Ornebius aff. aperta Otte & Alexander, 1983

Hegg, Danilo, 2024, Small crickets of New Zealand (Orthoptera: Grylloidea: Trigonidiidae and Mogoplistidae), with the description of two new genera and species, European Journal of Taxonomy 955 (1), pp. 1-87 : 68-75

Ornebius aff. aperta Otte & Alexander, 1983

Figs 33A–B, J–L, N , 35 , 36E –H, 37C–D , 38I

Diagnosis

Ornebius aff. aperta can be reliably differentiated from other species of Ornebius , including Ornebius aperta in Auckland, only by its song, a sequence of chirps made of four or five pulses at a peak frequency of 4 kHz or less. The interval between the first two pulses is much longer than the interval between the remaining pulses.

Male paraprocts pale brown, club-like in shape, with a long narrow neck at the base, and widest one fourth of the length from the apex.

Material examined (see also Supp. file 1: Table S10)

NEW ZEALAND – Northland (ND) • 1 ♂, 1 ♀; Mahinepua Bay ; 34.99641° S, 173.84348° E; 30 m a.s.l.; 30 Apr. 2021; D. Hegg leg.; in foliage; insect net; MPN OR0473 , OR0474 • 2 ♀♀; Kerikeri Holiday Park, Kerikeri ; 35.22928° S, 173.94294° E; 80 m a.s.l.; 22 Nov. 2021; D. Hegg leg.; in foliage; insect net; MPN OR0303 , OR0304 • 1 ♂; Kerikeri ; 35.21784° S, 173.96140° E; 30 m a.s.l.; 29 Nov. 2021; D. Hegg leg.; in foliage; insect net; MPN OR0297 • 5 ♂♂; Kerikeri ; 35.21875° S, 173.95472° E; 60 m a.s.l.; 19 Mar. 2022; D. Hegg leg.; in foliage; insect net; MPN OR0298 to OR0302 • 6 ♂♂, 4 ♀♀; Kerikeri ; 35.21750° S, 173.96174° E; 30 m a.s.l.; 30 Mar. 2024; D. Hegg leg.; in roadside vegetation; insect net; MPN OR0375 to OR0384 • 1 ♂, 3 ♀♀; Frank Holman Walking Track, Whangārei ; 35.71306° S, 174.31493° E; 40 m a.s.l.; 1 Aug. 2023; D. Hegg leg.; in foliage; sound recording and insect net; MPN OR0305 to OR0308 .

Description

A detailed description of Ornebius aff. aperta is not included here, since I am not designating or describing a new species. 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 aff. aperta from other species in the genus, including Ornebius aperta in Auckland.

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

MALE TERMINALIA ( Figs 33J–K , 36E–H ). Suranal plate without hair spikes projecting backwards from posterior margin, same as in Ornebius aperta ( Fig. 33D–E ). Paraprocts pale brown, club-like in shape, with a long narrow neck at base, and widest one fourth of length from apex ( Figs 33K , 36H ).

SONG. A melodious sequence of chirps with a peak frequency at 4 kHz or less, separated by intervals of two to three seconds; each chirp consisting of 4 or 5 pulses, the first two pulses 650 ms to 700 ms apart, the remaining pulses less than 100 ms apart. Pulse duration is approx. 30 ms. See also Fig. 35 and Table 8 .

Habitat and ecology

An arboreal scaly cricket, nocturnal, locally abundant. Its melodious song is heard from dusk into the night at forest edges, in urban parks and residential areas, and camping grounds.

Distribution

Northland. Presumably introduced from Australia by anthropogenic means. Native distribution range unknown.

Figures

Fig. 33. Ornebius aperta Otte & Alexander, 1983 (O.a.) and Ornebius aff. aperta Otte & Alexander, 1983 (O. aff. a.). All specimens stored at MPN. A–B. Head, lateral and frontal view, adult ♀. O. aff. a., Whangārei (OR0306). C. Dorsal view of forewing, adult ♂. O.a., Auckland (OR0294). D–E. Dorsal view of terminalia, O.a. adult ♂. D. Tamborine Mtn, QLD. Drawing from Otte & Alexander (1983: fig. 312e’). E. Auckland (OR0294). F. Left tympanum. O.a., Auckland (OR0294). G–I. Lateral view of paraprocts, O.a. adult ♂. G. Tamborine Mtn, QLD. Drawing from Otte & Alexander (1983: fig. 312p). H–I. Auckland. H. OR0294. I. OR0295. J. Dorsal view of genitalia. O. aff. a., adult ♂. Kerikeri (OR0298). K. Lateral view of paraprocts, O. aff. a., adult ♂. Kerikeri (OR0299). L. Egg. O. aff. a., Kerikeri (OR0381). M. Dorsal view of ovipositor tip. O. a., Auckland (OR0289). N. Lateral view of ovipositor. O. aff. a., Whangārei (OR0307). Black scale bars = 500 μm; white scale bar = 100 μm.

Fig. 35. Ornebius aff. aperta Otte & Alexander, 1983 song, recorded in the field at 23°C. Lane Cove, Northland. A. Spectrogram of a sequence of two chirps. B. Oscillogram of a sequence of two chirps. C. Oscillogram of one chirp consisting of five pulses. D. Power spectrum of one chirp.

Fig. 36. Ornebius Guérin-Méneville, 1844, micro CT scans of ♂ genitalia of New Zealand species. A–D. Ornebius aperta Otte & Alexander, 1983. Auckland (MPN OR0340). A–B. Dorsal view, crosssection. C. Lateral view. D. Exterior view of paraprocts. E–H. Ornebius aff. aperta Otte & Alexander, 1983. Kerikeri, Northland (MPN OR0375). E–F. Dorsal view, cross-section. G. Lateral view.H. Exterior view of paraprocts. Scale bars = 250 μm.

Fig. 37. Live scaly crickets (genus Ornebius) photographed in their natural environment.A–B. Ornebius aperta Otte &Alexander, 1983. Tahuna Torea Reserve,Auckland. A. Adult ♂. B.Adult ♀. C–D. Ornebius aff. aperta Otte & Alexander, 1983. Kerikeri, Northland. C. Adult ♂. D. Adult ♀.

Fig. 38. Map of New Zealand, showing the known distribution of taxa included in this study. Thin black lines indicate the boundaries of Crosby’s entomological regions (Crosby et al. 1998; Fig. 2). Coloured circles indicate the collection localities for the material examined.