Flies track constant odor plumes of different odors equally well. (A) Mean distribution of the flight trajectories of 25 flies presented with a continuous plume of apple cider vinegar. The frequency of occurrence is spatially coded with pseudo-color. The tight distribution centered at zero degrees indicates the precision and accuracy of plume tracking during flight. (B) The same trajectories as (A) are analyzed for cumulative plume deviation, the angular magnitude of deviation from the plume cumulatively summed over the trial. (C) Total plume deviation is similar across three different odors: ethyl butyrate, apple cider vinegar and banana, indicating equal tracking accuracy (t-test p > 0.05; n > = 25 flies for each odor). Error bars indicate SEM. (D) Total plume deviation was assessed after challenging flies to track different odor intensities of ethyl butyrate, vinegar and banana. The results indicate that tracking performance does not improve by decreasing odor concentration, but only degrades, and is not significantly different from water vapor control at odor concentrations diluted by two orders of magnitude (10-4) for all three odors tested. t-test was used to test for significance, ** denotes p < 0.01 and ns denotes p > 0.05; n > = 10 flies for each odor). Error bars indicate SEM.