Modelling evolutionarily stable strategies in oviposition site selection, with varying risks of predation and intraspecific competition

Abstract

Many ovipositing mosquitoes, as well as other species, can detect biotic factors that affect fitness. However, a female mosquito seeking a high quality oviposition site (e.g. one with low risk of predation and competition to her progeny) must often balance the competing risk of increasing probability of mortality to herself while she continues to search, against increased probability of finding a high quality site. Such oviposition site selection may affect adult population size. We examined a female mosquito's expected strategy of oviposition site selection under conditions of varying predator prevalence and adult mortality risk, by combining a detailed structured population model with a Markov chain implementation of the adult behavioural process. We used parameter values from the specific mosquito-predator system, Culiseta longiareolata-Notonecta maculata, although the overall results can be generalised to many mosquito species. Our model finds the evolutionarily stable strategy of oviposition site selection for different parameter combinations. Our model predicts that oviposition strategy does not vary smoothly with varying environmental risk of adult mortality, but that certain oviposition strategies become unstable at some parameter values. Mosquitoes will distribute their reproductive effort between breeding sites of varying predation risk only when adult mortality is low or larval competition high. Our model predicts that females will continue searching for predator-free pools, rather than oviposit in the first site encountered, regardless of the risk of mortality to the adult. The ecological basis for a reproductive strategy with alternative behaviours is important for understanding the effect of biotic factors on the population dynamics of Electronic supplementary material The online version of this article (mosquitoes, and for the development of biological control strategies, such as the dissemination of predator-cue chemicals.

Attracted to the enemy: Aedes aegypti prefers oviposition sites with predator-killed conspecifics

“…Antipredator oviposition behavior likely has costs (Lima and Dill 1989; Blaustein 1999). The time spent searching for a predator-free oviposition place can increase the probability of being eaten by an aerial predator, especially because gravid females are slow flying (Magnhagen 1991), or the cumulative probability of death due to any cause (Kershenbaum et al 2012). Blood fed mosquitoes are more vulnerable to predation by spiders after blood-feeding (Roitberg 2003).…”

“…Females of organisms with terrestrial adults and aquatic immatures must choose among discrete aquatic habitats for their offspring (Kershenbaum et al 2012). Considerable theory indicates that selection should favor those individuals that choose among habitats those that yield the greatest fitness payoff (Resetarits 1996, Binckley & Resetarits 2005, 2008, Kershenbaum et al 2012).…”

“…Considerable theory indicates that selection should favor those individuals that choose among habitats those that yield the greatest fitness payoff (Resetarits 1996, Binckley & Resetarits 2005, 2008, Kershenbaum et al 2012). This has led to explicit models that predict fitness is maximized when individuals choose to consign offspring to habitats that minimize the ratio of mortality rate to growth rate (i.e., minimize μ/g; Werner and Gilliam 1984, Resetarits 1996, Binckley and Resetarits 2008).…”

“…This has led to explicit models that predict fitness is maximized when individuals choose to consign offspring to habitats that minimize the ratio of mortality rate to growth rate (i.e., minimize μ/g; Werner and Gilliam 1984, Resetarits 1996, Binckley and Resetarits 2008). It is therefore expected that females choosing aquatic oviposition sites should be attracted to sites with high resources, low conspecific and competitor densities, and low predator abundances (Kershenbaum et al 2012). There is abundant evidence that many aquatic insects (e.g., Chesson 1984, Resetarits 2001, ÅÅbjörnsson et al 2002, Blaustein et al 2005, Binckley and Resetarits 2005, 2008, Vonesh et al 2009, Vonesh and Blaustein 2010) and amphibians (e.g., Resetarits and Wilbur 1989, Resetarits 1996, Reiger et al 2004, Binckley and Resetarits 2002, Orizaola and Braña 2003) make oviposition choices based on cues to predation risk, minimizing mortality for their offspring.…”

“…Kershenbaum et al (2012) considered how ovipositing females might choose optimally among sites with low predation vs. sites with low conspecific density. But predators have the potential to influence both prey density (directly by consumption) and resources for prey (indirectly via a trophic cascade; Carpenter et al 1985), and if ovipositing females respond to cues indicating both predation risk and growth opportunity, as predicted by μ/g models, predation may create conflicting cues arising from predators, victims, prey density, and prey resources within the same site.…”