Final Report for SW07-055
Selected stocks of honey bees from the Washington State University (WSU) Bee Breeding Program were propagated and distributed to Pacific Northwest (PNW) beekeepers throughout the project period (and continues). The primary germplasm disbursement mechanism was through the WSU-local/state beekeeping association collaborative apiaries and regional queen producers. These groups further distributed WSU selected honey bee stocks through their own local queen production activities with WSU queen “mothers.” Honey bee germplasm (semen) from three Old World honey bee subspecies were collected and hand-carried into the U.S. under a USDA-APHIS permit to WSS and used to inseminate domestic honey bee stocks in 2008, 2009 and 2010. After release from quarantine, genetic material from these imported lines were incorporated into our bee breeding program to increase genetic diversity in U.S. honey bee populations. We established a honey bee pathogen and disease diagnostic laboratory at WSU, funded by beekeeper contributions, and have provided no-cost diagnosis of more than 4,000 samples for PNW beekeepers throughout the granting period. Numerous presentations were made by WSS, students and staff to local and state beekeeping associations in ID, WA and OR, and beekeeping short courses at WSU promoted the use of regionally-selected honey bee stocks. One 50% FTE extension associate was added and continues outreach to regional beekeepers, with queen rearing and instrumental insemination courses in both eastern and western WA locations.
1. Develop local evaluation protocols for honey bee stock performance by beekeepers in Oregon, Idaho and Washington for use in selective scoring criteria.
Breeding methods and stock evaluation procedures were widely disseminated through local, regional and statewide presentations and during short course/field days. For a typical example, see attached “pnw breeding.pdf.”
2. Provide beekeeper access to selected honey bee germplasm by establishing collaborative apiaries. These apiaries will be supplied annually with the diversity of all maternal genetic lines under selection at WSU and will be used to train beekeepers in queen production. The propagation of daughter queens from WSU stocks by beekeepers will serve to distribute additional genetic variation into PNW bee populations.
Collaborative apiaries were established in multiple locations in Washington, representing seven local associations (member associations of the Washington State Beekeepers Associations) and were supplied annually with new WSU breeding stock. Individual beekeeper collaborators or small queen producers in Idaho and Oregon were supplied with WSU breeding stock upon request, and one collaborator in Idaho produced about 3,000 queens annually for his own use and some distribution. New germplasm from imported honey bee semen was incorporated in WSU stocks and provided to local associations and some California queen producer/collaborators (suppliers of virgin queens for the germplasm inseminations).
3. Train beekeepers in principles and methods of IPM, related to mite population monitoring, economic threshold-based treatment regimes and alternative treatment options. The implementation of IPM principles by beekeepers will assist in reducing pesticide use.
A fundamental part of all outreach presentations included discussion of breeding for mite resistance and mite monitoring (sticky boards) as alternatives to scheduled mite treatments. Non-synthetic miticides (formic acid, essential plant oils, sugar esters) were used when mite control was necessary. All breeding stocks at WSU are maintained and selected for program inclusion and disease resistance without antibiotic use to 1) select for bees that can clean up early infection on their own (freeze-killed brood assay) and 2) to reduce the chance of selecting for antibiotic-resistant pathogens. (see attached “pnw breeding.pdf”)
The honey bee is a fundamental contributor to the agricultural and economic environment in many Western states. Managed honey bee populations have declined in the U.S. since the introduction of Varroa mites, and mite-associated losses of honey bee populations create an uncertain future for commercial beekeepers and the pollination services they have provided. In 2007-2008, the recognition of a major increase in the ongoing loss of managed honey bees provided an expanded discussion of honey bee colony losses under the term “colony collapse disorder.”
We proposed to continue a selective bee breeding program that began at WSU in 2001, to expand the distribution of mite-tolerant stocks to PNW beekeepers and to increase awareness of sustainable IPM methodology within the beekeeping community to address several SARE goals. These included: reduced use of toxic materials in bee hives, improved genetic diversity in honey bees and the distribution of honey bee stocks that were more profitable and sustainable within the PNW region.
Integrated pest management in beekeeping does not have the historical precedent well-known to standard production agriculture. However, it is critical to develop and utilize alternative approaches to currently standard chemical treatments for mites based on a calendar schedule. Currently, Varroa mites have demonstrated growing resistance to both fluvalinate and coumaphos, the two principal registered pesticides being used by the commercial beekeeping industry. Alternative registered products are less efficacious and less amenable to use in large beekeeping operations. Therefore, movement of beekeeping toward an IPM approach and greater utilization of improved genetic resistance of honey bee stocks would enable beekeepers of the Pacific Northwest to better protect the primary agricultural pollinator and to maintain the purity of hive products consumed by the public.
Fundamental to achieving the stated objectives was the establishment of beekeeper-maintained collaborative research-teaching apiaries for both training and demonstration of evaluation methods (Objective 1), to provide training in queen propagation techniques and to distribute selected resistant honey bee stocks to the beekeepers of the Pacific Northwest (Objective 2), and for demonstration of current IPM methodology (Objective 3). Beekeeping is a field-intensive activity, and many of the concepts are better shown by a hands-on approach than by lecturing in a classroom setting. The collaborative apiaries contained 16-24 colonies representing the current genetic diversity of the breeding program. Apiaries were managed by local/state association beekeepers following standard management practices for the three years of the SARE-funded project. These apiaries provided a means for regional evaluation of selected stocks by local beekeepers and direct beekeeper access to the selected genetic stocks for queen rearing and mating activities. Each apiary represented the nucleus of a local breeding center for beekeepers, enabling them to propagate and further develop selected lines under local conditions. The direct involvement of beekeepers in different regions of the PNW provided the WSU honey bee breeding program with valuable feedback about the performance of our lines.
Direct assessment of WSU-selected honey bee stocks in large scale beekeeping operations, representing about 15,000 honey bee colonies, took place in Oregon and Washington. These collaborating beekeepers provided colonies to use for comparison of WSU and current commercial honey bee strains within migratory operations that included pollination and honey production activities.
Queen Production – The WSU breeding program produced several hundred daughter queens annually from queen and drone mothers who were selected for superior performance within family lines for mite tolerance, hygienic behavior, disease resistance and honey production. Collaborative research-teaching apiaries in Washington were supplied annually with selected honey bee stock for the duration of the proposal project (and continuing in 2011). The Oregon State Beekeepers Association requested queens to populate two collaborative apiaries. The demographics of Idaho beekeeping indicated a much higher proportion of commercial beekeepers, and primary interest in the SARE-funded project was by commercial beekeepers. Following outreach presentations to the Idaho State Association meeting in 2008 and 2009, one local Idaho beekeeping association (Treasure Valley Beekeepers – Boise) requested WSU selected queens, which were supplied in 2010. Overall, the majority of queens sent to Idaho during the project went to various commercial producers, including a commercial collaborator who made several thousand queens annually from WSU stocks to test in his own large operation.
Selection and breeding progress within the SARE-funded project involved the propagation of honey bees expressing higher resistance to parasitic mites and diseases, while also incorporating other traits of apicultural importance, such as gentle temperament and good honey yields. To assess our honey bee stocks for mite tolerance, we used an assay of the selectable trait “hygienic behavior.” Hygienic behavior describes the ability of worker bees to detect and remove diseased or dead larvae and pupae from capped brood cells. This trait has been demonstrated to confer resistance of honey bee colonies to brood diseases and also appears related to Varroa Sensitive Hygiene and increased resistance to Varroa mites. Using a freeze-killed brood assay, we compared the hygienic behavior of colonies and selected for breeding those that removed dead brood completely within 24 hours. (metric = proportion of dead brood removed/24 hours).
To select for the heritable component of the trait honey production, we used short-term weight gain during the main honey flow (bloom period). Each colony was weighed at the start of the honey flow and again two weeks later. The proportional increase in weight during this period has been shown to be highly correlated with overall honey gathering ability and final expected weight gain (cite Szabo). To select for temperament (often called “gentleness”), each colony was evaluated for behavior and given a numerical score during each colony inspection. The annual mean of the scores are compared and incorporated in the overall selection scheme. Other characteristics are also incorporated in the selection program following standard practices as follows: disease resistance(diseased colonies are deleted from consideration), overwintering ability (frames of bees and brood remaining at spring inspection) and Varroa mite levels (sticky boards placed at the bottom of the hive to count “mite fall”). A compilation of scores for all traits was made for each queen, and the top performers were used for breeding purposes. Progress for improvement in selected traits was documented (see attached “pnw breeding.pdf”).
We ceased all antibiotic treatment for the bacterial disease American foulbrood in WSU apiaries, preferring instead to eliminate diseased colonies. As a result, we noted a decline in the incidence of this disease over the duration of the selection program that continued during the project. The long-term goal of the breeding program is to select and propagate honey bees that did not require treatment for either foulbrood disease or parasitic mites. The 2008-2010 SARE-funded project moved the breeding program farther in that direction, and our present stocks seldom exhibit American foulbrood and have been maintained with minimal intervention for Varroa mite control compared to “standard” beekeeping practices.
The importation of additional honey bee germplasm in each year of the SARE-funded project provided an infusion of genetic diversity into the selected honey bee stocks and represents one of the few non-governmental importations of honey bee genetic material allowed since 1922. In addition to regional interest in these stocks, we are working with one of the major queen producing organizations in the U.S. (CBBA – California Bee Breeding Association) to further disseminate this genetic material into the U.S. honey bee population. Some limited releases were made in 2010 and will continue for the foreseeable future. During the SARE-funded project, we developed a practical means to cryopreserve honey bee semen and to use it for queen production. This advance will make possible the development and maintenance of a honey bee germplasm repository for the first time, much as is currently being maintained for a number of other agriculturally important animals (e.g. – cows, sheep, horses, pigs).
The impact of using honey bee stocks that expressed mite tolerance would be most evident in reduced pesticide use in beekeeping. In Washington state alone, approximately 200,000 – 250,000 colonies are used for tree fruit pollination. Incorporation of IPM to reduce miticide treatments with fluvalinate from twice to a single treatment per year would save $1.5 to $1.9 M per year. Further reductions, such as the ability to use biennial treatments or less would reduce costs accordingly. It was not possible to measure these impacts from commercial operations, because they typically use commercially produced queens that have not been selected for mite or disease resistance (but see milestone related to honey bee germplasm importation above). However, within the hobbyist and local beekeeping association community, there has been an increasing awareness of the impending failure of synthetic miticides as a viable means of mite control and a corresponding increase in the use of organic acids, essential oils and resistant honey bee stocks. In addition, with the publicity surrounding Colony Collapse Disorder, there has been an upswell in the number of new beekeepers in the PNW, as measureable by full to overflowing classes of “beekeeping for the beginner” at many of the local beekeeping associations. In Washington state alone there were at least three new local beekeeping associations that formed during the timeline of the SARE-funded project. Many of these “new” beekeepers are acutely interested in alternatives to pesticides and antibiotics in beekeeping and represent a strong and vibrant voice for sustainable beekeeping approaches.
Educational & Outreach Activities
1. Wu JY, Anelli CM, Sheppard WS (2011) Sub-Lethal Effects of Pesticide Residues in Brood Comb on Worker Honey Bee (Apis mellifera) Development and Longevity. PLoS ONE 6(2): e14720. doi:10.1371/journal.pone.0014720
2. Bourgeois, L., W. S. Sheppard, H. A. Sylvester, and T. E. Rinderer. 2010. Genetic stock identification of Russian honey bees. J. Econ. Entomol. 103:917-924.
3. Delaney, D. A., Meixner, N.M. Schiff., and W. S. Sheppard. 2009. Genetic characterization of commercial honey bee (Hymenoptera: Apidae) populations in the United States by using mitochondrial and microsatellite markers. Ann. Entomol. Soc. Amer. 102: 666-673.
4. Arias, M. C., D. Silvestre, F. O. Francisco, R. Weinlich and W. S. Sheppard. 2008. An oligonucleotide primer set for PCR amplification of the complete honey bee mitochondrial genome. Apidologie 39 : 475-480.
5. Strange, J.P., L.Garnery, and W.Sheppard. 2008. Morphological and molecular characterization of the Landes honey bee (Apis mellifera L.) ecotype for genetic conservation. J. Insect Conservation. 12: 527-537.
An economic analysis was not part of this project.
Areas needing additional study
- Establishment and management of a honey bee genetic repository
Sublethal and interactive relationships of pesticide residues on honey bee colony health
Genetic diversity of U.S. honey bee populations – current status
Comparison of disease and parasite resistant genetic stocks of honey bees to current commercial stocks