Heremusina pipatio, 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 : 22-26

Heremusina pipatio n. sp.

Figs. 2B – 7B , 8 , 16 , 17 , 30 , Pl. 2.

Types. Holotype. QUEENSLAND. Male, T 242499, 14.6 km N. along Normanton Rd. jct with Mt. Isa Hwy , NW Cloncurry, N.W.Q., grassland, A.E., 21.i.2008, 30°34.75'S 140°26.50'E (QM);

Paratypes. QUEENSLAND. 1♀, 14.6 km N. along Normanton Rd. jct with Mt. Isa Hwy , NW Cloncurry, N.W.Q., grassland, A.E., 21.i.2008, 30°34.75'S 140°26.50'E (QM) . 3♂, 3♀, 14.6 km N. along Normanton Rd. jct with Mt. Isa Hwy , NW Cloncurry, N.W.Q., grassland, A.E., 21.i.2008, 30°34.75'S 140°26.50'E ; 10♂, 2♀, location as previously, 22.ii.2008 (AE). 1♂, Mount Elliott Mine, 140 km SE of Mt. Isa, Qld., 16.ii.1995, T. Woodger ( MSM). 1♀, 14.6 km N. along Normanton Rd. jct with Mt. Isa Hwy, NW Cloncurry, N.W.Q., grassland, A.E., 21.i.2008, 30°34.75'S 140°26.50'E ; 1♂, 14.6 km N. along Normanton Rd. jct with Mt. Isa Hwy , NW Cloncurry, N.W.Q., grassland, A.E., 22.i.2008, 30°34.75'S 140°26.50'E ( ANIC) . 1♂, 14.6 km N. along Normanton Rd. jct with Mt. Isa Hwy , NW Cloncurry, N.W.Q., grassland, A.E., 21.i.2008, 30°34.75'S 140°26.50'E ( BMNH).

Distribution ( Fig. 8 ): Known only from two locations, one 15 km NNW of Cloncurry, the second approximately 100 km S. of Cloncurry at the Mount Elliott mine, both locations within the Selwyn Ranges. This region is broadly located on the slightly elevated divide between the northward flowing river systems feeding into the Gulf of Carpentaria, and the southwestern flowing rivers feeding into the Lake Eyre Basin ( Fig. 30 ).

Description. MALE (Pl. 2A). Head: Supra-antennal plate black with yellow-brown along anterior margins; postclypeus black medially, pale brown to yellow-brown around margins, these extending partially along transverse grooves; a very narrow medial vertical pale yellow-brown fascia extending dorsally from mid region; the medial postclypeus black area extends to dorsal surface as two broad bands, enclosed centrally and laterally by narrow pale yellow-brown margins; gena pale yellow-brown, with pale yellow pubescence; mandibular plate black, also with pale yellow-brown pubescence; vertex and frons predominantly black, the frons with a small anterior pale brown area adjacent to mid ocellus, the vertex with an irregular posterior pale yellow-brown margin adjacent to anterior pronotal margin, plus a small triangular pale yellow fascia along the epicranial suture extending and widening distally from mid ocellus; ocelli dark red; compound eyes dark brown; anteclypeus pale yellow-brown, medially brown; rostrum yellow-brown on mentum, remainder dark brown; antennae deep brown; pedicels brown.

Thorax: Pronotum predominantly sandy-brown including anterior margin, with a narrow yellow central fascia, slightly irregular in shape, enclosed by an irregular dark brown envelope along lateral and distal margin; broken brown to dark brown irregular thin markings occur adjacent to paramedial and lateral fissures, also along anterior margin of pronotal collar and the ventro-lateral thorax margins; pronotal collar dominantly sandy brown; metanotum sandy brown. Mesonotum with broad black submedial and lateral sigilla, the latter with irregular and broken outlines; the submedial sigilla fused medially, the fused distal margin abruptly narrows distally, then widens, so that the two outer corners coalesce into the scutal depressions; the remaining central area expands distally thereby filling much of the area between the anterior cruciform elevation arms; the colour of this complex medial patterning changes gradually from black anteriorly to brown at the cruciform elevation; remaining colour of mesonotum between submedial and lateral sigilla is pale sandy brown, this also including the cruciform elevation; wing grooves mostly pale sandy brown, dark brown in the inner parts of grooves.

Wings: Forewing: pterostigma slightly opaque, off-white colour; basal membrane pale orange-brown; costa predominantly pale sandy colour; remaining venation colouration pale sandy, becoming darker distally. Hind wing venation pale to medium brown; no infuscation; narrow development of opacity adjacent to 2A and 3A veins, more extensively developed in plaga.

Legs: Fore coxae medium brown, dark brown lensoid fasciae developed on anterior faces; mid and hind coxae pale sandy brown with dark brown fasciae on anterior faces; trochanters and femora predominantly pale brown with weak darker brown fasciae; fore femora with black erect spines; tibiae pale brown, tarsi and claws darker brown; meracantha poorly developed.

Opercula: Broadly rounded, slightly expanded distally; basal plate prominantly rounded and raised, with a gentle ridge extending from the basal plate to lateral rim; colouration pale straw yellow across whole of opercula.

Timbals: Similar to diagnosis, except that rib 4 does not extend continuously across timbal, being divided medially, the two halves nevertheless maintaining their alignment; some small variation is present between specimens in the extent of rib 5; intercalary ribs very thin, not easily seen, and apparently absent between long ribs 4 and 5. Long ribs relatively weakly sclerotised.

Abdomen and pygofer: Tergite 1 shiny black, pale brown around margins; tergite 2 predominantly black, this extending ventrally to auditory capsule, with medium to dark brown colouration along posterior tergite margin, also weakly paramedially; tergite 3 with black area on dorsal midline, extending to, but not over intersegmental membrane, also extending and thinning laterally along anterior margin; remaining colouration pale brown to yellow-brown, including intersegmental membrane; tergites 4 to 8 with dorsal black patches which become progressively smaller towards tergite 8; remaining colouration predominantly pale to medium straw-brown, more clearly developed on intersegmental membranes. Sternites pale straw yellow-brown; black ring-like area medially on sternite II, extending to anterior segment of sternite III. Pygofer medium to dark brown dorsally, pale yellowbrown laterally. Essential genital structures as in generic diagnosis.

FEMALE (Pl. 2B). Head: Similar to male. Supra-antennal plate black on inner margins, otherwise pale yellow-brown, including anterior margins. Postclypeus medially black on transverse ridges, pale yellow-brown elsewhere except for narrow brown medial vertical suture and a similar broader area dorsally on the suture; the black pigmentation only extends slightly between the transverse ridges; dorsal surface of postclypeus with a pair of black globular markings which extend to frons and are enclosed by pale yellow-brown margins abutting the vertex; vertex mostly shiny black except for triangular shaped yellow-brown area on epicranial suture and small irregular yellow-brown spots adjacent to inner and posterior margins of compound eyes; ocelli red; compound eyes brown; posterior margin of vertex yellow-brown; gena pale yellow-brown with pale yellow conspicuous pubescence; mandibular plate dominantly black with scattered short yellowish pubescence; anteclypeus black, the labrum and mentum pale yellow-brown, changing to deep brown on labium; antennae dark brown, paler on pedicels.

Thorax: Pronotum dominantly pale to medium brown with conspicuous pale yellow-green central fascia, this enclosed by a deep brown to black narrow envelope which widens along anterior pronotal margin and partially also along posterior margin; remaining posterior segment of the medial fascia replaced by pale yellow-green colour, this part of the fascia spreading widely along posterior pronotal margin to midway towards the lateral angles of pronotal collar; pronotal lateral fissures marked by narrow deep brown to black colouration, the anterior segment of paramedian fissure similarly coloured, but this deviates midway along the fissure forming a fascia between the two fissures; pronotal collar pale straw-yellow dorsally, deep brown laterally; anterior pronotal margin pale yellowbrown. Mesonotum with black submedial sigilla, fused medially, narrowing then widening and splitting distally, extending to scutal depressions, and as thin double fasciae to anterior area of cruciform elevation; lateral sigilla black, but fragmented in appearance, also with irregular outlines; these extend distally almost to anterior cruciform elevation arms; remaining mesonotum pale straw-yellow; cruciform elevation mostly pale yellow-brown, becoming brown medially and anteriorly, wing grooves sandy brown with two dark brown areas along each of the inner grooves. Metanotum visible dorsally, pale straw colour.

Wings: As in male, the basal membrane being orange.

Legs: Coxae pale yellow to yellow-brown with dark brown longitudinal fasciae developed especially on anterior faces, stronger on mid and hind coxae; trochanters and femora predominantly pale sandy brown with darker brown longitudinal fasciae; fore femora with erect black spines; tibiae and tarsi yellow-brown, dark brown distally; claws medium to dark brown.

Abdomen: Tergite 1 medium brown with narrow pale yellow-brown anterior margin. Tergites 2 to 8 predominantly pale yellow-brown, becoming paler along ventral margins, but each with a very pale brown triangular shaped marking located towards each of the tergite ventral margins. Tergites 2 to 8 each has a conspicuous black area of dorsal black pigmentation extending along the dorsal midline, each also extending submedially; these black pigmented areas are widest dorsally and do not cross the intersegmental membranes, each thinning submedially, each thinning more rapidly towards tergite 8, the marking on tergite 8 being small and slightly paler; tergite 9 pale yellowish with a pair of thin deep brown to black prominent submedial fasciae extending along tergite to each stigma, each then becoming paler and sharply bending inwards towards dorsal midline, but although not joined, each moves closer to the dorsal midline forming a distinct V-shaped fascia, the fasciae joining at the dorsal beak. Ovipositor sheath dark brown. Sternites uniformly yellowish, same as colour of ventral segments of the tergites. Ovipositor sheath extends 1.0– 1.3 mm beyond termination of final sternite.

Measurements. N= 12♂ 6♀. Ranges and means (in parentheses), mm; BL: ♂ 10.1–12.0 (11.1); ♀ 11.2–12.4 (11.5). FWL: ♂ 11.1–13.0 (12.1); ♀ 11.5–13.3 (12.7). HW: ♂ 2.9–3.3 (3.2); ♀ 3.0–3.5 (3.3). PW: ♂ 2.6–3.1 (2.9); ♀ 2.7–3.1 (3.0). AW: ♂ 3.9–4.8 (4.5); ♀ 3.7–4.1 (3.8). FWL/WR: ♂ 2.34–2.57 (2.46); ♀ 2.44–2.57 (2.51).

Etymology: A Latin based word referring to chirping, a song characteristic of this species.

Distinguishing Characters. H. udeoecetes n. sp. and H. pipatio n. sp. are very similar in size and shape, but differ slightly in colouration. Useful features include the greenish tergite colouration on H. udeoecetes n. sp., more extensive black tergite pigmentation in H. pipatio n. sp., the medial discontinuity of timbal rib 4 in H. pipatio n. sp., and the following differences in genital structures, best seen in lateral view ( Figs. 6A, B ), namely the longer dorsal beak and resulting wider separation between the dorsal beak and upper pygofer lobes in H. udeoecetes n. sp. specimens, together with the somewhat longer pygofer, the smaller medium lobe of uncus, the longer basal lobe, and the more pointed (rather than hooked) clasper termination in H. udeoecetes n. sp. (also seen well in dorsal view). The ratio of the length of the fore wing radial cell to length between distal end of radial cell to wing tip is slightly smaller in H. udeoecetes n. sp. (0.78 compared to 0.85 in H. pipatio n. sp.). Although these differences are relatively small, the distributions of these two species are widely different ( Fig. 8 ), and as shown below, the calling songs clearly differ.

Figures

FIGURE 6. Pygofer and male genitalia, lateral views, respectively, of the five new species described in this paper; (A), (B), Heremusina udeoecetes n. sp. and H. pipatio n. sp.; (C) to (E), Xeropsalta thomsoni n. sp. (see also Pl.4), X.aridula n. sp., X. rattrayi n. sp. Pygofer lengths are, respectively, 1.60, 1.70, 1.86, 1.91, and 1.9 mm.

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 16. Heremusina pipatio n. sp. song, field recording from ~15 km N. of Cloncurry, N.W. Queensland. Fig. 16A is a waveform overview showing the structure of the echemes which comprise sets of closely spaced single pulse emissions, without any isolated single pulses at the start of each echeme (except at the beginning of anew songsequence, as shown in this segment). Each echeme is followed with an isolated single pulse. The echeme durations (52–63 ms) are clearly shorter than those of H. udeoecetes n. sp., and the resulting echeme repetition rates therefore higher (9.2–10.7 Hz). Pulse repetition rates withinthe echemes range between 180–225 (mean207) Hz.Fig.16B, C, time expanded waveform plot of a single echeme, and the following isolated pulse, showing the pulses to be single pulses, presumably emitted by the alternation of the timbal contractions; Fig. 16C, D, higher resolution, time expanded waveform and envelope plots of three echeme pulses showing the initial high amplitude peaks immediately followed, without a gap, by weaker peaks, inferred as ribs 2–5 emissions. Well developed, isolated secondary peaks (marked as 'S') occur 1.7 ms following the preceding main peaks, these inferred to be secondary, relaxation ('OUT') pulses of the timbals. Filtered to 1 kHz.

FIGURE 17. Comparison of Heremusina pipatio n. sp. songs in relation to; (A) waveform plot showing temporal pulses structures; (B), spectrogram, showing a dominant frequency band between ~10 to 18 kHz, without significant frequency shift during the song; and (C), amplitude spectra showing the clearly developed frequency envelope between 10.7–18 kHz, with the dominant frequency estimated at 14.0 kHz, located at the low amplitude centre of the frequency envelope.Filtered to 1 kHz.

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.

FIGURE7. Pygofer and male genitalia,ventral views, respectively,of the five new species described in thispaper; (A), (B),H. udeoecetes n. sp. and H.pipatio n. sp.; (C) to (E), X. thomsoni n. sp. (see also Pl. 4), X. aridula n. sp., X. rattrayi n. sp. Sizes as in Fig. 6.