Colorado Queen Honey Bee Testing Project for Increased Sustainability

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2014: $24,922.00
Projected End Date: 12/31/2016
Region: Western
State: Colorado
Principal Investigator:
Kristine Holthaus
Colorado Queen Honey Bee Testing Project for Increased Sustainability

Annual Reports


  • Animals: bees


  • Animal Production: general animal production
  • Education and Training: demonstration, networking
  • Farm Business Management: cooperatives, marketing management
  • Pest Management: genetic resistance
  • Sustainable Communities: local and regional food systems, urban agriculture, sustainability measures


    The CO Queen Honey Bee Testing Project for Increased Sustainability was aimed at reducing or eliminating the dependence of chemical treatments on honey bee colonies to control the number one pest to honey bees, the varroa mite. Instead of relying on commercially available chemical treatments, we hoped to identify superior honey bee stock that would show increased resistance to the varroa mite as well as brood diseases, through their own genetic traits.

    114 honey bee packages were installed in our three Colorado producers apiaries. Test queens were selected from 5 different commercial producers propagating the most genetically varroa resistant stock available to US beekeepers in 2014.

    Testing and data collection of surviving colonies was started in May of 2015. Breeder candidates that scored the highest with our battery of tests were identified and used for additional propagation within each producer’s apiary. Additional virgin queens were also reared by our producers and distributed to CO beekeepers interested in participating in our project the end of June 2015.

    Unfortunately, during our first winter of 2014-2015, two of our producers suffered substantial colony losses. With limited data, and limited colony resistance to the varroa mites, both producers participation in the project came to an end in the fall of 2015.

    Our principal investigator continued the project over the winter of 2015-2016. Overwintering strengths, splits, honey production and additional propagation was completed throughout the 2016 summer season. Unfortunately, by the fall of 2016 all remaining project colonies within the Ft. Collins apiary were also showing extensive varroa mite populations and were treated with a newly registered organic treatment, oxalic acid vapor.   

    While we had great hopes and expectations for this project, it has continued to be extremely difficult to maintain honey bee colonies within the CO region without a proactive varroa mite control program… Thus, our ultimate project goal of producing a totally treatment free genetically resistant honey bee stock for Colorado beekeepers was not successful. 


    Our project began with the installation of 114 3lb. honey bee packages from Strachan Apiaries in April 2014. Throughout the summer each of our three producers installed and or propagated 36 honey bee queens from Olympic Wilderness Apiaries, Old Sol Apiaries, Harbo Bee Company, VP Queens and, in 2016, Kirk Webster. These select producers promote queen stock with reportedly superior genetic resistance to the number one honey bee pest, the varroa mite.

    Each producer also reared virgin queens for distribution at the CO State Beekeepers Association Summer meeting in June, 2014. Any CO beekeeper interested in participating in our project received up to two virgin queens to test in their own apiaries.

    However, the summer of 2014 proved challenging throughout the CO regions due to drought conditions and feeding all colonies carbohydrates and or pollen substitute to promote brood rearing and wax production was necessary.

    The goal of the first season was the installation, propagation, and feeding of all the test colonies to build to wintering strength in both cluster size and honey stores.

    A late spring in 2015 hampered spring build up for all our colonies. However, we were able to begin testing and data collection with our battery of tests by the end of May, 2015. The overwintered surviving colonies were tested for their hygienic behavior; the percentage of fertile to infertile varroa mites in the brood comb; as well as the percentage of varroa mites per colony. All three producers were involved in the testing.

    Once the strongest colonies within each apiary were identified, propagation was begun. Grafting, cell building and making up mating nucleus colonies was undertaken in each producer’s apiary.

    Additional distribution of virgin queens to interested CO beekeepers continued as an important part of this project and was done for the second year in June, 2015. Up to two virgin queens were distributed to CO beekeeper. These were to remain untreated and success or failures recorded each year.

    We presented a summary of our project and findings at our Western Apicultural Society’s annual conference in Oct. 2015. Graphs and results of our 2 year testing project gave conference attendees valuable feedback on these tested sources.

    Our two producers in Walsenburg and Longmont concluded their participation in our project after two years. Any of their surviving colonies would provide potential breeding stock within their selected regions.

    The Ft. Collins apiary was prepped for 2015-2016 winter conditions and would provide another year of additional data. One additional queen stock that was intended in our first introductions of the project was not available until spring of 2016. That stock was introduced during June 2016 and preliminary results indicate some success.

    Project objectives:

    Our three CO producers were selected from 3 different regions with 3 different levels of experience and expertise. The principal investigator, Kris Holthaus with the Ft. Collins apiary, has been a beekeeper since 1978 and has specialized in Queen Rearing survivor stock since 2001.

    Dean Chapla from the Longmont area has commercial beekeeping experience, growing up in CA and participating in the pollination needs of his family’s orchards. He was selected for his ability to address the commercial beekeepers’ challenges and needs for increased resistance to the varroa mite. His queen rearing techniques stemmed from a commercial background where quantities of queen cells/queens were produced.

    Our southernmost producer, Janet Fink from Walsenburg, has been very active in her region’s education, development and procurement of quality bees and queen stock. As a member of a previous grant study, The Rocky Mountain Survivor Queen Bee Project, she has been gaining valuable experience in queen rearing. (Year 1)

    We issued a preliminary survey to CO State Beekeepers that showed the greatest area of concern in their apiaries was the varroa mite. Two other areas that CO beekeepers were interested in improving were colony honey production and temperament. (Year 1)

    Based upon this input, 5 sources of queen stock was selected and installed. These sources included: Old Sol Apiary and Olympic Wilderness Apiary with 3 lines. The two additional lines were incorporated by the producers themselves with the use of Instrumentally Inseminated Varroa Sensitive Hygienic (VSH) Breeder Queens provided by John Harbo of Harbo Bees and VP Queens. Each producer then reared their own regional queen stock mated with their locally adapted drone stock to become part of our project. (Year 1)

    This breeder stock and the associated virgins were also used for interested CO beekeepers wanting to participate in the project in both 2014 and 2015. Each producer provided up to two virgins to each area participant the end of June 2014 & June 2015. These virgins were then mated within the participants’ localized region and remained untreated. (Year 1-2)

    Our website: was developed and maintained to show our progress on the project. Data, links, research, results and the producer’s apiaries were all listed to provide input on our CO state project. (Year 1-2)

    Testing protocols and procedures were developed and readied for spring 2015. (Year 1)

    All three producers gathered for testing overwintered colonies that consisted of greater than 2-3 frames of bees the end of May, 2015 (Year 2)

    A complete battery of tests was completed. (Year 2)

    1. Natural 24 hr. varroa mite drop count
    2. 24 hour hygienic behavior liquid nitrogen test
    3. Ratio of fertile to in-fertile varroa mite count
    4. Uncapping/Capping percentages
    5. Colony size
    6. Temperament of the colony

    Upon completion of these tests, selections were made for propagation and distribution. Grafting, cell building and additional mating nucleus colonies were made up in each producer’s apiary. (Year 2)

    The colonies then began their roles as production colonies in each apiary. Total production was also recorded. (Year 2)

    Presentations at our Western Apicultural Society Conference took place in Oct. 2015. Results of our tests and internet links to our project sources were included for all attendees. (Year 2)

    Presentations by our producers to their local and regional Beekeeping Clubs also took place throughout the two years of our project. (Year 1-2)

    We would like to develop a CO Queen Rearing Cooperative where our producers will be able to work with others in their regions by sharing their knowledge, stock, and suggestions on how to continue to increase genetic resistance to the varroa mite. (Future)

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.