Experimental Studies of Mimicry. 6. The Reaction of Toads (Bufo terrestris) to Honeybees (Apis mellifera) and Their Dronefly Mimics (Eristalis vinetorum)

1) Laboratory experiments were conducted to test visual mimicry of the honeybee (Apis mellifera) by the dronefly (Eristalis vinetorum) with 67 caged Southern Toads (Bufo terrestris) as predators. Twenty-two experimental and 22 control toads completed the experiment. 2) Both experimental and control toads began by eating the droneflymimic and a standard palatable insect, the mealworm (Tenebrio molitor), which they readily took throughout the experiment. 3) The experimental toads were then given live honeybees which they at first ate, but after being stung, learned to reject them on sight. When a final mimic was offered, it was eaten by less than half of these toads. 4) On the contrary, nearly all the control toads ate the final mimic. Batesian mimicry of the honeybee by the dronefly was therefore shown to be highly effective. 5) The control toads also freely ate dead honeybees with the stings removed which indicates that the noxious quality that makes the honeybee unpalatable to toads is the sting, perhaps reinforced by buzzing. 6) The acceptance of mealworms but refusal on sight of the initial drone-flies by 14 toads suggested that they had experienced honeybees in the wild prior to capture and is indirect evidence in support of mimicry.