Efeitos individuais e interativos do risco de predação, disponibilidade de recurso e tamanho do habitat no comportamento de seleção de habitat para oviposição do mosquito Aedes aegypti (Linnaeus; Culicidae)

Abstract

Oviposition Habitat Selection is a crucial process for species with complex life cycle, because most species do not exercise parental care. In this way, the success of the offspring depends on the habitats quality. So it is with the Aedes aegypti mosquito, whose female oviposits in discrete temporary pools (containers) distributed in the landscape. The choice of female mosquitoes searching of oviposition sites is based on physical-chemical characteristics of the habitats that indicate their quality. Natural selection should favor individuals capable of discriminating between habitats and giving preference to those most suitable for the survival, growth and development of offspring. There are an increasing number of studies that point to the predation risk, resource and habitat size as important indicators of quality, which act as mechanisms of oviposition habitat selection by mosquitoes female and other taxa. However, the understanding of how these factors, of a physical and biological nature, interact to affect the behavioral decisions by ovipositing females remains limited. In order to assess the individual and interactive effects of the risk, resource and habitat size on the oviposition habitat selection behavior of the Aedes aegypti mosquito, we perform a laboratorial experiment with design 2×2×2 factorial. Using artificial containers, the absence or presence of cues from the predator Poecilia vivípara (Poecilidae), little or much resource and greater or lesser habitat size (depth) were crossed. The results demonstrate that Ae. aegypti oviposited more frequently (qualitative oviposition indicator) and in greater quantity (quali-quantitative oviposition indicator) in habitats considered to be high quality (without risk, with more food and larger). The qualitative decision, denoted by the proportion of ovipposited replicas per female, was significantly affected by the individual effects of habitat size and food, but not the predation risk. The risk effect was dependent on the interaction with the resource. The quali-quantitative decision, denoted by the proportion of the number of eggs laid per female, was, again, significantly affected only by the individual effects of the habitat size and the resource, while the effect of the risk mediated by the latter. Interestingly, resource and habitat size interacted to affect the proportion of the number of eggs laid per female. Habitat size was the most important factor in assessing the habitat quality by the female, revealing the habitat temporality (risk of desiccation) as the main mechanism acting on the behavioral decision of ovipositing females. Resource and risk played a secondary and tertiary role, respectively, as their effects were, to a greater or lesser extent, mediated by one of the other factors (the risk mediated by food and this by habitat size). This interdependence reveals a trade-off associated with the mechanisms of habitat choice where females of Ae. aegypti probably respond in order to balance costs and benefits related to the risk of habitat drying, predation risk and energy acquisition. The results suggest that although the predation risk is an important factor driving the habitat choice for oviposition, it is no more important than the resource and the habitat size. These findings have relevant implications for the development of more effective strategies for controlling mosquitoes that carry disease, such as Ae.aegypti. In addition, they contribute to the understanding of how physical and chemical characteristics of habitats influence the oviposition of mosquitoes, helping to understand the patterns of distribution and abundance of species that oviposit in temporary aquatic habitats.