DO SOLITARY BEES OSMIA-CORNUTA LATR. AND OSMIA-LIGNARIA CRESSON USE PROXIMAL VISUAL CUES TO LOCALIZE THEIR NEST

Female Osmia repeatedly return to their nest to provision it with food and building material, The present study investigates the bees' nest localization performance by modifying visual cues in the near-vicinity of the nest. Each of several arrays of nesting holes was surrounded b y four geometrical shapes. Removing some or all of the shapes reduced the proportion of direct returns but never prevented a bee from findin g the appropriate array and, within that array, its own nest. The more the pattern was modified, the higher was the error score and the long er the delay, but no bee failed finally to find its nest. Shifting the pattern as well as the whole array of holes shifted homing orientatio n accordingly. There was no effect of the positions of the removed sha pes, of contrast inversion, or of modifying the holes array. Our data are discussed in the light of the snapshot theory.