Figure 2. Treatment schedule and survival for repeatedly treated foragers.

A. Survival curves for repeated treatment groups. Cocaine, vehicle control, and sham treated groups contained 51, 57, and 58 bees, respectively. Bees disappearing between marking and first treatment have not been included. Cocaine treated bees did not differ from vehicle (Kaplan-meier log-rank test: χ ² = 0.1, p = 0.750) nor sham control (Kaplan-meier log-rank test: χ ² = 3.4, p = 0.064), but there was a significant difference between the two control groups (Kaplan-meier log-rank test: χ ² = 5.4, p = 0.02). B. The schedule of treatments used in the repeated treatment experiments.