Bioacoustics of Zebragryllus guianensis

Description. Very small species for the genus, with slightly protruding eyes. Head wider than pronotum. Pronotum more narrow distally. TIII with 4–5 (female) and 5 (males) inner, and 5 (female) and 5–6 (males, mean 5.5) outer subapical spurs, the 5th inner and the 6th outer sometimes much smaller when present. Basitarsomeres III with 3 inner, and 5 outer dorsal spines in addition to apical spines, in both males and female; spines smaller than in other species. Coloration. Head black brown; lower part of the face above epistemal suture black brown or dark reddish brown; maxillary palpi dark brown, joint 4 slightly lighter dorso-basally. Antennae with a white basal ring (scape + 7–8 antennomeres in males (mean 7.5); scape very light brown on margins, first antennomere very light brown + 7 white antennomeres in female), followed by a brown ring (26–31 brown antennomeres in males (mean 28.8), 27– 31 brown antennomeres in female), a second white ring (11–15 white antennomeres in males (mean 13.3), 13–15 white antennomeres in female), then dark brown (antennae broken at that level in all observed specimens). TI, TII light brown. FI, FII dark brown with a large white dorsal patch covering part of inner and outer sides. TIII and basitarsomeres III light brown with lighter spurs. FIII ( Fig. 4 A) dark brown, lower margin white, this longitudinal band narrow on outer side, wider on inner side, and connected to a transverse wide band at about three fourth of FIII length; an additional white oblique band close to FIII base. Cerci black brown with a white basal ring. Male. FWs covering the base of cerci, but not the subgenital plate. Stridulatory apparatus ( Fig. 2 B): harp with two to four veins (sometimes incomplete), mirror divided into many cells, stridulatory file with about 93 teeth (n=1). Subgenital plate long and truncate apically ( Fig. 2 G). Male genitalia. Pseudepiphallic sclerite short and not very wide; median lophi acute and “foliaceous” dorsally ( Fig. 4 C), rounded ventrally ( Fig. 4 D); lateral lophi short and wide. Pseudepiphallic parameres going beyond median lophi. Pseudepiphallic apodemes very short. Ectophallic fold narrow and very long, visible dorsally between median lophi ( Fig. 4 C). Ectophallic apodemes and apodeme on top of dorsal cavity all very long and about equal in size. Female. Apterous. Coloration pattern ( Fig. 5 B): Mesonotum (hardly visible) and distal margin of metanotum whitish, the white pattern of metanotum making a wide half-circular band, prolonged mediodorsally on tergite 1; tergites 4, 5 and 6 (and to a less extent tergite 3) with a pair of white bands, separated along mid dorsum by a narrow black area; these bands located along tergite anterior margin dorsally, more lateral at tergite mid length, and reaching the tergite posterior limit laterally; white band on tergite 4 brightest and widest laterally. Subgenital plate wider than long, truncate distally, distal margin hardly concave ( Fig. 6 F, G). Sternite before subgenital plate light brown, with a whitish, crescent-shaped spot along distal margin. Ovipositor very short, much shorter than TIII. Female genitalia. Copulatory papilla asymmetrical, wide and well sclerotized distally, much narrow and less sclerotized anteriorly ( Fig. 6 H–J). Measurements (in mm). Lpron wpron LFW wFW LFIII wFIII LTIII File Holotype 1.5 2.1 5 3.5 6 2,2 4,4 Paratypes 1.5–1.6 2.4 4.9–5.1 3.6 5.8–6.1 2.1–2.2 4–4.4 93 teeth (n=1) mean (n=3) 1.5 2.3 5 3.6 6 2.2 4.3 Lpron wpron LFIII wFIII LTIII Lovip Allotype 1.9 2.3 6.7 2.4 4.5 3.4 Calling song. One male has been recorded in the field (MNHN-EO-ENSIF3114; recording temperature not documented). This species produces series of echemes ( Fig. 8 B) where the echeme duration is 0.24±0.03 ms, echeme period is 1.22±0.4 ms and the duty cycle is 19%. Each echeme contains 8±1 syllables where duration of a syllable is 0.02±0.002 ms, period is 0.03±0.003 ms and the duty cycle is 62%; the dominant frequency is 3 kHz.