Bioacoustics of Isophya bumerangoides

Remarks : The species is characterized by the shape of cerci in the male. Our results show that the new species can be distinguished from the closely related species, I. reticulata , I. sureyai , I. rizeensis and I. redtenbacheri confidently on the basis of the examined morphometric and bioacoustic characters (most of them own unpublished data). In the examined male specimens we found significant differences among fastigium, tegmina, cerci and subgenital plate. We have also found some differences among the stridulatory files; however, the stridulatory file varies considerably in these species ( I. rizeensis 77–103 (new data)); I. redtenbacheri about 75; I. sureyai 115–145; I. reticulata 102–123, own unpublished data). The arrangement pattern of stridulatory pegs also differ for the species (compared with I. redtenbacheri Fig. 3 B, E, F, H and for I. rizeensis see Sevgili, 2003).

Male : Fastigium small with distinct groove, convergent, narrower than half scapus on apex. General appearance of pronotum as saddle, anterior and posterior margin of the pronotum almost straight, metazona clearly wider than prozona and laterally depressed in mesozona in dorsally ( Figs. 1 A, 2A, B, D); middle of transverse groove situated behind middle of pronotum; in lateral wiev dorsal side of the pronotum distinctly concave, prozona slightly but metazona clearly raised, ventral margin of paranota sligthly convex ( Fig 1 B; 2A, B, D). Tegmina longer than pronotum ( Fig. 1 B, 2A, B, D and Table 1 ) with striking reticulated, right margin of left tegmen slightly protruding where around proximal part of Cu2; Cu2 narrower than third antennal segment and about 2/3 times longer than posterior margin of pronotum, speculum rectangular. Hind femora without spine ventrally, about four times longer than pronotum. Stridulatory file ( Fig. 3 A, C, D, G): Left tegmina with about 85–98 teeth, reaching posterior margin of tegmina; in ventral view arcuate; shortest distance between proximal and distal most tooth about 2.43 mm . Epiproct wide, almost twice as wide as long. Cercus ( Fig. 1 C, D) slender, slightly curved at basal 1/3, strongly curved but slightly tapering towards the apex. Apex not pointed, ending a distinct denticle. Subgenital plate ( Figs. 1 E, F; 2A1, B1, D1) swollen, slightly narrowed apically, posterior margin with wide but slightly notch. (mm; min–max (mean±SD)) Male (n=18) Female (n= 11) Male (n=50) Female (n= 30) Body length 16.00–23.91 (21.19±2.16) 17.00–22.34 (19.65±2.53) 17.70–27.57 (24.60±3.39) 19.00–27.05 (23.91±3.10) Pronotum 2.96–3.84 (3.37±0.27) 3.30–4.34 (3.95±0.42) 3.10–4.20 (3.77±0.31) 3.80–4.80 (4.25±0.33) Tegmina Hindfemur Ovipositor 3.30–4.66 (4.16±0.35) 12.65–14.94 (14.13±0.61) -- 1.80–3.53 (2.67±0.62) 14.45–16.20 (15.10±0.69) 7.80–8.31 (8.12±0.21) 3.90–5.32 (4.82±0.44) 14.40–17.96 (16.39±1.24) -- 2.40–3.50 (3.07±0.40) 16.00–19.20 (17.61±1.06) 9.00–12.00 (10.73±1.03) Tegmina/Pronotum 1.26 0.74 1.30 0.77 Body length/Hindfemur Hindfemur/Ovipositor 1.56 -- 1.53 1.78 1.58 -- 1.49 1.61 Ovipositor/Pronotum -- 1.94 -- 2.63 Female : Fastigium as wide as half of scapus at the base, slightly wider than male’s, lateral margins convergent, longitudionally impressed above. Pronotal disk almost cylindrical, slightly wider in metazona, posterior margin straight, in profile dorsal surface of pronotum slighlt concave; ventral edges of paranota broadly convex ( Figs. 1 G, H; 4A, B). Tegmina longer than half length of pronotum, extending to beyond middle of first tergite, with reticulate venations ( Figs. 1 G; 4A, B). Hind femur about 4.2 times pronotal length. Cerci robust, short, extending to beyond posterior edge of epiproct. Subgenital plate broadly half round, without protruding ( Fig. 1 I). Ovipositor ( Figs. 1 J, 5A) gradually upcurved, 2.63 times longer than pronotum, upper margin with 6–7, lower margin with 7–9 denticles. Gonangulum slightly swollen, hind edge relatively straight. Lamella strong and folded, strongly impressed dorsally forming with gonangulum a distinct pit ( Fig. 5 A, A1). Coloration: Like most species within the genus Isophya , the species is polymorphic for coloration. There are two or three color patterns, with dark, dark-green and pale color morphs in males ( Fig. 6 A–D). These morphs can be found inhabit the same habitats. Females can similarly be classified according to color pattern, but the variation is not as distinct as in males, like in I. rizeensis (Sevgili, 2003; Saġlam & Çaġlar, 2007 ). Bioacoustics : 14 males recorded at 28 ºC. Males produce their calling song by tegmino-tegminal stridulation. The male calling song produced mainly in the evening and at night. Male calling song : The song consists of two distinct syllables ( Fig. 7 A, B), recorded at 28ºC. The song can be formulated as (A1…a1......B), (A1…a1.B+click) or sometimes (A........B+click), repeated at very variable intervals (about mean: 59 s) with rather irregular repetition rate of 5 -24 calling songs per 5 minutes. Each song lasts for about 288–527 ms (mean: 372±36.35 SD, n= 164). A1 syllable consists of a series 16–84 (mean: 4311 SD, n= 164) impulses (duration mean: 59 ms 6.5 SD) with increasing in amplitude at the beginning in some recordings. The signal amplitude in A1 and a1 syllables slightly increases at the beginning and decreases from the middle part to the last impulses. The last syllable (B) is different from A1 and a1, consists of 46–92 impulses (mean: 697.6, n= 164), their signal amplitudes are distinctly crescendo and slightly decrescendo in the last impulses. The last syllable lasts 90–155 ms (mean: 118.28±13.66SD, n= 164). In some calling songs, there is minor syllable, is smaller than A1 and has 5–35 impulses (a1), last about 8–42 ms. The after-clicks follow the last syllable after a short interval of 29–97 ms (mean: 56.23±12.37SD, n= 21) with a few impulses in some calling songs. The male song has a wide band frequency spectrum with intensive components between 5–90 kHz ( Fig. 8 ). Within that range three intensity peaks can be observed: a less intensive one between about 10-50 kHz and a more intensive range between about 19–30 kHz (peak frequence mean: 23.48 (min.-max. 15.73–28.92). Female song : Females’ response as mating acceptance with the singing male is a series of a few impulse group produced after the last syllable (B) with short major and minor impulses ( Fig. 9 ). The duration of between male song and females’ response song varied between 15–187 ms (mean: 39.35±24.22SD, n= 43 from two females, at 28?C). The beginning group of the response song contains usually major 1–3 impulses, the second group contains 1–7 minor impulses ( Fig. 10 A). Whole female song lasts about 68 ms (n= 45). The carrier wave has its most intensive components between 21–28 kHz (mean: 24. 85, n= 19) ( Fig. 11 ).