In this situation, we presume that with the evolution of social immunity, complex immune reactions at the individual level (immune priming and immunological memory) have been reduced to a minimum in honeybees and substituted by a new and more efficient strategy.
This social immunity complements individual immune defences of all group members and comprises sanitary behaviours, use of antimicrobials and modification of interaction frequencies (e.g. [ 3- 5]).
This suggests that the immune response in bees is subdued in favor of social immunity, yet some specific immune factors are up-regulated in response to infection.
Accordingly, it was suggested that external immune defences including social immunity may have alleviated selection pressure from the canonical innate immune factors as internal and external immune defences may trade off against each other.
The combination of an apparently quite complex innate immune system and social immunity may explain the resilience of these animals against pathogen infestation despite high population densities in their nests and genetic uniformity.
Thus males cannot take advantage of proposed colony-level social immunity [ 74] and a primed immune system might be an adaptation to life outside the colony.
While solitary species can only use personal immune responses to fight against infections, group-living species also possess the unique capability of mounting collective immune defenses, a phenomenon called social immunity [ 2, 4].
In addition, immune-related genes in A. cerana exhibited expression patterns that may reflect an advanced social immune system, advancing understanding of the molecular basis of social immunity.
In the case of honeybees, it seems that the best strategy that has evolved is an efficient system of social immunity, whereas only queens preserve more complex and costly immune reactions that can be passed on to offspring, conferring them with enhanced responses (Hernández López et al. 2014).
These results demonstrate that honey bee genomic responses to immunostimulation are substantially broader than the previously identified canonical immune response pathways, and may mediate the behavioral changes associated with social immunity by orchestrating changes in chemical signaling.
In some ways, ant colonies behave as if they're one large superorganism; rather than leaving each individual responsible for its own health, the colony has what researchers have called "social immunity".
