Theudoria melanocnemis (Stål, 1861)

Fig. 23H; 28B

Distribution: Argentina: Buenos Aires; Brazil: Paraná, São Paulo; Uruguay: Montevideo.

New record for the Paraná State.

Comments: Even if the species was previously recorded in Southeastern Brazil, this is the first record for Southern Brazil. Only males were collected at the ParNa Iguaçu, during aural observations carried out during the day, while they were stridulating on bushes and trees, both in the border and inside the forest.

Bioacoustics (Fig 24C–G): Males stridulate in the afternoon, presenting complex sequences of isolated pulses, syllables and echemes, with ca. four to six minutes of duration. Each sequence starts with sequences of pulses of slow intensity, followed by pulses in a crescendo of intensity, and longer than the previous sequences. After the sequences of pulses, the males emit a sequence of echemes. All the pulses and syllables are emitted with an increasing of intensity, but with an abrupt diminution of intensity at the end of those syllables and pulses.

Dominant frequency: 13.3 ± 1.4 kHz.

Bandwidth: 6.5 ± 1.3 kHz.

Duration: Pulses: 20 ± 6 ms; Syllable: 0.4 ± 0.08 s; Echeme: 1.3 ± 1 s.

Mute interval: Syllable: 15 ± 2 ms; Echeme: 0.7 ± 0.2 s.