Varying reproductive rates in queen Bombus impatiens: A reevaluation of bumble bee queen reproduction and behavior in early-stage nests

Animals exhibit a variety of unique life history strategies that are linked with fecundity and fitness. For social animals that exhibit brood care, understanding how individuals balance personal survival and reproduction with care for brood can provide key insights into social dynamics and evolution. Bumble bee queens initiate nests alone and carry out all brood care until their first worker brood emerge and take over these tasks. Early foundational work by bumble bee researchers described reproductive strategies employed by queens in early nesting stages. However, modern research has yet to fully characterize alternative reproductive strategies employed by bumble bee queens and examine their relationship to nest development and fitness. In this study, we examine the reproductive rate of Bombus impatiens queen nests, quantifying egg-laying, brood and nest development, and specifically the variance within these responses. We determined that queens differ in their reproductive strategies and demonstrate that egg-laying rates vary widely amongst queens and also within queens across their early nesting period. Overall, this work helps to substantiate early bumble bee queen biology descriptions and provides a clearer understanding of the variety of life history strategies that bumble bees execute and their relationship to nest growth and survival.