Differences in habituation and dishabituation between pollen and nectar foragers contribute to foraging division of labor

MORENO, EMILIA; ARENAS, ANDRÉS

Conferencia; Animal Behaviour Live: Annual Online Conference 2022; 2022

Division of labor is central to the ecological success of social insects. Among foragers of the honeybee Apis mllifera, specialization for collecting nectar or pollen correlates with bees´ sensitivity to sucrose. It has been shown that pollen foragers returning to the hive are more sensitive to sucrose than nectar foragers. Differences between nectar and pollen foragers have been also found in associative learning, with individuals performing better when rewarded with the stimuli to which they are more sensitive. Nevertheless, these differences haven’t been proved in non-associative learning. One of the most common non-associative learning processes is habituation, characterized by a graded decrease in a behavioral response as result of the repeated presentation of a stimulus. The habituated response can be dishabituated (recovered) by the same stimulus presented at a higher intensity or by an equivalent but different stimulus. Here, we hypothesized that pollen and nectar foragers differ in their habituation and dishabituation performance. We quantified bee’s performance by the proboscis extension reflex (PER), an innate response elicited when sucrose solution contacts the antennae. Habituation trial consisted in the repeated presentation of either: i) sucrose-water solution (10%w/w) on the antenna or ii) sucrose-water solution (10%w/w) on the antenna plus hand-collected kiwi pollen on the first tarsi. Dishabituation was tested in bees habituated with sucrose solution (i) by means of repeated presentation of sucrose solution (10%) on the antenna and pollen on the tarsi. Our results showed that habituation with sucrose solution was similar in pollen and nectar foragers. However, pollen foragers habituated less (they showed higher PER proportion during habituation) than nectar foragers if trials included pollen as habituating stimulus. Moreover, dishabituation was higher in pollen than in nectar foragers. Taken together, our results suggest that both forager types perceive pollen differently, resulting in different performance during habituation and dishabituation.