Signalling with air-borne sound and tremulations.

<p>(A) A female <i>Docidocercus gigliotosi</i> producing a series of tremulations on a plant by strong up and down movements of its abdomen; a single airborne sound pulse of a male is shown for comparison. (B) Rate of production of tremulations (blue) and air-borne sound signals (red) of a single male over the course of about 6 hours after sunset (halve moon conditions). The number of either of these two signals for a total of 11 males is shown in (C) (airborne sound) and (D) (tremulations).