Methods of Making Increase Colonies

September 2014

Where Bee Sex Goes Wrong

by John Connor

(excerpt)

We have learned a great deal about queens and drones in recent years. Certainly, all the media attention about CCD has forced many people—beekeepers and scientists alike—to look at the many ways that queen bees interact with their colonies, and how young queens react with drones during the mating process. This summer I have been working with Gudrun and Niko Koeniger of Germany and Jamie Ellis of the University of Florida on a translation and publication of a book, currently available in German, written by the Koenigers. Originally, I thought my job would be  to act as publisher of the English edition of this book, but as we have worked through the process, Dr. Ellis and I find ourselves as reviewers, editors and contributors to the book, both as native-born English speakers (keeping in mind that the Koeniger’s did the translation of the first draft from German to English) and as bee researchers with something to add to the story about bees and reproductive biology.

The new book, currently operating under the title of Mating Behavior of the Honey Bee, Apis mellifera L, is a powerful and revealing review of the work the Koenigers’ have accomplished during their career, working in Germany, Austria and many other locations in the world where bees live. They have carried bees into the Alps for mating studies and filmed the mating behavior of queens and drones. There are several points that they make in the book that I have mentioned over the years, but they have a different perspective on the science of mating behavior. They also have worked with many different species of Apis.

The Conflict of Mating in Social Organisms

Mating behavior for most species often takes considerable effort and a certain amount of good fortune. For the social honey bee, sexual behavior is even more intense. While young queens could encounter drones inside the hive, they do not respond to drones in their hive but instead they act as if they do not exist. If they encounter a sexually ready drone outside the hive during a cleansing or orientation flight, it is not going to result in mating either.

The taboo of most organisms is to minimize or eliminate inbreeding between related individuals. Brother-to-sister mating inside a hive would result in a high degree of inbreeding and the resulting colony would suffer from a loss of vigor and vitality. Likewise, a chance encounter outside of a hive between a drone and a young queen could also result in inbreeding if there are no other colonies within the local area.  Inbreeding does more than create a spotty brood pattern in a hive. When I worked with inbred queen lines used in the Starline hybrid during the 1970s, they showed me all the ills of inbreeding. Steve Taber used to joke that all an inbred queen wants to do is die, and he certainly was accurate in that these queens had behavioral and physiological limitations resulting from the high level of inbreeding. Inbred queens lacked vigor, they had reduced egg-laying rates and they were easy candidates for diseases and parasites, as well as replacement via supersedure. When they had mated to drones that carried the same allele for sex determination, the brood pattern was spotted with cells where diploid drones were placed and removed by their sisters soon after hatching from the egg. To manage these colonies, we needed support colonies that provided frames of emerging brood necessary to keep the colonies (almost always kept in five-frame nuclei) alive and preventing death of the line.

These were extreme conditions, but these dramatic effects of inbreeding certainly show us why Nature develops such extreme methods to prevent inbreeding. And in honey bees, we have some of the greatest extremes Nature has ever created to minimize the chance that closely related queens and drones might mate.

Distance Mating
The detailed work the Koenigers have done clearly show the benefits of flying far away from the hive to find unrelated sexual partners. They have looked at the cost of producing large numbers of drones and few queens, and the additional cost of putting both reproductives into the air so they can mate. The first and ever amazing biological feature is the use of distant Drone Congregation Areas for mating.

DCAs are where drones and queens fly to for mating. These are locations that are clearly genetically defined, as drones from one season die and are not available to show the route to the next year’s drones. Instead, the drones, and the queens, have genetic information that instructs them on where to go. We still do not know what this programming includes, but some of the theories
include:

•     Flying to lower points on the horizon

•    Where flyways cross, as evidenced by research in the U.S. that show that non-descript areas seem to have a different set of focus factors than used in DCAs in mountainous areas.

Drones and queens fly different distances from the hive, the queen much further, a behavior that reduces the chances of a brother and sister bee encountering one another during mating. This behavior has likely developed, genetically, as a result of ...