Bioacoustics of Poecilimon isopterus

Diagnosis. The new species P. isopterus is aberrant in the group by its short pronotum, the indistinct inflation of metazona and its almost truncate caudal margin (I in Figures 3 , 4 , 7 , 8 ). However, it is clearly a member of the group based on the resemblance with P. inflatus , especially in the structure and coloration (black in apical half) of male cerci ( Figure 9I ) and by its song ( Figure 15C,D ). In addition it is similar to P. bilgeri by the less inflated and caudally truncate metazona of pronotum, but differs by the male cerci regularly incurved as a bow and black in the second half, the longer ovipositor and black abdominal terga in the first 1/2–2/3. It differs from P. inflatus by the metazona indistinctly inflated and caudally not produced, male cerci apically flattened and with 3–5 denticles and female subgenital plate narrowed apically (almost triangular in the new species while roughly quadrangular in P. inflatus ). A striking distinction of the new species is the small male tegmina especially in relation to its body size, and the smaller size of male tegmina in comparison to female tegmina (male left tegmen— 2.1–2.7 mm , in female about 2.8 mm ; 3.1–4 mm in other members of the group) ( Figure 23 ). Male stridulatory file is also characteristic being shortest in the group ( 1–1.4 mm against over 1.4 to 2.5 mm in other members of the group) with finest distal teeth.

Description ( holotype , male) . Fastigium of vertex <1/3 of scapus ( Figure 3I ). Pronotum short, median sulcus located before to the middle, cylindrical in prozona and weakly inflated in metazona, posterior margin of the disc is truncate or slightly concave, medial carina absent, disk bordered by large light lines; paranotal margin straight along prozona and oblique or indistinctly S-shaped along metazona (I in Figures 3 , 4 ). Tegmina hardly visible beyond the pronotum, stridulatory file with 60–76 small teeth (very fine at both ends of the file). The length of stridulatory file 1.0– 1.4 mm ( Figure 6I ). Cerci cylindrical, straight in proximal half and weakly curved apically, with flattened apex and 3–4 small denticles on external margin ( Figure 9I ); subgenital plate slightly longer than wide and oval in its distal half, distal margin with a small triangular notch ( Figure 11I ). Epiproct roughly 1.5x wider than long, with a convex caudal margin ( Figure 10I ). Female. Similar to male. Pronotum very similar in shape to that of the male (I in Figures 7 , 8 ). Subgenital plate twice wider than long and with a distinct incision ( Figure 12I ); ovipositor typical for the genus, roughly 5 times as long as its medial width ( Figure 13I ). Coloration. Occiput with two black spots; disc of pronotum brownish, bordered by light stripes and with blackish pattern along these light stripes; paranota greenish-brown, Abdominal terga black in the first 1/2–2/3 part and brown in remaining part. In female (from İbradı) paranota greenish, disc brown and bordered by light stripes and with irregular dark pattern internal and external to the light bands.