Mecopoda fallax He, 2019 Recordings: THAILAND: 3254538 (CI), Phetchabun, Nam Nao 1000 m a.s.l., 13 ix 1989, leg. S. Ingrisch (song and stridulatory organs). MALAYSIA: CHX066, MALAYSIA: Pahang, Krau Game Reserve (study area) bei Kuala Kerau, Kuala Lompat near Temerloh (3°43’N, 102°16’E), 28 iii–12 iv 1981, leg. K.-G. Heller & M. Volleth (song only). VIETNAM: one specimen from Vinh Phu, Hoa Binh and Gia Lai Provinces, leg. A. Gorochov; stridulatory file only. The species was described from China (Liu Yf et al. 2019, Liu Cx et al. 2020), but is obviously more widespread. The long lasting trilling song of M. fallax (Fig. 6) is composed of quite short song units (less than one second) which are repeated without intervals. Within these units regular changes in amplitude are observed (Fig. 7). The duration of one unit was 0.3–0.8 s in China (T=24–29ºC; Liu Yf et al. 2019, Liu Cx et al. 2020), 0.7 s in Thailand (T=21.5ºC) and 0.2 s in Malaysia (T=27ºC). M. fallax has a long stridulatory file carrying about 110 teeth (Fig. 11 E). Concerning the inter-tooth distances, the file is relatively homogenous. The distances start anally around 40–50 µm, reach the maximum at about 60–70 µm and become smaller than 40 µm only very near to the articulation (Fig. 12). It will be interesting to study the songs and the relationships between the two Vietnamese species M. prominens and M. ampla and the widespread M. fallax. All three have with quite similar files (Figs. 11–12) and occur in Vietnam.

Published as part of Heller, Klaus-Gerhard, Baker, Ed, Ingrisch, Sigfrid, Korsunovskaya, Olga, Liu, Chun-Xiang, Riede, Klaus & Warchałowska-Šliwa, Elżbieta, 2021, Bioacoustics and systematics of Mecopoda (and related forms) from South East Asia and adjacent areas (Orthoptera, Tettigonioidea, Mecopodinae) including some chromosome data, pp. 101-144 in Zootaxa 5005 (2) on pages 123-124, DOI: 10.11646/zootaxa.5005.2.1, http://zenodo.org/record/5141281