The price of insurance: costs and benefits of worker production in a facultatively social bee

Selection on traits that maximize maternal fitness represents a recurrent mechanism underlying early evolutionary transitions towards social organization. We use genetic and demographic data to perform a cost-benefit analysis comparing alternative reproductive strategies in a bee capable of both subsocial and social nesting. We find that, while alloparental care provides few fitness benefits for worker daughters, social nesting is an advantageous strategy by way of assured fitness returns to social mothers.