Response to Alarm Pheromone by European and Africanized Honeybees

Abstract

SummaryWorkers of two honeybee (Apis mellifera L.) geographical types, European and Africanized, in Venezuela were assayed for response to sting-associated alarm pheromone. Groups of young bees were exposed to either isopentyl acetate (IPA) or a mixture of 10 alarm chemicals, including IPA, at five concentrations. Africanized bees were more active before exposure to the pheromones, responded with greater intensity and in greater numbers, and continued to respond for a longer time. Europeans bees responded more quickly for concentrations of 1/100 and 1/1000; otherwise, the speed of response was the same as for Africanized bees. It was concluded that relatively more intense colony defence by Africanized bees is caused, in part, by greater responsiveness to alarm pheromones.