Honey bee (Apis mellifera) sociability and nestmate affiliation is dependent on the social environment experienced post-eclosion

Abstract

Underpinning the formation of a social group is the motivation of individuals to aggregate and interact with conspecifics, termed sociability. Here, we developed an assay, inspired by vertebrate approaches to evaluate social behaviours, to simultaneously examine the development of honey bee () sociability and nestmate affiliation. Focal bees were placed in a testing chamber which was separated from groups of nestmates and conspecific non-nestmates by single-layer mesh screens. Assessing how much time bees spent contacting the two mesh screens allowed us to quantify simultaneously how much bees sought proximity and interaction with other bees and their preference for nestmates over non-nestmates. Both sociability and nestmate affiliation could be detected soon after emergence as an adult. Isolation early in adult life impaired honey bee sociability but there was no evidence for a critical period for the development of the trait, as isolated bees exposed to their hive for 24 h when as old as 6 days still recovered high levels of sociability. Our data show that, even for advanced social insects, sociability is a developmental phenomenon and experience dependent.

Biogenic amine modulation of honey bee sociability and nestmate affiliation

“…They were fed 40% honey-water daily and had no direct contact with other bees as adults since their cell was capped during the larval stages. Although bees as young as 5 days old consume pollen as well as honey, no difference in assay performance was found for isolated bees raised on different diets [ 47 ], hence we are confident the honey diet is sufficient for bees in this assay. All bees were tested at 5 days old.…”

“…In vertebrate studies, the level of sociability and strength of affiliations are assessed with two-choice preference assays [ 44 – 46 ]. Recently, a bioassay comparable to vertebrate and locust preference assays was developed for eusocial insects [ 47 ] and revealed that honey bees are highly sociable and prefer to remain in proximity to nestmates rather than non-nestmates when given a choice. Rearing animals in isolation and later testing them in assays that measure their sociability and preferential affiliations has revealed the influence of the developmental environment on vertebrate sociability and subsequent social behaviours [ 48 – 49 ].…”

“…Rearing animals in isolation and later testing them in assays that measure their sociability and preferential affiliations has revealed the influence of the developmental environment on vertebrate sociability and subsequent social behaviours [ 48 – 49 ]. Recently, it was found that honey bee sociability and affiliation is also experience-dependent, but high levels of sociability could be reinstated by brief exposure to the hive environment even after 5 days of age [ 47 ]. Here we combine the insect assay with pharmacological treatments to test for biogenic amine involvement in bee sociability and nestmate affiliation.…”

“…Although more invasive as the lens of the median ocellus must be removed for injection, the solvent is a bee-specific saline solution [ 51 ]. Based on the developmental findings [ 47 ], we treated 5-day-old bees with DA, OA, 5HT, an agonist or antagonist, and tested their sociability and nestmate affiliation. We treated and tested both isolated and naturally raised honey bees to investigate if biogenic amine receptor activation or inhibition is important in the initiation of approach and aggregation in socially naïve bees, as has been reported in locusts [ 36 ], or modulates these behaviours that have already developed in socially experienced bees.…”

Effects of group size on learning and memory in the honey bee, Apis mellifera

“…Cockroaches, which normally live in groups, exhibit exploration avoidance, reduced willingness to interact socially, and reduced ability to assess mating partners when raised in isolation (Lihoreau et al, 2009). Additionally, isolated honey bees have reduced interactions with conspecifics and no preference in interacting with nest mates over non-nest mates, unlike hiveraised bees (Hewlett et al, 2018). As the above literature suggests, isolation in normally social organisms leads to behavioural, structural and biochemical abnormalities in both vertebrates and invertebrates.…”