TRAPLINE FORAGING BY BUMBLEBEES .1. PERSISTENCE OF FLIGHTPATH GEOMETRY

By setting out arrays of potted plants of Penstemon strictus, I tested whether freely foraging bumblebee (Bombus spp.) workers would establi sh regular foraging routes that reflected the geometry of the array. T hey did, passing through an asymmetrical array in a pattern that minim ized interplant flight distances. After the array was changed to a sym metrical pattern, however the experienced bees continued to show their previous asymmetrical flight patterns. New bees without experience on the asymmetrical array showed no asymmetry on the symmetrical array. I term this persistence of flight-path geometry ''trapline holdover,'' and discuss its implications for the study of animals' learning and f oraging behavior.