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.

Applied research

Our research is also driven by advancing our ability to manage honey bee colonies for hobby and commercial purposes. Arguably the most beneficial insect in agriculture is the honey bee, which serves as an invaluable pollinator of crops and a producer of honey and other hive products. Researchers have estimated that honey bees account for approximately $14.6 billion in pollination services and increased crop yields nationwide. In the state of North Carolina alone, services provided for the pollination of crops accounted for approximately $97 million in 2000, and an additional $10 million was generated in honey sales and other hive products. Crops that are primarily dependent upon honey bees for pollination in N.C. include cucumbers ($36.2 million), apples ($18.3 million), blueberries ($18.1 million), watermelons ($9.6 million), squash ($9.2 million), and melons ($5.0 million). A better understanding of honey bee biology and bee management will bolster this industry that directly impacts approximately one-third of all agricultural food products.

Beekeepers currently face many daunting issues. First, a litany of diseases have plagued colonies and have significantly changed how honey bees are managed. Like most domesticated animals, honey bees may acquire any number of infections agents as a consequence of spatial overcrowding and equipment sharing. The cost to prevent and treat disease is considerable, and a central focus of apicultural research has been to reduce the impact of infections. Two parasitic mites, Varroa destructor and Acarapis woodi, have decimated feral and commercial populations in the short span of two decades. American foulbrood (AFB), a serious brood pathogen of honey bee colonies, is extremely difficult to eradicate from honey, wax, and hive equipment once they have been contaminated. The most recent pest is the small hive beetle (SHB; Aethina tumida), which is currently concentrated in the southeastern states and has become a source of colony mortality and destruction of valuable or expensive stored equipment.

Second, the invasion of the “Africanized” bee from South America has changed the practice of keeping bees as well as the public’s perception of them. The AHB gained its “killer bee” moniker because of its increased defensive behavior, and has become known (somewhat undeservedly) as a serious public health issue. The AHB was first reported in Texas in the early 1990’s and has since become established throughout the southwest. Professional beekeeping in the U.S. maintains strong ties to the southern third of the country due to its mild winters and longer foraging seasons. Migratory beekeepers annually overwinter their colonies in the southern states then pollinate various crops as they move northward. Queen and package productions are also concentrated in California, Georgia, and other southern states to supply the rest of the country with commercial stock in the early spring. These industries will be impacted severely by the AHB, particularly if they migrate into the southeastern states.

Third, as a consequence of disease (and, to some extent, the AHB) there has been a dramatic loss of colonies throughout the country. For example, there has been a significant reduction in the number of managed honey bee colonies within North Carolina, from an estimate of 180,000 down to 100,000 in the past 20 years. Because the AHB is currently restricted to Texas and the desert southwest, this 44% decrease is largely attributable to the parasitic mite Varroa destructor and the resultant increased cost of colony management. The dwindling number of feral and commercial honey bee colonies has had significant ramifications on crop pollination, thus reversing this trend will benefit the beekeeping and agricultural industries alike.

Our program is currently addressing each of these concerns through various extension and research endeavors. Our goal is to promote new technologies and management practices that will minimize the economic and social impact that these issues create.

Facilities

The on-campus research spaces are located in Gardner Hall, the main building of the Entomology Department. It contains approximately 1,000 square feet of laboratory and office space. The office suite contains several work areas, a library dedicated to behavioral ecology and social insect biology, and computer analysis facilities. The genetics lab contains the necessary equipment and reagents to perform molecular analyses of honey bee colonies. The off-campus facilities are located on the Lake Wheeler University Farm complex. The building is approximately 4,000 square feet and contains 10 laboratory and office spaces, a basement for equipment storage, two glass-walled porches, and a garage. The facility is located on five acres of property, surrounded by hundreds of acres of farm land, and therefore provides ample space to place many bee hives. The main building includes a library dedicated to apiculture and honey bee literature (available to the public by appointment), a conference center for presentations and extension-based activities, a chemical lab, a multipurpose lab, and a queen breeding/instrumental insemination lab. Click here for directions to the Lake Wheeler Honey Bee Research Facility.