EFFICIENT FLORET INSPECTION BY HONEYBEES IN CAPITULA OF CARDUUS-ACANTHOIDES

1. The floret inspection by honeybees Apis mellifera ligustica on infl orescences of Carduus acanthoides was studied in a natural patch. Firs t-day stage capitula were protected with a net hood against insect vis its. The next day, the net hood was removed at the time of maximal nec tar accumulation, allowing a bee to visit the inflorescence. Walking t rajectories on the capitula, the number of florets inspected and the d uration of the visit were recorded. After the bee's departure, the inf lorescence was cut off and analysed in the laboratory to determine the presence or absence of nectar in each of its florets. 2. Bees made in spection trajectories without a defined systematic pattern. 3. The num ber of floret inspections performed represented a high percentage of t he available florets (57.37 +/- 2.81%; mean +/- SE; n = 8). 4. The num ber of depleted florets coincided with the number of floret inspection s. 5. The number of times a floret is visited in a bee's trajectory is non-random. 6. Strategies that might account for this high foraging e fficiency are discussed.