A field study on the acoustic behaviour of mobile singers in the bush cricketPsorodonotus illyricus

Abstract

The bush cricket Psorodonotus illyricus is indigenous to the Balkans. Singing males of this species are highly mobile. The acoustic factors which might influence the locomotion were investigated in the field. The mobility of the males results in an often random distribution pattern. Interactions between the males are purely acoustic, and the duets are characterized by periods of good and poor alternation. Playback experiments, field observations and tape recordings of duetting males indicate that singing rate and sound intensity affect alternation behaviour and locomotion. However, the effect of the two song parameters is related to the time of the day, a phenomenon which might be due to (a) changes in the sound field around a singing male, and (b) altering microclimatic factors during the activity period of the insects.