Geographic Variation In Culex Oviposition Habitat Selection Responses To A Predator, Notonecta Irrorata

1. Predators have effects on prey populations through both consumptive and non-consumptive effects. Predator's presence is expected to drive variation in prey oviposition habitat selection behaviour, but differences in biotic and abiotic characteristics of habitats, or trait variation, may produce geographic variation in species interactions.2. We conducted a series of experiments in two geographic locations, Mississippi and Missouri, USA, to assess oviposition responses of Culex mosquitoes (prey) to the presence of Notonecta irrorata (predator). We first tested whether mosquitoes in each location respond to the presence of N. irrorata, with follow-up experiments to determine whether mosquitoes respond to variation in N. irrorata density, whether N. irrorata from each location generate different responses by the same Culex population, and whether diet and consumption of conspecifics affect oviposition.3. We found that Culex restuans in Missouri had reduced oviposition when N. irrorata were present. In Mississippi, C. restuans did not respond to the presence of N. irrorata from either Mississippi or Missouri, to the variation in density of N. irrorata, or to N. irrorata that had been fed larval mosquitoes.4. Our study documents the first instance of geographic variation in oviposition response of a prey species to a predator species.