Fig 1.
Absolute value of antennal responses from three insect species (western honeybee, hissing cockroach and grapevine moth) to drug volatiles (n = 3).
The percentage value indicates the amount of pure drug relative to the whole sample (pure drug plus cutting agents).
Fig 2.
Honeybee antennal responses to four dilutions of the test samples in acetone, relative to the response to a cis-3-hexenol standard (concentration 1 ng/μl in acetone).
Error bars indicate standard deviations (n = 10).
Fig 3.
Example plot showing an individual honeybee conditioning experiment.
The gray line indicates the walking trace from left to right in the conditioning chamber. Magenta and green boxes indicate heroin and cis-3-hexenol odor stimuli, respectively, and the side from which the odor was applied. Yellow lines indicate shock impulses. The upper plot shows the conditioning phase, the lower plot the test phase without shocks after a 5-min interval.
Fig 4.
Mean attractance index values of the blank/blank and the heroin/cis-3-hexenol experiment in the test phase without an unconditioned stimulus.
Odor A was the conditioned odor paired with the unconditioned stimulus in the conditioning phase, and odor B was presented always without the unconditioned stimulus. Error bars indicate standard errors (n = 50) and ** indicates a significant difference (p ≤ 0.001).