Xeropsalta thomsoni, Ewart, 2018

Ewart, A., 2018, Two new genera and five new species of Mugadina - like small grass cicadas (Hemiptera: Cicadidae: Cicadettini) from Central and Eastern Australia: comparative morphology, songs, behaviour and distributions, Zootaxa 4413 (1), pp. 1-56 : 28-34

Xeropsalta thomsoni n. sp.

Fig. 2C to 7C, 8, 18–21, 30, Pl. 3, 6B.

Jundah Grass Ticker (No. 344), Ewart 2009, 127 (Pl. 2, M), 128, 144; Noonbah Tan, Marshall et al. 2016 Fig. 2b, p . 25

Types. QUEENSLAND. Holotype male, T244500, Waterloo shearing sheds, Thomson R., Noonbah Stn., SWQ, A.E., 2.ii.2009, 24°13'37.0''S 143°17'15.7''E, specimen recorded (QM) . Paratypes: QUEENSLAND. 13♂, Thomson R. crossing, 4 km W. Jundah, SWQ., 1.ii.1999, AE . 24°49.36'S 143°01.14'E, 2 specimens recorded; 1♂, Waterloo shearing sheds, Thomson R., Noonbah Stn. , SWQ, 2.ii.2009, 24°13'37.0''S 143°17'15.7''E, specimen recorded (AE) ; 2♂, Diamantina River, Birdsville , SWQ, 25°54'00.8''S 139°21'15.4E'', 15.i.2007, L. Popple & J. Hereward, Lignum, 633-0001 to 633-0002 [633-0001 recorded]; 4♂, Simpson Desert NP, Big Red sand dune, in grass and small forbs, 25°54'02''S 139°04'01E'', 15.01.2007, L. Popple & J. Hereward, 633-0003 to 633-0006 (LWP); 1M #, 09.AU.QL.EAT., 20 km E of Windorah, SWQ., 25°25.782'S 142°47.628'E, 2.ii. 2009, 121m, K. Hill & D. Marshall, molecular voucher 09.AU.QL.EAT.01, specimen recorded ; 1♂, Noonbah ( Stn ), SWQ, 24°05'S 143°09'E, 13.i.2000, A.J. Emmott, in Vergemont Ck ; 1♂, 02.AU.QL. VER.11, Vergemont channels, Noonbah ( Stn. ), 14.i.2002, 24.0888°S 143.146°E, K. Hill, D. Marshall, J. Cooley & M.S. Moulds ; 1♂, FL.02.QL.WJH.01.T02, Thomson River crossing, Jundah, 15.i.2002, 24.8317°S 143.049°E, K. Hill , D. Marshall, J. Cooley & M.S. Moulds ( MSM); 1♂, Thomson R. crossing, 4 km W. Jundah, SWQ., 1.ii. 1999, AE . 24°49.36'S 143°01.14'E (ANIC). 1♂, Thomson R. crossing, 4 km W. Jundah, SWQ., 1.ii.1999, AE. 24°49.36'S 143°01.14'E ( BMNH). SOUTH AUSTRALIA : 1♀, Australia: SA, AU.SA.CCL, Cooper Creek camp on Birdsville Track , 10m, 28°37.428'S 138°42.585'E, 30.i.2015, D. Marshall (QM); 10M #, 2♀, Australia: SA, AU.SA.CCL, Cooper Creek camp on Birdsville Track , 10m, 28°37.428'S 138°42.585'E, 30.i.2015, D. Marshall, male songs recorded; Australia: SA: AU.SA.OON, 1M #, 25 km N of Maree on Birdsville Track . 36m, 29°28.562'S 138°13.455'E, 29.i.2015, D. Marshall; 3♂, 30°02'S 138°41'E, 20km S of Moolawatana Hstd , S.A., 23.i.1976, M.S. & B.J. Moulds ; 1♂, as previously, with genitalia preparation, HIL1 (MSM). NEW SOUTH WALES : 1♂, Australia: 09.AU.NS.WGS.01.T03, 30 km NNW of Tibooburra, Strzelecki Desert , 29.1706°S 141.949°E, 03.ii.2009, D. Marshall ( MSM) .

Distribution ( Figs. 8 , 30 ) and Habitat. Occurs relatively widely in Central Australia, occurring along the arid flood plains and seasonal grasslands of the Lake Eyre basin, including the Diamantina, Thomson, Cooper Creek, Warburton , and Bulloo rivers and other river systems draining towards and into the Lake Eyre Basin. These cover the regions of southwestern Queensland, northeastern South Australia, and the northwestern corner of N.S.W. Specimens have been captured in January and February, emergences only following significant rains.

Specific locations in S.W. Queensland include Vergemont Channels at Noonbah Station (32 km NW of Stonehenge) ; Thomson River crossings near Jundah; Cooper Creek crossing, 20 km southeast of Windorah ; Birdsville, and approximately 30 km W. of Birdsville, eastern Simpson Desert environment. In South Australia, locations include the Cooper River crossing on the Birdsville Track, 25 km N of Maree on Birdsville Track, and 20km S. of Moolawatana Hstd. (northwest of Lake Frome) . The NSW occurrence is 30 km NNW of Tibooburra, Strzelecki Desert , near the ' Silver City Highway'.

Description. MALE (Pl. 3A, B)

Head: Supra-antennal plate black, brown adjacent to pedicels; postclypeus pale to medium brown along lateral and ventral margins, also along vertical midline and dorsal surface, remaining medial area black, with brown colouration partially extending between transverse ridges; gena and mandibular plate pale to medium brown, partially covered by pale brown pubescence; frons predominantly pale brown, with localised black margins; vertex pale brown with localised black areas around lateral ocelli; epicranial suture pale brown; ocelli pink to dull red; anteclypeus pale brown with deep brown dorso-lateral margins; mentum and rostrum pale brown, dark brown along lateral margins of rostrum; pedicels medium to dark brown; antennae deep brown to black.

Thorax: Pronotum predominantly pale brown, with a relatively broad dark brown envelope enclosing the thin pale brown central fascia, the dark brown to black envelope splaying outwards along the anterior pronotal margin and more extensively along the anterior margin of pronotal collar; dark brown to black patches along the lateral fissures, also patches of dark colour between lateral and paramedian fissures, also locally within paramedian fissures; anterior pronotal margin pale brown, pronotal collar pale brown, the lateral angle of collar dark brown; metanotum pale yellowish-brown.

Mesonotum: with black submedian and lateral sigilla, the margins somewhat irregular and broken; distal termination of submedian sigilla expands outwards into and between the anterior arms of cruciform elevation including scutal depression; remaining colouration pale brown; cruciform elevation pale brown, darker medially; wing grooves pale yellow-brown with pale yellow pubescence.

Wings: Fore wing pterostigma very faintly pigmented, slightly translucent; basal membrane white to off-white; leading edge of costa dark brown, remaining venation medium to pale brown, slightly darker proximal to wing margins; hind wing without infuscation; plaga and areas adjacent to 3A and 2A veins opaque white, remaining venation pale brown tending darker proximal to margins.

Legs: Fore coxae and trochanters pale brown medially, dark brown peripherally; mid and hind coxae and trochanters mainly pale brown, dark brown along the anterior and distal faces; fore femora pale brown medially, darker brown around margins, dark brown spine; mid and hind femora pale brown with dark brown fasciae; fore tibiae and tarsi medium brown, dark brown claws; mid and hind tibiae and trochanters pale brown with thin darker brown fasciae, and dark tips to claws.

Opercula: Uniformly pale yellow-brown; basal area domed; general outline rounded with slight but distinct elongation along axis between crest and disto-median margin.

Timbals: Rib structures as in diagnosis, with long rib 4 fused dorsally to basal spur.

Abdomen and pygofer: Tergite 1 pale yellow-brown with submedial dark brown to black areas; tergites 2 to 7 with conspicuous dorsal medium brown areas of similar size, not covering intersegmental membranes, the colouration on tergite 2 darker than other tergites; specimens from the Birdsville and more southerly locations are notable in exhibiting deep brown to black and more sharply defined dorsal tergite colouration patterns (Plate 3B); auditory capsules mostly black to deep brown, in some specimens with upper part paler yellow-brown; lateral tergite colouration is dominantly pale yellow-brown, but ventro-laterally is interrupted by conspicuous black roughly triangular-shaped patches, not extending on to intersegmental membranes; the colouration along the ventro-lateral margins returns to pale yellow-brown; tergite 8 predominantly pale brown to yellowish-brown, with a very narrow dorsal medium brown area, and a localised brown area laterally. Sternite II pale yellow-brown, localised dark patch medially; sternite III pale yellow-brown, with a localised brown medial patch, and a localised smaller black area anterio-medially; sternites IV to VII pale yellow-brown, with diffuse darker brown medial patches, not crossing the intersegmental membranes; sternite VIII pale yellowish-brown with a pair of well defined dark brown submedial anterior areas. Pygofer predominantly pale brown with localised narrow black lateral anterior margin. Essential genital structures as in generic diagnosis.

FEMALE (Pl. 6B). Available female specimens are almost uniformly pale-yellow to pale yellow-brown, near to straw coloured. The colouration is completely different to that of the males, as also seen in X. aridula (see below), this providing a cryptic appearance within the grasslands in which this species inhabits.

Head. Supra-antennal plate, vertex, frons, postclypeus, gena, mandibular plates, pedicels, and anteclypeus uniformly pale to medium yellow-brown; the medial segments only of the transverse ridges pale to medium brown; ocelli pale pink; compound eyes brown; small brown patches present on supra-antennal plates and adjacent vertex; labrum and labium pale to medium brown, darker apically; rostrum extends to mid-coxae.

Thorax. Pronotum and pronotal collar mainly straw colour, central fascia outline weakly visible; weak brown markings dorsally on pronotal collar. Mesonotum mainly pale straw colour, the outlines of the sigilla just discernable, less so for the lateral sigilla. Metanotum straw yellow.

Wings. Venation pale brown to yellow-brown; basal membrane off-white to colourless. Legs. Uniformly yellow to pale yellow-brown, becoming pale brown to medium brown on tarsi, claws dark brown.

Abdomen. Tergites all pale straw colour with a narrow medium brown dorsal fascia extending along tergites 1 to 7, in some specimens from cruciform elevation. Sternites uniformly pale straw colour; ovipositor sheath pale to medium brown; ovipositor sheath extends 1.8 to 2.1 mm beyond termination of final sternite.

Measurements. Thomson River specimens, S.W Queensland: N= 13♂. Ranges and means (in parentheses), mm; BL: ♂ 11.3–13.8 (12.9); ♀ 10.8–12.5 (12.0). FWL: ♂ 11.4–13.3 (12.1); ♀ 10.7–12.0 (11.4). HW: ♂ 2.7–3.1 (2.9); ♀ 2.7–2.9 (2.8). PW: ♂ 2.6–3.0 (2.9); ♀ 2.7–2.9 (2.8). AW: ♂ 3.9–4.5 (4.3); ♀ 3.2–3.8 (3.5). FWL/WR: ♂ 2.47–2.96 (2.64); ♀ 2.51–2.73 (2.61).

Cooper Creek specimens, southerly extension to Simpson Desert, South Australia; N= 96 3♀. Ranges and means (in parentheses), mm; BL: ³ 12.9–15.5 (14.3); ♀ 13.5–14.3 (14.1). FWL: ³ 13.2–14.8 (13.9); ♀ 13.3–14.4 (14.0). HW: ³ 3.3–3.7 (3.5); ♀ 3.4–3.5 (3.5). PW: ³ 3.4–3.7 (3.6); ♀ 3.3–3.5 (3.4). AW: ³ 4.8–5.1 (4.9); ♀ 4.0– 4.4 (4.2). FWL/WR: ³ 2.48–2.65 (2.63); ♀ 2.44–2.71 (2.58).

These measurements indicate that the specimens from the Cooper Creek location are slightly larger than those from the Thomson River locations.

Etymology: Named after Sir Edward Thomson after whom the Thomson River is named. This species was initially discovered along the Thomson River systems, south western Queensland.

Figures

FIGURE 8. Map of Central and Northeastern Australia, showing the currently known occurrences of Heremusina udeoecetes n. sp., H. pipatio n. sp., Xeropsalta thomsoni n. sp., X.aridula n. sp., and X. rattrayi n. sp. The heavy dot-dash line shows the approximate northern and eastern boundaries of the ecoregion which defines the dominance of deserts and xeric shrublands within inland Australia (based on National Reserve System map, published by the Australian Government). The fine dotted lines are major roads, the names of some prominent towns listed. Lake Eyre and associated ephemoral lakes are shown by the darker shading. The approximate outlines of the modern dunefields comprising much of the Simpson and Strzelecki deserts are shown by the lighter shading, these based on 'Google Earth' images.

FIGURE 25. Xeropsalta rattrayi n. sp., all cage recordings: (A), overview waveform showing the repeated and moderately extended echemes, approximately 1–1.5 s in duration, with multiple interspersed short echemes (0.16–0.27 s durations, mean RR 2.5 Hz).A distinctiveproperty of all these echemes is their termination with sharply defined, and relatively abrupt increase in amplitudes. (B), time expanded waveform of a longer echeme (see Fig. 25A for location), illustrating the changing amplitudes, initially low intensity, followed atapproximately 0.3 sec witha marked increase whichextends for about 0.4–0.5s, followed by a decreasing amplitude segment (approximately 0.2 s duration), and the final sharp increase at the echeme termination. (C), a more detailed time expanded segment from the initial 90 ms of the echeme (illustrated in previous Fig. 25 B); this illustrates the initial syllable doublets, these progressively merging into longer macrosyllable with 6 pulses. (D), time expanded view of a complete short echeme (location shown in Fig. 25A), illustrating the extended low amplitude macrosyllables, these initially comprised syllable doublets, which very slowly increase in amplitude and progressively merge, leading at the end of the echeme to the final sharp amplitude 'inflation'.Unfiltered.

FIGURE 30. Generalised map of central and northeastern Australia showing the distributions of the described Heremusina n. gen. andXeropsalta n. gen. species, as in Fig. 8, compared to the geography of selected river systems of inland Australia.The more heavily dotted lines show the systems draining towards the Lake Eyre Basin; the finely dotted lines of the rivers systems of the southeastern area of the Northern Territory are internally draining, not reaching beyond the State boundaries, while the river systems of northern and eastern Queensland, northern Northern Territory and NSW drain into the surrounding oceans.

FIGURE2. Lateralabdomen views of the five new species described in thispaper;(A), (B), Heremusina udeoecetes n. sp.and H. pipatio n. sp.; (C) to (E), Xeropsalta thomsoni n. sp., X. aridula n. sp., X.rattrayi n. sp., respectively.