Investigating the role of sexual conflict in parasitoid- host eco-evolutionary dynamics

Finding ways to grow enough food to sustain the ever-growing human population while minimising detrimental impacts on the natural environment is a pressing global challenge [1,2]. Current food production systems rely heavily on the use of agro-chemicals for pest control, the negative impacts of which are extreme for species, ecosystems and for

climate change [3-7]. Integrated pest management (IPM) is one strategy that will be critical if we are to feed the human population without inflicting irreversible environmental damage. IPM prioritizes biodiversity-based pest control and considers the use of chemical pesticides only as a last resort [8].

Parasitoid wasps are a large group of insects, which are commonly used as a chemical-free means of controlling insect pests (biological control). Adults are free-living, females lay their eggs on or in other species and their offspring feed on this host, typically another insect, invariably killing it. In addition to their economic value, parasitoid wasps have long

been used by blue skies researchers to understand fundamental questions about evolution, ecology and physiology [9,10]. This research has supported their use in crop protection and assisted biocontrol practitioners in selecting the most appropriate species to control a given pest [9,10]. Despite the abundance of studies on parasitoid behavioural ecology, these species have

received little attention in studies of sexual selection and sexual conflict [11]. Sexual conflict occurs when the optimum strategy or trait is different for males and females [12]. For instance, the optimal mating rate is generally higher for males than females. This can result in reduced fitness for females if accepting or resisting superfluous male copulation

attempts is costly [12, 13]. If these costs manifest as reduced offspring production, there can be consequences for recruitment and even population viability [13] For parasitoid wasps in natural and agricultural settings, sexual conflict may have profound consequences for parasitism rates. Understanding the extent to which sexual

conflict influences individual and population fitness in these insects provides new and valuable information on how aspects of these species' mating systems can influence host-parasitoid dynamics and coevolution as well as the efficacy of pest control under different IPM scenarios.