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Hybrid Vigor

Our customers often ask us if the VSH (varroa sensitive hygiene) trait is so desirable then why doesn’t Wildflower Meadows sell pure VSH queens?  Or, why are Wildflower Meadows’ queen bees VSH-Italian hybrids instead of pure VSH queens?  After all, if it takes a great deal of selective breeding to produce a high level of VSH behavior in bee stock and VSH behavior is so valuable, why dilute the pure VSH stock by crossing it with Italian stock that is not purely VSH?  The answer to this question is in the concept of “hybrid vigor,” otherwise known by its scientific name, heterosis.

Hybrid vigor is a scientifically proven concept that states when two relatively inbred populations are crossed, the performance of the hybrid offspring – in terms of size, fitness, growth rate, fertility, etc. – is improved over the two parental groups when taken individually.  For this reason, hybridization has long been practiced in agriculture.  Plant and animal breeders often take advantage of this concept by crossing two pure bred lines, each with desirable traits, to create offspring that maintain those traits, but in turn is stronger than the parents.  As proof, today over 90% of seeds planted in the United States are hybrids, and not pure strains.  Cattle ranchers commonly cross breeds of cattle creating hybrids such as Angus x Hereford or Angus x Brahman, as well as many other combinations to create more robust offspring.  For the same reason, most broiler chickens that are raised for meat production are also hybrids.  And so on . . .

Hybrid vigor is usually best noted in the first generation of purebred offspring, which is known as an F1 Hybrid.  Later generations of hybrids, which are crosses of the hybrids themselves, known as F2 Hybrids, F3 Hybrids, etc., can vary greatly from one another, and usually express less hybrid vigor than the first generation.  Therefore, the majority of hybrids that are utilized in agriculture are F1 Hybrids, or first generation hybrids.

At Wildflower Meadows, our queen bees for sale are the first generation of offspring of pure VSH stock (which contains the genetic advantage of mite resistance) crossed with Italian stock (which contains the genetic advantage of gentleness and robust brood production).  This gives Wildflower Meadows’ queens, when compared to other queen breeders’ queens (many who specialize in only purebred lines) the proven benefit and advantages of F1 Hybrid vigor.

What Are VSH (Varroa Sensitive Hygiene) Bees?

VSH (Varroa Sensitive Hygiene) is a trait in honeybees that enables a colony to survive without mite controls.  The VSH trait causes VSH hygienic behavior, which is the removal of mite-infested cells from the brood nest.  This VSH behavior serves as a natural and physical check on the varroa mites’ ability to reproduce and expand their population inside of a beehive.  VSH is not a unique race of bee, rather it is a behavioral trait that can be bred into any stock.  Wildflower Meadows produces VSH-Italian queen bees for sale, but any race of honeybee can express the varroa sensitive hygiene trait, such as Carniolan, Russian, Caucasian, etc.

The VSH trait is not necessarily linked with the overall performance of a beehive, rather it is only a measurement of mite resistance.  Bees that are 100% VSH can be very good colonies or very poor colonies, as other aspects of a colony’s performance, such as brood production, honey production or even temperament, are all independent of the VSH trait.

The VSH trait is an additive trait.  This means that varroa sensitive hygiene queens that are naturally mated to unselected drones will still produce the VSH trait in their offspring.  Even though the offspring may not have all of the VSH alleles (an allele is a variation of a given gene), a percentage of the VSH trait is passed on to the next generation, thus resulting in an improved level of mite resistance, which can sometimes even be equal to bees that have 100% of the VSH alleles.

VSH hygienic behavior is expressed on cells that have been capped for four to six days; in other words, young capped brood.  VSH bees will either pull or eat mite-infested pupae from the young brood cells, resulting in the death of the immature varroa mites that are present in the cells.

At Wildflower Meadows, our breeder queens contain 100% of the VSH alleles, which we insure through instrumental insemination by crossing 100% VSH queens with 100% VSH drones.  The offspring of these breeders naturally mate with our most desirable and productive VSH-Italian drones, resulting in Wildflower Meadows’ VSH-Italian queen bees.

Eighty Years Later: A Tribute To O.W. Park

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Today we take for granted the idea that beekeepers can prevent American Foulbrood and other infectious diseases with antibiotics.  Back in the early 20’th century, however, there existed no effective way to control infections.  Penicillin had not even been discovered until 1928, and it was a number of years later before the first antibiotics became commercially available.

With the absence of antibiotics, beekeepers of the time struggled mightily with American Foulbrood, an infectious disease that routinely killed beehives (and still does today).  The only way that beekeepers of the time could control this deadly disease was to burn infected hives and equipment to keep the disease from spreading.  Even to this day, a sizable percentage of beekeeping books still speak of the need to burn equipment that is infected with American Foulbrood.  That this message of burning infected equipment carries forward all the way into 2016 is a testimony as to how severe this rampant and deadly disease was – and especially with the advent of resistant antibiotics – still is.

It is easy today for all of us to take for granted the concepts of “resistant bees,” “hygienic behavior,” “treatment free beekeeping,” etc.  These are commonly used terms, and relatively well-known concepts in today’s beekeeping world – especially when it comes to queen rearing.   It is hard to imagine that eighty years ago, in the mid 1930’s, these concepts did not exist.  Beekeepers weren’t even aware that bees could be selectively bred to establish these desirable traits in honeybees.

In 1935, a visionary beekeeper, O.W. Park, noticed that certain colonies seemed to be resistant or immune to American Foulbrood.  He had an idea:  What if honeybees could be bred to be resistant to American Foulbrood, and the disease could be controlled with the genetics of the bees themselves?  Starting with 25 strong and apparently resistant colonies, along with six control colonies, Mr. Park, along with his associates, set out to test this theory.  He then purposely exposed and infected all 31 colonies with infected American Foulbrood larvae!

What then happened?  All of the six control colonies, and many of the 25 resistant colonies died.  But, amazingly, seven of the resistant colonies survived.   In 1936 Mr. Park then bred a second generation of colonies from this “survivor stock,” which proved to show an even greater level of resistance in the next generation.  In the process, Mr. Park pioneered the concept of identifying resistant bees, and selectively breeding bees for disease resistance.  He also proved that this concept works, and can yield real and positive results.

2016 marks the eightieth anniversary of this landmark study on disease resistance in honeybees.  A full eighty years later, beekeepers continue to carry on in the shadows of the visionary, O. W. Park.