Abstract
The development and testing of a bioassay system to evaluate the potency of floral odours as mediators of long-range floral nectar source location by mosquitoes are described. The bioassay is quantitative and behaviourally discriminating, upwind flying and landing acting as indices of behavioural activity over the 24-h light:dark cycle. In initial tests, the responses of Aedes aegypti (L.) to the flowers and floral odours of ox-eye daisy (Leucanthemum vulgare) were investigated. A. aegypti exhibited a biphasic diel cycle of nectar-feeding behaviour and landed on modified flowers that retained either their disc or ray florets. Most significantly, the mosquitoes responded in a similar way to the odour of L. vulgare in the absence of visual stimuli or nutritional cues. They did not respond to solvent extracts of ox-eye daisy flowers.