The costs of social interaction on survival and reproduction of arrhenotokous spider mite Tetranychus urticae

Abstract

The social environment (especially interactions with other conspecifics) experienced by animals is a key factor influencing their behaviour and even fitness. Traditionally intersexual interaction has been the main focus, whereas the costs of intrasexual interaction have not been adequately studied. In this study the influence of both intersexual and intrasexual interactions on the survival of both sexes in an arrhenotokous spider mite Tetranychus urticae (Acari: Tetranychidae) were determined. The reproductive performance of females in different social environments were also investigated. The results show that for both sexes, isolated individuals outlived their counterparts when compared with paired conspecifics, indicating that the cost of interaction with the same sex and the opposite sex have negative consequences for fitness (e.g. females involved in intrasexual interaction showed reduced fecundity). These findings highlight fitness cost(s) of social interactions on the lifespan and reproduction of organisms. Both intrasexual and intersexual interactions can be important determinants in shaping the fitness of animals.