Viriacca viridis Ingrisch, 1998

Tan, Ming Kai, Muhammad, Amira Aqilah, Gorochov, Andrei V. & Abdullah, Nurul Ashikin, 2024, An account on some katydids (Orthoptera: Tettigonioidea) from Panti Forest Reserve in Johor, Peninsular Malaysia, Zootaxa 5415 (1), pp. 117-143 : 126-129

Viriacca viridis Ingrisch, 1998

( Figs. 9–12 )

Viriacca viridis Ingrisch, 1998: 97 — Tan, 2012: 47; Tan, 2017: 70

Specimens examined. PENINSULAR MALAYSIA: Johor State: PFR • 1♀; Lukut Trail; N1.81518, E103.87832, 125.2± 7.3 m.a.s.l.; 18 August 2023, 20h22; under the foliage of a small tree; coll. M. K. Tan, Amira A. Muhammad & N. Ashikin Abdullah; PANTI.23.34 ( MZUM) • 1♁; Lukut Trail ; N1.81535, E103.87824, 129.5± 7.5 m.a.s.l.; 18 August 2023, 20h31; on the foliage of a small tree; coll. M. K. Tan, Amira A. Muhammad & N. Ashikin Abdullah; PANTI.23.36 ( ZRC) • 1♁; Lukut Trail ; N1.81549, E103.87816, 133.6± 6.7 m.a.s.l.; 18 August 2023, 20h45; feeding on the foliage of a small tree; coll. M. K. Tan, Amira A. Muhammad & N. Ashikin Abdullah; PANTI.23.38 ( ZRC) • 1♀; Lukut Trail; N1.81612, E103.87822, 152.6± 6.6 m.a.s.l.; 18 August 2023, 21h09; on the branch near the ground; coll. M. K. Tan, Amira A. Muhammad & N. Ashikin Abdullah; PANTI.23.42 ( MZUM) • 1♀; Sisek Trail; N1.82692, E103.83286, 91.8± 6.7 m.a.s.l.; 19 August 2023, 21h17; under the foliage of a small tree; coll. M. K. Tan, Amira A. Muhammad & N. Ashikin Abdullah; PANTI.23.55 ( ZRC)

Remarks. Material from PFR represents a new locality record after Singapore, Negeri Sembilan, Selangor and Pahang ( Ingrisch, 1998; Tan, 2012, 2017).

Ecology. In Singapore, this species is limited mainly to the freshwater swamp forest. But in PFR, this species can be found more commonly in secondary forest.

Type locality. PENINSULAR MALAYSIA: Negeri Sembilan State: Pasoh Forest Reserve

Distribution. PENINSULAR MALAYSIA (Johor State: PFR [new]; Negeri Sembilan State: Pasoh Forest Reserve; Selangor State: Templer Park; Pahang State: Krau Wildlife Reserve); SINGAPORE

Calling song (2♁, 30.4°C) ( Fig. 12 ). The calling song consists of echemes that can vary in duration (1.1–20.9 s) and sometimes extend to become a continuous trill. A short echeme, on average, has a duration of 3.4 s. Each echeme commences with syllables with increasing amplitudes until a maximum. At times, the echeme is truncated by short pause. The syllable duration is 19.4±0.9 ms (17.6–21.7 ms) and the interval between consecutive syllables is 12.8±1.1 ms (10.4–15.7 ms). The syllable repetition rate is 31±1 syllables s−1 (29–33 syllables s−1). The call spectrum is broad-based and has a peak frequency of 26.4±1.1 kHz (24.5–28.8 kHz).

The calling song of Viriacca viridis has a similar structure (i.e., echemes that can become continuous trills) as those of Viriacca insularis Gorochov, 2011 from Pulau Tioman (Pahang) and Viriacca modesta Gorochov, 2013 from Borneo ( Tan et al., 2023). The call spectrum does not differ, ranging from 21.5–28.8 kHz. However, the syllable repetition rate is slightly lower than that of V. modesta (average 34 syllables s−1) and higher than that of V. insularis (average 22 syllables s−1).

Figures

FIGURE 9. Viriacca viridis ♁ adult in its natural environment, feeding on fruits.

FIGURE 10. Viriacca viridis ♀ adult in its natural environment.

FIGURE 11. Viriacca viridis ♁ abdominal apex in dorsal (A) and lateral (B) views, titillators in dorsal (C) and ventral (D) views. Scale bars: 1 mm.

FIGURE 12. Viriacca viridis ♁ calling song recorded in the laboratory: oscillograms (A, C) and spectrograms (B, D) showing echemes of different durations (A, B) and five syllables (C, D).