Figure 5.

Olfactory behaviour. (a) Historical tracking: manually traced paths of individual walking D. ampelophila (the former name for D. melanogaster) from the edge of a 5 × 5 inch arena toward a piece of fermenting banana at the centre. Reproduced from [1], with permission. (b) State-of-the-art tracking: schematic of a wind tunnel through which a controlled odour plume can be introduced; a multi-camera system enables automated three-dimensional tracking of flies interacting with this plume in flight. On the right is the trajectory (top and side views) of D. melanogaster in a continuous plume of ethanol. Grey dashed lines on the left indicate the upwind wall of the tunnel towards which the animal flies. The trajectories are colour-coded for the instantaneous concentration of odour at a given point in the plume (as measured using a photoionization detector); the reconstructed odour experience of the animal over the course of its flight is plotted below the trajectories. Two time-synchronized reference points are indicated with orange and green arrowheads. Adapted from [214], with permission.