Bee Science with Dewey Caron: Honey Bee Domestication

0:02 Hi, I'm Dr. Dewey Caron. I come to you from Portland, Oregon, just after return from the Pacific Northwest Conference in Wenatchee, Washington I present another audio postcard in my once-monthly Beekeeping Today mini-series podcast, Bee Science, with Dr. Dewey Caron. This is the 11th installment in this series. In each episode, I seek to blend research, field experience, and seasonal content, focusing on the why behind honey bee biology and behavior. I welcome, in fact, I encourage, your suggestions for timely topics. When this Bee Science is posted, I will be in Europe.

0:44 I have scheduled talks with B people in Hungary and Germany and a talk to a local group. In preparation for this trip, I've been doing background research. One of the things that stands out is efforts by COLOSS. a group supported in part by the European Union to promote the importance of local bee stock. There are efforts in several countries to seek to encourage local beekeepers to avoid intercountry transport of bee stock. More on COLOSS in a bit, but let me provide a bit more background. It's no exaggeration that for thousands of years farmers have selected plant varieties and animals in their care for their specific environment They selected livestock and plant varieties adapted to local conditions.

1:29 In the past 200 years, selection has intensified Specific commercial breeds of livestock now are commonly maintained, such as in dairy cows, egg chickens, even fish. These improved breeds varieties are increasingly distributed across wide areas, often far away from their areas of origin. These changes are usually termed domestication for animal livestock A definition of domestication is, quote, a multi-generational evolutionary process in which humans take control of the breeding, care and survival of a wild animal population to make it more useful and better suited to human needs.

2:15 Unquote Domestication usually means genetic changes using artificial selection, and it seeks to make animals more docile, less aggressive, and more tolerant of human presence. and sometimes prettier. Think of domestication, for example, dogs, chickens, or even cattle. Question we sometimes get when we talk about our tiniest livestock species, that is the honey bee, of course. Have we domesticated our honey bees? How do you answer, or would you answer this question if someone asked you, is the honey bee domesticated? There's no one correct answer.

2:56 We might say no, because escape swarms can survive as feral colonies when they find a suitable sheltered location. Thus no might be your response. honey bees are not domesticated. But we could say yes Thinking of golden Italian honey bee queens, we might say we have genetically changed our bees to make them prettier And we have selected bees that use less propolis. So we could conclude we have selected for something that humans tolerate more. And of course, since the only queens we can buy from commercial sources in is stock that is being selected for hygienic behavior.

3:36 Well, you might not want to answer yes or no, but prefer to say, well, maybe we have started to change honey bees, and they are not domesticated to the extent of things like dogs, cats, our familiar livestock In the US, our earliest effort to improve stock was to import different bees. We had a bottleneck, of course, of this stuff that initially came, and after 1920 there was a law prohibiting importation of more bees. L. L. Langstroth, the developer of the movable comb hive bearing his name, was one of the earliest to import Italian bees, for example. and that was continued too recently when the USDA imported Russian bees because they were more resistant to mites.

4:19 And I mentioned hygienic bees, advertised and sold by commercial beekeeping operations. The currently used queen rearing technique dates back to 1889 when Gilbert Doolittle developed a comprehensive system for rearing large numbers of queen cells. His method used queen right colonies, with the old queen isolated by Queenix Sudor. Doolittle emphasized the importance of stimulating a swarming or supersedure situation in the cell building colonies, and a constant rich food supply for the production of high quality queens. That system is still used today. In the 1950s, the bee supply company and Dada Sons hired Bud Cale to initiate a hybrid breeding effort.

5:08 He was take able to take advantage of hybrid vigor developing the starline bee. It was a first cross between four different strains of Italian bees developed mainly for commercial large-scale beekeepers, and what then was an expanded migratory colony movement. A different stock, designed more for smaller scale beekeepers, was the Midnight Line, developed from Caucasian and Carniolan bee crosses. Of course, also at the same time going on in Europe, and the more probably more famous hybrid bee is the Buckfast bee, which was originally bred by Adam, brother Adam in the U.

5:51 K. Hybrid Draker is most advantageous to the beekeeper, but the stock improvement method is also a disadvantage. because subsequent generations of queens produced from those bees when crossed with local drones will progressively lose their hybrid vigor advantage and, too frequently, they acquire undesirable characteristics, such as defensiveness. The people I'm meeting, like many USB keepers, believe the conservation of honey bee biodiversity is critical for maintaining adaptive traits of honey bee populations to their local environments.

6:33 That's easier said than done. Sukove, Steve Sheppard, and Dave Tarpy in a twenty eleven CRC book stated, quote The many problems that currently face the U. S. honey bee population has underscored the need for sufficient genetic diversity at the colony, breeding, and population levels. Genetic diversity has been reduced by three distinctive bottleneck effects, namely, the limited historical importation of sun species in queens, the selection pressure of parasites and pathogens, particularly parasite mites, and the consolidated commercial production practices that have reduced the number of queen mothers in the breeding population.

7:18 And they continue, the current perceived problems of poor queens can be significantly improved by addressing the ongoing genetic bottlenecks in our breeding systems. and increasing the overall genetic diversity of the honey bee population. Of course there's spot speaking of the US where we've had these bottlenecks, in Europe where I'm going, that has not been the case. The the our Apis mellifera is native to these regions in Europe. Widespread movement of colonies in the U. S. is in contrast to Europe, where movement has been less common until more recently. Different European countries have sought to maintain local bee diversity, unrestricted migratory beekeeping, as in common in the U.

8:05 S. , moving non-locally selected stock, Can set back years of diversity conservation efforts. Conservation initiatives are being led by beekeeping associations, multi-county groups such as COLOSS, and research institutions. The European focus is then on conservation via utilization. This translates to any different subspecies and ecotypes of honey bees being preserved through selective breeding and controlled mating. This is to counteract the ongoing replacement and admixture of populations, means that local stock selection and neighbors using their bees for neighbors needing pollination service.

8:48 This doesn't mean stock selected in more favorable locations with a longer B season, then moving it to a more northerly locations either to start B's or for moving in colonies from one site or another to for pollination. Major challenges for breeding honey bees locally include finding suitable local sites for drone saturation and locally finding and of course maintaining the genetic diversity of bees suitable for those local conditions. It's much easier to accept the bees from somewhere else than doing the effort necessary to maintain that local diversity In the real world, domesticated dairy, cows, pigs, and bees of a specific breed may perform in very different ways in the different environments in which they are placed When beekeepers purchase newly mated queens, that queen has in her ovaries and spermaticca, the total genetics of future generations, as long as the queen remains the colony matriarch Since such queens are purchased from a handful of queen breeders in the United States, honey bees and beekeeping hives across the U.

9:57 S. generally have the same, somewhat limited, genetic diversity. honey bees have already been successfully bred for very few selected traits, among them hygienic bees. Recall that viromite treatment failure was considered to be the major factor in colony losses. of over 60% of colonies in two of the three previous seasons. As we know, Varroa is the single greatest problem affecting honey bees in the United States today Bee breeding has also been done for honey production, since that helps pays the bills. Breed A may produce more honey than honey bee breed in the north.

10:39 But the opposite could be true in the South, where B produces more than A. This is termed a crossover effect. Alternatively, the stock performance may be less marked, with one strain being superior to the other in both locations, both environments. but to a lesser extent in one than the other. A term in biological terms we call that a scaling effect. Selection of honey bees has intensified Specific commercial bee breeds, think of the pole line, for example, developed by the USDA Baton Rouge Laboratory, have been developed and utilized largely by commercial beekeepers north and south, east and west Due to demands for early hive splitting, demand for early season queens has dramatically increased.

11:28 Additionally, backyard and new beekeepers start hundreds of new colonies early every year Many, many to replace the losses overwinter. Surviving overwinter colonies build the bees. Beekeepers need to add the queen. These new queens are produced in Hawaii or the northern end of the Central Valley of California or in Florida and Georgia on the east coast. A few individual beekeepers produce queens in Mississippi, Louisiana, Texas, mainly for their own use. Such queens are meant to be distributed across wide areas far away from their areas of origin In Europe, honey bees from several different locations, thinking France, Italy, Spain, Croatia, reveal that significant genotype environment interactions The acronym is GEI.

12:20 Genotype Environment Interactions demonstrate that local genotypes outperform non-local ones in their native environments These findings highlight local adaptations such as efficient use of floral resources, resistant to regional pathogens, and better survival under stress conditions Survival is the most direct measure of colonies' ability to exploit available resources and to cope with local stressors. Thus it serves as one of the main indicators of adaptation. As heavy losses in the U. S. think in 2005 , 6, 7, for example, CCD, the colony collapse order, was unfolding.

13:00 There were various anecdotal reports about local strains of honey bees that were apparently less affected by these losses. With ye EU funding in Europe, the honey bee research association COLOSS, and I'm using that term, and colos actually is a combination of words indicating colony or C O losses, L O S S, so co losses, um designated groups that are looking at colony losses, was set up in Europe COA 's conducted uh GEI. That's that gen that uh uh indication that I said the genotype environment interactions, GEI They set up a study based 15 years ago.

13:48 This is in the period 2009 to 2012. And the project tested 621 honey bee colonies from 16 genetic origins across 11 countries. none being subjected to treatments against Varroa or other diseases for the purpose of the study. At each location the local genotype was together to tested together against at least two foreign origins with a starting number of about 10 colonies per site. Results? Well the results showed that local colonies had higher survival rates, on average 83 days longer, than the non-local ones Plus were stronger colonies as they measured in both brood in adults, and colonies that had better productivity compared to non-local colonies, productivity here in honey production.

14:40 The higher survival under strong natural selection pressure in the absence of treatment for Varroa, for example, there was no Varroa treatments administered. indicates a clear effort of local adaptation. Varroa infestation was the main cause of colony death Reported to be at 80 uh thirty-six percent, I'm sorry, thirty-eight percent, followed by queen problems, about half of that, 17%, and infection with no zema, seven percent. The remainder percentage were a whole variety of different things. These results were published as a special edition of the Journal of Apiculture Research, Volume 53.

15:24 and also in an ABJ article. Both of these are cited in the end notes. More recently, additional COA studies, again EU funded, validated the earlier study results. This study assessed the potential of honey bee selection for improving honey bee health and production for commercial breeding and beekeeping in Europe. In total, 23 genotypes with some degree of resistance were included. More than 2,500 queens from the potential resistant lines were produced by 25 queen producers and distributed to 21 performance testers and 85 commercial honey producers.

16:08 As in the earlier study, local genotypes excelled in productivity, behavioral traits, and colony strength. particularly under the environmental stress, the stress stressor here mainly being Varroa. Local strains were shown to be best. Again, this is cited in the end notes In Europe, at least, the belief is genotype environmental interactions, this this GEI, the genotype environmental interactions And honey bees underscores the importance of breeding programs tailored to local conditions. By prioritizing local genotypes, these programs are demonstrating enhanced county vitality continued maintenance of genetic diversity, and sustainable productivity, supporting honey bee populations that, for example, address challenges proposed by climate change So I want to see some of the principle COLOSS individuals on this October-November visit.

17:10 I finished today with a couple of comments on a status in the U. S. As indicated, do we have bottlenecks because we've not been importing stock for uh many years with U. S. law. And so we don't have the the range of diversity necessarily that's available to those uh uh uh individuals and and countries in Europe where the bee is native. So that has certainly been one of our handicaps. But there are some that seek to maintain the diversity we do have of our bees, and who also use that to select among that total stock, bees that are more suited for the environment. Now I'm only going to list a couple and I would love to hear of other efforts from listeners that you wish to share, and I can come back with that at a future podcast.

18:01 As we know, in the U. S. the ARS honey bee Breeding Genetics and Physiology Research Lab in Baton Rouge has introduced the Russian bee. They developed the pole line, bee, and is the leading federal laboratory investigating aspects of bee breeding The Purdue University folks have led the way in investigations on grooming behavior and have released their selected stock to groups and at least the surrounding states. and that share their program and they of course share their program of progress on the grooming at bee meetings. If we have a bee stock that is resistant to Varroa mites, it might well be the feral bees in your neighborhood Tom Sealey sampled pharaoh bees at the 4,200 acre Arnaut Forest, a preserved close to Ithaca, New York prior to arrival of Varroa mites in nineteen seventy eight, and in subsequent sampling has found that the feral population has continued at the same density roughly a colony in a tree hollow, averaging about every half mile in spacing, since the bees arrived They inhabit smaller cavities, they swarm more frequently, and that brood break that results may be a factor in their success.

19:22 They are also smaller-bodied and have a shorter development time than the normal 21 days for honey bees, perhaps other factors that help in their success. For sustainability, Tom has led the charge to suggest you seek to capture swarms from bees living in a wild area, not the swarms emanating from your neighbor who buys bees every year as a way to incorporate more diversity into your bees, and subsequently to have less mite-related annual losses The bees in the forest are holding their own. That could be in forest and more wild areas where you live as well.

20:02 Another I wish to cite is Randy Oliver teaches each year an intermediate course to the Alameda, California, which is the Oakland area beekeepers. This year, as in previous, he told participants, quote, Backyard urban beekeepers are important In advancing mite resistance development in wild feral populations that they take swarms from unquote. He recommended as saying uh assaying mites frequently and treating the vulnerable colonies He says it's not necessary to treat all colonies when only one has a problem. He says it is important to requeen non resistant colonies and propagate colonies that control their mite population on their own.

20:51 Of course, using this same principle, Randy has developed Golden West Queen stock from his local selection process. In line with this view, this group, the Alameda Group Beekeepers, strongly recommend use of local stock. And member avoidance of bringing stock in from elsewhere. My last example is the group that is the Sustainable Beekeepers Guild of Michigan. SBGMI, Sustainable Beekeepers Guild of Michigan. They focus on raising cold-hardy, mite-resistant, and locally adapted survivor stock through their Northern Queen initiative That is based in Michigan, but not exclusively just two uh beekeepers raising queens in that northern state.

21:40 It's a collaborating network of several beekeepers that promote a care aside -free, chemical-free management and localize survivor stock. Members breed and distribute mite-resistant cold adaptive queens tailored to northern climates. They document that regional feral populations retain unique genetic diversity. and local adaptations despite heavy commercial movement. So our debate will continue. Local versus national distribution of those traits of what we have in our limited pool devised by others and then shipped to other types of environments, other types of climates.

22:27 where they may or they may not be suitable. I hope your bees are doing well this late in the season. I hope you have a favorable overwintering period with the colony and the stock that you have. So until next time, Be well. Thank you.