Neduba macneilli

N. sierranus has a bimodal (two-part) song. A specimen recorded in the field at 16°C repeated its song at a rate of about song per second. The human ear resolves the song as a few brief stuttering ticks, leading without pause into a buzz (Fig 2A). The buzz is a single pulse train (Fig 2B). A specimen with 170 file teeth produced 107 pulses ine ach buzz pulse train )averaged over 10 consecutive songs). The tick mode consists of a PTG repeated (usually) 3 or 4 times as the song is initiated. Each group is comprsed of a low-rate pulse train preceding a sharp-fronted, more intense, high-rate pule strain (Fig 2B).

The most intense carrier frequencies of both species li near 20kHz (Fig 3A, B). N. macneilli has a main intensity peak netween 15 and 22kHz with a lesser perak centres on 35kHz. The dominat peak of N. sierranus occurs within the range 16-23kHz and is particulalry pronounced at 19kHz. These frequencies exceed the response cpaability of most tape recorders and microphones; thus sonograms, such as that given by Rentz and Birchim (1968) for N. macneilli, may present only a small fraction of the sound energy actually produced by the animal.

In both species teh temina are mirror images of each other. Swollenlateral and mesal veins diverge form the wing base (A and B of Fig 4) and subtend a plateau of transparent cells, comprised of relatively stiff, thin cuticle. A membranous (flexible) skirt (C) hangs ventrally from the lateral vein. The medial margin of each tegmen functions as a scraper (D). The file (E) lies toward the midline between the massive veins and is only weakly attached to them. This stridulatory apparatus encloses a chamber of air on the dorsum of teh insect. The floor of this chamber is the terga of tehmeso- and metathorax and the first few abdominal segments. Each tegmen contributes the region bounded by the two large veins as half of the chamber roof. The skirt reaches and trails out upon the insect's back, delimiting the sides of the chamber and closing it off posteriorly. Tegminal structure is essentially teh same in both species; tehy differ only in teh far greater number of teeth ocurring on the file of N. sierranus.[1]

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