The influence of a queen-produced substance, 9HDA, on swarm clustering behavior in the honeybeeApis mellifera L.

The effect of enantiomers of the queen-produced substance, 9-hydroxy-(E)-2-decenoic acid (9HDA) on swarm clustering behavior of the honeybeeApis mellifera was studied. Caged queens were removed from the swarms at the start of each test and were replaced with small Petri dishes containing one of the following treatments: 100 μgS(+) enantiomer of 9HDA, 100 μgR(-) enantiomer of 9HDA, 200 μg racemic (R, S) 9HDA, and a vehicle-treated control. Each swarm was considered to have dispersed when it had lost 50% of its starting weight. All treatments with 9HDA resulted in significantly longer swarm aggregation when compared with the control. Enantiomers were not shown to have different effects at theP ≤ 0.05 level of significance. However, observations on swarm behavior indicated that theR(-) enantiomer was the most active in retarding swarm dispersal.