Predatory behaviour of female guppies (Poecilia reticulata) in a mosquito control context: the importance of social and habitat factors

It is vital to consider behaviour when selecting an appropriate biological control agent, as behaviour can affect both the likelihood of the agent successfully controlling the target organism, and the chance of inadvertent negative effects on native ecosystems. Guppies, Poecilia reticulata, have been introduced widely outside of their native range for mosquito control, yet very little is known about their feeding decisions when more than one prey species is present, and how these decisions are mediated by social and physical aspects of the foraging environment. We investigated female guppy foraging behaviour in a two-prey system (Anopheles and Culex mosquito larvae). When feeding alone, female guppies displayed a preference for Culex larvae. However, the extent of preference was significantly affected by both the presence of conspecifics and cover, in a non-additive manner. This suggests that the presence of alternative prey will influence the effectiveness of guppies in biological control, as well as their potential ecological impact. The exact nature of this influence depends on the interaction between social and habitat factors.