Myopsalta riverina, Popple, 2017
Popple, Lindsay W., 2017, A revision of the Myopsalta crucifera (Ashton) species group (Hemiptera: Cicadidae: Cicadettini) with 14 new species from mainland Australia, Zootaxa 4340 (1), pp. 1-98: 74-76
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Myopsalta riverina n. sp.
Types. Holotype: ♂ AUSTRALIA NSW, 33 km SSW. of Rankins Springs, 20.xi.2010, L.W. Popple, D. Emery, 33°55'03'' Sx 145°56'25''E, 677-0001, Mallee , K.421150 (AM); Paratypes: NEW SOUTH WALES : 1♂ same data as holotype, 677-0005 (QM) ; 1♂ same data as holotype, 677-0004 ( MSM) ; 3♂ 20 km W. Rankin Springs 33°53.35'S 146°05.34'E, 19.xi.2010, Popple & Emery (DE); 2♂ same data as holotype, 677-0002, 677-0003 (LWP).
Etymology. The name (presented in the form of a feminine, Latin adjective) refers to the region of New South Wales in which this species was first discovered: the Riverina.
Head: Postclypeus predominantly shiny black, lateral margins pinkish-brown, with a small brown triangular marking on dorsal side; supra-antennal plates black, anterior edges pinkish-brown; genae black; mandibular plates black, covered by long silvery pubescence; frons black; vertex black with a small brown area extending narrowly along epicranial suture from near median ocellus to near margin of pronotal, covered in sparse silver pubescence; ocelli pale red; compound eyes brown; anteclypeus shiny black; rostrum black, extending beyond posterior margins of mid coxae; antennae dark brown to black.
Thorax: Pronotum black with a broken pale brown central fascia and with diffuse dark reddish-brown colouration near paramedian and lateral fissures; pronotal collar black, with reddish-brown dorso-lateral posterior margins; metanotum black; mesonotum, including submedian and lateral sigilla, extensively black, with narrow reddish-brown to pale browm areas between submedian and lateral sigilla extending on to arms and lateral sides of cruciform elevation and posterior half of wing grooves; posterior third of mesonotum with dense fine and sparse long silver pubescence.
Wings: Fore wings hyaline; basal cells orange to pale orange-brown, becoming greyish distally; pterostigmata dark reddish-brown; veins, black, with some pale brown within the interior costal veins and clavical folds. Hind wing plagas white at base, grading to dark grey-brown along basal two thirds, this colour extending broadly along jugal folds and terminating before apices, hyaline over remainder; veins dark brown.
Legs: Fore coxae black, outer edges brown, apices pale brown to pinkish-brown; mid and hind coxae black, apices pale brown; meracantha spikes dark brown to black, becoming pale brown apically, overlapping opercula; fore femora black with pale brown longitudinal areas on outer anterior sides, apices pale brown, joints pinkishbrown; mid femora black, apices pale brown, joints pinkish-brown; hind femora dark brown to black, apices and joints pale brown; fore tibiae black; mid and hind tibiae dark brown, each with two pale brown bands, one above base, other towards apex; fore and mid tarsi dark brown; hind tarsi brown; pretarsi brown with dark brown apical areas; claws dark brown.
Opercula ( Fig. 1M View FIGURE 1 ): Broadly rounded; dull black over basal half, dull brown over remainder; plates slightly undulating, medial areas weakly depressed.
Timbals ( Fig. 21E View FIGURE 21 ): Anterior rib 5 abbreviated; rib 4 also abbreviated, with isolated, oval-shaped remnant extension ventrally; ribs 1 and 2 joined ventrally and fused dorsally to basal spur; anterior termination of basal spur fused with ribs 3–4, with rib 5 unattached; prominent intercalary short ribs in medial areas between ribs 1 and 2, 2 and 3, and 3 and 4 (three in total).
Abdomen: Tergite 1 black; tergite 2 wider along dorsal midline than tergites 3 to 7; tergites 2 to 7 black, all with dense short silver pubescence on dorso-lateral sides and with extensive long and short silver pubescence on lateral sides; tergite 8 black, covered in short silver pubescence; intersegmental membranes pale brown; epipleurites black, with sparse silver pubescence; sternite II black laterally, brown ventro-laterally, with a dark brown area medially, which broadens posteriorly; sternites III to V reddish-brown laterally, with dark brown to black areas medially, which broaden posteriorly, gradually increasing in size distally in each successive sternite; sternites VI and VII black with diffuse pale brown areas at extreme anterio-lateral margins; sternite VIII dark reddish-brown to black; anterior sternites visible in lateral view.
Genitalia ( Figs 22I, J View FIGURE 22 ): Pygofer black dorsally, dark reddish-brown laterally; upper lobes in ventral view slightly undulating, with terminals directed inwards and tapering broadly; basal lobes in ventral view relatively linear, flat, in lateral view small, rounded and bulbous; median lobe of uncus rounded, exhibiting limited protrusion; claspers in ventral view conspicuous, diverging from point of downward deflection, with relatively narrow apices; pseudoparameres projecting further (ventrally) than endotheca and ventral support; ventral support acute, projecting slightly beyond endotheca; endotheca partially sclerotised.
Measurements. N= 8♂. Ranges and means (in parentheses), mm; BL: ♂ 15.1–16.5 (15.76). FWL: ♂ 18.0– 19.2 (18.68). HW: ♂ 4.7–5.3 (5.03). PW: ♂ 4.7–5.7 (5.23). AW: ♂ 4.7–5.5 (5.19). FWL/W: ♂ 2.60–2.88 (2.76).
Morphological distinguishing features. Males of Myopsalta riverina n. sp. can be distinguished from M. atrata , M. binotata , M. coolahensis , M. gordoni n. sp., M. lactea , M. libritor , M. waterhousei and M. xerograsidia n. sp. by the colour of the basal membranes of the fore wings, which is pale brown or pale orange rather than white to pale grey. They can be distinguished from M. melanobasis n. sp. and M. platyptera n. sp. by the appearance of the fore wing clavus, which is entirely hyaline and not opaque at the base. They can be separated from M. albiventris n. sp. and M. wollomombii by the colouration of the sternites, which is predominantly dark brown (cf. almost entirely pale brown). They can be differentiated from M. umbra n. sp. by the colour of the costal veins, which is dark brown rather than reddish-brown. They can be distinguished from M. crucifera n. sp., M. leona n. sp., M. mackinlayi n. sp., M. parvula n. sp. and M. septa n. sp. by having a head width> 4.6 mm. They can be distinguished from M. chrysopedia n. sp. by having a fore wing length/width ratio of <2.9 and from M. longicauda n. sp. by having tergites that are entirely black (not partly brown). They can be separated from M. bassiana n. sp. and M. majurae n. sp. by the colouration of the opercula, which is predominantly brown rather than dark brown to black.
Distribution, habitat and behaviour ( Fig. 28 View FIGURE 28 ). Myopsalta riverina is known only from the original specimens collected by the author and David Emery from 33 km SSW. of Rankins Springs (east of Goolgowi) in southern inland New South Wales. Adults have been found in roadside Mallee ( Eucalyptus socialis and E. dumosa ) on weathered red soils, during mid November. Males sing sporadically during warm, sunny conditions. Like many cicadas that inhabit mallee woodland, they call infrequently on hot days.
Calling song ( Fig. 29 View FIGURE 29 ). To the ear, the song of M. riverina appears to contain monotonously repeated long echemes, each increasing slightly in amplitude throughout and each separated by short sequences of macrosyllables. Detailed examination of three available recordings reveals that the echemes are organised collectively into phrases of quite variable duration. Indeed each phrase contains 2 to 60 (or more) echemes (1.0– 1.5 s duration), each separated by gaps (0.17– 0.38 s duration). The gaps are typically not silent, instead containing 3–7 macrosyllables (0.02– 0.06 s duration, 2–4 syllables, with the syllables themselves not coalesced). The end of the phrase is signified by a short gap of approximately 0.04 s duration followed by a long macrosyllable (0.07– 0.09 s duration) and a longer gap (0.10– 0.12 s duration) (all statistics, n= 17 recordings). Following the stereotypical structure of male-female communication in this group, it is anticipated that the female would respond with a wingflick during the long gap at the end of each phrase.
This species has been observed calling during the day and it is not known whether it also sings at dusk. The calling song maintains an even frequency distribution throughout, with a high amplitude plateau of 12.2–18.5 kHz and a dominant frequency of 14.2–14.7 kHz.
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