Bioacoustics of Poecilimon pechevi

Diagnosis. P. pechevi belongs to the Poecilimon ampliatus group, as defined by Heller & Lehmann (2004) . It is most similar to P. ebneri by sharing various synapomorphies as the general coloration and body shape, the number of stridulatory teeth, and especially the shape of female lamella. On the other hand, similarities exist with P. ampliatus in the shape of male cerci, in P. pechevi cerci being slightly shorter and thicker. Male calling song is typical for the group and strongly resembles the song of both P. ebneri and P. ampliatus (compare Heller 1988 ; Heller & Lehmann 2004 ). The most important difference between P. pechevi and P. ampliatus is the presence of a glandular bulge at the first abdominal tergite of the latter, which is thus an autapomorphy of P. ampliatus . Other differences from P. ampliatus include: 1) the colouration of P. pechevi is paler, similar to that of P. ebneri ; 2) lower number of stridulatory teeth (68–73 against 95 in ampliatus ; but see below and Anichini et al. 2016); 3) the differences in song are weak (as typical for the group in general). Differences from P. ebneri include mainly male cerci. In P. pechevi cerci are very short and bulky with sinuate outcurved apex bearing a single hook-shaped tooth, while in P. ebneri cerci are longer, tip is gently incurved and bearing usually two (rarely 1 to 4) pointed teeth (compare with Heller & Lehmann 2004 ). Female lamella in P. pechevi closely resembles P. ebneri and P. ampliatus (compare Fig. 2A, B in Heller & Lehmann 2004 ; errors exist in the legend of that plate and Figs 2–5 should be read as 2— P. ebneri , 3— P. marmaraensis , 4— P. amissus and 5— P. intermedius ) being dorso-ventrally flattened and triangularly pointed at the lower part of gonangulum..

Redescription. Studied material. Holotype : ³, Bulgaria , Blagoevgrad prov. , Western Bordering Mountains, Vlakhina Mountain, Kadiytsa summit: Kadiytsa, 1700 m ( Andreeva 1978 ) (labelled 1600–2000 m ) ( Peshev & Andreeva 1986 ), 31.07.1974 . Paratypes : same locality, 3 ³³, 5 ♀♀ , leg. E. Andreeva, NMNHS & 1 ³, 1 ♀ , leg. G. Peshev, NMNHS & 8 ³³, 5 ♀♀ , leg. E. Andreeva, HMB; other material: same locality, 1700-1800 m , 41.797ºN , 22.969ºE , xerophyte low bush- and mesoxerophyte grass associations, 04. – 05.08.2006 , common, 4 ³³, 2 ♀♀ , leg. D. Chobanov, NMNHS & CC. Note: Andreeva (1978) presents a detailed but insufficient description of a new species, Poecilimon pechevi . The figures in the latter publication are quite schematic and, as found later, somewhat incorrect. The differential diagnosis is too brief and the new species is compared only with P. zwicki Ramme, 1933 . Actually, from the figure of the apical part of cerci ( Andreeva 1978 : Plate I, 5), a similarity with P. ampliatus may be observed. As a result, P. pechevi remained a taxon with unclear status and position within the genus Poecilimon . Furthermore, its isolated population and local endemic status required definition of its conservation importance. Small, stocky build, with moderately shiny integument. Measurements as shown by Andreeva (1978) or also slightly smaller. Male ( Fig. 3a, b, d, e ). The fastigium verticis is half the width of the scapus, equal or wider and slightly longer than the second antennal limb, with parallel sides, moderately projecting fore- and upward. The pronotum is widest in its middle, the metazone is moderately dome-shaped bulging and slightly constricted backwards; its hind margin is concave. The mid sulcus passes just before the middle of pronotum. The lateral plates of pronotum have rounded corners. The acoustic stigma has small aperture. The tegmina are slightly covered by pronotum (<1/2 of their length), small, almost oval, with excision at the medial (anal) edge. The stridulatory vein is narrow, easily visible on the translucent membranous surface of the tegmen. The stridulatory file ( Fig. 3 g–i) is 2.2 mm long (if only the closely arranged teeth are measured) and 0.09 mm in its widest point. The file bears 68–73 (2 ³³) large, sparsely distributed stridulatory teeth, getting smaller towards the basal and apical end of the file. Few small isolated teeth/ indentations are disposed at the apical and basal ends of the file, where CuP is strongly tapered (with those the file measures 2.4–2.5 mm ). On 0.5 mm the basal part of file contains 17 teeth and the middle part—13 teeth. The fore femur ( 4–4.5 mm ) is slightly shorter than the pronotum (~ 4.5 mm ). Hind femora lack spines on their ventral keels. Hind margins of the abdominal tergites are slightly triangularly protruded in the middle; first tergum (observe below tegmina) lacks glandular bulge. The epiproct is rounded, wider than long. The cerci ( Fig. 3d, e ) are short, stout, basally very wide and smoothly tapering towards apex. Their apical part (slightly shorter than the basal one) is angularly S-shaped and ends with a small, hook-shaped spine. The subgenital plate is very long (up to 5 mm ), equal or fairly longer than pronotum and clearly surpasses the tip of cerci. The apical third of the subgenital plate is much narrower than the basal two-thirds, with parallel lateral margins and weak medial crest lacking in the basal part. The apical margin is angularly convex. Coloration. The body is pale, yellowish-green, with many rusty-brown speckles. A thin whitish band passes along the middle of the vertex, occiput and the distal part of tergites. The sides of metazone are bordered by a reddish band, widened backwards. Sometimes such reddish band is developed along the middle of metazone and then it connects the lateral ones. The tegmina are yellowish with dark stridulatory area and dark brown CuP-vein. The dorsal side of abdominal tergites is paler and forms a longitudinal lighter area on abdomen. The abdominal tergites have a dark spot medio-basally, which has a tendency of elongation backwards. Female ( Fig. 3c, f ). The fastigium is slightly broader than in the male—about 2/3 of the width of scapus. The pronotum is almost cylindrical, weakly incurved dorsally, with slightly concave hind margin. The tegmina are strongly reduced, non-overlapping, pear-shaped, fully covered by pronotum. Abdominal tergites almost lack medial protrusion. The epiproct is tapered towards the end, longer than broad. The cerci are conical, wide at the base, slightly longer than the epiproct. The subgenital plate is short, widely rounded at the apex. The basal fold of the upper edge of lower ovipositor valve (lamella) is weakly flattened and laterally protruded and does not form clearly delimited groove above it ( Fig 3f ). Coloration. Usually greener than in the male; the speckles are smaller and less dense. The reddish bands on pronotum are weakly developed.