Monday, August 6, 2007 - 1:30 PM

COS 8-1: Linking behavioral, landscape, and population ecology: The oviposition preference-offspring performance relationship in tree hole mosquitoes

Alicia M. Ellis, Dartmouth College

Although theory predicts a positive relationship between oviposition preferences and the developmental performance of offspring, the strength of this relationship may depend not only on breeding site quality, but also on the complex interactions between environmental heterogeneity and density-dependent processes.  Environmental heterogeneity may not only alter the strength of density dependence, but may fundamentally alter density-dependent relationships and the correlation between preference and performance.  Here, I present the results from a series of observational and manipulative field experiments with tree hole mosquitoes to: (1) establish oviposition preferences, and (2) determine how performance is influenced by the density of conspecifics, the type of resource in the oviposition site, and the type of habitat in which the oviposition site is located.

Observed patterns of oviposition and results from a mark-release-recapture experiment indicated a weak preference for deciduous forests over evergreen forests. Manipulative field studies indicated that performance did not differ among these habitats at low offspring densities, but was higher in deciduous forest habitats at high densities. This divergence of fitness among habitats with increasing density may explain observed preferences, and may lead to a negative preference – performance relationship when population densities are low but a positive relationship when population densities are high.  Failure to recognize the interaction between offspring density and environmental heterogeneity may therefore limit our understanding of the processes influencing the preference – performance relationship and the evolutionary processes determining oviposition preferences in natural systems.