A rapid bioassay for detection of adulterated beeswax

Proboscis extension was used to test the ability of honey bees (Apis mellifera L.) to detect beeswax adulterated with carnauba wax (Copernicia cerifera Arruda Camara). Subjects were exposed to either 100% beeswax (honeycomb) (e.g., no carnauba wax), 100% beeswax (melted) (e.g., as commercial beeswax cake), 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10% beeswax/carnauba mixtures, 0% beeswax (i.e., 100% carnauba wax), or unscented air. Maximum responding was observed in bees exposed to the scent of honey comb or melted beeswax cake. The addition of as little as 10% carnauba wax was readily detected and resulted in reduced proboscis extensions. Few proboscis extensions occurred to bees exposed to unscented air or 100% carnauba wax. The results indicate that the proboscis extension reflex can be used as a rapid, inexpensive, and reliable bioassay for the detection of adulterated beeswax. The bioassay will be useful in developing countries where chemical and physical methods are unavailable for detecting adulterated beeswax and can serve as an initial component in a comprehensive program of adulteration detection. An equation that predicts the probability of a proboscis response given the percent of adulterated wax is presented.