The secret stridulatory file under the right tegmen in katydids <br />(Orthoptera, Ensifera, Tettigonioidea)

Abstract

Males of most species of crickets and katydids produce species-specific calling songs to attract conspecific females. The typical stridulatory apparatus of the Ensifera consists of a file-and-scraper system in the basal dorsal region of the forewings (tegmina): the file on the underside of the cubital vein of one tegmen is composed of a series of lamelliform teeth and is run against the sclerotized scraper at the edge of the other tegmen. The region directly distal of the cubital vein is often thin and glassy and serves to amplify and spread the sound. In stridulating crickets the tegmina are quite symmetrical with both the left and the right one containing a file, which is considered the ancestral condition (Béthoux 2012). Most of these crickets adopted a right-over-left wing overlap and use only the right file. The few extant species of the ancient group Hagloidea have bilaterally symmetrical tegmina, both with functional files, and individual males can change the overlap (Morris & Gwynne 1978). Katydids are distinguished by a left-over-right wing overlap, with a stridulatory file on the underside of the left tegmen, and a scraper on the right one, which usually is also equipped with a mirror as resonating structure.

Functional morphology of tegmina-based stridulation in the relict speciesCyphoderris monstrosa(Orthoptera: Ensifera: Prophalangopsidae)

“…1D) (Bailey and Broughton, 1970;Montealegre-Z and Postles, 2010). In many cases, there exists a mirror on the left wing, and a file on the right wing, but the former is usually partially damped and filled with cross-veins, and the latter greatly atrophied (Montealegre-Z and Mason, 2005;Montealegre-Z and Postles, 2010;Chamorro-Rengifo et al, 2014). These morphological wing characteristics result in an obligatory wing arrangement of 'left-over-right' for stridulatory sound production.…”

Stridulation of the clear-wing meadow katydidXiphelimum amplipennis, adaptive bandwidth

“…The tooth-bearing transversely running CuPb veins (Bethoux 2012), i.e., the file veins, show differences related to force translocation. These differences are katydid-typical for S. sphagnorum (Fig 3B ): the left tegmen file (ff) is thick and functional, the right (vf) is undeveloped, aptly termed vestigial or 'secret' (Chamorro-Rengifo et al 2014).…”

Ultrasonic songs and stridulum anatomy of Asiophlugis crystal predatory katydids (Tettigonioidea: Meconematinae: Phlugidini)

“…The songs of Phlugidini are similar in that they are entirely ultrasonic, supporting the fact that Meconematinae species usually employ ultrasonic calls (Helfert and Sänger 1998;Montealegre-Z et al 2006Montealegre-Z et al , 2017Chamorro-Rengifo et al 2014;Chamorro-Rengifo and Braun 2016;Sarria-S et al 2017). A. rete (A. thai junior synonym) sings at frequencies between 30 and 50 kHz (Helfert and Sänger 1998) and neotropical species such as Phlugis ocraceovittata Piza, 1960 also sings at frequencies between 40 and 60 kHz (Chamorro-Rengifo and Braun 2016).…”

“…They have diversified more in South America, with as many as 59 species known to science (Cigliano et al 2019). Except for the acoustic behaviour of two species of Phlugis (see Chamorro-Rengifo et al 2014;Chamorro-Rengifo and Braun 2016;Sarria-S et al 2017), very little is known about the acoustics and biomechanics of sound production in this group. This is also the case for their relatives from Southeast Asia, which include species from the genus Asiophlugis Gorochov 1998 ( Figure 1).…”