Honey bees, live as a group of organisms that form a cooperative unit: a colony. Colonies, like individuals, have a cycle of growth and development. When a colony transitions between developmental stages, the workers must coordinate the transition. The goal of this project is to understand the cues that non-reproductive worker honey bees use to detect the developmental stage of their colony and coordinate the switch between producing more workers and producing reproductive males and females (drones and queens). This research will encourage collaboration between researchers studying animal behavior, chemical ecology, and electrical engineering. Current methods used by beekeepers to assess the strength and developmental stage of a honey bee colony are based on metrics that humans can easily determine, but are almost certainly not those used by the bees. Honey bees are the primary pollinator of agricultural crops worldwide, providing billions of dollars of pollination services. By identifying the metrics that bees use to detect their own colony's development, this research will help beekeepers determine which colonies need to be managed, and when. Better colony management can in turn improve crop production. The outcomes of this research will be shared through beekeeping classes. This project will also train graduate and undergraduate researchers in behavioral ecology, chemical ecology and engineering.
Descriptive work has shown that social insect colonies invest first in workers (for growth) and then switch to producing reproductive individuals. Theoretical work has shown why colonies invest as they do, but it is unknown how developmental transitions are coordinated. The researchers recently discovered that a threshold number of workers is the trigger that induces honey bee colonies to invest in reproduction, but how workers detect this reproductive threshold is unknown. The goal of this research is to test two hypotheses of the mechanism by which individual honey bees assess their colony?s size: (1) beeswax comb vibrations, and (2) volatile chemical compounds. Using accelerometers to measure comb vibrations, and gas chromatography to analyze chemical compounds, the researchers will determine whether these cues reliably change with colony size. The cues will then be experimentally manipulated, to determine which one(s) the workers use to detect that their colony is above the reproductive threshold. Understanding the cues that superorganisms use to coordinate their developmental transitions will give insights into how evolution has solved similar problems at different levels of biological organization such as individuals and societies.
