LEARNING IN HONEYBEES (APIS-MELLIFERA) AS A FUNCTION OF SUCROSE CONCENTRATION - ANALYSIS OF THE RETROSPECTIVE EFFECT

Foraging honeybees (Apis mellifera), trained with 2 successively prese nted targets labeled with different odors, one target baited with a sm all drop of 50% sucrose solution and the other baited with a small dro p of 20% sucrose solution, soon come to respond more promptly on 50% t han on 20% trials (prospective effect) and more promptly after 20% tha n after 50% trials (retrospective effect), with a pronounced interacti on between the two effects. In training with unlabeled targets, the re trospective effect is absent, which argues against postingestive inhib ition as an explanation, but the effect appears precipitously, along w ith the prospective effect and the interaction, when odor labels are i ntroduced (Experiment 1). Three subsequent experiments provided no evi dence for an associative explanation of the retrospective effect in te rms of discrimination supported by adaptation-based differential reinf orcement.