Failure to Select: The Cause of Weakness in Bees

Establishing Resistance

This page contains a short exploration of the difficulties of establishing resistance in the honeybee population, contrasting Norman Carreck's 'top-down' approach with my own 'bottom-up' strategy.  

Discussion Paper: Problems of establishing resistance; a response to Norman Carreck

In the two most recent issues of BBKA News Norman Carreck has supplied a very useful overview of the current situation with regard to varroa resistant bees, showing that there is optimism about the possibility of locating and raising resistant strains under controlled conditions at Sussex University.[1] In his conclusions however Carreck supplies a strategy for future use of such strains that seems deeply pessimistic:

"Once a suitable strain has been located at Sussex, this will passed on to members of the Bee Farmers Association for testing in the field, and ultimately for multiplication and sale of queens to beekeepers. Inevitably the process of bee breeding is time consuming and labour intensive, but it is to be hoped that we can significantly improve the hygienic behaviour of our own strain of bee. The degree to which such improved bees will ever be widely used in Britain is, however, dependent on the development of a significant greater rearing industry than currently exists in the UK."

"Bee breeding is of course a continuous process, and one should not underestimate the practical difficulties of maintaining a desired strain of bee. In addition, inbreeding in any organism is, in the long term harmful, and due to their haploiddiploid nature, honeybees have less genetic diversity than that of many other groups of insects."

If I understand correctly, Carreck works from the basis that the sole hope for future UK beekeeping lies is the management of continuing disease problems, through massive and continuous queen rearing, foreseeing insurmountable obstacles to the establishment of the resistant strains. This article will argue that this picture does not represent the best strategy for the future of UK beekeeping. The obstacles Carreck anticipates can be sidestepped, and the perils inherent in the reduction of genetic variation that he recognises can be entirely avoided. An alternative vision is possible, in which a return to a thriving honeybee population needing no such support is within reach. Carreck's pessimism, according to this view, is entirely unwarranted.

The strategy required by this vision differs from Carreck's in two key ways. First, it recognises, and seeks to eliminate a widely unrecognised flaw in modern beekeeping. Systematic failure to select for resistance when bees are reproduced has led to the routine maintenance of bloodlines unadapted to the current pest and disease environment. Secondly, it brings to the fore the role of wild honeybees in locating and maintaining resistant strains, through the mechanism of natural selection. The aim then will be to work at reducing the damage done to bloodlines by failure to select, and to work at recovering the beneficial input of wild honeybees.

To make the case for the first change I must establish the grounds for my diagnosis of the leading cause of unadapted strains. Failure to select for resistance is, I have suggested, the result of the widespread practice of reproduction from previously medicated stocks. I offer then a premise, upon which the arguments for my vision will be predicated:

Reproduction from medicated bees results in the replication of unadapted bee strains, and undermines the emergence of resistance in apiaries.

That reproduction from sick specimens is a terrible idea was to previous generations common knowledge. It is an ancient and unchallenged principle of husbandry. To produce healthy stock it is absolutely necessary to breed only from healthy stock. Reproduction from strains that have been kept alive through medication completely undermines this principle. It produces at best a new generation requiring just the same medication as that required by the parents. If repeated it leads to a spiral of decay in health, as the predator evolves to take full advantage of the available foodsource. It is important to note that this traditional wisdom is fully supported by modern biology. The modern analysis of the mechanisms by which resistance arises in nature - by continuous adaptation of the fittest strains to the ever-changing environment - supplies a full understanding of both the processes that breeders take advantage of, and the way in which medication disrupts the development of resistance.

We can then work from the understanding that reproduction from stock that has been artificially maintained short-circuits the mechanism by which those strains best suited to the environment replace those strains less well suited. Our premise is support by sound science, allowing us to apply this general analysis to the particular problems faced by beekeepers with some confidence. We can understand that every time we allow reproduction from artificially maintained colonies, we send ill-adapted bloodlines into the next generation. Every time we allow drones to fly from such colonies we send ill-adapted genes into the locality, undermining both the resistance that would otherwise develop naturally in the wild populations, and any resistant strains that might be present in our neighbours' apiaries. Shockingly, it can be seen that the failure of bees to develop resistance is entirely due to our own actions. Both well-established biological science and the most fundamental aspect of traditional stock rearing practice show us that we beekeepers are actually the cause of our own problem.

To return to Norman Carreck's conclusions, and the obstacles he foresees to the maintenance of resistant bloodlines. We can now appreciate that the situation he anticipates would be the result of the presence of artificially maintained strains, unadapted to the prevailing disease environment. These strains would undercut any hope of imported resistant strains becoming established. Equipped with this understanding we can now imagine an entirely different approach, and to begin to explore strategies designed toward an entirely different outcome from that which he foresees as the best possible. Rather than looking forward to a depressing future in which bred queens must repeatedly renew continually sickening bloodlines, we can instead imagine a return to a world in which beekeeping is entirely free of a constant war between chemicals and ever-evolving mites. In this picture both beekeepers and wild honey bees work together, and thrive in unison.

We can do this by rejecting the idea that we must constantly fight a losing battle against unadapted bloodlines, and replacing it with the notion that we can remove those bloodlines from the field altogether.

This can be achieved by nothing more than a return to time-tested traditional methods, using the established and scientifically-supported principles of sound husbandry, together with an active programme of support for the wild population that continually hones bee health through natural selection for the fittest strains.

A grassroots shift in the approach to reproduction, and an appreciation of the critical benefits supplied by a healthy wild population offers, then, an infinitely more cheering hope for the future of beekeeping. This strategy works with the grain of nature, and dovetails perfectly with the aims of conservationists, and wider environmental concerns about loss of ecological diversity. Furthermore, we can, happily, work on a largely local basis. Nothing more than simple guidance is needed from central bodies; traditional principles and a fairly basic understanding of the relevant mechanisms supply all the tools required. Area by area, beekeepers can plan to control their local disease environment, simply by facilitating the emergence of resistance - aided, if needed, by resistant bloodlines from Sussex and elsewhere. This vision represents a huge improvement over the pessimistic picture painted by Carreck, and is, I suggest, an aim worthy of close examination.


Mike Bispham
http://www.suttonjoinery.co.uk/CCD/

[1] Varroa Tolerant Bees: Dream or Reality, BBKA News No.s 176 & 177; http://www.britishbee.org.uk/members...ews_Apri09.pdf & http://www.britishbee.org.uk/members...ws_June_09.pdf
(Sadly these articles are closed off to those who don't have a BBKA password. Members can download them from http://www.britishbee.org.uk/members/bbka_news.php If you can get hold of a recent copy of BBKA News there is a username and password on the front page.)

(What follows is a response I made to Gavin on the BBKA forum, which brings out some further ideas.)