"Hybrid vigor" refers to a cross between two different breeds or races, not to a cross between two different lines within a breed. Think of cattle breeding. The "hybrid vigor" seen in black baldies, for example, comes from crossing a black angus and a hereford. The offspring from two separate lines within the black angus breed will not have the "hybrid vigor." The reason, in a simplified explanation, is that even separate lines within a breed are still remarkably similar to one another.
I would suggest this is not the best example since the two breeds mentioned are both from the british isle and are therefore not that distantly related. a better example (and the one most often used in animal science text) would be any english cattle breed crossed to zebu stock.
I would suspect (based on what other more knowledgeable folks have told me) that the idea of keeping the russian stock 'pure' in regards to mating has much more to do with the aggressive nature of the cross than anything else. for most beekeepers and many queen breeder how you might accomplish this simple thing would seem to me to be quite complex.
Just a couple of notes on some very interesting aspects to this thread.
Firstly, a BIG shout-out for the thesis link. Its cool research and a monumental amount of effort. I'm grateful that someone did this and also that someone posted it.
With regard to the Russian program, I don't really think that it is necessary, possible or desirable to maintain the Russian lines exactly as they were in Primorsky. The main concept is to preserve the totality of the genetic material imported by the USDA. Closed mating yards help, but the main thing is to maintain LARGE apiaries of Russian only stock in multiple geographic locations to prevent genetic bottle-necks, drift, and genes lost to calamity.
Also I think that the relationship between artificial and natural selection is clear, but not necessarily relevant to this thread. I guess you might label me an "evolutionist". Breeding systems using inbred lines, crossed to one another to produce heterosis work well, but often result in a net loss of genetic material. This means that there is a value to both AI and the work of groups like the Russian bee consortium. Now that AHB and varroa are putting the squeeze on feral bee populations, this work is more valuable than ever. This post is just my random pseudo-science ramblings and I would hasten to point out that the pleural of anecdote is not "data".
And what makes the Russian bees better able to tolerate Varroa?
The Russians stock have been proven by experiments to groom off the mites primarily by using the center pair of legs.
Abstract OneApis mellifera and oneApis cerana observation hive were used to test the
Ralph Büchler1 , Wilhelm Drescher2 and Ingo Tornier2
(1) Abteilung für Bienenzucht, HLT, Erlenstr. 9, 3575 Kirchhain, Germany
(2) Institut für Landwirtschaftliche Zoologie und Bienenkunde der Universität, Bonn, Germany
Abstract OneApis mellifera and oneApis cerana observation hive were used to test the response to individually introducedVarroa jacobsoni mites. Within 60s, 88.6% of the involved cerana worker bees (n=44) showed auto-grooming behaviour. Within 5 min, allo-grooming behaviour, involving up to four nestmates, was observed in 33.3% of the infested bees. Successful mite removal was observed in 75% of the not-prematurely discontinued observations (n=36); 32% of the mites removed were caught with the mandibles.
For mellifera auto-grooming behaviour was observed in most cases but delayed in comparison to cerana, and allo-grooming behaviour was rarely observed. Within 5 min, 48% of the mites in notprematurely discontinued observations (n=25) were removed, but none of the mites was caught with the mandibles.
ForApis dorsata auto-grooming behaviour in response to the infestation withTropilaelaps clareae andVarroa mites is reported for the first time.Varroa was removed at a higher rate thanTropilaelaps. The higher survival chance ofTropilaelaps seems to be due to differences in mite behaviour and the preference for certain parts of the bee-body
Bees that resist mites are busy groomers. 12/04
This data is a little old . But, factual.
Bees that resist mites are busy groomers
Agricultural Research, Dec, 2004 by Erin Peabody
We're not the only ones to brush off an annoying mosquito or other buggy pest.
Honey bees, when plagued by tiny tracheal mites, will use their legs like a fine-tooth comb to rid themselves of the life-threatening parasites. But, as entomologists with the Agricultural Research Service recently confirmed, some honey bees groom themselves more fastidiously than others.
For the first time, ARS bee researchers Robert Danka and Jose Villa provoked grooming responses in honey bees by placing tracheal mites directly onto individual bees. Tracheal mites invade the breathing tubes, or airways, of adult honey bees--eventually harming or killing the important pollen carriers.
Origin of the Russian Bee Stock
1st you build the Trans Siberian RR
2nd you discover the local established Russian honey bee stocks in the Primorsky Territory, Russia.
Origin of the Russian Bee Stock
Varroa resistant Russian honey bee stocks, which were introduced to North America in1990's, originated in Primorsky Territory, Russia. This region is in the eastern most part of Russia lying between 43o and 48o latitude, with winter temperatures falling as low as -40oC. It is part of the Apis cerana natural range, however, in the late 19th century, A. mellifera was introduced by Ukranian settlers. This was the first area where A. mellifera was exposed to varroa mites. The European honey bees of this area are dark, indicating that they are Carniolan ancestry (Danka et al. 1995). The first problems associated with mites in this area were reported in the 1960's to 70's.
The European honeybee was imported into this area
In 1905 the trans-Siberian railroad was completed, opening eastern Russia to the rest of Europe. The European honeybee was imported into this area which had only been inhabited by the Asian honey bee Apis cerana, the natural host of Varroa mites.
The Asian honeybee and varroa mites have co-evolved into a balanced host/parasite relationship without much harm being done. Varroa only reproduces on drone pupae in these bees, and drones are only available part of the year, so high populations of mites never build up.
When the European bees encountered varroa, things were different. Varroa is able to reproduce on worker pupae which allows extremely high numbers of mites to build up. This high infestation eventually kills the colony. Beekeepers have been keeping mite populations down at great effort and expense, using miticides such as Apistan ( fluvalinate). But today, mite resistance to fluvalinate is clearly taking place, and will likely spread across the country just as rapidly as varroa did originally.
Feral bees or bees managed without miticides have intense natural selection pressure, allowing only the most mite resistant colonies to survive. There are at least four resistance mechanisms that scientists have identified. They include, bees grooming mites off themselves and each other, hygienic behavior of removing infested pupae, acceleration of brood development, and suppression of mite reproduction. The ultimate goal of bee breeders is to produce bees with all these traits in a single stock of bees. It's hoped that the Russian bees will provide resistant genes that will let us take a giant step forward in the breeding effort. An earlier USDA introduction of bees from Yugoslavia did much in enhancing resistance to another serious pest, the tracheal mite.
Every beekeeper can help in the effort by using some of these Russian bees in their hives. Drones are produced from the queen's unfertilized eggs, so all drones from the Russian queens will be 100% Russian. This fact will greatly help in the spreading of the resistant genes, as drones fly for miles in search of queens to mate. If all goes well we may see the emergence of Varroa resistant bees across the country.
The USDA scientists, led by Dr. Thomas Rinderer, have done their part, now it's up to breeders and beekeepers to do their part in distributing these resistant bees. It may be our best option for getting off the chemical treadmill.
nothing on the ISI science citation index for a journal article by Bryant on this. one great thing about the internet is being able to find MS and PhD thesis and dissertations that has never been published.
Originally Posted by MichaelW