wightbees
Queen Bee
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I see your thinking there Colin
I was just suggesting why from the excerpt posted regarding treating early in year 1, you would need to treat before starting the trial. Obviously if you are requeening a colony rejected from the study the most likely reason for that in a resistance study is high varroa load, therefore you would start by reducing that load when the new queen is put in.
That would make sense to me.
https://hal.inria.fr/file/index/docid/890949/filename/hal-00890949.pdfVarroa mites are transferred by drifting and robbing. The degree of drifting depends on the drifting tendency of forager bees and on the defensive reactions by the invaded colonies against foreign bees. The defensive reactions also affect robbery between bee colonies. Robbery increases with the growing ability of bees to perceive food sources. It was therefore of interest to determine whether there were any differences in drifting tendency, defensive reactions and scouting ability between bees of different origin, and whether these resulted in differential Varroa invasion. In the experiment reported in this paper, drifting tendency and mite transfer in 3 bee origins have been investigated. Three 5-comb nuclei of Mellifera, Carniolan, and Buckfast origin with artificially inseminated queens were alternately placed in a circle. They were treated continuously with the acaricide Bayvarol®. In the centre of the circle a mite donator colony was placed with controlled mite infestation.
One hundred bees per colony were marked and mite transfer and drifting observed from August 15, 1990-November 1st, 1990. Compared to Carniolan bees, drifting in Mellifera bees was = 4-fold and in Buckfast bees = 5-fold. Acceptance of foreign bees was highest in Buckfast and Carniolan colonies and lowest in Mellifera colonies. Mite invasion in Carniolan colonies was 51.5% higher than in Mellifera colonies and in Buckfast colonies 72.7% higher. The observed differences in Varroa mite invasion in colonies of Mellifera, Carniolan and Buckfast origins indicate different degrees of drifting tendency, defensive reactions against foreign bees, and scouting ability of the bees of different origins. The recorded values for acceptance of foreign bees suggest that tolerance towards foreign bees depends on the genetic origin. Defensive reactions and scouting ability are presently under investigation.
I think it is simply an assisted natural selection to select for resistance without reducing fitness so much as to jeopardise the whole program or lose other desirable traits. The alternative being the ‘nuclear winter’ scenario, as Kefuss and others used, where no treatment is applied and the few survivors are used in the breeding program.
On natural reinfestation rates amongst subspecies as a varroa tolerance trait, there is an interesting study from the Institut für Landwirtschaftliche Zoologie und Bienenkunde using instrumentally inseminated queens.
Varroa mites are transferred by drifting and robbing. The degree of drifting depends on the drifting tendency of forager bees and on the defensive reactions by the invaded colonies against foreign bees. The defensive reactions also affect robbery between bee colonies. Robbery increases with the growing ability of bees to perceive food sources. It was therefore of interest to determine whether there were any differences in drifting tendency, defensive reactions and scouting ability between bees of different origin, and whether these resulted in differential Varroa invasion. In the experiment reported in this paper, drifting tendency and mite transfer in 3 bee origins have been investigated. Three 5-comb nuclei of Mellifera, Carniolan, and Buckfast origin with artificially inseminated queens were alternately placed in a circle. They were treated continuously with the acaricide Bayvarol®. In the centre of the circle a mite donator colony was placed with controlled mite infestation.
One hundred bees per colony were marked and mite transfer and drifting observed from August 15, 1990-November 1st, 1990. Compared to Carniolan bees, drifting in Mellifera bees was = 4-fold and in Buckfast bees = 5-fold. Acceptance of foreign bees was highest in Buckfast and Carniolan colonies and lowest in Mellifera colonies. Mite invasion in Carniolan colonies was 51.5% higher than in Mellifera colonies and in Buckfast colonies 72.7% higher. The observed differences in Varroa mite invasion in colonies of Mellifera, Carniolan and Buckfast origins indicate different degrees of drifting tendency, defensive reactions against foreign bees, and scouting ability of the bees of different origins. The recorded values for acceptance of foreign bees suggest that tolerance towards foreign bees depends on the genetic origin. Defensive reactions and scouting ability are presently under investigation.
Could be a factor in minimising a major source of infestation in areas where managed colonies are untreated or where there are feral colonies.
With regard to drifting in the apiary, I came across this paper last week, which might be worth reflecting on:
...........
Such comb-level manipulations between different sources might feature particularly prominently in the apiaries of queen rearers/bee breeders. Some of these manipulations will probably be unavoidable but they do represent a significant cause of drift that is amenable to moderation by the beekeeper. It would not surprise me if this cause of drifting is every bit as important as the genetics of the colonies in question.
.............
Thanks for that.
I wouldn’t be too worried about internal drifting as I can monitor/control the level of varroa in my own. You can't prevent your colonies robbing out collapsing outside colonies but if entrance defence against non apiary bees is as significant a vector as the study seems to suggest, then it should be a useful trait.
I think it is simply an assisted natural selection to select for resistance without reducing fitness so much as to jeopardise the whole program or lose other desirable traits. The alternative being the ‘nuclear winter’ scenario, as Kefuss and others used, where no treatment is applied and the few survivors are used in the breeding program.
On natural reinfestation rates amongst subspecies as a varroa tolerance trait, there is an interesting study from the Institut für Landwirtschaftliche Zoologie und Bienenkunde using instrumentally inseminated queens.
https://hal.inria.fr/file/index/docid/890949/filename/hal-00890949.pdf
Could be a factor in minimising a major source of infestation in areas where managed colonies are untreated or where there are feral colonies.
Interestingly, in his book "Background to Bee Breeding", John Atkinson suggests that those responsible for the Carniolan programme confided in him that they had chosen the wrong subspecies and that they should have gone for AMM instead. I suspect they were right.
Lol. however musical to my ears this is, everything in that book should be read with a pinch of salt imho.
His writing style was certainly ribald. In just about every chapter of "Background to Bee Breeding" he flirted with (and typically overstepped) the boundaries of propiety in quite a deliberate manner. Furthermore, he didn't let a potentially punchy message get in the way of a good bit of idiosyncratic storytelling. Even when he stuck to the point, he could be very abstruse, the pamphlet "Micronucs: experimental approach to queen mating" being a case in point. I doubt that anyone could get away with any of this editorially these days.Lol. however musical to my ears this is, everything in that book should be read with a pinch of salt imho.
Icing Sugar;579044. Do any of us have genuine reason to doubt his claim that the coordinators of the German Carniolan project retrospectively regretted their choice of subspecies? [/QUOTE said:Since he is no longer with us, it is impossible to say who said what to whom. Repeating the assertion makes it neither more, nor less, likely to be true. It is all rather irrelevant anyway since that is what they did choose.
His writing style was certainly ribald. In just about every chapter of "Background to Bee Breeding" he flirted with (and typically overstepped) the boundaries of propiety in quite a deliberate manner. Furthermore, he didn't let a potentially punchy message get in the way of a good bit of idiosyncratic storytelling. Even when he stuck to the point, he could be very abstruse, the pamphlet "Micronucs: experimental approach to queen mating" being a case in point. I doubt that anyone could get away with any of this editorially these days.
Despite all of that (or perhaps because of it) he comes across as an interesting and straightforward character who spoke his mind and probably someone I would have enjoyed meeting at least once.
Whilst some of us might be dismissive of his style now, any allowances for his individuality and sense of humour should not compromise the validity of the things he had to say, nearly all of which looks reasonable to me. For goodness sake, "Background to Beekeeping" ends with an appendix of peer reviewed scientific papers that he penned. If you run a search of "John Atkinson" on this forum he appears to be widely held in high regard if the relevant threads are anything to go by.
Do any of us have genuine reason to doubt his claim that the coordinators of the German Carniolan project retrospectively regretted their choice of subspecies?
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