Conflicting selection on workers underlies global honey bee colony losses

Figures & data

Figure 1. Life history trade-offs between longevity and other traits in social insect workers arising from conflicting selection between periods with brood rearing and without. When colonies rear brood (light grey box), selection on worker longevity is relaxed and other costly traits can be highly expressed if required (e.g. immune defense or detoxification). However, when colonies do not rear brood (darker grey box), worker longevity is under strong selection to maintain the minimum number of workers necessary for colony functionality. Therefore, expression of other traits is compromised. If workers are challenged in such periods without brood rearing colony death is consequently more likely to occur (black dots = phenotypic trait expression, dashed lines = differential trait expression due to conflicting selection).