Lack of correlation between vertical distribution and carrier frequency, and preference for open spaces in arboreal katydids that use extreme ultrasound, in Gorgona, Colombia (Orthoptera: Tettigoniidae)

<p>Male Tettigoniidae emit sound to attract conspecific females. The sound is produced by stridulation.During stridulation the forewings open and close, but it is during the closing stroke that the scraper contacts thefile teeth to generate the predominant sound components, which are amplified by adjacent wing cells specializedin sound radiation. The sounds usually exceed the sonic boundary and might occur above 40 kHz, reachingextreme ultrasonic frequencies of 150kHz in some species. Here we test the hypothesis that Tettigoniidaespecies should prefer microhabitats that favour efficient signal transmission, i.e. that there is a relationshipof sound frequency with the vertical distribution of the species (from ground to canopy) at Gorgona NationalNatural Park, Colombia. We sampled 16 trees and four different altitudinal levels between 1 and 20m above theunderstory vegetation. We placed collecting blankets separated by vertical distances of 5m, and knocked insectsdown using the technique known as fogging. We found no correlation between vertical distribution and carrierfrequency, but there was a preference for open spaces (below the canopy and above the understory) in speciesusing extreme ultrasound. This is the first quantitative description of the vertical distribution in neotropical speciesof the family Tettigoniidae and its relationship to the calling song frequency.</p>