APIS—a novel approach for conditioning honey bees

Abstract

Honey bees perform robustly in different conditioning paradigms. This makes them excellent candidates for studying mechanisms of learning and memory at both an individual and a population level. Here we introduce a novel method of honey bee conditioning: APIS, the Automatic Performance Index System. In an enclosed walking arena where the interior is covered with an electric grid, presentation of odours from either end can be combined with weak electric shocks to form aversive associations. To quantify behavioural responses, we continuously monitor the movement of the bee by an automatic tracking system. We found that escapes from one side to the other, changes in velocity as well as distance and time spent away from the punished odour are suitable parameters to describe the bee’s learning capabilities. Our data show that in a short-term memory test the response rate for the conditioned stimulus in APIS correlates well with response rate obtained from conventional Proboscis Extension Response (PER)-conditioning. Additionally, we discovered that bees modulate their behaviour to aversively learned odours by reducing their rate, speed and magnitude of escapes and that both generalisation and extinction seem to be different between appetitive and aversive stimuli. The advantages of this automatic system make it ideal for assessing learning rates in a standardised and convenient way, and its flexibility adds to our toolbox for studying honey bee behaviour.