Bioacoustics of Zebragryllus nauta

Diagnosis. Within the genus, very small species easily recognized by its coloration (head and pronotum shining dark brown, antennae brown, legs light yellowish brown without white marks, including FIII, Fig. 3 H; female pattern little contrasted). Male. FWs entirely covering the abdomen, going slightly beyond subgenital plate; coloration light yellowish brown, translucent, with yellowish or brown veins. Stridulatory file with 65 teeth (n=1). Male genitalia. Pseudepiphallic sclerite long and triangular; lateral lophi dejected ventrally and not visible dorsally ( Fig. 4 K, L). Female. FWs long, reaching tergite 2 mid length, slightly overlapping ( Fig. 5 F); venation reticulate. Abdomen brown, tergite 3 yellowish ( Fig. 5 E). Female genitalia. Copulatory papilla rounded, with a ventral subapical, transverse crest ( Fig. 7 L–N).

Description. In addition of the characters of the genus: General coloration shining brown; head dark brown, area above epistemal suture, a thin line around the eyes and the area below antennal pits yellow, antennae light brown (no white ring before 70 antennomeres, where antennae are cut in the specimens at hand); maxillary palpi: joints 3 and 4 light brown, joint 5 light brown basally, otherwise black brown with yellowish distal margin; pronotum dark brown; legs light yellowish brown; cerci brown, their bases lighter. Basitarsomeres III with 4–5 (male) and 3 (female) inner, and 5–6 in male and 4–5 in female outer dorsal spines, in addition to apical ones. Male. FWs entirely covering the abdomen, going slightly beyond subgenital plate; coloration light yellowish brown, translucent, with yellowish or brown veins. Mirror wider than long, subdivided into several cells ( Fig. 2 E); stridulatory file with 65 teeth (n=1). Subgenital plate as on Fig. 2 L. Male genitalia. Pseudepiphallic sclerite long and triangular ( Fig. 4 K, L); median lophi regularly narrowed toward apex; lateral lophi very short and completely dejected ventrally (thus no more visible dorsally, Fig. 4 K); pseudepiphallic anterior margin deeply concave, but squared; pseudepiphallic parameres very short, in very anterior location; ectophallic apodemes long, making a kind of half cylinder around the endophallic sclerite; ectophallic fold narrow over its whole length, truncated apically. Female. FWs quite long for the genus, reaching tergite 2 mid length, slightly overlapping ( Fig. 5 F); venation reticulate; FWs whitish brown, translucid, the lateral part of dorsal field lighter, veins brown. Abdomen brown, tergite 3 yellowish ( Fig. 5 E). Subgenital plate wider than long; distal margin slightly concave ( Fig. 7 J–K). Female genitalia. Copulatory papilla having the shape of a thick almost circular sclerite, with a transverse preapical carina on ventral side ( Fig. 7 L–N); spermathecal duct widened basally. Measurements (in mm). Lpron wpron LFW wFW LFIII wFIII LTIII File Holotype 1.6 2.5 5.6 3.8 5.7 2,2 3.8 65 Lpron wpron LFW LFIII wFIII LTIII Lovip Allotype 1.6 2.3 1.2 6 2.2 3.8 3.7