Olfactory associative learning in two African stingless bee species ( Meliponula ferruginea and M. bocandei , Meliponini)

Worldwide only a few of the more than 500 stingless bee species has been studied in any detail. Most studies on stingless bees have been conducted in the Neotropics, whereas a very few have been undertaken in Africa. Foraging success is dependent to a greater or lesser extent on olfactory cues or signals. A prerequisite to effective foraging via odors is that the bees are able to associate odors with a nectar reward and memorize this information. In the context of olfactory learning, only five species of stingless bees have been studied using classical conditioning of the proboscis extension reflex (PER). Foragers are capable of using previously experienced olfactory information when choosing food sources, but they rarely respond in differential PER assays. This study examines for the first time the olfactory learning abilities of African stingless bees. A differential conditioning assay was used to study learning and memory of Meliponula ferruginea and Meliponula bocandei. Our results clearly show that both stingless bee species associate odors with a reward. Learning performance of both stingless bee species was poor compared to Apis m. scutellata. This might reflect that the experimental procedure has been optimized for Apis mellifera. However, the PER paradigm seems to be suitable to study learning, memory, and olfactory perception in Meliponula. As in honeybees, this paradigm will open the way to answer ecological, psychological, and neurobiological questions in these species.