Patterns of variation in the acoustic calling signals of Chloriona planthoppers (Homoptera: Delphacidae) coexisting on the common reed Phragmites australis

Populations of the Tour species of Chloriona commonly found in the Netherlands C dorsata, C. glaucescens, C. smaragdula and C. vasconica –were cultured in the laboratory on Phragmites australis, their exclusive host plant in the field. The low frequency substrate-transmitted signals produced during the calling phase of mating behaviour were digitally analysed for the males and females of each species. Variables selected to cover most aspects of the call were measured, and variation was quantified within species and statistically tested among species using univariate and multivariate techniques. The calls of the males were more complex in structure than those of the females, with two different phase patterns recognized, and were species-specific. C. glaucescens and C vasconica were also separated on variables of the female call, but C dorsata and C. smaragdula completely overlapped. No significant differences were found between the calls of the long-winged and.short-winged female morphs of C. smaragdula. A possible role for variation in calling signals, and responses to them, in the evolution and maintenance of reproductive isolation in Chlonona is discussed.