NC State University

Basic Research

Our research is driven by a fascination in how social insect colonies function as an adaptive unit. We are particularly interested in the behaviors associated with honey bee queens, since it is their offspring that determine a colony's phenotype and, ultimately, it is their genes that are passed on to subsequent generations.

We conduct research into two aspects of queen bee behavior which relate to two general issues of behavioral ecology. The first is the unusual mating behavior of honey bee queens. A queen bee is curiously promiscuous, mating with upwards of 20 (or more) males on her nuptial flights. We have investigated both why multiple mating evolved and how such high mating frequencies are obtained, and we are continuing to pursue these questions in new directions. We are currently investigating the potential benefits that a colony acquires as a result of its queen mating multiply by using the technique of instrumental insemination of honey bee queens, which enables us to experimentally manipulate the type and number of mates that a queen receives and to test the possible advantages of increased mating numbers. We have used this approach to determine if multiple mating reduces the prevalence of infectious diseases within colonies. We have also investigated the factors that influence the behaviors of queens during their nuptial flights, and describe their effects on the resultant genetic structure of colonies. To acomplish this, we use PCR-based molecular techniques to quantify the genetic structure of colonies as a result of queen mating behavior.

The second research focus is to understand the complex mix of cooperation and conflict within honey bee colonies. Because a queen mates multiply, a colony consists of many genetically distinct subfamilies that may not always share a common reproductive interest. Reproductive conflicts are most conspicuous during colony reproduction, or swarming, when many virgin queens are raised from these subfamilies and fatally compete with each other to take over the natal nest. Some of our previous research suggests that workers indirectly influence queen fights by favoring certain queens over others. We wish to further explore the mechanisms that regulate this process by better understanding how workers cooperate, rather than compete, by regulating queen rearing to maximize the reproductive success of the entire colony rather than their respective subfamilies; that is, how nestmates have overcome potential disunity to act as a cohesive unit.