Yoyetta corbinorum, Emery, 2025

Emery, David L., 2025, Description of four new cicada species in the genus Yoyetta Moulds (Hemiptera: Cicadidae: Cicadettinae), from Eastern Australia, Zootaxa 5665 (4), pp. 509-542 : 531-537

Yoyetta corbinorum sp. nov.

( Plates 7–8 , Figs. 9–10 )

Types. Holotype ♂, Toolangi CFA (Country Fire Authority) Stn., 37°32'32"S 145°28'29"E, 23.i.2017, N., C. & D. Emery (to light, EME0778-006 ) (HEM-9295; NMV).

Paratypes. VICTORIA. 2♂♂ 2♀♀, Wirrawilla Rainforest Park, Toolangi , 37°31'39"S 145°31'17"E, 1.i.2023, K. Green, N. & D. Emery & T. Corbin (at light, EME0778-059 – 061 ) (HEM-9297–9299; NMV) ; 3♂♂, same location as holotype, 11.i.2017, S. Emery & T. Corbin (at light, EME0778-001 – 3 ) ; 2♂♂, same location, 23.i.2017, S. Emery & T. Corbin (to light, EME0778-004 , 006 , -004 genitalia prep) ; 1♀, Ridge Rd, Mt. Dandenong , 37°49'27"S 145°21'32"E, 20.i.2017, S. Emery & T. Corbin (to light, EME0778-005 ) ; 1♀, same location, 29.i.2017, S. Emery & T. Corbin ( EME0778-007 ) ; 2♂♂ 2♀♀, Olinda golf course, 37°51'13"S 145°22'19"E, 29.xi-7.xii.2017, S. Emery & T. Corbin (emerging, EME0778-011 – 14 ) ; 1♀, same location, 25.xii.2018, S. Emery & T. Corbin (emerging, EME0778-015 ) ; 1♂, Ridge Rd, Mt. Dandenong , 37°49'27"S 145°21'32"E, 25.xii.2018, S. Emery & T. Corbin ( EME0778-016 ) ; 1♀, same location, 3.xi.2019, S. Emery & T. Corbin ( EME0778-017 ) ; 1♂, same location, 30.xii.2019, S. Emery & T. Corbin ( EME0778-018 ) ; 1♂, same location, 20.xii.2022, S. Emery & T. Corbin ( EME0778-020 ) ; 1♀, Wirrawilla Rainforest Park, Toolangi , 37°31'39" S 145°31'17"E, 7.i.2017, K. Green (at light, EME0778-021 ) ; 1♂ 2♀♀, same location as previous, 26.xii.2022, K. Green (at light, EME0778-024 – 26 ) ; 43♂♂ 1♀♀, same location as previous, 1.i.2023, K. Green, N. & D. Emery & T. Corbin (at light, EME0778-027 , 029–058 , 064–078 ) ( DE) ; 5♂♂ 4♀♀, same location, 7.i.2017, K. Green (at light) ; 6♂♂ 3♀♀, same location, 26.xii.2022, K. Green (at light) ( KG) . 1♂, Wirrawilla Rainforest Park, Toolangi , 37°31'39"S 145°31'17"E, 7.i.2017, K. Green (at light, EME0778-022 ) ; 1♀, same location as previous, 26.xii.2022, K. Green (at light, EME0778-023 ) 1♂ 1♀, same location as previous, 1.i.2023, K. Green, N. & D. Emery & T. Corbin (at light, EME0778-028 ) ( TJB) ; 1♂, AUSTRALIA-VIC, Olinda Golf Course , 37°51'13"S 145°22'19"E, 6.ii.2017, S. & T. Corbin, EME0778-010 ; 1♀, AUSTRALIA-VIC, Ridge Rd, Mt Dandenong , 37°49'27"S 145°21'32"E, S. Emery / T. Corbin, EME0778-008 ( LWP) ; 2♂♂ 1♀, Wirrawilla Rainforest Park, Toolangi , 37°31'39" S 145°31'17"E, 1.i.2023, K. Green, N. & D. Emery & T. Corbin (at light, EME0778-076 – 078 ) ( MM) .

Distribution, habitat and seasonality. ( Plate 8E–F ; Fig. 1 ). This species is often the first to emerge in eastern Melbourne, usually around late September or early October and can persist until late January. It favours the upper branches of Eucalyptus regnans (Mountain Ash) at altitudes> 600m, and specimens are currently restricted to the Dandenong and Yarra ranges east of Melbourne. Since males appear to call constantly at rest from great heights, Y. corbinorum sp. nov. have only been captured emerging around 2100h on shrubs, ferns and grasses close to stands of Mountain Ash. However, they are readily attracted to light, appearing in large numbers at Wirrawilla Reserve in late December 2022.

Etymology. Noun plural; named after Drs. Samantha (nee Emery) and Thomas Corbin who have collected and recorded the majority of specimens of Y. corbinorum sp. nov., and an impressive range of other Victorian and NSW cicadas (especially Yoyetta species) over the past decade.

Description of adult male. ( Plate 7A–B, E , 8A–C , Fig. 9 ).

Head wider than lateral margins of pronotum; mostly black with a dull brown triangular spot between lateral ocelli based on posterior margin, brown along margins of eyes in lighter specimens; supra-antennal plates black; ocelli light brown; postclypeus burnt brown dorsally, with a lighter brown stripe on midline, black below, posterior margin brown, brown spots on anterior and central midline; lorum orange-brown, gena black, anteclypeus black, rostrum black, reaching between mid- and hind coxae; antennae black.

Thorax mostly black in most specimens, brown markings variably prominent across specimens. Pronotum with variable dark brown patches, green-brown laterally, a dark brown fascia along anterior midline abutting posteriorly with a black circular to diamond structure impinging on the pronotal collar centrally; pronotal collar brown, narrow centrally, brown with black along lateral margins. Mesonotum black, with dull to prominent brown “W” around submedian sigilla, following parapsidal sutures anteriorly, thorax brown laterally; cruciform elevation black along arms, lateral depressions brown; wing grooves black. Metanotum black, dark brown along ridge, bright orange on anterior margin. Thorax below mainly black with dark brown anepisternum 2 and epimeral lobes edged orange-red around mid and hind leg cavities.

Legs black with orange-red striped markings, variable between individuals. Coxae black with reddish ridges, trochanter variably reddish-orange; fore femora brightly striped red-black, black along femoral spines; mid and hind femora black with single reddish stripe; tarsi striped red-black, lighter on hind tarsi; claws dark brown to black; meracantha black with red edges, marginally overlapping opercula.

Wings with fusion of forewing veins M and CuA around half length of basal cell; forewing costal veins reddish-brown, pterostigma with orange-brown mottling; basal membranes bright orange-red; basal cell translucent; veins mainly dark brown to black, with eight apical cells; hind wing plaga pale orange-grey to cream at base and margins through anal cell and jejum, becoming transparent towards central third, with six apical cells.

Opercula ( Plate 8A ) medium, spatulate, following body axis ventrolaterally, depressed centrally; black over basal half, cream over remainder; clearly separated.

Timbals ( Plate 8B ) with four complete long ribs spanning the timbal membrane, fused dorsally on basal spur; rib 4 broken centrally; rib 5 short, detached, occupying dorsal half of timbal only; timbal plate with well developed, large ridged dome on posterior timbal plate grey, extending across two-thirds of timbal; apodeme pit oval-shaped and conspicuous.

Abdomen with tergite 1 black; tergite 2 black with variable brown posterior margin; tergites 3-7 black with prominent red-brown to orange posterior margins, increasing on tergite 7, extending laterally and expanding along margins of epipleurites; epipleurites flexed ventrally, black with orange posterior margins; tergite 8 black, with brown posterior margin, a brown spot on lateral surface ( Plate 8C ). Sternite I black; sternite II black, dull orange posteriorly; sternites III-VII bright orange anteriorly, fading to yellow posteriorly, with a central black spot black spot variably present on sternites III-VI; sternite VIII dull orange-black with yellowish pubescence.

Genitalia ( Fig. 9 ). Pygofer light brown to black; apical spine orange-brown, anal styles light orange; upper and lower lobes dark brown. Pygofer upper lobe peaked at apex; basal pygofer lobe small weakly developed, broadly rounded. Uncus black, median lobe well developed in lateral view ovoid stumpy, lobes in ventral view rounded laterally; claspers prominent, divided, drop-like, with apices gradually tapering laterally. Aedeagus with pseudoparameres not extending as far as theca; theca recurved ventrally at 180° towards apex, with broad transparent flanges along margin of recurvature, these smooth dorsally, strongly serrated ventrally,>2x diameter of theca, with marked dorsal ornamentation adjacent to apex of theca; apex grooved on internal surface, curved dorsally around 60 o towards a knob-like tip, transparent, sclerotised, with prominent cornuti on dorsal and ventral faces.

Description of adult female ( Plates 7C–D, F , 8D ).

Generally similar morphology to male, but larger, strikingly coloured mottled brown to more greenish-brown, especially in newly-emerged specimens.

Head similar to male, ventral postclypeus with more orange-red markings.

Thorax conspicuously brown to ochraceous green-brown, pronotal collar green to brown with central black spot; black along parapsidal sutures; sigilla ranging from light brown to olive green; scutal depression black. Ventral thorax variably ochraceous.

Abdomen with more prominent and widespread red-brown markings on tergites, black coloration restricted to lateral margins ( Plate 8D ). Tergite 8 brown to olive green, with lateral black spot; variable burnt orange markings on epipleurites 3–7. Sternite I mainly green to dark brown; sternites II–VII ranging from burnt to dull orange with small black markings of variable density along midline; abdominal segment 9 black with dorsomedial, brown to green stripe, expanding laterally near posterior margin, stigma dark brown to black, dorsal beak black. Anal styles black; ovipositor sheath dark brown to black; ovipositor brown, tending black towards apex, reaching apex of abdomen.

Wings with greenish-brown costa, some specimens with R+Sc and RA green to blue ( Plate 7F ); veins CuA and CuP+1A blue to green in most specimens (which fades to brown in stored specimens); hindwing plaga tinged orange-grey.

Measurements (in mm; range with mean in parentheses for 15 males and 10 females, including smallest and largest specimens). Length of body including head: male 21.5–23.0 (22.3); female 22.7–25.2 (24.2). Length of forewing: male 25.0–28.2 (27.3); female 27.8–31.3 (30.3). Width of forewing: male 7.9–9.4 (8.5); female 8.4–9.8 (9.4). Width of head (including eyes): male 5.8–6.5 (6.0); female 6.1–7.4 (6.7). Width of pronotum (across lateral angles): male 5.7–6.3 (6.1); female 6.0–6.9 (6.6). Width of abdomen (across second segment): male 5.8–6.5 (6.1); female 6.0–7.2 (6.9). Ovipositor length: 6.5–7.2 (6.9).

Morphological variation within species. The morphology and coloration of male Yoyetta corbinorum sp. nov. are consistent amongst specimens collected to date. Freshly emerged females exhibit principally ochraceous green coloration across the dorsal head, thorax and abdomen, which evolves into more orange-brown with time after eclusion, also allowing the annular banding on the abdomen to become more distinct. It was noted that females from the Dandenong Ranges had less prominent black markings along the ventral midline than those from Wirrawilla.

Morphological distinguishing features. Interestingly, at an altitude> 500m, Y. corbinorum sp. nov. cohabits with Y. grandis Emery, Emery & Popple Y. subalpina Emery, Emery & Popple , Y kershawi Goding & Froggatt and Y. hunterorum Moulds , all of which express prominent white hindwing plaga. In contrast, Y. corbinorum sp. nov. does not cohabit with any currently described Yoyetta species that have BLs <20.6mm, and hindwing v-shaped plagas tinged orange-grey visible along vein 2a and 3a and within the anal cell. Males of Y. corbinorum sp. nov. can be differentiated from other Yoyetta species by 6 characters: (1) the absence of prominent white hindwing plaga; (2) BL> 20.6mm; (3) a highly serrated, knob-like thecal apex; (4) a relatively short medial lobe of the uncus; (5) four timbal ribs with rib 4 discontinuous centrally; and (6) complete annular, orange-brown, posterior margins of the tergites.

Amongst Yoyetta females with typical hindwing v-shaped plagas tinged orange-grey along vein 2a and 3a, some 12 species have BLs less than those of female Y. corbinorum sp. nov. (<22.7mm) Females of this species can be differentiated from the remaining species by the following combination of characters: (1), the greenish coloration of female Y. corbinorum sp. nov.; (2) the extensive red-brown posterior margins of the tergites of Y. corbinorum sp. nov.; (3) small black markings along midline of sternites; and, (4) an ovipositor that does not extend beyond abdominal segment 9.

Calling song ( Fig. 10 ). The male calling song of Y. corbinorum sp. nov. is a series of repetitive chirps. Further examination of the calling song (all statistics, n =5 from the Dandenong Ranges) in Fig. 10 illustrates a ‘chirp’ is a macrosyllable ranging from 0.029 to 0.050 s duration, with a gap between each macrosyllable ranging from 0.214 to 0.245 s duration. The frequency plateau ranges between 8.1 and 14.3 kHz, with a dominant frequency between 9.3 and 10.9 kHz ( Fig. 10C ).

Males call from around 0800h and appear to remain at rest for periods approaching 15-30min. Males will still call under cloud cover, even when temperatures fall to around 15C. Female wing flicking has not been detected except in captivity (approximately 0.05 s after a male chirp), and is likely due to their elevated locations in the treetops. Finger snapping to attract males has been successful only on limited occasions, again likely to the height of their preferred locations.

The male calling song of Yoyetta corbinorum sp. nov. most closely resembles those of Y. robertsonae and Y. robusta Popple & Emery and Y. repetens Emery, Emery & Popple. While Y. robertsonae shares an overlapping distribution with Y. corbinorum sp. nov., its call consists of a series of three ticks, whereas Y. corbinorum sp. nov. produces a single macrosyllable. This strident chirping is similar to that of Y. robusta but occurs at a higher frequency (>9.3kHz for Y. corbinorum sp. nov. and around 8.3 kHz for Y. robusta ), and their distributions do not overlap. Additionally, Y. corbinorum sp. nov. is not known to exhibit call variation when at rest, unlike Y. robusta . When compared with Y. repetens , the macrosyllables of Y. corbinorum sp. nov. are shorter (29–50ms duration) compared with the former and their locations do not overlap.

Figures

FIGURE 1. Map of south-eastern Australia showing the geographical distribution of Y. bushi sp. nov. (circles), Y. nathani sp. nov. (triangles), Y. crepita sp. nov. (stars) and Y. corbinorum sp. nov. (squares).

PLATE 7 Yoyetta corbinorum sp. nov.; (A), holotype male, Toolangi, Vic (37°32'S 145°28'E), dorsal habitus; (B) holotype male, ventral habitus; (C) female, Olinda, Vic (37°51'S 145°22'E), dorsal habitus; (D) female, ventral habitus; (E), live male Toolangi, Vic (37°32'S 145°28'E); (F), live female, Toolangi, Vic (37°32'S 145°28'E). Live photo credits, Nathan Emery. Scale bars = 10 mm.

PLATE 8 Yoyetta corbinorum sp. nov.; (A), male left opercula; specimen from Toolangi, Vic; (B), male left timbal, with dorsal edge at left and posterior margin at bottom. Specimen from Toolangi, Vic; (C), male, left lateral abdomen; specimen from Toolangi, Vic; (D), female, lateral left abdomen. Specimen from Toolangi, Vic; (E–F), typical habitats of Mountain Ash forest (Eucalyptus regnans), Olinda, Vic. Live photo credits, Nathan Emery. Scale bars = 1 mm (A, B); 5mm (C, D).

FIGURE 9. Y. corbinorum sp. nov.: illustration of male pygofer and internal genitalia; (a), viewed laterally from the left; (b), viewed ventrally; (c), aedeagus; (d), apex of theca. Characters as depicted in Fig. 2. Specimen from Toolangi (3 7°32'S 145°28'E).

FIGURE 10. Male calling song structure of Y. corbinorum sp. nov., illustrated in waveform plots, including (A) typical chirping song; (B) expanded section from A showing two macrosyllables. The final subfigure (C) is a spectrogram displaying song frequency. This specimen was recorded in captivity at Mt. Dandenong (37°49'S 145°21'E by S. & T. Corbin using RS1 (see Methods and Terminology).