Bioacoustics of Nisitrus vittatus

Calling song (Kuala Belalong, n = 2 males , 20 echemes; MNHN-SO-2020-2859 to MNHN-SO-2020-2860) ( Fig. 25D–F ) At 27.0°C, the calling song consists of long homogeneous bouts made of short echemes consisting of triplets of syllables; echeme duration is 32.47± 3.79 ms (27.00–38.65 ms); echeme period is 55.20±5.90 ms (50.52–74.27 ms); downtime between consecutive echemes is 22.73 ± 7.26 ms (14.16–41.82 ms). Durations for the first to third syllables of the triplet are as follows: 6.93 ± 1.73 ms (4.57–9.95 ms), 7.51 ± 2.03 ms (4.80–11.67 ms) and 7.22 ± 2.82 ms (3.24–12.44 ms). The call spectrum consists of a series of harmonics with three distinct peaks corresponding to the first three harmonics: first harmonic (fundamental frequency) at 6.86 ± 0.28 kHz (6.46–7.15 kHz), is usually the dominant frequency; second harmonic peaking at 14.08 ± 0.39 kHz (13.35–14.64 kHz); third harmonic peaking at 19.96 ± 0.35 kHz (19.12–20.67 kHz).

Revised diagnosis Species of average size, colouration contrasting with black and yellow, characterised by black vertex, frons yellow, orange brown legs. Male area between M and R yellow, veins black or yellow; cells beneath R partly yellow, otherwise transparent.Anal-most and middle chords distinctly diverging apically, basalmost chord extend from midpoint/after midpoint of middle chord. Female copulatory papilla without truncated lobule at ventro-anterior end. Species very similar to N. malaya sp. nov. , from which it differs by male genitalia with pseudepiphallus faintly less robust, narrower, anterior margin less concave; female copulatory papilla without truncated lobule at ventro-anterior end. Juvenile differs strikingly in colour patterns. Male calling song also differs by shorter echeme period.