Unnatural Contexts Cause Honey Bee Guards to Adopt Non‐Guarding Behaviours Towards Allospecifics and Conspecifics

Abstract

Context plays an important role in a discriminator's ability to make appropriate recognition decisions, such as accepting what is acceptable and rejecting what is not acceptable. Previously it was shown that in both honey bees and stingless bees, discriminating workers (guards) make more errors towards conspecific non‐nestmates when the guards are removed from the natural hive entrance. However, it may be that guards, in addition to making incorrect recognition decisions, also may adopt non‐guarding behaviours. Here, we tested honey bee guards in two contexts (natural versus unnatural) against five types of introduced arthropods (conspecific nestmates and non‐nestmates; allospecific wasps, beetles and woodlice), which should be rejected without error. We scored a guard's response as accept, reject, avoid and ignore. Total errors significantly increased from natural to unnatural contexts. Specifically, guards were significantly more likely to make an acceptance error, guarding and accepting both conspecific and allospecific non‐nestmates, in the unnatural context. Importantly, guards were significantly more likely to adopt a non‐guarding behaviour in the unnatural context, which usually involved ignoring or avoiding, where a guard makes contact but then immediately retreats, the introduced arthropod. Overall, these data demonstrate the context is important. Removing a guard from the home that it protects elicits either incorrect discrimination or, additionally, a complete lack of discriminator behaviour altogether.

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

“…Relatedness and familiarity of the colonies used is unknown and all were located in the same bee yard and plain white hive boxes used, an arrangement that would allow drifting of bees between colonies (Pfeiffer and Crailsheim, 1998). However, the strength and variability in NM affiliation seen in this study is consistent with previous recognition studies that used guard and non-guard bees in NM recognition assays away from the context of the hive (Couvillon et al, 2013(Couvillon et al, , 2015. In this assay, either friendly approach behaviour or an aggressive attack would still be recorded as time spent on their mesh.…”

“…A group of nestmate and nonnestmate conspecifics were presented simultaneously to determine whether the focal bee preferentially affiliated with its nestmates over unfamiliar conspecifics. Although successful discrimination between nestmates and non-nestmates is reduced in contexts away from the hive (Couvillon et al, 2013(Couvillon et al, , 2015, generally bees are more aggressive toward unfamiliar conspecifics and preferentially aggregate with nestmates (Breed et al, 1985;Downs and Ratnieks, 1999). We would therefore expect naturally raised bees to spend more time with nestmates than non-nestmates.…”

Natural biocide disrupts nestmate recognition in honeybees

“…If exposure to the fungus also altered their behaviour alongside their chemical profile, for example making exposed bees less reactive or aggressive, they could more easily sneak inside the colony. In facts, previous studies 53,54 demonstrated that context or type of stimulus can have major effects on recognition. In the case of bees, guard are significantly more likely to make acceptance errors when tested in an unnatural context 53 , while the level of aggressive response can vary depending on the characteristics of presented stimulus as for example with Polistes wasps which show a lower degree of aggression when presented with only the cuticular fraction of a conspecific compared to a whole body wasp lure 54 .…”

“…In facts, previous studies 53,54 demonstrated that context or type of stimulus can have major effects on recognition. In the case of bees, guard are significantly more likely to make acceptance errors when tested in an unnatural context 53 , while the level of aggressive response can vary depending on the characteristics of presented stimulus as for example with Polistes wasps which show a lower degree of aggression when presented with only the cuticular fraction of a conspecific compared to a whole body wasp lure 54 . Overall, exposure to the fungus alters the CHCs of foragers bearing the mycosis after exposure to B. bassiana spores and this appears to be correlated to a significant change in the acceptance behaviour by guards towards fungus-exposed bees, especially increasing acceptance of exposed non-nestmates regardless of the experimental context, and such alteration.…”