‘Social detoxification system’?
Genome-level deficits in detoxification and immunity
relative to other insects may be an evolutionary consequence
of A. mellifera eusociality. In terms of immunity,
bees display cooperative behavioral defenses against
parasites and pathogens, including ‘social fever’ to kill
temperature-sensitive bacteria, collection of antimicrobial
plant resins for propolis, and removal of diseased brood,
that collectively comprise a ‘social immunity’ system
[36,37], which may have reduced reliance on genomeencoded
physiological immunity. Whether social behaviors
contribute comparably to xenobiotic detoxification,
leading to or compensating for reduced detoxification
gene inventories, has not yet received attention. Behavioral
mechanisms that may reduce toxin exposure include
selective foraging with detection and avoidance of toxins
in nectar and pollen, dilution of toxins by mixing nectars
and pollens, processing of nectar into honey, and culturing
fungi and other microbes to convert pollen into
beebread. These behaviors may significantly reduce
the number and concentration of toxins requiring enzymatic
processing — a ‘‘Phase 0’’ of sorts in the traditional
scheme of xenobiotic detoxification (Figure 1).
The size and perennial nature of honeybee colonies
necessitate nectar and pollen collection from a broad
diversity of flower species; while bees encounter multitudinous
environmental chemical signals, the extent to