The song is a steady sequence of paired lisps (Fig. 13). At 16 C 16 lisp pairs are repeated in 10 s. The oscilloscope resolves each lisp into a very faint minor pulse train followed by a much longer in tense major pulse train. This PTG remains the same for both lisps of the pair. The complex-wave pulses of the trains tend to run together toward the concluding half of the major pulse train. The spectrum (Fig. 2) has a very tall sharp peak near 11 kHz and a broader higher frequency peak centred on 27 kHz.
It is possible to confuse the song of S. femorata with the two-lisp call of L. hebardi, but S. femorata appears to have a higher song rate for any temperature and there are quality differences e.g. a quavering quality to Lophaspis due to the greater number of pulse trains per lisp; the double lisp of S. femorata thus sounds 'crisper'.[1]
References
- . Song Structure and Description of Some Costa Rican Katydids (Orthoptera: Tettigoniidae). Transactions of the American Entomological Society. 1982;108(1/2):287-314. Available at: http://www.jstor.org/stable/25078301.