Ectadia diuturna Heller & Liu

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 : 39-42

Ectadia diuturna Heller & Liu sp. n. Figs 3, 4, 5, 6, 9morphology, Figs 10, 11, 12, 13song, Fig. 14 chromosomes

Ectadia sp. in Heller et al. 2015, p. 3, 6. fig. 5

Material examined.

- Holotype male, China, Yunnan, Honghe, Pingbian, Daweishan Forest Reserve, 22°56.55'N, 103°41.43'E, 1700-2100 m a.s.l., 15-17 viii 2013, leg. Liu Chunxiang, #CH7660, in ethanol. Depository IZCAS.

Paratypes 11 males (#CH7659, 61-62), 6 females (#CH7663-5), dried/in ethanol, same data as holotype, all in IZCAS except #CH7659, 61, 64 (in CH). In addition sound recordings of two males, not collected.

Diagnosis.

- Differs from all species of the genus in proportions of anal (1/3) and basal (2/3) part of the stridulatory file and number (about 100; Table 1) and distribution of teeth on the stridulatory file (Figs 2, 3). From E. apicalis , which has a similar stridulatory file, it differs by larger size and the hind wings being clearly longer than the tegmina while slightly shorter in E. apicalis . In general habitus it is most similar to E. fulva , but has a much lower number of teeth on stridulatory file (see Fig. 3) and narrower tegmina (Fig. 4).

Description.

- Male. General habitus see Fig. 5.

Fastigium verticis narrower than first segment of antennae, sulcate dorsally, not contacting fastigium frontis. Complex eyes approximately round. Pronotum with disc nearly flat, only last quarter elevated; anterior margin slightly concave, posterior margin truncate with small notch in middle; medial carina inconspicuous; transverse sulcus V-shaped; lateral carina weakly developed; lateral lobe of pronotum much longer than high, anterior margin straight, posterior margin obtuse-rounded, ventral margin oblique downward posteriorly, humeral sinus present but inconspicuous.

Prothoracic spiracle large, but mostly covered by a posterior extension of paranotum.

Tegmen shorter than hind wing, posteriorly with long parallel part (Figs 4A, 5A); venation see Fig. 4. Mirror in stridulatory area of right tegmen with a more or less circular deepening, similar to that in E. fulva (Fig. 6). The vein demarcating the distal end of the stridulatory area curved smoothly, not with an edge as in E. fulva (Fig. 6). Stridulatory file comparatively straight but slightly thinner in middle, with circa 90 densely spaced fine teeth in basal area and about 10 widely spaced large teeth in distal (=apical or anal) area (Fig. 3). Fore coxae without spine, fore tibiae dorsally sulcate and spinuliferous. All femora ventrally spinulose; mid and hind femur with 5-6 spines on outer ventral margins; hind tibiae with many spines on both dorsal margins. Tenth abdominal tergite prolonged backwards, hind margin emarginate; cerci stoutest at base, basal quarter sharply acuminated, then first slightly widening, later gradually narrowed till apex, dorso-ventrally flattened; subgenital plate split for almost apical two thirds, up-curved (Figs 7, 8). Internal genitalia membranous, no sclerotized titillator.

Color

- Body and tegmina green, parts of legs, dorsal side of pronotum and dorsal field of tegmina brown, tegmina with some small brown dots (Figs 4, 5).

Female.

- Mostly similar to male except abdominal apex and tegmina (stridulatory organs).

Pronotom with disc nearly flat; ventral and dorsal edge of paranotum parallel.

Right tegmen at posterior edge in basal part with about 9 short cross veins carrying stout spines used to produce the female acoustic response (similar as shown in Heller et al. 1997); more distally small cross veins and even longitudinal veins with many slender spines, probably used to prevent accidental wing opening. In left tegmen, posterior edge in basal part scraper-like in-curved. Supra-anal plate triangular; cerci rather short, conical. Ovipositor fairly broad and short, upcurved, both margins at tip denticulate (Fig. 9). Subgenital plate triangular, apex obtusely rounded.

Color.

- Green except a white mid-line on pronotum and dorsal edges of tegmina (Fig. 5B).

Egg

>- Thin, flattened, ovoid, typical phaneropterine shape.

Measurements (length in mm)

- Body: male 14-20, female 17-22; pronotum: male 3.7-4.8, female 3.9-4.2; tegmen: male 26.7-31, female 22-25.3; tegmen width (greatest): male 5.1-6.5, female 4.9-5.1; hind wing: male 33-38; female 26-29.4; post femur: male 20.9-24, female 20.5-23.4; length of ovipositor: 6.5-8.1; width of ovipositor 1.9-2.1, length of egg 4.7-4.8; width of egg 1.6-1.8 (n=12 males, 6 females, partly dried, partly in ethanol).

Song

- Time-amplitude-pattern. In Ectadia diuturna sp. n. one song unit typically lasted about 30 to 60 s (all data for 25°C except otherwise mentioned; up to 80 s in the field at 18°C). It was followed by the next unit after a silent interval as short as some seconds, but also as long as some minutes. The shortest intervals were observed when males and females were in acoustical contact. Each unit contained four phrases each of which consisted of a different combination of micro- and macrosyllables. A simple and clear example is shown in Fig. 10A. However, often the different phrases were connected by transitional phrases. A song unit started with a series of tick-like microsyllables, separated by intervals of about 150 ms (phrase A; see Fig. 11 for details). Sometimes the intervals between the ticks were larger and more irregular. Between these loud syllables (occasionally?) short and soft sounds were observed. At the end of a phrase typically two tick sounds followed each other quite closely (10 ms interval) a few times. Such phrases were also heard isolated outside complete song units, possibly representing unsuccessful attempts to start a song unit. After this phrase a series of macrosyllables followed (phrase B), in which always two types of impulse groups alternated, a long series (ca. 70 impulses; duration 120 ms), sometimes split into two or more by one or several unusually large intervals, and a short series (ca. 55 densely packed impulses; duration 30-40 ms). Both groups differed distinctly in carrier frequency (see below). In amplitude, this phrase was always lower than the loud phrase A. Its duration was the most variable of all phrases, from nearly missing up to ten seconds. Phrase C consisted of a long series of stereotypic elements (period about 500 ms), each containing two pairs of impulse groups as seen in phrase B. These pairs were separated from the next pair by an interval of about 200 ms. During this interval one (or two) loud microsyllables were produced and additionally a series of softer isolated impulses. While in Fig. 10 an abrupt change from phrase B to C can be seen, in many other recordings there is a long transition with phrase C elements appearing more and more frequently (see e.g. Fig. 12). Phrase D finally consisted of several repetitions of the impulse series from phrase C (period about 400 ms) without macrosyllables.

The females responded near the end of a song unit (Fig. 12). They answered mostly not only once, but several to many times (1-25 responses per song unit). The responses occurred nearly always during phrase D, and often also additionally at the end of phrase C. Very rarely they were heard during phrase A, in this case the females possibly assuming a late phrase D from the previous song unit. In many phaneropterine species, the females respond with a species-specific delay after the male song or some parts of it (e.g. Heller and Helversen 1986). This is probably also the case in E. diuturna sp. n., but the response delay is difficult to measure exactly, because often several possible trigger events are closely together, and the response consists of several loud impulses distributed over more than 100 ms. The delay is obvious in the range of 150-250 ms. In any case, often very soft impulses (more than 20 dB softer than the main response) were observed that occurred much faster (70-80 ms) than the loud impulses.

Carrier frequency

- During one song unit, parts with quite different spectral composition were observed. The short, tick-like elements of which phase A and D consisted and which occurred also in phase C, had always a quite similar spectrum. Its peak was situated at about 20 kHz, in the lower half with strong components starting abruptly at about 5 kHz, in the higher half continuously decreasing in power until 40 kHz (Fig. 13). Also the softer and shorter impulse groups found in phase B and C were similar to this pattern presenting a relatively narrow peak at 20 kHz and a side-peak at 40 kHz. However, the longer and often louder impulse groups from phase B and C differed distinctly. Their spectrum contained two clearly separated peaks. Besides a high and narrow peak at 10 kHz it showed a broad maximum at 60 kHz (Fig. 13). These impulse groups alternated with the shorter and softer impulse groups (see fig. 5 in Heller et al. 2015). The female response had its maximum between 10 and 20 kHz (recorded in audible range only).

Chromosomes

- The analyzed species is characterized by a male chromosome number 2n=29 and sex determination system X0. All chromosomes are acrocentric and the X chromosome is the largest element in the set. C-banding of mitotic metaphase revealed constitutive heterochromatin blocks (thin C-bands) in the paracentromeric region in most chromosomal elements, with the exception of one small pair of autosomes (thick C-bands). Constitutive heterochromatin polymorphism involving telomeric C-bands was located in the first-sized pair (Fig. 14A). The observed rDNA-FISH signal on this largest pair, similar to C-bands, varied in size, suggesting the occurrence of polymorphism in copy number of rDNA sequences (Fig. 14B).

Habitat

- Common in low bushes around buildings (Fig. 5C).

Etymology

- The name of the new species refers to its long lasting song: diuturna . Latin adjective, meaning long lasting

Distribution

- Known only from Yunnan, China.