Salomona ustulata Redtenbacher, 1891

Morris, Glenn K, Ingrisch, Sigfrid, Willemse, Fer, Willemse, Luc, De Luca, Paul A. & Klimas, Dita, 2025, Stridulation songs of some Tettigoniidae (Ensifera, Orthoptera) from Papua New Guinea, Zootaxa 5600 (1), pp. 1-81 : 46

Salomona ustulata Redtenbacher, 1891

( Figs 45 , 51 , 52 )

Specimens studied: 4 males, 1 female PNG, McAdam Nat. Park , Bulolo Gorge, 28 viii 1981, (G.K. Morris NBC Leiden, MKMM) .

Systematics. The specimens fit fully the diagnosis in Redtenbacher (1891), Karny (1926, as S. lambda ) and especially as given in a synopsis of this large genus by C. Willemse (1957). The reliability of a number of characters could be underlined, among others frons, male cercus, measurements, pattern of coloration. Opportunity is taken here to give some details of the strigin in this species. The left file in ventral view ( Fig. 51 ) straight, fusiform, widest part in distal fourth, length 1.9 mm, in profile sinuate with its most bulging part also in distal 4th; number of teeth about 58, most of them regularly spaced, about 7 teeth per 0.25 mm but distally (towards posterior margin of elytron) more closely set. ‘Mirror’/speculum of both elytra short trapezoid, length 1.4 mm, greatest width 1.8 mm along proximal edge which is close to and parallel to the file: membrane transparent, bordering veins without modifications, no fold. The cell bordering the mirror (the harp) distally, and that anteriorly, widened and transparent. Titillators with outer pair of sclerites as a left and right triangular-shaped sclerotized sheet; inner one medially strongly sclerotized, strongly divergent basally, scarcely divergent apically, the latter with tip simply rounded.

Distribution and habitat. The locality of the series at hand is in between the two already known, Mt. Lamington near Kokoda in the south and Sattelburg, Huon Gulf in the north. Calling at height from trees.

Comments. Type species of the genus Salomona is S. marmorata (Blanchard,1846) by original monotypy.

Stridulation. Readily audible to a human listener, this insect’s song recalls the regularity of a ticking clock and ‘ticker’ was its assigned field name. Silent intervals of several seconds (e.g., 4 s, Fig. 52A ) separated tick bouts, a dozen or so ticks per bout. There is a very stable tick period of about 300 ms ( Fig. 52B ). Forming the substructure of the ticks are trains of scarcely time-separated sinusoid amplitude fluctuations ( Fig. 52C, E ). Time separation of pulses in this species is far less distinct than that seen with Salomona ‘darth’. This appears to be a kind of subresonant stridulation, with teeth engaging at just below the repetition rates needed for sustained resonance. The spectrum, in keeping with the waveform is relatively low Q with a broad peak occupying much of the higher audio and centred near 13 kHz.

Figures

FIGURE 45. Salomona ustulata Redt., 1891: adult female.

FIGURE 51. Salomona ustulata stridulatory file ventral surface left tegmen.

FIGURE 52. S. ustulata acoustic analysis: A) Four calling bouts at coarse time resolution. [dorsal aspect 11.5 cm 20°C, QMC]; song resolved by human ear as a succession of ticks; B) showing 5 such ticks; C) high resolution of one tick showing erratic amplitude envelope and run-on multiple tooth-event waveforms; D) Fourier spectrum has highest intensity audio band 8–16 kHz with lower intensity ultrasonics up to 40kHz; E) at high resolution waves almost suggesting resonance stridulation.