Ectadia fulva Brunner von Wattenwyl, 1893

Heller, Klaus-Gerhard, Ingrisch, Sigfrid, Warchalowska-Śliwa, Elzbieta & Liu, Chunxiang, 2017, The genus Ectadia (Orthoptera: Phaneropteridae: Phaneropterinae) in East Asia: description of a new species, comparison of its complex song and duetting behavior with that of E. fulva and notes on the biology of E. fulva, Journal of Orthoptera Research 26 (1), pp. 39-51 : 42-48

Ectadia fulva Brunner von Wattenwyl, 1893 Fig. 15morphology, Figs 16, 17 song

Material examined.

- For the behavioral studies four males and three females (out of series of nine each) were used, all offspring from animals from Thailand, Chiang Mai, Doi Suthep-Pui, 18°48'N, 98°55'E, 1100-1150 m a.s.l., 13.04.1995, ex ovo, bred in lab., leg. S. Ingrisch. Stridulatory files in six males, China, Yunnan Province, Jinping County, Fenshuiling National Nature Reserve, 22.88178768°E, 103.23377388°N, August 2012.

Description.

- The species has been sufficiently redescribed by Liu et al. 2004. It may be added that the fore wings of the male are vaulted, bulging laterally in proximal half of tegmen length, flat with rounded tip thereafter; those of the female are shortened with acute tip. In both sexes the hind wings surpass the fore wings. The species shows a green-brown color polymorphism in both sexes. Of the specimens collected in the field, two males and two females were green and two males and one female brown. The brown color is of lighter shade in females (more ochreous) than in males (medium brown with dark pattern). In the offspring of a green female bred in lab, 19 males and 12 females became green, four males and nine females brown. Body, legs, fore wings and the projecting part of the hind wings were either all green or all brown, in two females pale yellowish brown. The broad dorsal field of the male tegmen including the stridulatory area was always dark brown in both color morphs while the narrow dorsal field of the female tegmen was yellow in green females or pale brown bordered by a dark brown line in brown females. In resting position, E. fulva sits with the antennae and the fore legs stretched anteriorly in the body axis, the mid and the hind legs are stretched oblique posteriorly, while the abdomen and the wings are pointing dorso-posteriorly. That behavior resembles the situation in Ducetia (e.g. D. japonica ) or Elimaea 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 fine basal part of the file produced a long series of heavily damped impulses (Fig. 16; see also fig. 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, occasionally 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 movements were observed in both sexes.

Mating.

- In eight tests, a male (mean body mass 199 ± 16 mg; n=7) and a female (mean body mass 626 ± 71 mg; n = 6) were placed together for mating. Four couples mated with the males transferring only very small spermatophores (1.3 ± 0.6 mg; no data on mating duration available; Fig. 18). Obviously the spermatophores consisted only from a pair of ampullas without spermatophylax.

Nymphs.

- Postembryonic development occured over six nymphal instars as in many other Phaneropterinae (Fig. 19). Development from hatching to adult moult took 52-68 days at 20-23°C ( Ingrisch 1998). Nymphs can be green or light brown. First instars appear green colored.

Distribution

- See Fig. 1.