Bioacoustics of Anterastes antecessor

Diagnosis. The unique autapomorphies of this species that distinguish it from all others are: the short male cercus length of which is less than twice the transversal width along the tooth (it is tree times or more in all others) and the huge tooth of cercus located pre-apically; the male subgenital plate with the index maximal width/length more than two is another typical diagnostic character (the index value is less than two in the other species of Anterastes ). Additionally, compared to other species, the processes of male tenth tergum are short. The semi-circular incision of female subgenital plate is a character state shared by the four species of A. babadaghi group, but also separating the new species from other species of the genus (see Ciplak 2004 ). However, females of A. antecessor can easily be distinguished from the four species in A. babadaghi group by the short and robust ovipositor. The number of stridulatory pegs is ca. 53 (similar to A. niger ) while it is 60 or more in the others. The right margin of the left tegmen is posteriorly truncate as in A. uludaghensis and contrary to the other species. There are two general song patterns observed in Anterastes (Ciplak et al. unpublished data). In the A. serbicus group the male produces song consisting of irregularly repeated syllable groups which can not be defined as typical echemes ( Fig. 6 A, B). On the other hand four species within A. babadaghi group ( A. babadaghi , A. ucari , A. turcicus and A. niger ), as well as A. uludaghensis , produce a song of regular syllable groups ordered in echemes each of which including a certain number of syllables with a certain period ( Fig. 6 C, D). The song of A. antecessor , sp. n. , is not arranged in echemes and in respect to this character is similar to the songs of the first group. However, in A. serbicus group the syllable sequences are irregular in duration and syllable number while the sequences are regular in both. In the species of A. serbicus and A. babadaghi groups, as well as in the new species, the syllable includes two elements (a closing and an opening hemisyllable), while in A. uludaghensis the syllable includes four elements.

Description ( Holotype , male ). Fastigium of vertex rounded, twice or more the width of scapus, not sulcate. Pronotum relatively short, cylindrical or slightly depressed dorsally, with a trace of median carina, lateral carinae absent, hind margin widely obtuse ( Fig. 7 C). Micropterous, tegmina shorter than pronotum ( Fig. 7 C); right tegmen slightly longer than left tegmen; stridulatory file slightly sinuate, with ca. 53 teeth, teeth in the medial part wider than those on the proximal and distal ends; distal teeth small and conical. All three pairs of femora without ventral spines. Fore tibiae spineless on dorso-anterior margin and with three spines on dorso-posterior margin. Mid tibiae with one spine on dorso-anterior and four spines on dorso-posterior margins. Each of the ventro-anterior and ventro-posterior margins of fore and mid tibiae with six spines. Hind femur barely extends beyond the end of abdomen, swollen in the basal 2/3; 3.3–3.8 times as long as its maximal width; hind tibiae with one pair of spurs apico-ventrally; platulae are two-thirds of the length of metatarsus. Tenth abdominal tergum with two short, incurved and triangular processes, and with a wide shallow incision between them, setose medially and marginally ( Fig. 3 A). Cerci short and thick, with a huge pre-apical tooth, base of the tooth depressed and its apex strongly curved downward; width of cercus along the tooth almost equal to half the total cercal length ( Fig. 3 B). Male subgenital plate wider than long, with small styli, almost not incised at posterior margin ( Fig. 3 C). Titillators slender; apical and basal arms roughly equal in length; basal arms smooth and obtusely curved; apical arms almost straight in proximal 3/4 and strongly curved in apical 1/4, with a few small teeth in the middle of outer margin ( Fig. 3 D, E). Paratypes are similar to the holotype . Description of female ( paratype ) . Similar to male in general characteristics. Tegmina strongly abbreviated, not overlapping dorsally, but visible laterally; hind femur 3.1–3.3 times as long as its maximal width. Sixth and seventh abdominal sterna not modified. Subgenital plate wider than long, with a semi-circular incision and two tapered lobes apically ( Fig. 3 F, G). Ovipositor short, robust and slightly upcurved, 4–5 times as long as its maximal width; ventral valves with 15–20 tubercles in the apical one-sixth ( Fig. 4 B). Coloration. Black or blackish brown. A black pattern with a narrow light stripe is situated behind the eyes; pronotal disc dark brown, paranota with a large black spot or black pattern, margins with a dirty creamish posterioventral band; hind femur with a black spot dorso-anteriorly and indistinct black pattern dorso-externally; tegmina brownish ( Fig 4 A). Abdominal terga black, with irregular brownish pattern; ovipositor light brown with dark brown pattern. Measurements (in mm). Body, male 17.87 (17.4–18.6), female 17.10 (16.2–18.1); length of pronotum, male 4.2 (4.00–4.5), female 4.75 (4.–4.8); tegmina, male 2.85 (2.7–3.0); number of stridulatory pegs 53 (46–56); length of hind femur, male 10.33 (10.0–10.6), female 11.8 (11.7–11.9); maximum width of hind femur, male 2.7 (2.3–3.1), female 3.7 (3.6–3.8); length of ovipositor 18.1 (17–19); maximum width of ovipositor 1.8. Song. The male calling song of type specimens (the holotype and a paratype male) was recorded in the evening/nigth at 26 °C ( Fig. 5 ). The calling song is a long lasting sequence consisting of several regularly and continuously repeated syllables. The duration of one sequence ranges between 44 and 230 s (mean: 90 s) and the syllable number per sequence – between 1570–4900 (mean; 3330). Syllable period has a length of 0.025–0.031 ms (mean 0.027) and each syllable includes a noisy opening- and a loud closing- hemisyllable. The opening hemisyllable includes 1–3 inseparable impulses in a period of 0.008–0.01 ms (mean 0.0084). The closing hemisyllable contains 13–20 (mean 16) impulses and lasts 0.016–0.02 ms (mean 0.018).