Mugadina, Moulds (2012)

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 : 3

Genus MUGADINA Moulds (2012) .

Figs. 1 , 9 to 11.

This genus was recognised and described in detail by Moulds (2012, pp. 149–151), only two species having so far been described. The recognition and descriptions of the five new ' Mugadina -like' species in this work are built on the descriptions and figures prepared by Moulds. Fig. 1 illustrates and compares the main morphological characters of M. marshalli (Distant) , the type species of Mugadina , and M. emma (Goding and Froggatt) . These two species are similar and not easily separated except by song (see below). Subtle differences appear to exist in the genitalia in ventral and lateral views ( Figs. 1C–F ), and in opercula shapes ( Fig. 1I, J ), which may be useful. Infuscation on the forewings is common in M. emma , but is variable, and not always present, while abdomen colour can be useful in Queensland (but not in inland N.S.W.), commonly yellow in M. marshalli , tending yellow-orange in M. emma . Both species are grassland cicadas, inhabiting wide areas in eastern Queensland and N.S.W., mostly west of the Dividing Range ( Moulds 2012; Popple 2014–2017), although far removed from the inland distributions of the new species described below.

Figures

FIGURE 1. Mugadina emma and M. marshalli, comparison of selected morphological characters of both species. (A), (B), lateral views of abdomen. (C), (D), lateral views of male genitalia, both lengths 1.9 mm. (E), (F), ventral views of same genitalia; (G, H), timbals; dorsal to right, and (I), (J) left opercula. Figs. C, D based on specimens from 4 km north of Amby, southern Queensland and Figs. D, F from Lake Broadwater, southeast Queensland. Figs. A, G, I, based on specimens from Boonah, southeastern Queensland and Figs. B,H, J from Drillham, southern Queensland.The scale bars represent 1 mm.

FIGURE 9. Mugadina marshalli song. Waveform (A, B, D) and complimentary envelope (C, E) plots, of the ticking song of M. marshalli, recorded in open net, in grassland near Kaimkillenbun, southeast Queensland (A to C) and Yelarbon, S. Queensland, in situ with parabola in grassland (D, E). Fig. 9A shows an overview plot of the repeated pulses ('ticks'), the pulse repetition rates (PRR) varying between 4.9–5.4 Hz. Figs. 9B, C, are time expanded illustrating details of an individual pulse, showing that when viewed in detail, each actually comprises two dominant (primary) pulses, each followed by a weaker, but clearly separatepulse, the time gaps being 1.9and 2.8ms.These are interpretedas secondary pulses,produced by timbal'OUT' (relaxation) movement. The two initial strong pulses exhibit weaker and almost coalesced pulses, which is suggested to result from the 'firing' of long ribs 2 to 5 (implying that the dominant pulses are produced by the 'IN' movements of timbal 1). The presence of two complete sets of pulses that comprise each 'tick' are inferred to result from a very short but significant delay in the contraction (firing) between the two timbals. Figs.9D, E, represent time expanded plots from another M. marshalli from a separate location, showing the similar arrangement and structures of the pulses, although the gaps between the primary and secondary pulses are significantly longer.Filtered to 1 kHz.