Bernard Roger

RECOGNITION OF COMPLEX ODORS BY RESTRAINED AND FREE-FLYING HONEYBEES, Apis mellifera

Complex odor recognition in the honeybee was investigated using two behavioral assays: (1) the conditioning of the proboscis extension (CPE) with restrained individuals, and (2) the observation of foragers visiting an artificial feeder in a flight room. Nine compounds, previously identified as oilseed rape flower volatiles, were tested either individually or in mixtures. Different sets of experiments were done to determine: (1) the acquisition rate of the nine compounds in the CPE assay, and (2) the discrimination of the individual compounds after conditioning to a mixture, using the CPE assay and free-flying foragers. After conditioning to a complex mixture, honeybees established a hierarchy among the components, with some of them accounting for a major part of the behavioral activity of the mixture. Both behavioral assays led to the same classification of compounds, indicating good agreement between discriminating abilities of restrained individuals and of a population of foragers. The key compounds for recognition of these mixtures were those that were well learned when presented individually. However, the recognition of some compounds was affected by the other components of the mixture, with the activity of some compounds being either enhanced or reduced.

Individual learning ability and complex odor recognition in the honey bee, Apis mellifera L.

Individually restrained worker bees were trained to recognize complex odors in a conditioned proboscis extension assay. Three groups of bees were considered, based on the responses recorded during the experimental procedure: selective learners, nonselective learners, and nonlearners. For conditioning, three concentrations of two synthetic mixtures were used. The distribution of bees between groups was not significantly affected by the nature or by the concentration of the conditioning mixture. After conditioning, bees were tested with the individual compounds, and the responses were analyzed with respect to the three groups. Selective learners showed discriminative responses to a few key compounds, while nonselective learners responded to all the compounds, and nonlearners to none. These results showed that complex odor recognition is based on the recognition of key components and relies on the ability of bees to learn.

VARIATION EN FONCTION DE L'AGE DES OUVRIÈRES D'ABEILLES (APIS MELLIFICA LIGUSTIÇA S.) DU POUVOIR D'ATTRACTION D'UN EXTRAIT DE PHÉROMONES ROYALES

Le comportement de cour des ouvrières à l’égard d’une reine féconde a pu être reproduit au moyen de leurres. La substance responsable de l’attraction, non totalement identifiée dans sa fraction volatile, est localisée dans les glandes mandibulaires de la reine. La mise au point d’un test biologique appliqué à des lots d’ouvrières d’âge variable (1 à 30 jours) soumises à une même dilution de cet extrait (1/16 tête de reine) permet de montrer une plus grande sensibilité des jeunes ouvrières de 1 à 6 jours à l’égard du leurre royal. L’existence d’une période « critique » au plan du comportement correspond aux données neurobiologiques concernant le développement du système olfactif.