Myopsalta libritor, Emery & Emery & Popple, 2015

Emery, Nathan J., Emery, David L. & Popple, Lindsay W., 2015, Redescription of Myopsalta atrata (Goding and Froggatt) and Description of Two New Species of Myopsalta Moulds (Hemiptera: Cicadidae) from Central Western New South Wales, Records of the Australian Museum 67 (6), pp. 185-199 : 195-199

Myopsalta libritor sp.nov.

Figs. 2C , 9–11

Type material. Holotype: ♂, 5 km E Coolah NSW, 31°47'17"S 149°46'27"E, 521 m, 13.xi.13, N. & D. Emery ( AM K447936 ) . Paratypes: 4♂♂, 5 km E Coolah NSW, 31°47'17"S 149°46'27"E, 521 m, 13.xi.13, N. & D. Emery ; 2♂♂, same location, 14.xi.14, N. & D. Emery ; 1♂, Merriwa , NSW, 32°08'19"S 150°21'00"E, 244 m, 16.i.14, S. Emery & T. Corbin ; 6♂♂, 2♀♀, same location, 14.xi.14, N. & D. Emery (recorded) ; 4♂♂, 1♀, 1 km S. Coolah , NSW, 31°49'44"S 148°43'43"E, 520 m, 14.x.14, N., C. & D. Emery ; 3♂♂, Junction of Golden Highway and Krui River, 32 ° 05'48"S; 150 ° 07'07"E, 14.xi.14, N. & D. Emery (all DE) ; 1♂, 5 km E Coolah NSW, 31°47'17"S 149°46'27"E, 521 m, 13.xi.13, N. & D. Emery ; 1♂, 1♀, Australia NSW, Merriwa , 32°08'19"S 150°21'00"E, 244 m, 14.xi.2014, N.& D. Emery (both LWP) ; 1♀, 5 km E Coolah NSW, 31°47'17"S 149°46'27"E, 521 m, 13.xi.13, N. & D. Emery ( AM K447937 ) .

Etymology. The Latin word libritor (masculine) is presented in its original form as a noun in apposition. It is defined as a hurler, thrower or gunner and is a reference to the machine gun-like sound of the calling song of this cicada.

Description. Male ( Figs 2C , 9 A–B). Head including outer margins of eyes slightly wider than mesonotum; black, with olivaceous triangular marking anterior to ocelli, apex directed anteriorly over postclypeus; ocelli pink to red; postclypeus entirely black; anteclypeus shiny black; rostrum black, with length almost reaching anterior edge of posterior coxae; eyes black; antennae black, supra-antennal plates black.

Thorax mainly black. Pronotum black; pronotal collar shiny black with lateral margins rounded, wider than mesonotum. Mesonotum black; cruciform elevation black; metanotum black.

Legs. Coxae black, thin ochraceous stripe on lateral edge, with black lateral fascia; femora black with two ochraceous longitudinal stripes, femoral spines black, erect; femoral joint ochraceous; fore tibia black; mid tibia ochraceous with thin posterior black stripe, hind tibia ochraceous with proximal black spot, spines on hind tibia pale brown to translucent; fore tarsi black, mid and hind tarsi ochraceous; claws black.

Wings with fore wing costal veins ochraceous, becoming black distally from the node, subcostal vein black; basal membranes translucent; forewings veins M and CuA fused before meeting basal cell, vein 2A+3A black, other veins black at base, becoming ochraceous posteriorly; hind wing plaga white, mottled black centrally, becoming clear posteriorly, white plaga along veins 2A and 3A, anal cell 2 variably mottled black anteriorly, becoming clear posteriorly, with six apical cells.

Opercula prominent, following body axis lateroventrally, broadly sickle-shaped rounded posteriorly, ochraceous, black at base; clearly separated. Meracanthus small, black at base with lateral edges ochraceous to tip, narrow, pointed, not overlapping opercula.

Timbals ( Fig. 2C ) with five distinct long ribs; long ribs 1–3 brown to black dorsally, much paler ventrally and becoming identical in colour to surrounding grey membrane, spanning height of timbal; long rib 4 grey-brown, discontinuous, with an isolated ventral extension; long rib 5 grey brown, comparatively shorter; long ribs 1–3 fused dorsally along basal spur; timbal dome opaque, extending over half width of timbale, grooved diagonally; apodeme pit oval-shaped, grey-black and conspicuous.

Abdomen with tergites 1 to 7 black, tergite 1 shorter than other tergites, tergite 8 black, posterior and lateral areas dark ochraceous. Sternite I black, sternite II black with lateral posterior margin pale brown, sternite III pale brown, with a black spot in each lateral depression, and a prominent black marking on midline, sometimes reducing posteriorly, sternites IV–VII pale brown with a prominent black midline and dark translucent lateral margins; sternites VIII and IX pale brown with white pubescence.

Genitalia ( Fig. 10 ). Pygofer black dorsally, ochraceous laterally, dorsal beak black, anal styles yellow, not extended as far as dorsal beak; upper lobe of pygofer extended almost as far as dorsal beak, with apex rounded at tip; basal lobe not produced, very rounded. Uncus black laterally, medial lobe yellow, in lateral view beak-like and stumpy, in ventral view tapered at lateral termination; claspers with apices gradually tapering laterally to an acute termination. Aedeagus with pseudoparameres extending well beyond theca; endotheca sclerotized, extending beyond ventral support, apex smooth.

Female ( Fig. 9C,D ).

Head including outer margins of eyes slightly wider than mesonotum; black, ochraceous triangular marking anterior to ocelli, apex directed anteriorly over postclypeus, ocelli red; postclypeus entirely black; anteclypeus shiny black; rostrum black, with length almost reaching anterior edge of posterior coxae; eyes black; antennae black, supra-antennal plates black.

Thorax black; pronotal collar black with lateral margins ochraceous, rounded, wider than mesonotum. Mesonotum black; cruciform elevation black, lateral depression ochraceous posteriorly; metanotum black with ochraceous ridges.

Legs with anterior and posterior coxae black, joints black, remainder ochraceous anterior; femora striped black- ochraceous, femoral joint ochraceous; fore tibia black; mid and hind tibiae black; spines on fore and mid legs translucent with black tips; tarsi black; claws black.

Wings with fore wing costal veins ochraceous, becoming black distally from the node, subcostal vein black; basal membranes translucent; forewings veins M and CuA fused before meeting basal cell, vein 2A+3A black, other veins black at base, becoming ochraceous posteriorly; hind wing plaga white along veins 2A and 3A, mottled black centrally, becoming clear posteriorly; with six apical cells.

Abdomen with tergites 1 to 7 black, posterior margins ochraceous, becoming more pronounced laterally, tergite 1 shorter than other tergites, tergite 8 black, posterior and lateral areas ochraceous. Sternite I black; sternite II black with lateral posterior margin pale brown; sternites III–VII pale brown, pale orange on posterior margins, with central black markings decreasing posteriorly to sternite VI; gonocoxite VIII pale brown with white pubescence. Abdominal segment 9 black, pale brown laterally with black stigma; dorsal beak black. Ovipositor ochraceous-brown at base, becoming black at tip, extending 1 mm past body.

Measurements (in mm; range with mean in parentheses: 12 males, 4 females). Body length: male 11.3–12.6 (11.9); female (incl. ovipositor) 13.9–15.0 (14.6). Fore wing length: male 12.3–14.4 (13.4); female 13.9–16.5 (15.2). Forewing width; male 4.9–6.2 (5.4); female 5.7–6.0 (5.9). Head width: male 3.9–4.2 (4.1); female 4.5–4.9 (4.7). Pronotum width: male 3.8–4.2 (4.0); female 4.0–4.5 (4.3). Abdomen width: male 4.3–5.3 (5.0); female 4.4–4.6 (4.5).

Distinguishing features. Myopsalta libritor sp.nov. can be distinguished from M. binotata (Goding & Froggatt) , M. lactea (Distant) and M. waterhousei (Distant) by lacking fore wing infuscations. The predominantly black dorsal coloration of M. libritor distinguishes it from M. crucifera (Ashton) and M. mackinlayi (Distant) , which are mainly brown above. The female specimens of M. libritor sp.nov. do not possess the dominantly orange-brown sternite coloration of M. atrata . Specimens of M. libritor sp.nov. can be distinguished from M. wollomombii and M. coolahensis sp.nov. by the presence of central black markings that are absent on the sternites of the latter two species.

Calling song ( Fig. 11 ). This species has a simple repetitive call that comprises a series of long macrosyllables and culminates in a pair of shorter macrosyllables ( Figure 11 ). Each long macrosyllable is between 57 and 66 milliseconds (ms) in duration (each contains between 10 and 12 syllables; all statistics n = 1 recording). A short period of silence between 50 and 55 ms duration occurs between each long macrosyllable.

Each short macrosyllable is between 25 and 30 ms duration, and comprises between 8 and 10 syllables. A short period of silence between 50 and 55 ms duration occurs between each short macrosyllable.

The single recording indicates a highest amplitude frequency plateau between 10 and 14 kHz, and a dominant frequency of 12.2 kHz ( Fig. 11 ). A secondary small peak between 16 and 18 kHz is also associated with the call of this species.

Distribution, habitat and behaviour. Known from around Coolah and 80 km SE to Merriwa, NSW, close to the Coolaburragundy, Krui and Merriwa rivers ( Fig. 5 ). Cicadas were located around the upper third of roadside plants and grass <1 m, and in adjacent paddocks and parks that were close to perennial watercourses. Cicadas were absent from similar vegetation on local creeks, slopes and hills. Males were most active in direct sunlight and flew <5 m between singing sites. When wind gusts increased above 15 km /h, cicadas ceased singing and moved towards the base of plants. Depending on the season, cicadas emerged in mid-October and could persist until mid-January.

ACKNOWLEDGMENTS. Specimens were collected under Scientific Research permit SL100650 from Environment and Heritage NSW. The authors thank Samantha and Catherine Emery for field work assistance and Bryce Smith for providing additional confirmed audio recordings of M. atrata , and Max Moulds for constructive advice on the manuscript. We are grateful to Chris Manchester and Nicole Fisher (ANIC) for assistance with photography and registration of the M. atrata types and clarification of label data.

Figures

Figure 2. Photos of male left timbals, with dorsal edge at left and posterior margin at bottom: (A) Myopsalta atrata (Goding & Froggatt), Royal National Park (34°06'59"S 151°03'30"E); (B) Myopsalta coolahensis sp.nov., Coolah (31°56'25"S 149°52'18"E); (C) Myopsalta libritor sp.nov., Merriwa (32°08'19"S 150°21'00"E). Scale bars = 200 µm.

Figure 5. Map of eastern Australia showing the geographical distribution of M. atrata (closed circles), M. coolahensis sp.nov. (open squares) and M. libritor sp.nov. (closed triangles).

Figure 9. Myopsalta libritor sp.nov. (A) male, Coolah (31°47'17"S 149°46'27"E), dorsal habitus; (B) male, Coolah, ventral habitus; (C) female, Merriwa (32°08'19"S 150°21'00"E), dorsal habitus; (D) female, Merriwa, ventral habitus. Scale bars = 2 mm.

Figure 10. Myopsalta libritor sp.nov.—illustration of male pygoferand internal genitalia;(A) viewed laterally from the left;(B) viewed ventrally;(C) aedeagus, lateral view; and (D) aedeagus, rotated 30° left from central view C. See caption to Fig. 3 for abbreviations.

Figure 11. Male calling song structure of Myopsalta libritor sp.nov., illustrated in waveform plot form. Each lower plot is expanded from the one above, to illustrate the finer temporal structure of each song comparison. The spectrogram at the bottom of the figure displays song frequency. The specimen was recorded in grass by NJE at Merriwa (32°08'19"S 150°21'00"E) at 09h00 on 14 November 2014.