Fig. 6. Sample tracks of mosquitoes in response to (A) a ribbon CO₂ plume, (B) 20% skin odour, (C) 20% skin odour after contact with a ribbon plume of CO₂, and (D) undiluted skin odour. Dots represent the mosquito's position at intervals of 100 ms. Contact with the odour plume is indicated by a light blue colour. B (left) shows two typical tracks of mosquitoes flying through a diluted skin odour plume. Only rarely did 20% skin odour induce sustained upwind flight to the odour source (right).