Ewartia etesia, Popple, Lindsay W., 2017

Popple, Lindsay W., 2017, A revision of the Ewartia oldfieldi (Distant) species complex (Hemiptera: Cicadidae: Cicadettinae) with five new species from eastern and northern Australia, Zootaxa 4263 (3), pp. 401-449 : 432-438

Ewartia etesia n. sp.

(Plates 2A, 2B; Figs 2 D, 8D, 24A, 25–28, 29A, 29B)

Types. Holotype: ♂ ‘ Australia NT’ / ‘AU.NT.MTE 76 km E of Mataranka’ / ‘ 14°54.888’S 133°42.780’E’ / ‘ 77m 3 Feb. 2006 ’ / ‘ Hill, Marshall, Moulds’ ( NTM) ; Paratypes: NORTHERN TERRITORY: 1♀ same data as holotype ( NTM) ; 2♂ 14.19S 132.25E, N.T.: Katherine Gorge , 24km NE. of Katherine, 16.x.1972, Upton & Barrett (both ANIC) ; 2♂ Litchfield Caravan Park , 13°07.35’S ; 130°39.16’E, 26.xi.08, D. Emery & L. Popple; 1♂ Fogg Dam Rd , 28.xi.08, D. Emery & L. Popple (all DE) ; 2♂ 1.5 km S. of Fogg Dam , 28.xi.2008, Acacia sp., L. Popple, D. Emery, 12°35.324’S 131°18.679’S, 226-0001 to 226-0002 ; 3♂ Australia NT, Wangi Tourist Park , 25–26.xi.2008, L. Popple, D. Emery, 13°07.577’S 130°39.312’E, 226-0003 to 226-0005 (all LWP) ; 1♂ NTR.KWW 30km W. of Katherine, N.T., 163m. 14°40.8S 132°05.1’E, 24.i.2004, Cooley, Hill, Marshall, Moulds; 1♂ same data as previous, VOUCHER, 04.NTR.KWW.10, T. “northern oldfieldi ” ; 1♀ Australia: NT, AU.NT. NOU, Jct. road to Nourlangie Rock & Kakadu Hwy, Kakadu N.P., 12°48.482’S 132°44.802’E, 20.ii.2008, Hill, Marshall, Moulds, Owen & Humphrey ; 1♂ same data as previous, C. SIMON LAB VOUCHER, legs in ETOH, body pinned, 08.AU.NT . NOU.04, “ oldfieldi complex”, specimen recorded; 17♂ same data as holotype ; 1♂ same data as holotype, C. Simon, LAB VOUCHER, 06.AU.NT.MTE.05, oldfieldi “high-bush” ; 1♂ same data as holotype, 06.AU.NT.MTE.06 ; 1♂ NTR.KWW, 30km W. of Katherine, N.T., 163m, 14°40.8’S 132°05’E, 24.i.2004, Cooley, Hill, Marshall, Moulds; 1♂ Merl camping area, Kakadu Nat. Park, N.T., 12°25’S 132°57’E, 21.i.1993, 40 m, G. and A. Daniels ; 1♂ 1♀ Mataranka , Elsey Park, 9.xii.1993, riverine forest, uv [light], S. & J. Peck, 93-115 ; 1♂ Maningrida , 4.i.1976, J. Grigg (all MSM) ; 1♂ 1♀ same data as holotype (both QM); WESTERN AUSTRALIA : 1♂ Zebidee Springs , El Questro Stn., E. Kimberley, W.A., 28.xii.1991, M.S. & B.J. Moulds ( MSM).

Etymology. The Latin word etesia meaning “monsoon”, referring to the species occurrence in the center of the monsoon tropics.

PLATE 2. A: Ewartia etesia n. sp. holotype male; B: E. etesia n. sp. female; C: E. thamna n. sp. holotype male; D: E. thamna n. sp. female; E: E. carina n. sp. holotype male. It should be noted that the fore wings of each of these species have similar proportions, despite some appearing broader than others in these images. For instance, the fore wings in C and D appear misleadingly broad as a result of these specimens having slightly drooped fore wings. Scale bars = 5 mm.

Description. Male (Plate 2A, Figs 2 D, 8D, 24A).

Head (including eyes) wider than mesonotum; ventral surface mainly pale yellow-brown; postclypeus and anteclypeus green to pale brown; rostrum pale brown anteriorly, becoming contrastingly dark brown towards apex; dorsal surface olive-brown to brown with a subtle, though broad ochraceous to dark brown band extending between the eyes; vertex and area immediately anterior of median ocellus tending dark brown; supra-antennal plate olivebrown; ocelli pink; with scattered silver pubescence throughout and long silver pubescence behind eyes. Eyes reddish-brown in living specimens, often faded to brown in preserved specimens. Antennae dark brown, paler towards apex.

Thorax with scattered silver short pubescence. Pronotum brown to olive-brown; an ochraceous to reddishbrown midline extending from back of head, with anterior margin as broad as distance between inner margins of lateral ocelli, this midline narrowing medially, then broadening conspicuously towards the posterior until reaching margin of pronotal collar; pronotal collar green to brown, reddish-brown medially. Mesonotum green to pale brown; midline broad, reddish-brown, abruptly paler on lateral margins; submedian sigilla brown to dark ochraceous, often inconspicuous relative to midline; lateral sigilla brown to olive-brown, sometimes indistinct; cruciform elevation reddish-brown to dark brown; wing grooves and metanotum pale olive-brown to orangebrown, with silver long pubescence.

Legs with coxae and femora pale green or pale yellow-brown; tibiae pale green to pale brown; tarsi pale brown becoming darker towards apex of claws.

Wings with fore wing costal veins green to pale yellow-brown; pterostigma pale brown to reddish-brown; basal membranes orange; veins CuA, CuP and M green to pale brown; other veins brown; veins CuA and M fused posterior to apex of basal cell; with eight apical cells. Hind wing veins pale brown or pale green, becoming darker on the posterior side of the apical cells; plaga surrounded by pale brown coloration anteriorly, otherwise transparent; with six apical cells.

Opercula broadly rounded, green to orange-brown, with plates relatively flat.

Timbals with five long ribs; short (intercalary) ribs present between each long rib. Long ribs 1–3 attached to basal spur. Long rib 5 comparatively shorter. All ribs sclerotised, pale brown and of low contrast against timbal membrane.

Abdomen. Tergites mainly dull olive-green, often pale brown anteriorly; darker midline> 1 mm wide, appearing wider than midline on thorax, though diffuse at lateral edges, reddish-brown to ochraceous, yellowbrown dorsolaterally. Sternites olive green to pale brown, depending on state of preservation of the specimen.

Genitalia. Pygofer, including dorsal beak, olive-green to brown; upper lobes prominent, with apices graduating to a broad point; basal lobes present and bulbous, with apices broadly rounded. Uncus pale brown, in lateral view extended with apex rounded; lobes in ventral view small, medial lobe small, ovoid; claspers prominent with posterior section dark and outwardly curved, with apices broadly rounded ventrally and blunt laterally. Aedeagus with pseudoparameres extending well beyond theca; endotheca fleshy; ventral support not extending to the same extent as endotheca.

Female (Plate 2B).

Markings and coloration identical to male. Abdominal segment 9 olive-green to brown, with a prominent midline, reddish-brown to ochraceous medially, yellow-brown on lateral margins; ovipositor sheath extends approximately 3 mm beyond termination of this segment.

Measurements. N= 10♂ 7♀. Means and ranges (in parentheses), mm; BL: ♂ 14.39 (10.2–16.9), ♀ 21.47 (20.0–23.5); FWL: ♂ 20.17 (18.3–21.5), ♀ 22.11 (21.0–23.7); FWW: ♂ 6.4 (5.8–7.3), ♀ 6.8 (6.2–7.4); HW: ♂ 5.47 (5.2–5.8), ♀ 5.69 (5.4–6.5); PW: ♂ 4.83 (4.5–5.3), ♀ 5.17 (4.8–5.7); AW: ♂ 5.18 (4.7–5.7), ♀ 4.86 (4.4–5.3).

Distinguishing features. Ewartia etesia n. sp. has a conspicuous, brown stripe medially along the dorsum, which extends from the proximal edge of the pronotum posteriorly to the apex of the abdomen. This feature distinguishes it readily from E. brevis , E. carina n. sp. and E. cuensis , although a similar stripe is present in E. lapidosa n. sp., E. oldfieldi , E. roberti n. sp. and E. thamna n. sp. (see Fig. 2 ). Notably, however, in E. thamna n. sp., the stripe is present only along the posterior half of the mesonotum and is effectively absent from the pronotum. In most cases, males of E. etesia n. sp. can be distinguished from the superficially similar E. oldfieldi , E. roberti n. sp. and E. lapidosa n. sp. by their narrow head widths (ź 5.8 mm), although there are exceptions in E. roberti n. sp. and E. lapidosa n. sp. with head widths as narrow as 5.3 mm, which overlap with E. etesia n. sp. In these cases, it is helpful to note the non-overlapping geographical distributions of the these species ( E. oldfieldi , E. roberti n. sp. and E. lapidosa n. sp. in eastern Australia and E. etesia n. sp. restricted to the Top End of the Northern Territory). In addition, the female ovipositor of E. etesia n. sp. is conspicuously longer than any other species in the genus, extending approximately 3 mm beyond the apex of abdominal segment 9 (c.f. <2.0– 2.5 mm in E. oldfieldi and <1 mm in all other species).

Distribution and habitat. Ewartia etesia n. sp. is restricted to the Top End of the Northern Territory, with the exception of a single record from El Questro Station, in the Kimberley region of north-east Western Australia. In the Top End it has been found from Litchfield National Park east to Maningrida and south to the Mataranka district ( Fig. 25 ). Populations occur in association with wattles, including Acacia lamprocarpa and A. latescens . Adults have been collected between October and February.

Calling song. The complex calling song mode of E. etesia n. sp. ( Figs 26 , 27 ) contains repeated, short subphrases (0.45– 0.67 s duration; all statistics n = 16). Each subphrase is composed of a brief syllable sequence (0.360– 0.460 s duration) in which the gaps between syllables (initially 0.034– 0.061 s duration) sequentially reduce until the syllables (each 9–12 ms duration) coalesce into a macrosyllable (4–9 syllables, 0.038– 0.093 s duration) or an echeme (0.101– 0.161 s duration). The placement of the accentuation in this species is subtle. It occurs at the end of some subphrases after the macrosyllable or echeme in the form of a series of 1–3 discrete syllables, each followed by a gap (0.061– 0.083 s duration) (e.g. Fig. 27 ). This calling song mode is typically produced at intervals throughout the day.

The transition between calling song modes in this species may be unusually protracted, whereby the complex calling song suddenly becomes disjointed. This is due to the following: (1) the syllable sequence preceding each echeme is truncated into 1–3 syllables, (2) the macrosyllables stop being produced, and (3) a series of 3–4 discrete syllables (some of these may be double syllables) produced following each echeme. The song then undergoes further reduction of syllables surrounding the echeme and morphs into the simple calling song. In some cases, this transition may be so gradual that it is hard to detect definitively. Once fully formed, however, the simple calling song mode of this species is, nevertheless, quite distinct from the complex mode. The simple mode ( Fig. 28 ) contains monotonously repeated phrases (0.54– 0.62 s duration). Each phrase is composed of 1–3 syllables (each 0.009– 0.012 s duration), each separated by gaps of successively reducing duration (each 0.005– 0.024 s), which is then followed by an echeme (0.143– 0.261 s duration). Sometimes the echeme is followed by a gap (0.014– 0.081 s duration) and then another 1–4 syllables and /or macrosyllables (each 0.009– 0.030 s duration; intervening gaps 0.007– 0.085 s duration). A final gap (0.116– 0.296 s duration) completes the phrase. This calling song mode predominates at dusk and is also occasionally produced during the day.

As per other species in the Ewartia oldfieldi species complex, in E. etesia n. sp. the calling song frequency spectra do not change between song modes. In each mode the calling song typically has a highest amplitude frequency plateau between 10.0 and 15.7 kHz, with a dominant frequency between 11.8 and 13.6 kHz (mean=12.6, n=13; Figs 29 A, 29B).

Figures

FIGURE 2. Digital illustrations comparing head and thorax morphology between different species in the Ewartia oldfieldi (Distant) species complex, including A: E. oldfieldi, B: E. roberti n. sp., C: E. lapidosa n. sp., D: E etesia n. sp., E: E. thamna n. sp., and F: E. carina n. sp.

FIGURE 25. Map of northern Australia showing the known geographical distribution of Ewartia etesia n. sp., E. thamna n. sp. and E. carina n. sp. Larger symbols represent specimen records and smaller symbols are song recording or aural records.

FIGURE 26. Wave plots illustrating the complex calling song mode of Ewartia etesia n. sp. presented in expanded detail and labelled with relevant acoustic terminology. A: five complete subphrases. B: expanded diagram of the final subphrase showing syllable, climatic echeme and accentuation components. C: detailed composition of a single syllable and the accentuation component, which in this case contains two discrete syllables followed by a long gap. The recording was obtained from Wangi Tourist Park (13 ° 08 ’ S 130 ° 39 ’ E) using RS 3 (see Methods).

FIGURE 27. Wave plots illustrating the structure of a single subphrase of the complex mode of the male calling song of Ewartia etesia n. sp. from four different localities, including A: Wangi Tourist Park (13 ° 08 ’ S 130 ° 39 ’ E), B: Townsend Bridge (12 ° 58 ' S 130 ° 46 ' E), C: 76 km E. of Mataranka (14 ° 55 ' S 133 ° 43 ' E) and D: Junction of Kakadu Highway and Nourlangie Rock Road (12 ° 48 ' S 132 ° 45 ' E). Recordings were obtained using RS 3 (A) and RS 5 (B – D) (see Methods).

FIGURE 28. Wave plots illustrating the structure of the simple mode of the male calling song of Ewartia etesia n. sp. from four different localities, including A: Wangi Tourist Park (13 ° 08 ’ S 130 ° 39 ’ E), B: Townsend Bridge (12 ° 58 ' S 130 ° 46 ' E), C: 76 km E. of Mataranka (14 ° 55 ' S 133 ° 43 ' E) and D: Junction of Kakadu Highway and Nourlangie Rock Road (12 ° 48 ' S 132 ° 45 ' E). Each plot includes two phrases, which vary slightly in composition between the different recordings. The recording from Townsend Bridge was made during the day. Each of the other recordings was made at dusk, with the exception of the Wangi Tourist Park recording, which was made at dawn. Recordings were obtained using RS 3 (A) and RS 5 (B – D) (see Methods).

FIGURE 29. Frequency spectra comparisons between taxa in the Ewartia oldfieldi (Distant) species complex, including A: Ewartia etesia n. sp. (from Wangi Tourist Park: 13 ° 08 ’ S 130 ° 39 ’ E), B: E. etesia n. sp. (from 76 km E. of Mataranka: 14 ° 55 ' S 133 ° 43 ' E), C: E. thamna n. sp. (from 76 km E. of Mataranka: 14 ° 55 ' S 133 ° 43 ' E) and D: E. carina n. sp. (from McIlwraith Range: 13 ° 43 ’ S, 143 ° 19 ’ E). The horizontal bars show the ranges of each highest amplitude frequency plateau (bounded by the 90 th percentile of each amplitude spectrum). Recordings were obtained using RS 3 (A) and RS 5 (B – D) (see Methods).