Jordan Twombly Ellis

The honey bee (Apis mellifera) is an economically important pollinator and a tractable system for studying the behavioral consequences of eusociality. As a eusocial species, honey bees live in colonies of thousands of sterile female workers with only one reproductively active female. Therefore, a sterile worker’s own genetic fitness is best served by acting in the interest of her colony, even if that behavior curtails her own lifespan. In this study, we test the hypothesis that developmentally stressed worker bees altruistically remove themselves to protect their colony from the negative costs of an inefficient workforce. To confirm that this behavior is a reaction to severe stress, and not a parasite driven behavior, or a result of bees trying to rid the colony of disease, we stressed bees with either cold or Varroa mites during pupation. Bees that we stressed with mite parasitization or cold shock, as well as their control counterparts, were tagged upon emergence and introduced to a common observation hive. We took daily attendance of the focal bees as well as checked a trap engineered to capture self-removing bees every hour. We have found that the stressed bees live for significantly less time than their unstressed counterparts. While there seems to be a trend emerging that only the mite stressed bees remove themselves more than their control counterparts, we need more trials to confirm this. Going forward we plan to measure the hypopharyngeal glands and Juvenile Hormone titers of the bees that prematurely exited to further confirm the drivers of this behavior.

Comments are closed.