Materials and Methods
Ten Tübingen and Dijon wild-type and 91R flies were incubated with the contact insecticides DDT (Dichlorodiphenyltrichloroethane) and chlorpyriphos and Chlorantraniliprole in glass vials (first cohort). As in the following experiments, the number of knockdown flies was recorded every hour for four hours at room temperature. Knockdown occurred when flies showed paralysis. After incubation of the first cohort flies, the vial was emptied and a second cohort of male or female flies was added to the vial. In the honeybee experiment, a single Apis melliferaworker (from Pforzheim, Germany) was incubated in the vial instead of the first cohort of flies. Second cohort flies were added to the vial after four hours of incubation when the honeybee was dead. For proboscis removal experiments, flies without proboscis served as the first cohort flies. In the silica beads experiment, ten silica beads were added to a vial without flies. After removal of the beads,10 flies were incubated in the same vial. Also, ten flies were exposed to the removed silica beads to test for DDT adhesion to the beads. Ten wild-type females were added to the vial containing rapeseed oil and DDT. Chitin was added to a second cohort of 10 wild-type females. Detail protocols are provided as supporting information. All raw data are available upon request.