Background/Question/Methods
<p>Two important risks for the progeny of mosquitoes ovipositing in temporary pools are risk of predation and risk of desiccation. We used a natural rock pool survey, a natural rock pool experiment, and two artificial pool experiments to examine how risk of predation by the backswimmer, Notonecta maculata, and predictors of habitat permanence (pool depth and pool surface area) influenced among-pool distributions of egg rafts of two common rock pool mosquitoes, Culiseta longiareolata and Culex laticinctus. More egg rafts in larger surface area pools would not necessarily indicate a stronger preference for larger pools.  It may simply indicate an increased encounter rate as the mosquito searches for breeding sites.  Models were developed and compared using Akaike Information Criterion (AIC) to distinguish between higher oviposition rates in larger pools due to higher encounter rates (based on surface area or pool periphery) and higher oviposition rates due to preference by the female.
Results/Conclusions
The predator strongly repelled oviposition by these two mosquitoes, regardless of experimental venue – natural or artificial pools. Pool depth was not a good predictor of egg raft abundance in the survey or in the artificial pool experiment.  Mosquitoes oviposited at similar rates in experimental pools when comparing a water depth that would provide sufficient time for larval development to a water depth that would not allow sufficient time for larval development.  In all studies, egg raft abundance was positively associated with surface area. The AIC models indicated no preference by C. longiareolata females for pool size when selecting an oviposition habitat.  These models also suggest that higher oviposition rates observed in C. laticinctus are in fact due to a preference for larger pools by gravid females.