Ornebius aperta Otte & Alexander, 1983

Figs 33C–I, M, 34, 36A–D, 37A–B, 38H

Ornebius aperta Otte & Alexander, 1983: 396–397, figs 311, 312b, p, e’, 314, table 31.

Ornebius aperta – Gwynne et al. 1988: 36–45, fig. 26. — Ramsay 1990: 37–38; 1991: 9–14, figs 1–6. — Andrade & Mason 2000: 483–495, figs 1–3. — Rentz & Su 2019: 277, fig. 34b, p, e’.

Diagnosis

Ornebius aperta can be reliably differentiated from other species of Ornebius, and from the population further north in Northland, only by its song, a sequence of chirps made of three pulses at a peak frequency between 4.5 and 5.6 kHz. The interval between the first two pulses is much longer than the interval between the second and third pulses.

Male paraprocts pale brown, club-like in shape, narrowest at the base and widest one fifth of the length from the apex.

Etymology

After aperta, ‘hill’, because of its origin from Tamborine Mountain in Australia. From one of “several small dictionaries covering a number of languages spread across Australia ” (D. Otte pers. com. 2023). Aperta is used as a name in apposition.

Material examined (see also Supp. file 1: Table S9)

Holotype

AUSTRALIA • ♂, adult; Queensland, Tamborine Mountain; 27.973° S, 153.198° E; 500 m a.s.l.; 25 Feb. 1969; D. Otte and R. Alexander leg.; tangles of vine in rain forest; ANIC 14 008971.

Other material

NEW ZEALAND – Taranaki (TK) • 1 ♂; Bell Block, New Plymouth; 39.02029° S, 174.15025° E; 20 m a.s.l.; 20 Apr. 2023; sound recording and photograph; iNaturalist 155725347 . – Waikato (WO) • 1 ♂; Cambridge; 37.90589° S, 175.47892° E; 60 m a.s.l.; 24 Mar. 2024; D. Hegg leg.; in hedge; sound recording; iNaturalist 203709782 . – Coromandel (CL) • 2 ♀♀; Driving Creek, Coromandel; 36.73316° S, 175.50230° E; 50 m a.s.l.; 5 Apr. 2024; D. Hegg and S. Wagner leg.; in foliage; insect net; MPN OR0387, OR0388 • 3 ♂♂, 2 ♀♀; Coromandel; 36.76232° S, 175.49229° E; 5 m a.s.l.; 6Apr. 2024; D. Hegg leg.; in low foliage; sound recording and insect net; MPN OR0389 to OR0393 . – Auckland (AK) • 3 ♂♂, 6 ♀♀; Tahuna Torea Reserve, Auckland; 36.87172° S, 174.88219° E; 5 m a.s.l.; 29 Aug. 2023; D. Hegg leg.; on tree leaves in forest; sound recording and insect net; MPN OR0288 to OR0296 • 2 ♂♂; same data as for preceding; 26 Mar. 2024; D. Hegg leg.; MPN OR0340, OR0341 • 1 ♂; Orewa Beach, Auckland; 36.59544° S, 174.69950° E; 5 m a.s.l.; 25 Apr. 2023; D. Hegg leg.; on wall of building; jar; MPN OR0287 • 1 ♂, 1 ♀; Linley Reserve, Auckland; 36.79358° S, 174.73276° E; 40 m a.s.l.; 8 Apr. 2024; D. Hegg leg.; in foliage; insect net; MPN OR0399, OR0400 .

Description

For a detailed description of Ornebius aperta see Otte & Alexander (1983: 396–397) and Ramsay (1991). Images of the main characters are in Fig. 33. The male genitalia and the song are described in detail below, since they are the only traits that differentiate Ornebius aperta from other species in the genus, including Ornebius aff. aperta in Northland.

MEASUREMENTS. See Table 8. Females are larger than males.

MALE TERMINALIA (Figs 33D–E, G–I, 36A–D). Suranal plate without hair spikes projecting backwards from posterior margin (Fig. 33D–E). Paraprocts pale brown, club-like in shape, narrowest at base and widest one fifth of length from apex (Figs 33G–I, 36D).

SONG. A melodious sequence of chirps with a peak frequency between 4.5 kHz and 5.6 kHz, separated by intervals of approx. 1 second; each chirp consisting of 3 pulses, the first two pulses 280 ms apart, the second and third pulses 40 ms apart. Pulse duration is approx. 30 ms. See also Fig. 34 and Table 8.

Habitat and ecology

An arboreal scaly cricket, nocturnal, locally abundant. Its melodious song is heard from dusk into the night in urban parks and in the streets of Auckland; the cricket is common in hedges in residential areas.

Distribution

Auckland and surrounds; also Coromandel, Waikato and New Plymouth, Taranaki. Introduced to New Zealand by anthropogenic means. Origin in Tamborine Mountain, Queensland, Australia; accidentally introduced to Perth, Western Australia.