Classical olfactory conditioning promotes long-term memory and improves odor-cued flight orientation in the South American native bumblebee Bombus pauloensis

PALOTTINI FLORENCIA; PALOTTINI FLORENCIA; NERY DENISE; NERY DENISE; FARINA WALTER MARCELO; FARINA WALTER MARCELO

Current Zoology

Oxford University press

Lugar: Oxford; Año: 2020

1674-5507

When collecting a flower, bumblebees learn to associate floral features with reward, preferring, and specializing in the most profitable ones they visit (Chittka et al. 1999). The proboscis extension reflex (PER) occurs naturally in the feeding context allowing individuals to access the floral nectaries. Under controlled conditions, the PER paradigm is a well-established controlled learning procedure used in honeybees (Takeda 1961), and some bumblebees of the genus Bombus (Laloi et al. 1999). The assessment of cognitive capacities in an operant context has been studied mainly in B. terrestris and B. impatiens (Chittka 1998; Mirwan and Kevan 2014). However, little is known about the ability to evoke associative memories in an operant context, which had been acquired in a classical one. In turn, on the contrary, the Bombus genus also has the capacity to form long-term memories (Chittka 1998; McAulay et al. 2015). In particular, the South American bumblebee B. pauloensis (sin. B. atratus) can learn a pure odor when it is presented in a paired association with a sugar reward within a PER paradigm (Palottini et al. 2018). As other species, this one is a commercially reared pollinator that is increasingly managed in pollination services of some South American countries and they could be important for increasing production of crops (Palottini et al. 2018). The present research aimed to examine the long-term memory capabilities of B. pauloensis in an olfactory classical PER conditioning procedure and testing its memory 24 and 48 h after training. We also evaluated its capacity to transfer the information acquired by training the bumblebees in a classical PER conditioning context and then submitting them to a choice experiment in a flying cage (FC). Methodological details can be found in the Supplementary materials (Supplementary Figure S1). Briefly, we performed a long-term memory assay 24 and 48 h after a PER training for the first experiment (Long-Term Memory Assay), and for the second experiment (Information Transfer Assay) we trained bees in a PER conditioning and later tested them in an FC were they had to choose between the learnt and a novel floral odor, both without reward.