Fabrication of an olfactometer for mosquito behavioural studies

Background & objectives: Olfaction is the major sensory modality involved in the resource searchingbehaviour of insects including vector mosquitoes (Diptera: Culicidae). To date, our current countrywideknowledge on the host-seeking behaviour of Iranian mosquitoes is mainly confined to hostpreference which has exclusively come from field studies. Olfactometer is a scientific tool bywhich more naive aspects of man-vector contact can be clarified under controlled and less biasedconditions.Methods: The wind tunnel and stimulus delivery system was constructed from acrylic materialsbased on previously introduced models with some modifications. Air supply and required lightwere ensured by a powerful compressor and incandescent bulbs, respectively. Desired level oftemperature was maintained by controllable heating radiators. For humidity production a uniquein-built piezo system was devised in the course of the air flow. Fine regulators facilitated thecontinuous generatation of the humidity at a preset level.Results: Titanium tetrachloride smoke plus monitoring of the wind speed revealed that the flow ofair was proper and invariable. A desired level of humidity and temperature could be set up in just10 and 15–45 min, respectively. These physical parameters varied only ±2% (humidity) and±0.15ºC (temperature) in a typical 20 min duration.Conclusion: The first sophisticated olfactometer in the field of medical entomology in Iran isreported here. Fast set up and stability of physical parameters are its salient features. It is expectedthat with the aid of this olfactometer further information on the physiological principles of thehost-seeking behaviour of mosquitoes become available soon.