Fig. 1

Wind tunnel and position of human host. a Three dimensional schematic of wind tunnel set-up, with a flight arena 1.2 × 1.2 × 2 m long. (i) shutter, (ii) charcoal filter, (iii) impelling fan, (iv) fan heater, (v) atomising humidifier, (vi) brushed-cotton cloth screen, (vii) odour delivery chamber, (viii) carbon dioxide source, (ix) upwind net screen, (x) flight arena, (xi) downwind net screen, (xii) insect release chamber, (xiii) terminal downwind net, (xiv) insect release cage, (xv) visible light-emitting diode (LED) array of white fairy lights on laboratory floor (~60 cm below flight arena), (xvi) black boxes containing infrared (IR) LEDs on laboratory floor and (xvii) cameras. Effects of lighting on appearance of arena floor and human host behind netting: b View of flight arena from downwind end with mosquito release unit (a-xii) removed, showing human volunteer just visible behind upwind screen, with experiment lighting only (IR-LEDs not visible and white LEDs brightly lit) and IR-pass filters on arena floor. c Same view taken with flash photography. d Same view with addition of laboratory room lights, showing position of IR-LED black boxes on laboratory floor and laboratory fluorescent ceiling lights visible through clear flight arena ceiling. Human host is sitting on stool in compartment a-vii with her waist ~5 cm below floor level of flight arena, mouth and extra CO₂ at ~35 cm above floor level, behind white mosquito netting that obscures visual cues of the host