Ornebius bioculatus Tan, Ingrisch, Baroga-Barbecho & Yap, 2019

Tan, Ming Kai, Salvador, Jewel Anne G., Sabang, Aira Mae M., Bahoy, Daphne Cayle M., Nuñeza, Olga Macas & Robillard, Tony, 2023, Taxonomy and bioacoustics of little-known Grylloidea crickets (Orthoptera, Ensifera) from Mindanao, Philippines, Zootaxa 5323 (3), pp. 301-348 : 342-343

Ornebius bioculatus Tan, Ingrisch, Baroga-Barbecho & Yap, 2019

( Fig. 36 )

Ornebius bioculatus Tan et al., 2019b: 170

Specimens examined. PHILIPPINES • 1♁; Mindanao, Misamis Oriental, Gingoog City, Barangay Lunotan , near Mt Sumagaya ; N8.70109, E125.01304, 1258.0±5.0 m.a.s.l.; 13 February 2023, 20h35; mossy forest, on a dead branch; coll. M.K. Tan, J.A.G. Salvador, A.M. Sabang, A. Gono, D.C.M. Bahoy & K. Grumo; MIN.23.15 ( MSUIIT)

Remarks. This species was first described from Siargao Island ( Tan et al., 2019b). The male collected near Mt Sumagaya resembles the type in the overall colouration; FWs pale yellow with the apex having a broad black margin interrupted by two pale spots; the shape and white colouration of paraproct process white; and the genitalia having a pair of lobes of lateral valve folded dorsoventrally, forming a spiral at the apex. Here, we recorded and describe the calling song for the first time and add a locality record for this scaly cricket.

Ecology. This species were found in lowland secondary forest in Siargao Island as well as mossy forest at high altitude in Lunotan.

Type locality. PHILIPPINES, Siargao Island

Distribution. PHILIPPINES (Siargao Island; Misamis Oriental on Mindanao Island)

Calling song (1J, 21.1±0.5°C) ( Fig. 36 ). The calling song is made up of echeme with variable number of discrete syllables; on average 13±3 syllables but ranges from 9 to 20 syllables. Consequently, each echeme has a duration of 5.08±1.26 s (3.08–8.27 s). The first few syllables tend to be of lower amplitudes; amplitude of syllable gradually increases to a maximum and stabilises. The average syllable duration is 51.3±3.5 ms (42.8–57.8 ms) and average interval between consecutive syllables is 375.6±5.7 ms (365.3–386.3 ms). The frequency spectrum is pure-tonal and forms a harmonic, with the energy peaking at the fundamental frequency. The dominant frequency is 5.53 kHz.

Figures

FIGURE 36. Ornebius bioculatus ♁ calling song: oscillograms showing one echeme (A); spectrogram of the same echeme (B); power spectra of a syllable (C) where the grey line represents the power [dB] (axis name and scale in grey) and the black solid peak represents the relative amplitude (axis name in black).