A modular system for trapping and mass-marking bumblebees: applications for studying food choiceand foraging range

Two new techniques for the study of bumblebee behavioural ecology are described. Interchangeable nest entrance modules allow (i) unimpeded bee traffic, (ii) trapping of incoming foragers for counting and removal of pollen loads; or (iii) colour marking of bees leaving the colony using dye powder. The forager traps captured all returning foragers while in place and 35% of them were carrying pollen loads. During the four week experiment, the percentage of mixed pollen loads decreased and the proportion of pollen loads from mass-flowering resources increased. The dye dispensers automatically marked 86% of foragers as they left the colony ( approximately 28 bees per hour), and 37% of returning bees were marked. Different colours were used for bees in each colony, which could then be observed in the field.