Xylopertha retusa
Creators: name: Liu, Lan-Yu
name: Beaver, Roger A.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Bostrichidae
Xylopertha
Xylopertha retusa

description: Xylopertha retusa (Olivier, 1790)
Figs 1C–D, 2A, 3A, 4A, 5A–B
Bostrichus retusus Olivier, 1790: 110.
Apate sinuata Fabricius, 1792: 362. Synonymy: Schilsky 1899: 291.
Apate aterrimus Faldermann, 1837: 250. Synonymy: Lesne 1901: 578.
Xylonites retusus – Lesne 1901: 577.
Xylopertha retusa – Fisher 1950: 143.
Type material of X. retusa was not located, but the species is well-known in the Mediterranean area, and the senior author has examined numerous specimens determined by Lesne, Vrydagh and others in IRSNB, LYL, MAIC, MIZPAN, MNB, MTM, NHMUK, NMBS, NMPC, NMS, NMW, SDEI, SNSD, ZMHB and ZSM, mainly from North Africa, South and Central Europe, Turkey, and Iran.
Diagnosis
The species is easily separable from X. praeusta and X. reflexicauda by the absence of spines on the elytra in both sexes. The male can be separated from X. elegans sp. nov. by the presence of long, erect hairs on the upper margin of the elytral declivity (absent in X. elegans sp. nov.), and by the form of the 8th tergite and genitalia (Fig. 5A–B: X. retusa; Fig. 5E–F: X. elegans sp. nov.). In the female of X. retusa, the apex of each elytron is strongly emarginate, the emargination filled by a pair of ventrally-directed processes with rounded tips next to the suture (Fig. 3A); in X. elegans sp. nov., the apex of each elytron projects as a broad, approximately rectangular process, its apex with a small pointed tooth next to the suture, the processes separated by a shallow U-shaped emargination, a broad emargination lateral to each process (Fig. 3C). In the female of X. retusa, the fourth ventrite is visible across its entire width, and the base of the emargination of the 5th ventrite does not project ventrally (Fig. 4A); in X. elegans sp. nov., the 3rd abdominal ventrite projects medially over the 4th, which is visible only at the sides, and the 5th ventrite is very deeply, broadly emarginate, the base of the emargination projecting as a thin lamina behind the process on the 3rd ventrite (Fig. 4B).
Material examined
AUSTRIA: 1 ♂, 1 ♀, [Mistelbach, 16 May 1992, Schillhammer leg.]; 1 ♂, [A.B. Leche, Seewinkel, Apr. 1967, Holzschuh leg.] (LYL).
BELGIUM: 1 ♀, [Yvoir, 7 Jul. 1946, A. Collart leg.] (LYL, more than 50 in IRSNB from South Europe).
CZECH REPUBLIC: 1 ♀, [Bohemia, Dievic Dřevíč, 8 Jun. 1995, P. Zahradnik leg.] (LYL, 80 more in NMPC).
FRANCE: 1 ♂, 1 ♀, (no locality); 1 ♀, (no locality), [deciduous forest, #51, I.G. 19.501].
MACEDONIA: 1 ♂, [10 km N of Struga, 4 Jun. 1992, Zbaždi, P. Zahradnik leg.] (LYL).
IRAN: 2 ♀♀, [Prov. Mazandaran, vic. Kolijak, mountain slope, 36°28′18″ N, 51°40′14″ E, 1840 m, 5 May 2010, A. Weigel leg. #22a.] (1 ♀ in LYL, 1 ♀ in NME).
The specific identity of more than 800 further specimens was checked in the following museums: IRSNB, MAIC, MIZPAN, MNB, MTM, NHMUK, NMBS, NMPC, NMS, NMW, SDEI, SNSD, ZNHB and ZSM, but detailed locality data were not recorded. All specimens came from the distributional area given below.
Description
BODY. 3–6 mm long, about 2.8–3.0 times as long as wide, elongate. Black or dark brown, moderately shiny, antennae and tarsi reddish, the posterior part of the elytra often paler.
HEAD. Clypeus finely and densely punctured, not convex in front. Frons with puncturation less fine and less dense than the clypeus, slightly rough, and covered by fairly long, fine pubescence directed upwards. First and second segments of antennal club as wide as long.
PRONOTUM. Slightly wider than long, fairly strongly narrowed in the anterior third, bearing golden, long, erect pubescence on the anterior angles; area above head finely and more or less roughly punctured; median and posterior areas shiny with fine, sparse puncturation; sides evenly rounded; posterior angles rounded; widest in basal part.
ELYTRA. 1.8–2.2 times longer than wide, parallel-sided at disc and widest at middle of declivity. Elytral disc moderately dense puncturation, not coarser posteriorly. Upper margin of the elytral declivity bearing reddish, quite long erect pubescence, denser in the male. Elytral suture projecting on declivity, more strongly towards the apex. Elytral declivity without spines on each elytron in both sexes.
LEGS. External face of the anterior tibiae broadly grooved, not narrowed towards the apex. Segments 2 and 3 of anterior tarsi distinctly wider than the others.
Male
ELYTRA. Widened posteriorly. Upper margin of elytral declivity bearing long, erect pubescence. Elytral suture not raised on disc, strongly raised on declivity. Declivity rather finely punctured in the upper half, almost impunctate below, sometimes transversely ridged on much of its surface. Apical declivity larger than in female, more sharply truncate, a little concave, bordered on the lower-lateral side by a carina not extending to the sutural angle, the carina expanded at the sides of the declivity to form a marginal callus. Sutural angles pointed, conjointly projecting or weakly separated at the apex (Fig. 1C–D).
ABDOMEN. Anterior margin of 8th tergite fringed by long erect outwardly directed hairs. Genitalia strongly sclerotised, with extended lobes laterally, fringed with long hairs at apex and on a small inwardly projecting lobe towards base on each side. Aedeagus simple, without long apophyses (Fig. 5A–B).
Female
HEAD. Frons covered by longer, denser upwardly directed hairs than in male.
ELYTRA. Parallel, suture strongly raised on declivity. Declivity strongly and densely punctured with a truncate raised area at apical third. Lateral margin of declivity sinuate. Apex of each elytron strongly emarginate, the emargination filled by a pair of ventrally-directed processes with rounded tips next to suture (Fig. 3A).
ABDOMEN. Third abdominal ventrite not projecting medially over 4th, which is visible across its entire width; 5th segment longer than 2 to 4 together, strongly, longitudinally grooved in the middle, and provided on its posterior margin with two large teeth, contiguous at the base, strongly pointed, and slightly recurved dorsally near the apex; on the outer side of the teeth the posterior margin of the segment is semicircularly emarginate (Fig. 4A).
Distribution
Central and southern Europe, North Africa (except Egypt), Cyprus, Israel, Turkey, Iran, part of Caucasia and Siberia (Liu et al. 2016b).
Biology
The species has been recorded from the wood of trees in the families Fabaceae, Fagaceae, Moraceae, Ulmaceae Mirb. and Vitaceae Juss. (Lesne 1901; Bahillo de la Puebla et al. 2007; Marković & Stojanović 2012; Buse et al. 2013). The species is active from May to July in Southern Europe (Cymorek 1961 as Xylonites retusus; Bahillo de la Puebla et al. 2007), but from October to December in Israel (Buse et al. 2013). In Central Europe, the beetles prefer boring into dry oak branches; the larvae tunnel particularly in the sapwood; they overwinter in diapause and pupate in spring (Cymorek 1961 as Xylonites retusus). Several clerid and a melyrid predators (Coleoptera: Cleridae, Melyridae) are listed by Bahillo de la Puebla et al. (2007). Yu et al. (2012) list three species of braconid Hymenoptera as parasitoids.
description: Published as part of Liu, Lan-Yu & Beaver, Roger A., 2017, A review of the powderpost beetle genus, Xylopertha Guérin-Méneville, 1845, with a new species and new synonymy (Coleoptera: Bostrichidae: Bostrichinae: Xyloperthini), pp. 1-22 in European Journal of Taxonomy 380 on pages 13-15, DOI: 10.5852/ejt.2017.380, http://zenodo.org/record/1118246