Bioacoustics of Paussus (Hylotorus) abditus

Description of male holotype specimen ( Figure 2 ) . Standardized body length from tip of head to tip of elytra 4.1 mm , width across mid-elytra 1.5 mm . Body with dorsal and lower side, legs and antennae brown, frontal margins of head and frontal margins of posterior part of pronotum narrowly black. Head, pronotum, elytra with dorsal pubescence of scattered, short, light, lanceolate, narrowly scaliform, apically rounded setae; middle of posterior pronotum glabrous, smooth, glossy; pubescence of appendages equally scattered yet of thinner setae; setae mostly erect to slanting, more appressed at lateral head and antennomere I. Surface shiny except frontal head, neck and antennomere I (scape) with fine, matte microsculpture; punctuation inconspicuous, only scape with coarse, dense punctures; elytra weakly rugose. Head almost as long as wide, with frontal margin notched in the middle and frontal lobes broadly rounded; eyes slightly vaulted; temples not projecting, at dorsal view forming a regular curve with eye; vertex produced in two rounded protuberances, separated by shallow longitudinal emargination; cephalic openings on top of protuberances vestigial, closed, indicated by small, shallow, oval impressions, difficult to see. Antennomere I devoid of well-marked longitudinal edges; antennal club boat shaped, 1.5 times longer than wide (basal tooth disregarded), tumid; frontal margin of the club with two fenestriform pits near base; anterior basal angle of club small, acute; posterior basal projection large, apically rounded; hind part of the club with large posterior excavation comprising the basal two thirds only; at posterior view dorsal and ventral margins of excavation undulate of four and five tumid tubercles, each with 1 to 3 apical setae; club with distinct tuft of setae (trichome) near ventral base. Labrum with anterior margin weakly emarginate. Maxillary palpomeres similar to Figs 6G,H in Robertson and Moore (2016) ; palpomere II large, approximately as long as wide, with mesal margin almost straight, mesal apical angle broadly rounded, outer margin rounded with apical angle not produced; maxillary palpomere II three times wider than following palpomere; palpomere III and IV subequal in length, III little wider than terminal palpomere. Lacinia bifalcate (as usual), moderately setose, with 7–8 setae at anterior margin. Labial palpomeres similar to Figs 6C, 7N in Robertson & Moore (2016) ; palpomere III long, narrow, 4.5 times as long as wide, apically rounded. Ligula at ventral view with longitudinal carinula on disc; apical margin bisinuate with apical median margin broadly rounded and lateral anterior angles produced anteriorly. Gula: width/length ratio of gula at narrowest point 0.6. Pronotum hardly wider than long, transversely bipartite, with large trichomes at both ends of groove; anterior part little wider than head, low, with transverse dorsal edge of collar-like structure broadly rounded, slightly emarginated in the middle, lateral angles little produced; posterior part narrowed towards base. Elytra with even, scattered pubescence; hindwings present. Fused abdominal ventrites 1–3 with scraper of stridulatory organ present (synapomorphic character of Paussus L. s.l. ). Pygidium with disc flat and lower (anatomically posterior) margin narrowly explanate, dorsally (apically) set with dense fringe of long hair, ventrally with series of short, separate setae. Legs (femora and tibiae) from the front to the back increasingly more compressed and dilated, hind tibiae twice as long as wide; tibial terminal spurs absent; terminal tarsomere of posterior tarsus as long as three preceding ones together; tarsomeres ventrally without setulose pads. Additional description of female paratype : The description of the male holotype specimen fits also to the female paratype , with a few additions as follows. The pubescence is partially rubbed off; the cephalic pores are virtually absent and at close inspection only recognizable as a minute, longitudinal, slightly darkened structure, possibly a remnant of part of the pores’ margin; eyes little smaller than in male and hardly vaulted; hind tibiae even shorter and wider than in the male; the gonocoxae were dissected, the diverging tips are of normal shape of Paussus s.l. ;