Varitrella (Cantotrella) bakeri ( Chopard, 1925 )

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 : 315-316

Varitrella (Cantotrella) bakeri ( Chopard, 1925)

( Figs 13–16 )

Madasumma bakeri Chopard, 1925: 322

Varitrella bakeri — Gorochov, 2003: 279 (new combination and drawings of genitalia, but holotype not examined); Gorochov, 2006: 33 (placed in subgenus Cantotrella)

Specimen examined. Holotype: PHILIPPINES • ♁; Mindanao, Surigao; coll. C.F. Baker; MNHN-EO-ENSIF6696

New specimens examined. PHILIPPINES •1♁; Mindanao, Misamis Oriental, Gingoog City, Barangay Lunotan , foot of Mt Balatukan ; N8.70485, E125.00648, 1193.0±5.3 m.a.s.l.; 15 February 2023, 09h26; on a shrub; coll. J. Lapay; MIN.23.44 ( ZRC) ( Figs 13 , 14 ) • 1♁; Mindanao, Misamis Oriental, Gingoog City, Barangay Kalagunoy, foot of Mt Balatukan ; N8.73898, E125.03278, 1050 m.a.s.l.; 29 April 2023, 20h00; open area outside the mossy forest, on a fern foliage; coll. A.M. Sabang & D.C.M. Bahoy; specimen damaged but genitalia preserved ( MSUIIT)

Remarks. The male specimens which we collected from Mt Balatukan resemble the holotype of V. bakeri (MNHN-EO-ENSIF6696) and V. bakeri sensu Gorochov (2003) from Mindanao Island in the ectophallic fold [rachis (= guiding rod)] in profile view, which is characteristic of the species and differentiate it from a similar-looking congener, i.e., Varitrella (Cantotrella) saussurei (Stål, 1877) from northern Philippines (i.e., Babuyan Islands) ( Figs 14 , 15 ). The male specimens from Mt Balatukan also have identical subgenital plate as the male examined by Gorochov (2003) [ V. bakeri sensu Gorochov (2003) ]. The male FWs of our specimens nonetheless differs from the holotype by the presence of a distinct white spot (vaguely present in the holotype).

Ecology. Unknown.

Type locality. PHILIPPINES, Mindanao Island , Surigao City

Distribution. PHILIPPINES (Mindanao Island: Surigao City in Surigao del Norte, Gingoog City in Misamis Oriental)

Calling song (1J, 21.1±0.5°C) ( Fig. 16 ). The calling song consists of an echeme made up of 18±1 syllables (13–20 syllables) and has an average duration of 3.48±0.27 s (2.53–4.04 s). Each syllable has an average duration of 33.11±1.50 ms (29.30–36.80 ms). The average interval between consecutive syllables is 172.6±4.1 ms (164.2–183.7 ms). The frequency spectrum is pure-tonal and forms a harmonic, with the energy peaking at the fundamental frequency. The dominant frequency is 4.99±0.11 kHz (4.78–5.16 kHz).

Figures

FIGURE 13. Varitrella (Cantotrella) bakeri: head and pronotum in dorsal (A) and lateral (B) views; face in anterior view (C); FWs in dorsal (D) and lateral (E) views. Scale bars: 5 mm (D, E), 2 mm (A–C).

FIGURE 14. Varitrella (Cantotrella) bakeri ♁ genitalia in dorsal (A), ventral (B) and lateral (C) views. Scale bar: 1 mm.

FIGURE 15. Varitrella (Cantotrella) bakeri ♁ holotype genitalia in dorsal (A) and lateral (B) views. Scale bar: 1 mm.

FIGURE 16. Varitrella (Cantotrella) bakeri ♁ calling song: oscillograms showing two echemes (A) and one echeme (B); spectrogram of the same echeme (C); power spectra of a syllable (D) 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).