Abstract
Natural selection is predicted to favor females that can detect risks of desiccation and predation when choosing among temporary pools for oviposition. Pool size may serve both as a cue for desiccation risk and as a predictor for future colonization by predators or for the probability of present, undetected predators. Therefore, oviposition responses to pool size are expected to interact with the presence of predators that can be detected. We measured oviposition by two mosquito species, Culiseta longiareolata and Culex laticinctus, in a mesocosm experiment, crossing two pool surface sizes with presence or absence of the hemipteran predator, Notonecta maculata, which is chemically detectable by mosquitoes. Both mosquito species strongly avoided Notonecta pools. Using a mechanistic statistical model, we accounted for the higher encounter rate of females with larger pools, and determined their true oviposition preferences for pool size. C. laticinctus showed a clear preference for larger pools, but C. longiareolata, a species with larvae more vulnerable to predation, showed no significant preference for pool size. This study confirms the importance of risk of predation in explaining oviposition patterns, and suggests a possible inter-specific variation in the trade-off between predation and desiccation risks.
Acknowledgements
We thank Naomi Hill, Eden Orion, Moshe Kiflawi and Ori Segev for technical help and fruitful discussion, Burt Kotler for critiquing an earlier version of this paper, and three anonymous reviewers for helpful comments. This work was supported by Israel Science Foundation Grant 600/02 awarded to LB.
Disclosure statement
No potential conflict of interest was reported by the authors.