Visual and olfactory responses of haematophagous Diptera to host stimuli

Key biotic and environmental constraints on the host-orientated behaviour o f haematophagous Diptera are summarized. For each major group of biting Dip tera, responses to host stimuli are reviewed, including activation and rang ing behaviour, long-range and short-range olfactory responses and visual re sponses. Limitations to the comparison of results between groups of species , and the practical problems of experimental method and equipment are discu ssed.