Bioacoustics of Vellea cruenta

Description of the male . Colour. Body yellowish, posterior margin of pronotum lobes black, lateral mesosternum black, tarsi blackish, spine of femora black, those broad-based only black on superior margin ( Fig. 10A ). 4–5 brown spots on posterior part of tegmina, second pair of wings with a wide reddish area ( Fig. 10B ). Head without fronto-genal carinae. Fastigium of vertex compressed, narrower than first antennal segment, sloping steeply to frons, sulcate above. Eyes round, prominent, wider than subocular groove. Pronotum straight along anterior margin, without median carina; lateral carinae just visible in the posterior part, mainly after pronotum excision; surface smooth and covered by small pilosity. Fore coxae armed with a fine spine. Fore and mid femora unarmed. Hind femora with 10–11 ventral spines in both margins, of which the last 3–4 are large, broad-based and expanded into flat, pointed lobes ( Fig. 10D ). Fore tibiae with closed tympanum on inner and open on outer side, with 4 spines on ventral margins, and 1–2 on outer dorsal margin + 1 spur. Mid tibiae with 8 spines on ventral margins and 3 + 1 spur on inner dorsal margin. Hind tibiae with 18–20 ventral spines on both margins and ca. 30 broad-based small spines on dorsal margins + 3 apical spurs on each side ( Fig. 10D ). Both pairs of wings fully developed. Stridulatory area of left tegmen a little elevated above wing plane ( Fig. 10B ); stridulatory file curved, 1.8 mm long and consisting of ca. 30 teeth evenly spaced ( Fig. 10C ). 10th abdominal tergite straight with two lateral small down-curved tips ( Figs 10E, 10F ). Cerci stout, in-curved and pointed ( Figs 10E, 10F ). Subgenital plate upcurved, narrow, long, tri-carinate and apically concave, styli absent ( Figs 10G, 10H ).

Comments: This species presents a broad geographic distribution. The individuals collected at the ParNa Iguaçu present a remarkable variation regarding body size and coloration, but, however, the shape of both cerci and subgenital plate, besides the wing venation, are rather like such structures of the holotype . Bioacoustics ( Fig. 24H–J ): Males stridulate during both the night and day, producing short sequences of syllables. These sequences present six to nine syllables, each one with different amplitude from another. Each syllable is composed by four to six pulses, that increases in intensity until the last third, when the intensity starts decreasing. Dominant frequency : 10.2 ± 1.4 kHz. Bandwidth : 6.5 ± 1.7 kHz. Duration : Pulse: 1.6 ± 0.3 ms; Syllable: 28 ± 5.6 ms; Mute interval : Pulse: 6.1 ± 0.3 ms; Syllable: 89 ± 3.7 ms;