Bioacoustics of Gonamytta deboisselae

Differential diagnosis. This new species appears to be most closely related to Gonamytta scrofina (Beier) stat. nov. from northern Zambia . It differs in the shape of the male cerci, which are proportionally thicker and significantly more curved upwards in G. scrofina (fig. 2G); the modification of the male 10th tergite, which is deeply and broadly recessed in G. scrofina but only moderately so in the new species; and the venation of the tegmen, which carries a bifurcated vein Rs in G. deboisselae (fig. 1C) but is forked 4 times in G. scrofina . From G. hintheliana , known only from the female holotype and the female holotype of its junior synonym Amytta planicollis Chopard ( Beier 1965 ) (fig. 1I), it differs in the shorter, more rounded female subgenital plate (fig. 1F); and from G. occidentalis it differs in the structure of the male cerci that are significantly less narrowed and curved apically (fig. 2H). Genetic barcode. The sequence of the cytochrome c oxidase subunit I gene (COI) with 654 bp was submitted to GenBank with the accession number MZ398138 General. Body small, slender, cylindrical, macropterous (figs. 1G, H). Head.— Fastigium of vertex triangular, blunt apically, almost reaching tip of scapus, flat dorsally; antennal scapus unarmed; antennae about twice as long as body; frons slightly convex, oblique; eyes globular, moderately protruding. Thorax. Pronotum surface smooth, lateral lobe twice as long as high; humeral sinus of pronotum present, anterior margin of pronotum flat; metazona flat, its posterior edge narrowly rounded. Sternum flat, prosternum unarmed. Legs. Legs slender. Front femur unarmed ventrally, in cross section round dorsally but flat ventrally; genicular lobes unarmed; front tibia unarmed dorsally, with 6 spines (including apical one) on posterior and 4 on anterior ventral margin; tympanum bilaterally open. Mid femur unarmed ventrally; genicular lobes unarmed; mid tibia not noticeably thickened in proximal section, unarmed dorsally, with 5 spines on posterior and 5 on anterior ventral margin. Hind femur unarmed ventrally; genicular lobes unarmed; hind tibia armed on both dorsal and ventral margins, spines on ventral margins smaller and more sparsely distributed; dorsal spines of hind tibia of equal size on both edges. Wings. Tegmen surpassing apex of hind femur; anterior margin straight; hind wing slightly longer than tegmen. Costal field of tegmen wide, gradually narrowing towards wing tip, ending at 3/4 of tegmen; veins Sc and R close together, parallel along their entire length; Rs branching off before middle of tegmen, with 2 apical branches; vein R1 branching of in apical third of tegmen, with 2 apical branches (fig. 1C); right stridulatory area with small but well-developed mirror (fig. 1B); left stridulatory area with small, roughly trapezoidal mirror (fig. 1A). Stridulatory file elevated on thickened vein, weakly bent, with 72 teeth, 0.81 mm long, 0.038 mm wide (fig. 1D). Abdomen.— Epiproct small, triangular; 10th tergite with posterior edge with shallow, triangular incision; cercus unarmed, long and slender, evenly bent inwards and upwards (figs. 2A–C); paraprocts unmodified; sclerotized epiphallus sclerotized, bulbous, covered with minute scales; its apical part visible externally (figs. 2D–F). Subgenital plate broadly trapezoidal; styli cylindrical, about 4 times as long as wide and as long as 1/5 of subgenital plate, slightly convergent. Ovipositor. Ovipositor slender, straight, shorter than hind femur; dorsal edge of upper valvula smooth, parallel to lower valvula; apex pointed, with both valvulae smooth (fig. 1E). Coloration. Coloration light green; antennal scapus without markings, antennae concolorous; eyes uniformly colored, brown; face without any markings; occiput without markings, prozona green. Tegmen green with brown posterior edge; hind wing hyaline; genicular lobes of front legs without markings; hind femur uniformly colored; abdominal sterna and subgenital plate without markings. Bioacoustics. The call of G. deboisselae is high duty, consisting of a long, uninterrupted train of short syllables (mean syllable duration 0.01513 s , SD= 0.00135; n=140) at the rate of 35.5 syllables/sec (at 22°C), with the frequency peak at 38.2 kHz and a strong harmonic at 114.7 kHz (fig. 3). The call is largely ultrasonic and thus inaudible to the human ear.