Meeting Abstract

63.7  Wednesday, Jan. 6  The evolution and thermal dependence of inducible defences in mosquito larvae. VAN UITREGT, V.O.*; HURST, T.P.; WILSON, R.S.; The University of Queensland; Queensland Institute of Medical Research; The University of Queensland v.vanuitregt@uq.edu.au

Temperature profoundly influences the reaction rates and efficiency of all physiological systems. During predator-prey interactions we often expect temperature to directly influence the locomotor capabilities of both predator and prey, and thus alter the dynamics of the system. However, predation is seldom just a simple game of ‘cat and mouse’. Prey can induce behavioural and morphological defenses that increase their chances of escape and survival. Prey can commonly achieve this by reducing their activity and making themselves less conspicuous to predators. However, reducing activity constrains total foraging time and can lead to substantial energetic costs. For ectothermic prey, increases in temperature could magnify these costs by increasing total metabolic demands. We tested this idea by examining the effect of temperature on the costs of behavioural responses to predators in mosquito larvae. Larvae of the urban mosquito Aedes notoscriptus avoid predation by reducing activity. Our previous research has shown that the response is indeed costly, retarding growth and development and manifesting smaller adults that have a shorter adult lifespan when not fed. We expect these costs to be exacerbated in larvae reared at higher temperatures or, larvae will trade-off the increased costs by limiting their behavioural response at warmer temperatures. This study provides an examination of the influence of temperature on the costs of inducible defences in prey and provides insight into the subtle effects of the thermal environment on ecosystem dynamics.