Bioacoustics of Ectadia fulva

Redescription. – Male. Size a little larger than the former two species. Hind wing conspicuously longer than tegmen. Stridulatory file rather straight, circa 2/5 at base comparatively thick, middle 2/5 rather thin, and then becoming thicker toward apex; and with narrowly spaced fine teeth in 4/5 area from base as well as 10 widely spaced thick teeth in 1/5 apical area (Figs. 3, 8, 11). The whole area of the stridulatory apparatus of right tegmen bigger, its scraper cambered, comparatively narrow area situated more distally than main structure of the stridulatory apparatus, and proximal area between MA and MP+ CuIA, semi-transparent with a few veinlets (Fig. 14). The 10 th abdominal tergite slightly depressed, lightly prolonged backwards, with hind margin truncate. Supra-anal plate approximately rectangular. Cerci very broad at basal 1/3, then sharply acuminate, yataghanshaped. The subgenital plate with the broadest base, then becoming narrower, split for almost apical 3/5, upcurved. Female similar to male. Supra-anal plate triangular; Cerci rather short, conical; ovipositor fairly narrow and short, upcurved, both margins denticulate (Fig. 25); Subgenital plate triangular, apex obtuse-round (Fig. 28). Measurements (length in mm). – body: male 16.5, female 19.5; pronotum: male 4.0, female 4.1; tegmen: male 25, female 24; width of tegmen: male 6.5, female 3.5; hind wing: male 31.5, female 26; hind femur: male 19.5; female 20.5; ovipositor: 5.0. Variation. – One male specimen from Guangxi Prov. is distinctly larger than others [Measurements (length in mm). – body 18.5; pronotom 4.0; tegmen 30.0; width of tegmen 6.5; hind wing 38.0; hind femur 25.0]. Its stridulatory file was contaminated and no drawing can be obtained, so we put it in this species.

Song.— Time-amplitude-pattern. The male calling song consisted of song units each lasting about 1.5 s repeated after an interval of about 4 s (Fig. 16A). Each was made of a series of microsyllables (about 15), repeated with 20 Hz, followed by a long series of impulses with decreasing intervals. This song unit is produced by opening the tegmina very widely, then closing and opening them several times only in part, resulting in the microsyllables. The microsyllables are not tick-like sounds as in E. diuturna sp. n., but consist of compact series each with a few impulses. Then the male closed the tegmina completely and very slowly. The contact of the scraper with the ne basal part of the le produced a long series of heavily damped im- pulses (Fig. 16; see also g. 7 in Heller et al. 2014). The female responded immediately after the end of the male impulse series (Fig. 16), typically with one or a few impulses, oc- casionally with one or a small series up to a few hundred ms later in addition. Sometimes responses were observed even before the male series had ended. Carrier frequency.— Both parts of the song unit had a quite similar spectral composition with two peaks (Fig. 17). Besides a narrow low-frequent peak around 10 kHz there was a broad maximum at about 50-60 kHz. The female response showed a peak at 20 kHz, in width and placement intermediate between the two male peaks. Besides the acoustical signals soundless vibratory body move- ments were observed in both sexes.