Modulation of the honey bee (Apis mellifera) sting response by octopamine

The ability of octopamine (OA) to modulate various parameters of the honey bee sting response was observed using an isolated abdominal preparation. OA reduced the level of rhythmic neuromuscular activity (as measured by electromyogram recordings) during stimulated stinging response trials, but did not alter the activity in pre-stimulation baseline trials or post-stimulation recovery trials. However, OA also potentiated reflexive sting extension responses and this potentiation persisted for at least 3 h. The different effects of OA on this behavior indicate that there are multiple targets for the neuromodulatory activity of OA on the sting response and that these targets may include muscular, motorneural, sensory or integrative elements responsible for generating stinging behavior. In addition, rates of oxygen (O₂) consumption by abdominal preparations were found to be unaffected by OA treatment, indicating that respiration in the abdomen is not sensitive to OA modulation.