English Home


The New World Carniolan Programme

Interview with Susan Cobey, from Ohio State University

(by John Phipps, the editor of The Beekeepers Quarterly)


Q. 1. Brief description of queen breeding operation - location, number of units, years in operation and extent of  trade.

A. 1. The New World Carniolan, NWC, breeding  program was initially established in 1981  in northern California as part of a small business  running 1000 colonies and 1000 mating nucleus for production of queens,  honey and  pollination service. We produced 5,000 production queens annually.   

The NWC  program was moved to  Ohio State University in 1990, which allowed me to concentrate more on the breeding aspects and leave the production work to the industry. Presently, the NWC  foundation stock is based in Ohio  and consists of about  200 colonies. Strachan Apiaries in California also maintains a subpopulation of NWC. Breeder queens  are supplied to the industry and from these an  estimated 300,000 to 400,000 production queens are produced annually. 

Breeder stock is primarily  provided to commercial queen producers in California. This is also offered to an increasing market of small producers ; regional queen producers and  honey producers / pollinators who rear their own queens.  I also provide semen to several countries abroad, as this is a safe and easy way to move stock. It also promotes the use of instrumental insemination, as a follow-up to the classes I teach abroad.  

My emphasis now is focused on the educational aspects and promotion of honey bee stock improvement.  The NWC breeding program is used as a working model for my classes and to provide support for the overall program.


Q. 2. Your chosen preference of breeds and why - characteristics of races / hybrids / strains. 

A. 2.  Obviously, I have a strong bias. I initially choose Carnica  to offer something different. At the time, this race of bee was less common in the U.S. and difficult for beekeepers to maintain. My initial thought was that with instrumental insemination – at least I could maintain a dark line of bees in an area of predominately Italian bees.  I collected and backcrossing stocks from across the U.S. and Canada to establish the foundation of the breeding program, as importation was not a legal option.  

Over the past 25 years of working with this race of bee, I continue to be amazed by them. Overall, I like their elegance, adaptability, gentle temperament., their  production strategy and hardiness.  Carnica  have strong survival skills in the face of pests, disease, drought and harsh winters conditions. Colonies are well organized, the brood-nest is kept tight with a surrounding rainbow of pollen and honey packed above. No queen excluders are needed during the honey flow. They do not require a lot of management, provided you give them space for rapid growth in spring.  

Carnica is a spring bee, responding to increasing day length and the first hint of pollen. Spring population growth is explosive, hence the reputation for swarming if not proper managed. In Ohio, my NWC population is generally 2 to 3 weeks ahead of the locally kept bees, in terms of queen and drone rearing. Yet, they tend to winter in smaller clusters with efficient use of winter stores. 

Brood rearing starts early. I do not use simulative feed to enhance this, as I barely keep up.  Weather is often not an issue. You can work these bees when the days are overcast and drizzly. It is not unusual for the drones to fly under  marginal conditions.  The commercial queen producers using NWC breeders tell me their NWC queens tend to mate earlier and more successfully than their Italian stocks.  

Adapted to a short season and long, harsh winters, Carnica  bees are very responsive o the environment and adapts quickly to change. Conservative in their use of stores, colonies shut down brood production when resources are scarce. They have good longevity and will outlast Italians when co-fostered in colonies for experimental purposes. They are also strong fliers, as indicated by their dance language. 

Carniolans have become more popular in the U.S.  since the introduction of parasitic mites. We have seen a general “darkening” of the US honey bee population through natural selection, with the impact of tracheal mites.  Programs designed to select for resistance to Varroa mites also seem to favor working with Carnica.  I think their high adaptability makes then very responsive to selection.


Q. 3. Breeding methods used both in selection, raising and mating.

A. 3. My philosophy has always been to select for general overall performance within the breeding population. Of the breeders selected, I then select more specifically for traits of  resistance to Varroa, as this is the major challenge to beekeeping today. I closely follow the Page-Laidlaw Closed Population Breeding theory. 

Selection at the commercial level is very different from that of a research project, designed to identify, measure and isolate a specific behavior.  I am not concerned with the mechanisms involved,  the goal is to simply cross the best to the best. In this way, I hope to select for the variety and complexity of traits that make bees productive, adaptable, and able to resist pests and disease.  

Selection within a closed population requires a long term commitment, yet the result is more stable. I have a population expressing desirable traits, rather than a few prized queens. Annually, I select the top 25 to 35 % of the population, rear queens and drones from these colonies.  Daughter queens are mated to the pool of semen from this same source. Annually, I establish a new test population of 200 to 300 instrumentally inseminated queens. These are evaluated and the process repeated.  We are in the 25th generation this year.  

The selection criteria is kept simple, because the more colonies I evaluate, the more critical I can be. Several traits; brood viability, temperament, buildup and wintering,  are given a point value. Colonies are ranked and the top performers selected.   At this stage, which I call the  pre-selection test, a cut is made. Those selected are given a  weight gain test during the honey flow, tested for hygienic behavior, and sampled for mite levels. The top performers of these become the breeders to establish a new generation and the cycle continues. 

The goal is to maintain selection pressure on the breeding population over time. A large gene pool provides genetic diversity and must be maintained. To increase the life of the program, I  occasionally look for new sources of stock. The stock is tested and if proven of value, some drones from this are added to the NWC semen mix. In this way I can enhance the gene pool, yet avoid significant change in the population.  

Primarily, I want bees that are productive and a pleasure to work. I assume productive bees have the traits to minimize the impact of pests and disease. To enhance this, I also select for hygienic behavior and lower mite growth rates. Colonies are not given prophylactic  treatment to prevent diseases. The bees need this association to develop natural resistance.  

Varroa is the exception, for which I do treat. Mite levels are sampled throughout the year for selection purposes. “Soft”  chemical controls are used in colonies  where mites reach damaging levels. I am amazed at the variation in mite growth rates and the high levels that can be tolerated. It seems to be the pathogens associated with the mites that cause the damage when levels are high during the fall season. These colonies are de-queened, treated and given a healthy nucleus with a new queen. Most recover.  

As the research evolves and new selection tools are developed, these will be incorporated into the breeding  program.  Honey bees are flexible and dynamic, the breeding program must also have these characteristics.


Q. 4. Thoughts on the possibility of breeding a truly Varroa tolerant bee. 

A. 4.  I believe this can be achieved and is just a matter of time. Worldwide, there are many researchers working on various aspects and alternative approaches. I think we are now approaching a new phase, past crisis management and the reliance on “hard” chemical treatments. 

European honey bees, if left alone would likely develop tolerance/resistance if we allowed natural selection to take it course. The Africanized bee is a prime example. The maintenance of bees susceptible to parasitic mites has placed selection pressure on the mites to adapt to our arsenal of chemical treatments. Beekeepers can reduce mite levels  through management and selection practices, rather than the sole reliance on chemical treatments. We are now forced to recognize this, faced with the current failure of chemical treatments.  

Several honey bee traits are know to reduce  mite infestation levels such as ; grooming behavior, hygienic behavior, brood pheromones cues, reduced development time, etc. There are probably many more mechanisms we have yet to identify.  Learning to select and maintain stocks expressing these traits at the commercial level will be a turning point.  

New alternative methods of control may prove practical and effective, such as the developing research looking as fungus as a Varroa control. Brood pheromones have been identified and may be synthesized as a control method. 

With the sequencing of the honey bee genome, identifying genes of resistance is a possibility. We may also learn how to turn  genes on and off at critical stages as a means to maintain healthy colonies. The development of  transgenic bees that express resistance may be a possibility.  Known genes  of resistance  from Apis cerana could be transferred to Apis mellifera to express resistance.  

Studies of Varroa have revealed this is a highly specialized complex of species. Numerous mitotypes of Varroa have been identified. The mites  infesting European honey bees have been renamed. Further studies may reveal a means to genetically manipulate the mites to make them less virulent.  

Basically, the goal is learning how to achieve the natural balance of the  host –parasite relationship of Varroa and European bees, as exisits in Apis cerana. We originally upset this delicate balance and created the problem. Now we must solve it.  

Our “box of tools” is increasing  and becoming more sophisticated.  I am optimistic and think bee research and beekeeping has an exciting future ahead. I expect to see the development of things that  I can not  imagine at present, especially in the field of molecular genetics. 

Cyropreservation is another area of developing research. I see a future where I can order  a tube of semen of stock with specific known traits. It often takes a crisis to push us in this direction. This makes the future is exciting.


Q. 5. What do you believe are the major problems facing queen breeders today?

A.5. My response is based on the US beekeeping industry, as this is my experience.  To answer this question we first need to define the word “breeder”. A breeder is one who applies methods of evaluation, selection and controlled mating  to a breeding system for the purpose of stock improvement. The queen producer is one who propagates bees. The term “queen breeder” has been loosely and interchangeably used with the term “queen producer”.   

The basic problem is – there are too few bee breeders. Historically, bee breeding has largely been limited to research institutions.  This is partly due to the stumbling blocks unique to honey bee breeding , compared to the breeding of domestic animals.  Also, before the challenge of parasitic mites and African bees, the need to focus on selective breeding was not seriously emphasized or supported by the industry.  

Commercial queen producers focused on the efficiency of large scale production techniques and have become very skilled at this. Yes, selection efforts are made, though generally this is limited to simply choosing the top performing colonies within their operations, without regard to heritage or controlled mating.  Gains are made, though often the results are inconsistent and unpredictable.  

The process of honey bee selection  must be based upon behavioral traits at the colony level within a complex social unit, over time. Expression is dynamic, flexible and strongly influenced by the environment.  The interaction of genes, traits, individuals and relationships with the  colony influence expression. This complicates the selection process. The breeder must select for several traits to produce productive colonies. The isolation and selection of a single trait ( as necessary in research)  eliminates the social complexity of a colony responsible for its productivity and survival,  often resulting in poor colony performance.  There is a conflict in that you want to select  for consistency, yet need to maintain genetic diversity, and the breeding system used must address this.  

Another complicating factor is the ability to control mating. Few beekeepers use instrumental insemination. Many still hold the view these queens are less productive, despite a wealth of research data proving otherwise.  

The beekeeping industry needs to support a new commercial aspect of beekeeping – the bee breeder,  who can supply the queen producers with known and proven breeding stock.  Most queen producer do not have the time or resources to produce and maintain breeding stock and the current pricing of queens does not support this.  

The view of bee breeding is changing, with the increasing cost of chemical treatment and the development of mite resistance to these, coupled with high losses of colonies.  An investment  in breeding stock finally seems like a viable solution and getting  more serious attention.  

Another issue is the management of colonies at the commercial level. Colonies are pushed in the demand for production and  frequently moved for pollination.  Colony stress combined with the impact of parasitic mites makes it difficult for any queen to maintain a strong colony. We need to re-evaluate management and production practices at the commercial level.


The interview is published on this website by kind permission of the author.


Susan Cobey's websites: