African Honeybees: Establishing a CCE-ICIPE Collaboration in Kenya
Daniel Schmehl and Tracy Conklin
To most people, the term “African bees” conjures images of cloud-like swarms bearing stinging death to any and all who dare disturb them. Far from the ferocious killers that Hollywood films make them out to be, the African honeybee is an important subject of research in light of recent pollinator decline. An estimated one-third of US honeybee hives were lost in 2007 due to a mysterious ailment known as Colony Collapse Disorder (CCD) as well as several other honeybee pests and maladies. While most of the bees kept in the U.S. are European in origin, several other subspecies of honeybees reside in Africa. While some of these subspecies are indeed known for their aggressive behavior, this ability to defend themselves from predators, disease, and other environmental stressors may be the key to resolving the problems that the European honeybees now face.
In February and March of 2009, we (CCE members Jim Frazier, Jim Tumlinson, Daniel Schmehl, and Tracy Conklin, as well as Maryann Frazier, senior extension associate specializing on honeybees at Penn State) went to Kenya to begin a comparative study between African and European honeybees and establish a collaboration with the International Center for Insect Physiology and Ecology (icipe) in Nairobi. We were joined by Tom McCormack, a professional beekeeper with extensive experience working with Africanized bees in Central America. During the three-week stay, our group worked closely with icipe researchers to accomplish many experiments within each of our respective areas of research.
Daniel set out to determine whether African honeybees are more sensitive to pesticides than our European honeybees. In the U.S., European honeybees are used to pollinate numerous different agricultural crops, coming in contact with several different classes of pesticides that farmers spray to prevent pest damage. In Africa, farmers use far less pesticides than farmers in the US. Daniel examined whether African honeybees are able to tolerate pesticides at the same levels that European honeybees encounter in the U.S. In addition, Daniel measured the learning abilities of pesticide exposed African bees by using the proboscis extension response (PER) technique. In PER, an individual honeybee is trained to a specific odor using a sugar reward. Once trained, the honeybee extends its mouthparts – expecting a sugar reward – when it senses the odor. By comparing the control and pesticide-treated bees, we can infer what effect a given pesticide is having on the honeybee’s learning abilities. Changes in learning ability in response to pesticide exposure may result in breakdown of foraging and communication. Identical experiments will be implemented on European honeybees during summer 2009 to determine whether African and European honeybees are affected differently by identical pesticide exposure.
Tracy, meanwhile, tried to tease out the factors that affect attraction of the small hive beetle to beehives. The small hive beetle is a pest which originated in Africa, but this species has recently been introduced into the US. Small hive beetle larvae and adults feed on honey, pollen, and brood. The beetles can reach population levels which cause the bees to abscond, leaving behind a hive full of nothing but beetles. Baldwyn Torto, a collaborator at icipe, discovered that the small hive beetle carries a yeast which, when growing on pollen, produces honeybee alarm pheromone. This alarm pheromone blend is very attractive to the small hive beetle. Tracy assessed the levels of beetles and yeast in the African beehives as they corresponded with other hive factors such as temperature and humidity, hive volatiles, stores, and aggression. Tracy also had the opportunity to collect volatiles from the hives of stingless bees, a tropical group of tiny bees that are kept for their medicinal honey. Unfortunately, small hive beetle populations were very low due to the weather transition from the dry to rainy seasons. Ayuka T. Fombong, a master’s student at icipe, is carrying out further beetle counts and measurements during the rainy season.
As much as we enjoyed our work with the African bees, we did not spend all of our time in the lab and the apiary. We had the opportunity to safari in Nairobi and Amboseli National Parks to view the plentiful wildlife and beautiful scenery. We thoroughly enjoyed the cultural experience of shopping in Nairobi. We also had the privilege of viewing traditional Maasai dancing and visiting the Nairobi national museum. In addition, the tropical climate of Kenya afforded us many insect-collecting opportunities that weren’t limited to bees and beetles. Finally, and perhaps most memorably, we were overwhelmed by the hospitality and kindness of all of the people we met at icipe.
Our recent trip was just the beginning of a long series of collaborative projects with our friends in Kenya. As part of our ongoing African honeybee project, a few researchers from icipe will be visiting us here in State College in September 2009 to observe U.S. beekeeping practices. We are also eagerly anticipating our 2010 trip to Kenya to follow up and expand on this project. We look forward to bringing you another exciting report about African honeybees in Kenya.