Stridulation and associated behaviour in certain orthoptera. 1. analysis of the stridulation of, and behaviour between, males

Summary

• 1.

  The stridulation of the grasshoppers Stenobothrus lineatus, Omocestus virudulus, Chorthippus brunneus and Chorthippus parallelus was recorded on magnetic tape and analysed oscillographically and with an audio-spectrometer.

• 2.

  The various types of songs are described and inter- and intra-specific differences as revealed by physical analysis are shown to reside almost completely in differing pulse repetition frequencies.

• 3.

  The behaviour of adult mature males on stimulation with the normal song of their species is described. Normally this behaviour leads to group singing, with no locomotor movement, but males of all species except O. viridulus when segregated from their fellows for 24 hours or more show taxic locomotor reactions to the source of sound. The locomotor movements cease when a male joins a singing group.

• 4.

  It is suggested that this reaction may be related to the distributional ecology of the insects.