title: Bumblebee ocelli and navigation at dusk.
abstract: Western bumblebees fly straight while homing by polarized light, but zigzag when they use landmarks. That flight difference was used to determine the roles of the dorsal ocelli and parts of the compound eyes in homing. Polarized light and ocelli can prolong foraging at twilight, when landmarks are no longer visible.
authors.forename: W G
authors.initials: WG
authors.lastname: Wellington