Yoyetta crepita, 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 : 525-531

Yoyetta crepita sp. nov

( Plates 5–6 ; Figs.1 , 7–8 )

Types. Holotype ♂, Cooper Drive, Clandulla, 32 o 54'27"S 149 o 49'00"E, 30.xi.2020, D. Emery ( EME0713-001 ) (K.629044; AM).

Paratypes. NEW SOUTH WALES: 1♂ 1♀, same data as holotype ( EME0713-013 , -014) (K.629045, K.629046, AM) ; 1♂, 2km S Kandos , 32 o 52'26"S 149 o 57'57"E, 7.i.2010, D. Emery & L. Popple ; 7♂♂ 2♀♀, same data as holotype ( EME0713-003 – 007 , -010–012; -003 genitalia prep 713-1) ; 6♂♂ 1♀, same location as previous, 15.i.2021, N. & D. Emery ( EME0713-015 – 019 , -021–022) ( DE) ; 1♂, AUSTRALIA NSW, 5km S. of Kandos, Capertee Valley , open woodland, 8.i.2010, Popple & Emery, 32°54'06" Sx 149°57'32"E. 473-0006 ; 2♂♂, same data as holotype, 30.xi.2020, D. Emery ( EME0713-008 ,-009) ; 1♀, same location as holotype, 9.i.2021, N., C. & D. Emery ( EME0713- 020 ) ( LWP) ; 2♂♂, same location as holotype, 24.i.2023, D. Emery ( EME0713-023 – 024 ) ( MM) .

Distribution, habitat and seasonality. ( Plate 6E–F , Fig.1 ). At present, Yoyetta crepita sp. nov. has only been captured around Clandulla and Kandos in the Bylong Valley, NSW ( Fig. 1 ). This species appears to favour smooth barked eucalypts, particularly Eucalyptus melliodora (Yellow Box) and the rough-barked E. cannonii (Capertee Stringybark) . Individuals are located in the upper reaches of the eucalypts> 10m from ground level, but may descend briefly to lower levels during ticking flights (see “calling song”). At Clandulla, Y. crepita sp. nov. cohabits with Y. humphreyae Moulds & Popple , Y. timothyi Emery, Emery & Popple , Y. psammitica Emery, Emery & Popple and an additional undescribed Yoyetta species. Most specimens have been present from mid-November to late-January.

Etymology. The Latin “ crepita ” (medical term, from the verb “crepo”, meaning to crackle or creak) is designated for this species due to the crackling chorus produced by the males at intervals on sunny days.

Description of adult male ( Plates 5A–B, E , 6A–C . Fig. 7 )

Head approximately as wide as to slightly wider than mesonotum; dorsally mainly black, with a thin, brown fascia posterior to ocelli; ocelli pinkish-red on live specimens; postclypeus dorsally ochraceous, suffused with black, with a thin brown median fascia, ventral surface black, lateral ridges black, lateral margins pale brown; anteclypeus black; rostrum dark brown, black at apex, reaching anterior edge of hind coxae; lorum and gena dull black with pale brown anterior margins; eyes variably dull black to dark brown; antennae black, supra-antennal plates black.

Thorax predominantly shiny black with variable orange-brown fascia. Pronotum dorsally with brown midline fascia immediately posterior to pronotal collar extending along the anterior half of the midline; a black diamond shaped fascia posteriorly; with extensive orange-brown markings between sutures; pronotal collar black anteriorly and across lateral angles, orange-brown posteriorly and an “open U”-shaped fascias on midline directed anteriorly. Mesonotum black with dark orange-brown colouration between submedian and lateral sigilla; scutal depressions black; cruciform elevation orange with black midline and ridges; metanotum black along midline and lateral halves, darker orange-brown over medial half.

Legs. Coxae black with orange basal and apical margins; fore femora with anterior and posterior surfaces black, striped orange-brown laterally and medially, orange at joints, femoral spines black, directed 45 o posteriorly; mid and hind femora with outer side black, inner side dark brown to brown; fore and mid tibiae black to dark ochraceous, with spines variably dull ochraceous and black at tips; hind tibiae paler brown; tarsi black proximally, ochraceous to claws, claws ochraceous, black at tips.

Wings with forewing costal margin black to dark orange-brown; venation generally dark brown to node, black distally; basal cell translucent; basal membrane bright orange; smoky infusions throughout apical cells a1–a8. Hind wing venation dark brown to black, bright orange at base of M vein; v-shaped plagas orange along vein 2a and 3a and within anal cell, with 6 apical cells.

Opercula ( Plate 6B ) small, spatulate, following body axis ventrolaterally, depressed centrally; black over anterior (basal) third, light cream over; clearly separated. Meracanthus small, narrow, cream, black at base, pointed, overlapping anterior third of opercula.

Timbals ( Plate 6A ) with five distinct long ribs; long ribs 1–3 extending across surrounding membrane and fused dorsally along basal spur; long rib 4 with medial and lateral components connected by a narrow middle segment; long rib 5 independent of basal spur, comparatively shorter, extending ventrally across half of membrane; large, ridged dome on posterior timbal plate extending across two-thirds of timbal; apodeme pit oval-shaped and conspicuous.

Abdomen with tergite 1 black, orange-brown at posterior intersegmental membrane; tergite 2 black with prominent reddish-orange triangular marking located on the posterior half of tergite 2 posterior to timbals ( Plate 6C ), posterior margin burnt orange-brown over middle third, black laterally; tergites 3–7 orange-brown with black median triangular markings along midline, widest at tergite 3, decreasing in width on tergites 4–6, widening on posterior margin of tergite 7, posterior margins with consecutive black and burnt orange annular rings, black markings broadening slightly towards lateral extremities; tergite 8 shiny black, with a small amount of orange-brown colouration on the anterior lateral side; epipleurites orange, flexed ventrally. Sternite I black, slight orange at lateral margins and through tympanal cavity; sternite II black, with orange-brown coloration on lateral posterior margins; sternites III–VI orange; sternite VII orange with dark brown to black marking on posterior half of midline; sternite VIII black anteriorly, becoming dark orange-brown posteriorly, with slightly opalescent pubescence.

Genitalia ( Fig. 7 ). Pygofer mainly black; dorsal beak brown, anal styles orange-brown; pygofer upper lobe of moderate size with a rounded apex; basal pygofer lobe small weakly developed, broadly rounded. Uncus orange-brown; in lateral view beak-like and stumpy, median lobe of uncus moderate, lobes in ventral view bulbous, with rounded lateral termination; claspers clearly divided, with apices directed and gradually tapering laterally. Aedeagus recurved distally through 180 degrees, with transparent toothed flanges along margins of recurvature, these broadly smooth along dorsal and posterior edges, finely serrated and broadening to>2x width of theca ventrally, with dorsal ornamentation restricted to termination adjacent to apex of theca; apex short, sclerotised, transparent, lanceolate, without ornamentation, tip directed slightly upwards; pseudoparameres very long, reaching the distal recurvature of the aedeagus, very slender, each with a small rounded apical knob.

Description of adult female ( Plate 5C–D, F , 6D ).

Head, thorax, wings and legs similar to male but with more abundant orange-brown markings on the pronotum and mesonotum; metanotum suffused orange-black with black stripe along midline.

Abdomen. Tergite 1 orange, black centrally and laterally along posterior margin, orange over remainder; tergites 2–7 predominantly dark orange-brown each with a distinct black fascia along the midline, extending laterally along the third quarter of each tergite midline, most pronounced on tergites 3–5; the posterior margins striped bright redorange; tergite 8 with small black spot on midline, stippled black along anterior margin, burnt orange- brown over remainder. Epipleurites flexed ventrally with black infusion on each medial margin. Sternite I black, ochraceous posteriorly; sternite II black on midline and lateral margins, orange over remainder; sternites III-VII orange with smudged black infusions along midline; sternite VIII orange with distinct black oval marking directed laterally from the anterior margin to midway across the sternite; abdominal segment 9 brown along dorsal midline, black over anterior half, extending posteriorly, black ventral border expanding dorsally to a spot on the posterior margin ( Plate 6D ); ovipositor sheath black, ovipositor dark brown, becoming black posteriorly, not extending beyond abdominal segment 9.

Measurements (in mm; range with mean in parentheses for 10 males and 5 females, including smallest and largest specimens). Length of body including head: male, 17.7–20.6 (19.5); female, 18.7–20.4 (19.5). Length of forewing: male, 21.0–23.3 (22.4); female, 25.1–25.4 (25.3). Width of forewing: male, 7.3–8.2 (7.6); female, 8.0–8.2 (8.1). Width of head (including eyes): male, 4.5–5.5 (5.1); female, 5.7–6.0 (5.9). Width of pronotum (across lateral angles): male, 4.3–5.3 (5.0); female, 5.7–5.9 (5.8). Width of abdomen: male, 4.7–5.8 (5.4); female, 5.0–5.3 (5.1). Length of ovipositor: female, 4.8–5.4 (5.2).

Morphological variations between and within population. Both male and female Y. crepita sp. nov. exhibit a consistent morphology at Clandulla. It remains to be determined if variation exists within this species if specimens are found at additional locations.

Morphological distinguishing features. Y. crepita sp. nov. has a body length <20.6 mm and hindwing plagas orange-grey and extending along veins 2a and 3a and within the anal cell. This feature is shared with 12 other Yoyetta species. Males of Y. crepita sp. nov. can be distinguished from these species by the following combination of 6 characters: (1) the presence of smoky wings with infusions in forewing apical cells; (2) a prominent reddish-orange triangular marking located laterally on the posterior half of tergite 2 posterior to timbals; (3) bright orange basal membranes; (4) brown markings on the lateral areas of tergite 8; (5) reflection of the theca through 180 o and a slightly upturned lanceolate thecal apex; and, (6) when viewed laterally, a 90 o hinge on the basal plate of the aedeagus.

Females of Y. crepita sp. nov. have body lengths between 18.6–20.6 mm that differentiate them from females of 11 of the other 16 Yoyetta species that possess hindwing plagas orange-grey and extending along veins 2a and 3a and within the anal cell. An additional four features of female Y. crepita sp. nov. differentiates them for these other 5 species: (1) ovipositor not extending beyond abdominal segment 9; (2) extension of the black midline markings laterally around the posterior half of the tergites; (3) two black ovoid spots on sternite VIII; and (4) smudged black along midline of orange sternites.

Calling song ( Fig. 8 ). The male calling song of Y. crepita sp. nov. is a series of sharp, rapid ticks. Following analyses of the calling song structure (all statistics, n =3 from Clandulla locality), Fig. 8 shows each ‘tick’ is a single syllable between 0.005 and 0.016 s duration, and the gap between syllables ranges from 0.159 to 0.185 s duration. The frequency plateau ranges from 9 to 14.4 kHz, with a dominant frequency approximately between 10.5 and 11.9 kHz ( Fig. 8C ).

Groups of male Y. crepita sp. nov. emit a distinctive, rapid clicking chorus from the resident population at around 5 min intervals when sunny (and cease mid-chorus with any cloud cover). During these choral cacophonies, males may relocate, calling in flight and often resting for short intervals at lower heights before resuming flight. This behaviour is likely aimed at finding responding females, as males respond readily to finger clicking during the chorus, particularly when present in large numbers. Males may also call for brief periods when resting. Females are usually found on the main trunks around 5m from ground and have been observed wing-flicking during the chorus.

The calling song of Yoyetta crepita sp. nov. closely resembles those of Y. australicta Popple & Emery , which also produces single pulses. While both species have broad frequency plateaus, the pulse gap of Y. australicta is 0.27– 0.67s, greater than for Y. crepita sp. nov. (<0.19s). In addition, males of Y. crepita sp. nov. do not emit quiet macrosyllables at the end of their bouts of ticking.

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 5 Yoyetta crepita sp. nov.: (A) holotype male, Clandulla, NSW (32o54'S 149o49'E), dorsal habitus; (B) male, ventral habitus; (C) female paratype, Clandulla, dorsal habitus; (D), female, ventral habitus; (E) live male specimen, Clandulla (32°54'S 149°49'E); (F), live female specimen, Clandulla. Live photo credits Nathan Emery. Scale bars = 10 mm.

PLATE 6 Yoyetta crepita sp. nov.; (A), male left timbal, with dorsal edge at left and posterior margin at bottom. Specimen from Clandulla, NSW (32o54'S 149o49'E); (B) male left opercula; specimen from Clandulla, NSW; (C) male, left lateral abdomen; specimen from Clandulla NSW; (D), female, lateral left abdomen; specimen from Clandulla, NSW; (E), typical woodland habitat of Y. crepita sp. nov. at Clandulla, NSW; (F), typical habitat at Kandos, NSW. Scale bars = 1 mm (A, B); 5mm (C, D).

FIGURE 7. Y. crepita 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 Clandulla, NSW (32o54'S 149o49'E).

FIGURE 8. Male calling song structure of Y. crepita sp. nov., illustrated in waveform plots, including (A) typical rapid ticking song (in flight); (B) expanded section from A showing a single sharp pulse and subsequent decay. The final subfigure (C) is a spectrogram displaying song frequency. This specimen was recorded in the field at Clandulla, NSW (32o54'S 149o49'E), by NJE using RS1 (see Methods and Terminology).