubescence yellowish-brown, short, recumbent or semierect, on the sides and truncation somewhat longer (on truncation exclusively erect and slightly thicker). Ventral side blackishbrown, barely pubescent (only on the sides of prothorax and—especially—metaventrite longer setulae are more conspicuous). Hind margins of sternites paler. Legs brownish-red. Outer edge of protibiae finely denticulate, with single large terminal dent bent at almost right angle outwards; inner edge more densely pubescent and ending with very large hooked dent. Tarsi longer than tibiae, laterally flattened, seemingly 4-jointed: basal joint extremely small, barely discernible, closely attached to normally sized second; distal joints with pairs of large claws.

Diagnosis. Females of X. bidasi n. sp. are smaller than X. cornifrons (Baudi) (min. 14.5 mm) but larger than X. laticornis (Lesne) (max. 9 mm), easily distinguishable from other species by a conspicuous furrow between elevated outgrowths at the hind margins of the eyes: no such furrow occurs in any other representative of the genus. In shape of these outgrowths the new species resembles rather X. cornifrons than X. laticornis , in which they form transverse, narrowly separated carinulae. A significant characteristic distinguishing X. bidasi n. sp. from X. cornifrons is a finely transversely rugose frontal surface with fine separate setulae in the former as compared to a coarsely punctured surface with tufts of golden setae in the latter. Additionally in the new species elytral apices are not spiniformly prolonged ( Fig. 14 ) like in X. cornifrons , resembling rather X. laticornis , whose females, however, have all tarsomeres covered with very long erect setae, whereas in X. bidasi n. sp. long semierect setae occur only on basal joints.

Male X. bidasi n. sp. are smaller than X. cornifrons (Baudi) (min. 13 mm), but larger than X. laticornis (Lesne) (max. 9 mm). In colouration it resembles X. cornifrons , being totally different from the yellowish-brown to pale brown males of X. laticornis . The best diagnostic character of X. bidasi n. sp. is emargination of the anterior margin of epistome: very deep triangular in the new species ( Fig. 17 ), shallow and arcuate in other representatives of the genus ( Figs 18–19 ). Elytral apices, jointly rounded in contrast to spiniform in X. cornifrons , are somewhat similar to those in X. laticornis , the males of which, however, differ in having the entire body (including the tarsi) covered with very long erect setae.

Etymology. The name is proposed to honour our colleague, the excellent beetle-collector, Marek Bidas (Kielce, Poland) on the occasion of his retirement.

Bionomy. The species has been collected mainly in dry forest steppe and semidesertic areas of the Zagros Mts. ( Figs 20–21 ). Imagines have been reared in June and July from Pistacia sp. branches, 1–1.5 cm. in diameter, collected in April and May—considering these specimens as well as those collected in the field, it can be supposed that the maximum swarming occurs in June.

Figures

FIGURES 1–8. Palaearctic Xylomedes species, habitus in dorsal view. 1–2 X. bidasi n. sp.; 3–4 X. laticornis (Lesne); 5–6 X. cornifrons cornifrons (Baudi); 7–8 X. cornifrons rufocoronata (Fairm.). Figs 1, 3, 5, 7—females; figs 2, 4, 6, 8—males.

FIGURES 12–16. Elytral apices of Xylomedes species. 12–13 X. cornifrons cornifrons (Baudi), female; 14 X. bidasi n. sp., female; 15 X.cornifrons cornifrons (Baudi), male; 16 X. laticornis (Lesne), male. Fig. 12—posterior view; figs 13–16 semilateral view.

FIGURES 17–19. Male heads of Xylomedes species, frontal view. 17 X. bidasi n. sp.; 18 X. laticornis (Lesne); 19 X. cornifrons cornifrons (Baudi).

FIGURES 20–21. Biotopes of Xylomedes bidasi n. sp. 20 Iran, Zagros Mts., Mïān Jangal; 21 Iran, Zagros Mts., Dorud (phot. by A. Lasoń).