This project sought to deliver new understanding of the responses of pest insects to light for the purpose of improved agricultural pest control. Through access to experimental polyethylene horticultural films with novel transmission properties, I exploited new opportunities for exploring separate short- and long-wavelength mechanisms for pest suppression. The early experimental work of the project tested the effect of short- and long-wavelength ultraviolet light on the population growth of the generalist aphid, Myzus persicae, on cabbage (Brassica oleracea) plants. These polytunnel field experiments established new hypotheses for the role of long-wavelength ultraviolet radiation as an environmental cue for damaging short-wavelength ultraviolet radiation. Through a series of methodological developments, I quantified both the dose-response of environmentally-relevant ultraviolet on M. persicae mortality, and proposed a colour behavioural model for the feeding behaviour of M. persicae under different illumination conditions. Through synthesising these findings into a model of aphid hazard-avoidance, I show that the behaviour of M. persicae may be manipulated to increase its exposure to solar short-wavelength radiation, with consequences for population growth rate. As such, this mechanism may be used in protected agricultural practice as part of a wider integrated pest management strategy.