HONEYBEE NAVIGATION EN-ROUTE TO THE GOAL - VISUAL FLIGHT CONTROL AND ODOMETRY

Recent research has uncovered a number of different ways in which bees use cues derived from optic flow for navigational purposes. The dista nce flown to a food source is gauged by integrating the apparent motio n of the visual world that is experienced ew route, In other words, be es possess a visually driven 'odometer' that is robust to variations i n wind load and energy expenditure. Bees flying through a tunnel maint ain equidistance to the flanking walls by balancing the apparent speed s of the images of the walls. This strategy enables them to negotiate narrow passages or to fly between obstacles. The speed of flight in a tunnel is controlled by holding constant the average image velocity as seen by the two eyes. This avoids potential collisions by ensuring th at the bee slows down when flying through narrow passages. Bees landin g on a horizontal surface hold constant the image velocity of the surf ace as they approach it. This automatically ensures that flight speed decreases with altitude and is close to zero at touchdown. The movemen t-sensitive mechanisms underlying these various behaviours seem to be different, qualitatively as well as quantitatively, from those mediati ng the well-investigated optomotor response.