Yoyetta ngarabal, Popple & Emery, 2020

Popple, Lindsay W. & Emery, David L., 2020, Four New Species of Cicadas in the Yoyetta abdominalis (Distant) Species Group (Hemiptera: Cicadidae: Cicadettinae) from Southeastern Australia, Records of the Australian Museum 72 (4), pp. 123-147 : 141-143

Yoyetta ngarabal sp. nov.

urn:lsid:zoobank.org:act:4E000DFF-6DE7-40C1-BFE5-223A41956346

Figs 1 , 4D , 5D , 6D , 16–18

Holotype ♂, Old Grafton Road, Glen Elgin, 29.65546°S 152.04396°E, 7.i.2016, L. W. Popple, open forest, SL100704, 515-0007 (recorded) ( AM K.570297) . Paratypes — NEW SOUTH WALES: 1♂, same data as holotype, Pop 515-0010 ( QM) ; 1♂, same data as holotype, Pop515-0008 [genitalia prep] (DE) ; 1♂, same data as holotype, Pop515-0011 ( MSM) ; 1♂, same data as holotype, Pop515-0009 ( LWP) .

Etymology. Named in honour of the Ngarabal people, the traditional Aboriginal owners of the Glen Innes area and surrounds, including the site where this cicada has been found. The specific epithet is a noun in apposition.

Distribution, habitat and seasonality. This species is known only from a single locality at Glen Elgin east of Glen Innes in northern New South Wales ( Fig. 1 ). It occurs in moist open forest, dominated by eucalypts and she-oaks, with a grassy understorey ( Fig. 16 E–F). Adults have been observed only during January.

Calling song. Males of Y. ngarabal sp. nov. typically commence calling whilst stationary and continue to call in flight. Based upon high quality recordings from the type locality (n = 5), the calling song comprises repeated phrases, containing a syllable sequence (14–27 syllables with each syllable 0.010 –0.013 s duration and separated by silent gaps of 0.02– 0.03 s) and an echeme (0.06– 0.31 s), followed by a longer silent gap (0.11– 0.31 s) ( Fig. 17 ). The echemes at the end of each phrase show a sharp amplitude modulation, which is much louder than the preceding syllable sequence. In flight, the syllable sequence is often dropped, with long silent gaps of 1.3– 1.6 s occupying the intervals between each echeme.

The calling song has a dominant frequency of 8.9–9.6 kHz and a high amplitude plateau between approximately 6.8 and 11.1 kHz ( Fig. 17D ). Males were found to be responsive to simulated female wing-flick responses when these were timed precisely to occur at the end of each echeme (LWP, pers. obs., 7 January 2016).

Morphology. Male ( Figs 4D , 5D , 6D , 16 A–16B, 18). Head almost as wide as mesonotum, black, with a central dark brown fascia posterior to ocelli; ocelli pink; dorsal side of postclypeus black anteriorly, dark brown over remainder; ventral side of postclypeus black with black transverse grooves, with brown lateral margins; anteclypeus black, rostrum mainly brown, dark brown at apex, reaching anterior edge of hind coxae; lora black; gena black; eyes dull reddishbrown; antennae and supra-antennal plates black.

Thorax mainly black with variable dark brown patterning. Pronotum mainly black, a thin central dark brown line on anterior half, dark brown on lateral angles; fissures mainly black; pronotal collar black. Mesonotum mainly black, area between submedian and lateral sigilla dark brown, cruciform elevation arms black, lateral depressions dark brown. Metanotum black.

Legs. Fore coxae black with brown to pale brown lateral margins; mid and hind coxae black; coxal membranes red; basisterna black, kapepisterna brown posteriorly; meracantha small, narrow, pale orange-red, black at base, pointed, minimally overlapping opercula; femora mainly black, with brown areas on outer sides; femoral spines erect, brown at base, becoming black at tips; fore tibiae dark brown to black; mid tibiae black anteriorly, brown to orange-brown over remainder; hind-tibiae orange brown; tarsi orangebrown becoming black towards claws; claws dark brown, black at tips.

Wings with fore wing costal veins dark brown, darker central rib; pterostigma pinkish-brown; basal cell translucent pale yellow-brown with black anterior border; basal membranes orange, becoming darker distally; other veins dark brown to black, with eight apical cells, each hyaline with a slightly smoky appearance; hind wing plagas dull white with pink intrusions along margins of anal cell 3 and vein 2A, central area and posterior of jugum hyaline, with six apical cells.

Opercula ( Fig. 4D ) covering abdominal cavity, spatulate, following body axis ventrolaterally, depressed centrally, black over basal area, pale reddish-brown over remainder, clearly separated.

Timbals ( Fig. 5D ) with five distinct long ribs; long ribs 1–4 extending across surrounding membrane and fused dorsally along basal spur; long rib 5 independent of basal spur, slightly shorter, extending ventrally three quarters of membrane; intercalary ribs present, most prominent between long ribs 3 and 4, inconspicuous between long ribs 4 and 5; large ridged dome on posterior timbal plate extending across half of timbal; apodeme pit oval-shaped and conspicuous.

Abdomen with tergite 1–2 black; tergites 3–7 black with orange posterior margins; tergite 8 black ( Fig. 6D ). Epipleurites brown with orange posterior margins. Sternite II black centrally, orange-brown laterally; sternites III–VII orange-brown with prominent black central areas and orange posterior margins; sternite VIII dark brown to black anteriorly, becoming brown to orange-brown posteriorly, with brownish pubescence.

Genitalia ( Fig. 18 ). Pygofer shiny black; dorsal beak dark brown to black; anal styles orange; upper lobes shiny black; basal lobes black. Uncus dark brown, rounded, in lateral view extending as far posteriorly as anal styles, in ventral view bulbous; claspers black, apposed at base, clearly divided anteriorly, short, with apices rounded, gradually tapering laterally. Aedeagus with pseudoparameres extending around two-thirds the length of theca; theca recurved ventrally at 120° towards apex, with prominent transparent flange along the outer margin of recurvature, this broadly smooth along theca with substantial lateral ornamentations, together>5 times width of theca, terminating at apex; apex bifurcate in ventral view, terminals blunt, each with beak-like angulation ventrally, dual cornuti dorsally.

Female. Unknown.

Measurements (in mm; 5 males). Body length: 24.2–26.3 (25.4). Fore wing length: 29.5–30.4 (30.0). Fore wing width: 9.8–10.4 (10.1). Head width: 6.7–7.1 (7.0). Pronotum width: 7.0–7.6 (7.4). Abdomen width: male 6.6–7.9 (7.6).

Distinguishing features. Within the Y. abdominalis group, in both calling song and morphology, Y. ngarabal sp. nov. is most similar to Y. verrens Emery, Emery & Popple , which also occurs in northern New South Wales. Notably, Y. verrens has two modes of calling (“cascade mode” and “ratchet mode”; see Emery et al. 2019), whereas Y. ngarabal sp. nov. only has one. The calling song of Y. ngarabal sp. nov. is most comparable with the ratchet mode of Y. verrens . The most notable difference is in the abbreviated gap between syllables in the syllable sequence (0.021 – 0.031 s, c.f. 0.07– 0.14 s for Y. verrens ), which gives the call a more rattle-like quality. The amplitude modulation in the echeme is also more prominent in Y. ngarabal sp. nov. than in Y. verrens .

Both Y. ngarabal sp. nov. and Y. verrens share a characteristic trait that distinguishes both species from other species in the Y. abdominalis species group: the colouration of the hind wing plaga. In both species, it is dull white and restricted along the margins of anal cell 3 and vein 2A. In other species within the same species group, the opaque colouration is bold white and more extensive. Males of Y. ngarabal sp. nov. can be distinguished from males of Y. verrens by their larger size (head width ≥ 6.7 mm) and by the presence of bold black central markings on sternites III– VII (inconspicuous or absent in Y. verrens ). A single female was observed at Glen Elgin; however, it evaded capture. Observations indicate that the female has a conspicuously longer ovipositor than that reported for Y. verrens by Emery et al. (2019) (i.e. 2 mm). However, this observation requires a specimen for confirmation.

Figures

Figure 1. Map of south-eastern mainland Australia showing the geographical distribution of Yoyetta douglasi sp. nov. (grey circles), Y. enigmatica sp. nov. (grey triangles), Y. loftyensis sp. nov. (black triangles) and Y. ngarabal sp. nov. (black circles).

Figure 4. Photos of male left opercula: (A) Yoyetta douglasi sp. nov.; (B) Y.enigmatica sp. nov.; (C) Y. loftyensis sp. nov.; (D) Y.ngarabal sp. nov. Scale bars = 1 mm.

Figure 5. Photos of male left timbals, with dorsal edge at right and posterior margin at bottom: (A) Yoyetta douglasi sp. nov.; (B) Y. enigmatica sp. nov.; (C) Y. loftyensis sp. nov.; (D) Y. ngarabal sp. nov. Scale bars = 1 mm.

Figure 6. Lateral views of the caudal abdomen of: (A) Yoyetta douglasi sp. nov.; (B) Y. enigmatica sp. nov.; (C) Y. loftyensis sp. nov.; (D) Y. ngarabal sp. nov. Scale bars = 1 mm.

Figure 16. Yoyetta ngarabal sp.nov.(A) holotype male, Glen Elgin (29°39'S 152°03'E), dorsal habitus;(B) holotype male, ventral habitus; (C) live male, Glen Elgin, lateral view; (D) live male, Glen Elgin, dorsal view; (E) typical habitat, Glen Elgin (F) typical habitat, Glen Elgin. Scale bars = 10 mm.

Figure 17. Male calling song structure of Yoyetta ngarabal sp. nov. illustrated in waveform plots, including: (A) three complete phrases, each comprising a syllable sequence followed by an echeme; (B) expanded section from A showing the detailed structure of the syllable sequence; (C) expanded from (A) showing the detailed structure of a normal phrase followed by a cueing phrase and another normal phrase.The final subfigure (D) is a spectrogram displaying song frequency.This specimen was recorded in the field at Glen Elgin (29°39'S 152°03'E) by LWP.

Figure 18. Yoyetta ngarabal sp.nov.: illustration of male genitalia; (a) pygofer, viewed laterally from the left; (b) pygofer, viewed ventrally; (c) aedeagus viewed laterally from the left; (d) apical portion of theca, viewed laterally from the left; (e) terminal apex of theca; (f) apical portion of theca, viewed ventrally. Characters depicted as in Fig. 7. Specimen from Glen Elgin, (29°39'S 152°03'E).