The effect of mating on phonotactic behaviour in Gryllus bimaculatus (De Geer)

Abstract. Phonotaxis of G. bimaculatus females is expressed by a course-consistent, directional approach to a conspecific model calling song emitted alternatingly at sound intensities of 50–90 dB SPL and appears at the age of 6–7 days, the onset of maturation. Mating abolishes phonotaxis after about 1 h. By that time, the content of the attached spermatophore has migrated into the female's sper-matheca. Removal or emptying of the spermatheca, or severing the ventral nerve cord, fully reinstates phonotaxis, whereas ovariectomy has no effect. We suggest that mechanoreceptors record the expansion of the filled spermatheca and that the inhibitory message is communicated via the ventral nerve cord anteriorly to an unknown control centre in the brain. The loss of phonotaxis is combined with reduced locomotor activity and results in the female no longer being attracted to another calling male.