Tag Archive for: Resistant Bees

Chalkbrood

Of all the diseases and pathogens that can affect a honeybee colony – and there are many – chalkbrood is one of the less lethal.  Nevertheless, chalkbrood is still considered a common and somewhat detrimental disease of honeybee colonies.

Chalkbrood is a fungal infection that affects bee larvae, most commonly worker bee larva.  The infected larvae turn a chalky white color (hence the name) and become hard.  Sometimes, in the advanced stages, infected brood will turn a dark color, almost black.  One of the sure ways to tell if a colony is suffering from chalkbrood is to find the chalky dead larvae laying outside the entrance of a colony.  Worker bees, especially in colonies that have hygienic behavioral traits, do not tolerate dead larva well, and remove them as soon as they are able.  If a beekeeper finds a pile of chalky mummified larvae in the front of a colony, then it is almost a sure sign that chalkbrood is present.

Chalkbrood is one of those infections that can often be seen as a symptom, rather than a cause, of overall colony weakness.  In other words, weak and stressed out colonies are more susceptible to contract chalkbrood than healthy colonies, much in the same way that weakened and stressed people are more susceptible to catching colds.  Also, some strains of bees are simply more genetically susceptible to chalkbrood than others.

If chalkbrood is found in the early spring, it can be considered somewhat normal, a sign that the colony is struggling with handling a normal rapid ramp up of brood production at the same time that temperatures are still cold, and the colony hive population levels are low.  If this is the case, the chalkbrood typically clears itself up once the hive populations grow and there are more young bees available to tend to the brood and keep it warm.

If, on the other hand, chalkbrood is present during the summer or during a time when a colony should otherwise be healthy, a conscientious beekeeper should consider that there might possibly be something wrong with the colony and that it needs intervention.

Often the best cure for chalkbrood is giving the colony some attention and TLC.  This means thoroughly inspecting a colony to try and figure out what is causing it to be unhealthy.  Sometimes the solution involves providing the colony better nutrition, inspecting and treating for varroa mites and other pathogens, and perhaps replacing heavily infected frames with clean ones.  A conscientious beekeeper can also assist a colony by cleaning up any chalkbrood mummies that are clogging the entrance way or are laying on the bottom board of a bee colony.

Sometimes, simply requeening a colony solves the problem.  Fortunately, here at Wildflower Meadows, although our bees are not specifically selected for chalkbrood resistance, our overall grading process and selection for survivor stock tends to promote colonies that do not often succumb to chalkbrood.  Often, the gift of a young, healthy and vigorous queen with a good pedigree is all that a colony needs to get itself back on track.

Family Ties

Sometimes, here at Wildflower Meadows, we run across a colony that appears superior in all respects.  As a queen breeder, finding a special colony is always a promising affair.  So, of course, we wonder, perhaps we have discovered some sort of “super colony”; the honeybee equivalent to a superhero, like Wonder Woman.  Maybe if we could breed from this colony we could create a “Super Bee” or some other sort of legendary strain of bee.

However, not so fast . . .

It is tempting to think that the daughter of a superstar will be a superstar herself, but this is an oversimplification.  First of all, we have no idea what made the original colony perform so well.  Might it have been environmental factors rather than genetics?  Perhaps the bees found a pollen source that no other colony in the apiary found.  Or, what if they are situated in such a spot in the apiary that they are the recipient of drifting bees?  Maybe the reason that they are mite-free is not that they are resistant, but simply lucky enough to never have encountered them in large numbers.  In short, what if it is simply good luck that is making this colony appear so special?

Far more importantly, we need first consider whether the superstar colony itself is one of Wildflower Meadows’ pure and known bee lines, or instead a first-or-second-generation hybrid.  If the queen is a hybrid, her offspring are almost certainly going to be unpredictable.  The queen could be carrying many different latent or recessive genes that are not now visible, but could become apparent in next generations.  In general, it is best to breed from pure and known bee lines so that the offspring has a predictability in the immediate generation to follow.  As we described in a previous post, Hybrid Vigor, the most vigorous queens are the result of F1 (first-generation) hybrid bees.  The only way to create this vigor is by starting with pure lines, not with existing hybrids.  Therefore, it is important to remember that one beehive is not a proven line of bees!

This is why when Wildflower Meadows evaluates colonies for breeding potential, we need to consider more than one colony.  We really need to look at the queen’s entire family, and her family ties.  Ideally, we attempt to examine at least six of the sisters of the queen we are considering.  Are they too performing as well?  Are they too uniform?  In any breeding effort, the goal is consistency, and the only way to ensure consistency is to prove that the breeder herself is producing steady results.  The daughters should perform at least as well as the mothers, and should do so time and time again.

Raising Queens vs. Breeding Queens

Being a provider of queen honeybees carries with it several responsibilities.  First, and always foremost, is to raise quality queens.  Anyone who is raising queens has an obligation to focus on quality in all facets of the queen raising process.  This means paying attention to details and not cutting corners.  From selecting a breeder queen, to grafting larvae, to raising queen cells, to optimizing mating conditions, and all the way to caging and shipping queens, any failure to maintain a high standard of quality can, and likely will, result in the raising of sub-standard queens.

Raising queens, however, is only half of the formula for developing a quality queen.  What is equally important is the breeding of queens.  The queen producer wants queens, but the queen breeder wants more.  The queen breeder wants an improvement in the queen stock.  Therefore, breeding cannot be overlooked as a key component of the queen rearing process.  Most every queen producer, large or small, will start with a good breeder queen.  But this is a long way from selecting heritable properties in the bees from generation to generation.

Breeding queens involves reproducing genetic lines of bees from generation to generation by selecting for specific traits that the beekeeper desires.  It requires both promoting positive traits and removing undesirable traits.  It also requires generational focus on combining the very best of genetic material.  While some queen producers may overlook this part of the formula, fortunately, many conscientious queen producers throughout the years – and continuing through today – have understood the entire breadth and responsibility of raising queens.  These individuals are much more than producers of queens; they are true breeders of quality honeybees.

A Simple Organic Varroa Mite Treatment

As a queen producer, our goal at Wildflower Meadows is to constantly raise the level of natural varroa mite resistance in our stock with each new generation.  For varroa mite control, we rely on the VSH trait that we continuously breed into our stock.  The VSH trait enables the bees themselves to interfere with the varroa mites’ reproduction cycle, thus lowering the spread of varroa mites in the colony.  The VSH trait controls varroa mites naturally, and we rarely see problems with high mite counts.

From time to time, however, beekeepers ask us if we know of any organic varroa mite treatments that complement the VSH trait in Wildflower Meadows’ VSH-Italian queens.  Our answer is simple:  With Wildflower Meadows’ VSH-Italian queens, you do not need to treat your honeybees for varroa mites.  But, if your goal is to obtain the maximum level of varroa control, we recommend that you consider our simple organic varroa mite treatment.

Wildflower Meadows’ Simple Organic Varroa Mite Treatment *

To understand how this varroa treatment works, it is important to first understand that varroa mites must reproduce inside of a capped brood cell.  They can live inside a colony on the bodies of honeybees, but they cannot reproduce unless they settle inside a capped brood cell for the duration of the brood cell’s life.  When varroa mites are ready to reproduce, they seek out the cells of uncapped larvae that are just about to be capped.  They then enter and hide inside the cells, where they begin their reproductive process once the cells are capped.

Here is the key to controlling varroa reproduction:  If there are no larvae about to be capped, then there is no mite reproduction.  Without larvae being capped, varroa mites have nowhere to go to reproduce.  This is how African honeybees have been able to survive varroa mites so effectively.  Because African honeybees frequently swarm, they regularly create new swarms that often take at least a week or two to get established.  During this swarming period, there is no brood production.  As a result, the varroa mite population in the swarm naturally declines, and the mites have no way of reproducing and gaining a foothold.  The swarm basically starts its new life relatively free of varroa mites.

As beekeepers, we can easily recreate the same broodless conditions inside of our colonies.  The event of requeening is the perfect time to do this.  This simple organic varroa treatment works best during the summer when varroa mite populations are naturally on the rise, and it is an excellent accompaniment to summer or fall requeening.

The simple varroa treatment is to remove the old queen two to three weeks before adding a new Wildflower Meadows’ VSH-Italian queen.  About five days after removing the old queen, seek out and remove any natural queen cells.  Then check again a few days later to make sure that you did not miss any.  This colony can safely stay queenless for two to three weeks and still have a small amount of brood remaining for introducing the new queen two to three weeks later.  While the colony is queenless, new varroa mite reproduction will be impossible.  Many of the adult varroa mite will die of natural causes, while others will be removed by the bees’ normal grooming.  By the time that the new queen begins laying and her larvae reaches the stage of capping, several weeks will have passed.  During this period, the varroa mite population inside the colony will have been greatly reduced.

If you can recreate this two to three weeks’ window of no mite reproduction within your colony, then the varroa mite population will naturally decline, just as it does in a wild swarm, resulting in a relatively “fresh start” for the bees inside the colony.  Then, if after this period of varroa decline, you add a Wildflower Meadows’ VSH-Italian queen, the varroa mite population will continue to stay in check.

* This method is only advised for strong and robust colonies that can afford to be queenless for two to three weeks.  We do not advise this method for weak or dwindling colonies.

Powdered Sugar Roll

The VSH trait is one of the best-known ways of naturally controlling varroa mite growth without the use of chemicals or miticides.  But how does a beekeeper know whether a given colony is expressing high VSH levels?  The best way to determine this is to test the colony for varroa mites, and then compare the results of the test against colonies that are susceptible to mites.

At Wildflower Meadows we take pride in our mite-resistant VSH-Italian queen bees.  We perform mite counting tests on our bees throughout the year, and test multiple colonies within individual apiaries.  Although the most reliable way of testing for varroa mites is called the alcohol wash, we don’t always utilize the alcohol wash because it kills upwards of 300 bees per colony, per test!  So, because we are not big fans of intentionally killing our bees, more often than not, we prefer to use the powdered sugar roll to gain insight into varroa mite levels.

To perform the powdered sugar roll, we take approximately 300 bees (from the brood nest, where varroa mites are typically most active) and shake them into a jar that contains a small amount of powdered sugar. The powdered sugar, along with vigorous shaking, dislodges the varroa mites off of the bees.  Before long, the mites become loose and become mixed in with the powdered sugar.  By then pouring the mixture of powdered sugar and bees over a screen and onto a piece of white cardboard (see the photo above), the bees stay on top of the screen, but the sugar and mites fall through to the cardboard.  Against the background of the white cardboard it is easy to see and count any varroa mites from the sample.

Mite counts are usually estimated as varroa mites per 100 bees.  In general, three or less mites per 100 bees is considered an acceptable threshold – although this threshold is not a hard and fast rule, and much depends on the goals and tolerance of an individual beekeeper.

The downside of the powdered sugar roll is that it is rather difficult to know exactly how many bees were in the sample in the first place.  It is only with time and practice that a beekeeper can learn to accurately estimate the number of bees in each sample.

The best part about the powdered sugar roll, besides the information that it imparts, is that none of the bees have to die.  After only a half hour or so of testing, our apiaries become alive with “ghost bees” – worker bees that are perfectly healthy, but are covered from head to foot in sugar.  They look strange, but are happily welcomed by their sisters, who eagerly lick them clean!

In no time at all, everything returns back to normal; the bees clean up the sugar, we gain valuable information, and no bees die in the process.

The below link, courtesy of the University of Minnesota Department of Entomology, contains further detailed instructions on how to perform a powdered sugar roll (link opens as .pdf).

How to Do a Powdered Sugar Roll

Artificial Insemination Of VSH Queen Honeybees

It is surprising to us that the majority of queen breeders do not take advantage of the well-known and long-established tool of artificial insemination.  Even more surprising is that most queen breeders choose to ignore the proven advantages of directly adding the VSH trait to their breeder stock.  By ignoring the valuable tool of artificial insemination and the VSH trait, many queen breeders select stock relatively haphazardly with little or no knowledge of the source of the drones that influence not only the behavior of the breeder queens themselves, but also of the daughter queens that end up being sold to the public throughout the season.

Artificial insemination has been utilized by livestock breeders of farm animals for nearly 70 years, and has been available to queen honeybee breeders for nearly as long.  Its advantages are obvious and many, especially when it comes to honeybees, which naturally mate with multiple unknown drones in an uncontrolled environment (the sky).  Artificial insemination allows a conscientious queen breeder to control mating and to mate specific drones to specific queens.  This enables the breeder to directly select the desired genetic traits in the offspring, such as the VSH trait, gentleness traits, honey production, disease resistance and color.  Without artificial insemination, a queen breeder has no first-hand knowledge of the genetics in the breeder queen that are being passed along to the next several generations.

At Wildflower Meadows, all of our breeder queens are artificially inseminated with hand-selected VSH drones from proven, gentle and highly productive colonies.  This provides the core genetic footprint of our operation and allows us to continue to build and improve the Wildflower Meadows brand of VSH-Italian queen bees with each successive generation.

In the above photo Tom Glenn, legendary VSH queen breeder, artificially inseminates a Wildflower Meadows’ champion breeder queen.

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

park5

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.