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Treatment options, continued:


What bee ailments to treat, and how, can be a challenging question. Bees, like most other living things, are subject to ill-health (or worse), from a range of bacterial, fungal and viral diseases, as well as parasites. 


Many hobby beekeepers have a well-developed sense of concern for the natural world and are reluctant to resort to "chemical treatments".  But whether you are a hobbyist or commercial beekeeper, and whatever your philosophy towards the environment and ecology that bees are part of, minimising treatments makes sense.


Minimising treatments can help slow down the development of resistant strains of bacteria and viruses, and promote the natural ability of bees to withstand the pathogens that affect them. Reducing or avoiding a range of chemical treatments can also provide a marketing advantage when it comes to selling your hive products.

Inserting a sticky tray for monitoring a newly established colony

Inserting a sticky tray for monitoring a newly established colony

Why Treat?


The most basic question.  Why treat at all?  Shouldn't bees be able to fend for themselves?  Why baby them? This question makes us confront some fundamental aspects of beekeeping.  There are wild strains of honey bees, which are able to keep going without any input from humans. Unfortunately, they are also pretty much unmanageable. The honey bees available in North America are significantly domesticated and therefore less vigorous than their wilder ancestors, just like the rest of our domesticated livestock and pets. They need a bit more help to thrive and without it may sometimes not survive. 


The native bees in Africa and Asia remain wild or at best semi-domesticated. They are highly defensive and not suited to organised, human-managed beekeeping.  It is an awkward fact that the ability to build up the strongest colonies, defend them against predation, make lots of honey, and resist pests, also goes along with defensive behaviour in honey bees.  We want all the desirable characteristics in our managed bees, and breeders are constantly trying to optimise them, but in the end only types that are gentle enough can be managed by beekeepers. 


You can decide not to treat for anything, but unless you have bees with exceptional genetics, and unusual good luck on top of that, you will probably not be a beekeeper for long, for the simple reason that all your bees will be dead.  The loss (death) rate of colonies, although variable from year to year and between areas, is significant. 


Across Canada, winter losses for the past 8 years have ranged from about 20% to 35% (Canadian Association of Professional Apiculturists).New Brunswick losses are usually above the national average, from 20% to as high as 60%, averaging 35%.  At this rate if you do not increase your number of colonies each year, they will all be dead in about three years.  A 'normal' rate of winter loss in the presence of varroa mite impact is stated to be 15% (CAPA). It is not clear what this really means.


When thinking of whether to treat your bees for something, consider what you would do for other livestock you may have, for your pets, or for yourself.  We want to avoid taking unnecessary medications, but sometimes it is the logical and considerate thing to do.  If you want to remain a beekeeper for the long run, you’ll almost certainly need to use some treatments at times.

Why we do it: pure honey from your bees

Dead bees on the bottom board after winter



An ounce of prevention is worth a pound of cure.  The best treatment is the one you don’t need.  If you ensure your colonies are as healthy and strong as possible, they will be best able to resist whatever harmful agents come their way.  The need for treatments will be reduced.



Good nutrition and housing are as important for bees as they are for people. Reduce feeding with sugar as much as possible by leaving adequate honey in the hive. 


Site with good food sources

Choose a site with the greatest variety of flowering plants.  Bees need a varied diet to be healthy. Monocultures are bad for them, and can come with a risk of agricultural pesticide applications or residues.

A meadow of mixed wildflowers provides a good variety of pollen and nectar sources - a balanced diet for bees.


Give your bees a dry home, in a place with shelter from winter winds.  Avoid used equipment as it may carry diseases.  Do not paint the inside surfaces of a hive, or the frames. You can also make your hives from cedar or hemlock wood, which needs little or no paint on the outside either.

This bee yard location is open to the S and E but provides shelter from W and N winds

8 frame boxes made of NB hemlock

Equipment - Frames and foundation



The choice is basically wood or plastic. Does it matter? Possibly not, but wood is more natural, and there could be contaminants in the plastic.

Deep and medium wooden frames.


You have to start with something.  Plastic may be better than beeswax, which you may wish to avoid due to probable contamination with pesticides. You can make the transition from foundation to naturally drawn comb over time. Use small starter strips rather than whole sheets of foundation.


Are there concerns with plastic?  It’s hard to be certain, but there are grounds to be cautious.  Consider that every bee starts life as a tiny embryo in a minute pool of royal jelly at the bottom of the cell.  That environment should be as pristine as possible for optimum bee health.  Contaminants in plastic could cause adverse effects. It’s likely to be more of a problem if you are raising queens, whose health and fitness are known to be highly influenced by the quality of their early development.  Remember that every colony may need to raise a queen, if the existing one is lost or weakens.


Wax foundation

Pure beeswax foundation.  Looks and smell great.  What could be more natural? It seems the obvious choice, except  - where did that wax come from?  Almost certainly from commercial sources, maybe in North America, maybe from further afield.  What might be in it?  Just about anything that is used in a hive.  Wax is an effective sink for organic chemicals, and since commercial wax is a melting pot (literally) of wax from multiple sources, it’s a kind of integrated picture of all the treatments that are being applied to colonies from here to who knows where.  Studies have been done on what is in wax foundation, and the results are sobering.   Commercial wax turns out to be a witch’s brew of synthetic organics, including all the major compounds used against varroa, as well as other pesticides, even ones that are banned such as lindane.

Wired beeswax foundation.

If you consider the interactive effects of multiple contaminants it quickly becomes apparent we have no idea what the combined effects of all these contaminants will be, but they are not likely to be beneficial.


Recommendations on miticide labels will say to stop using the product so many weeks before removing any honey crop.  Unfortunately, the pesticide residues will still be there. 


Natural comb

You can work towards replacement of commercial foundation with naturally built comb, but you’ll still need some sort of foundation to start them off on the right track and avoid messed up frames.  This is a complex subject and we can’t cover it all here, but there is useful information available online.


You can also save your own wax and make your own foundation from it, if you enjoy tinkering about making moulds (Youtube has several examples of how to do this).  It may take some time to save up enough wax unless you have a number of hives.  It’s a good idea to remove as soon as possible any frames from ‘foreign’ sources like the ones your nucs might have arrived on, and any brood combs more than 3 or 4 years old.  The spring of the year following installation is a good time, when the bees have usually moved up and are not occupying those original frames. 

The start of a naturally drawn frame in a wooden starter strip. The bees will enlarge the comb until it fills the frame.

Naturally drawn comb being used for honey storage.


OK, you have done all the prevention you can think of, what might you still have to treat for?


Monitoring and diagnosis

“You can’t manage what you can’t measure”.  First, try your best to find out if you really have a problem. It is important to find out whether you do before deciding to apply a treatment, especially those that may cause resistance to emerge in the pest being targeted.


Applying a treatment when you do not know if the suspected condition exists, or ‘just in case’, risks being a waste of time and money, unnecessarily disruptive and possibly harmful to your bees and the environment. The broadscale use of anitbiotics or other pesticides is what leads to resistance in the target organisms.  Once resistance has developed, another pesticide must be substituted.  This is good for pesticide manufacturers, but not for anything else.  For example, resistance to Apistan and Checkmite has already developed, rendering these chemicals less effective.


Varroa mites

Varroa is probably the beekeeper’s worst single enemy.  Varroa infestation weakens bees, spreads viral diseases, and reduces overwintering survival dramatically.  Approaches for combating these parasites range from doing nothing, to multiple chemical treatments. This is a huge topic, and we can’t cover it all here. 


Firstly, monitor carefully, preferably using a screened bottom board with a sticky trap, paper or surface covered with something you can prepare yourself such as Vaseline, or Vaseline plus Crisco (see right). 


A good rule of thumb is to treat if you find more than 10 mites/hive/day on your board, averaged over three days.


Other beekeepers sample by shaking a sample of about 300 bees (1/3 cup) in a jar with alcohol or winter windshield fluid and counting the mites washed off.  With this method, once more than 3 mites per hundred bees are detected, it is time to treat. This method kills the bees being sampled.


As with everything else, avoiding the need to treat is the goal, but hard to achieve in terms of varroa.  Select the best genetic stock you can and do all you can to keep them healthy in every other way.  You will probably still have to intervene occasionally to control varroa.


lf you decide you need to treat, there are many options, which can be confusing due to a multitude of products with very similar-sounding names.  Those such as Checkmite, Apistan and Apivar are often termed ‘hard’ treatments and are synthetic compounds which accumulate in wax.  Varroa has developed widespread resistance to Apistan and Checkmite.  If you are a ‘green’ beekeeper these products will not be high on your list.


There are also many ‘soft’ treatments, although the term is misleading as many of the so-called soft options still involve highly toxic substances.  You can choose from a range of organic acids such as formic or oxalic, mineral oil fogging, sugar dusting, or hop-based treatments (once this get approved in Canada, estimated to be 2016).  Organic acid treatments seem to be gaining popularity as they are cheap and effective and these acids are part of the normal hive chemistry. 


The effectiveness of some of these treatments is debatable, with variable results being reported by different beekeepers in different areas.

Frass drop on a sticky board over a multi-day period. Cappings fragments, dropped pollen loads, beeswax flakes, insect parts. 1” grid.

Heavy mite drop following a formic acid treatment.

Oxalic Acid Treatment for Varroa (updated Jan 2017)


In recent years the treatment of varroa mite infestation using oxalic acid has become, if not the norm, at least very popular. It's popular because it is cheap and effective compared to other methods, as well as relatively safe and easy. Oxalic acid can be delivered to the bees in the form of a solution, or as a vapour. These methods are often abbreviated to OAD (where D is for dribble) and OAV (V for vapour). With OAD, oxalic acid is dissolved in a weak sugar syrup and dribbled or syringed between the frames. The dribble method is also sometimes called the 'trickle' method.


The OAV method has been approved for use in Canada since 2010 and 2015 in the US. This method appears to be the most popular in Canada. It is less messy than the OAD approach and seems to pose less risk to the bees.


What is needed for OAV varroa treatment:


  • Oxalic acid crystals ($10 or less is enough for many treatments)

  • A vaporizer ($100-200)

  • Power supply (car or motorcycle battery or portable power pack ($50 and up)

  • Respirator with acid gas filter cartridges ($65-75)

  • Goggles ($35-50 or get a combined mask/respirator)

  • Gloves (disposables are OK)


Oxalic acid, although a naturally occurring compound, is potentially hazardous and toxic if inhaled or ingested by humans. You need a good, well-fitting respirator mask fitted with absorbent canisters rated for acid gases. These are readily available from safety equipment suppliers or your beekeeping supplier. Goggles are also recommended to protect your eyes.


Several different styles of vaporizer are on the market. The Swiss made Varrox is well made and in widespread use.




A competitor to the Varrox is the Canadian-made vaporiser made by Heilyser Technology:


Both can be powered by a car battery or portable power pack. There are more products entering this fast-developing market every year. Commercial vaporizers using blowers to force the vapour into the hives are available but are much more expensive.


There are various approaches to using the OAV method but it usually involves a minimum of three fumigations 5-6 days apart, which can be delivered in spring, fall or both, depending on need. First year colonies developing from nucs often do not need a spring/early summer treatment but may need one in September. With fall treatments, a final fumigation should be scheduled to take place in December at a time when there is no brood rearing in the colony. This is important as oxalic acid does not kill mites within brood cells. Treatment at temperatures below 5-7C is considered less effective as the acid vapour cannot easily reach all the bees when they are in a tight winter cluster.


There do not appear to be significant adverse effects of OAV on bees (including the queen).


Beekeepers should read all they can about this and other varroa treatments to decide how to proceed. See the references below for a start. As with all medication or other treatments for your bees, there are many angles to consider.


Reference material


A thorough and up to date (2017) review of varroa management techniques is contained in this document authored by the Honey Bee Health Coalition:


A series of articles about the oxalic acid dribble method can be found on Randy Oliver's web site at:


The Alberta government recommendations for honey bee treatment has a lot of useful information on varroa treatments and other topics:$Department/deptdocs.nsf/all/prm13239/$FILE/2014-recommendations.pdf


As do the Ontario OMAFRA recommendations (although at this time only covering OAD, not OAV):


Another good and well-written article on the use of oxalic acid (2015):


Varroa Treatment with Icing Sugar Dusting, Drone Frames and Essential Oils


To treat a varroa mite problem, an icing sugar dusting can be effective. First, use a screened frame in the bottom board. Underneath the screen, place a sticky paper or a piece of cardboard covered with a layer of shortening. Very lightly dust all the top bars with approximately one cup of icing sugar and brush the sugar down between the frames. During a routine inspection you may want to dust each individual frame as you check it, being careful to dust just the bees and avoid dusting any open cells. As the bees clean each other, the mites lose their grip, falling through the screen and sticking on the paper. Begin treatment in the spring when you open the hive. Dust with icing sugar once a week for six weeks, stop for two weeks, and repeat. Continue until November when you wrap the hives for winter. Icing sugar dusting can even be done during a honey flow, just don’t dust the icing sugar directly into the honey supers.     


Another method of trapping varroa is to use a drone brood frame. The varroa mites prefer to lay their eggs inside drone cells. By utilizing a drone brood frame you can capture many mites within the capped cells and remove the frame from the hive before the drones emerge carrying the mites on their backs.


Essential oils are another useful tool given to us by nature. Mint oils in particular have been found effective against ridding bees of varroa. These can be administered effectively through grease patties. These patties can help fight against both varroa and tracheal mites as the grease makes it difficult for the mites to attach themselves to the bees (see recipe below).

Trachaeal mites

Not quite as serious as varroa, but harmful to the bees.  Many treatments for varroa also kill tracheal mites, including organic acid vapours (oxalic or formic).  Grease patties are often recommended as well and are an apparently benign and cheap treatment.  Here is a recipe for making a grease patty: ¼ cup vegetable shortening, ½ cup white sugar, 2 tablespoons honey or sugar syrup, 10 drops peppermint or wintergreen essential oil. Mix together and form into a patty. Place in hive on the top bars of the brood chamber in the fall after the honey supers have been removed.    


Virus problems

Bees are known to suffer from at least six serious virus diseases.  Ain addition to the well-known deformed wing virus (DWV), other viral diseases include sacbrood, chronic bee paralysis virus, Acute Bee Paralysis Virus (ABPV), Israel Acute Paralysis Virus (IAPV), Kashmir Bee Virus (KBV), and Cloudy Wing Virus (CWV).


There is not much you can do once your bees are affected with viruses.  There are no chemical or other treatments available. Seeing bees with DWV is often a sign that you have a significant mite problem, and it is best addressed by whatever varroa treatment you are using.


Mite management and maintaining stong colonies are your best bets.



Nosema is a microorganism with some characteristics of a fungus which can multiply in the bees’ digestive system, causing ill health at high levels of infection. Nosema disease can cause premature ageing and death of workers, queen loss in winter, slow spring build-up, and other adverse effects.  


Seeing fecal spotting on your hive in spring does not mean your bees have nosema.  High levels of fecal staining can occur with little or no nosema present.


Although it is possible to get a measure of nosema infection levels by relatively simple microscopic analysis, many beekeepers do not do this and apply treatments routinely with no testing.


If you are sure your bees have nosema, the choices are then to hope that your bees can shrug it off (which often happens in summer), or treat with Fumagillin, an antibiotic that might also kill off beneficial gut bacterial.  Some level of nosema infection is ‘natural’, but excessive levels can be serious.  Good nutrition is considered a major factor in keeping nosema under control.  Bees pollinating monocultures such as blueberries are likely to be more susceptible.  Nosema ‘problems’ often resolve in spring as the weather and bees’ diet improves.


American Foulbrood

Although the incidence of AFB is generally low, it is one of the nastier bee ailments and needs serious intervention to prevent spread.  You can’t mess about with this once definitive symptoms are seen. If you do not intervene you will be putting all your bees at risk as well as those of all your neighbours.  Treatment usually means curtains for the infected colony, as all the bees and frames need to be incinerated and the hive boxes thoroughly scorched, or burned. 


Tetracycline-resistant AFB already exists and ‘preventative’ treatment with antibiotics is not recommended practice.  In some European countries, oxytetracyline is not registered for the treatment of honey bees due to concerns over resistance and related matters (e.g. oxytetracyline is used to treat some human infections).


Affected colonies can be effectively saved by removing them from the infected comb and honey sources, and shaking them out into a new hive with new frames and foundation.  This method was first described over 150 years ago by pioneering New York state beekeeper Moses Quinby.  The infected equipment will still need to be destroyed.


Always clean your hive tools between hives with alcohol. If you buy used equipment, make sure there is no disease history by asking the vendor and checking with the Provincial Apiary Inspector, Fletcher Colpitts. If in doubt, buy new.


European Foulbrood

Cousin of AFB but not as serious; regarded as a stress disease that will often resolve without treatment.


Small hive beetle

Unfortunately in 2017 New Brunswick joined a growing list of parts of the world where the small hive beetle (SHB) may be found.   SHB has previously been found in Quebec (2008), Ontario (2010) and Manitoba (2002 and 2006).  They have also been reported in Maine (2010 Maine state apiarists report).  NB beekeepers are urged to be on the lookout for this pest and to familiarise themsleves with its habits, and ways of managing it.  Read the detailed CBA's FAQ on small hive beetle here.






Small hive beetles and bees on comb.








Wax moth

Fortunately for us in Atlantic Canada, we have long, frigid winters. This isn't usually a plus, but if you store your empty supers in an unheated space, all forms of the wax moth (egg, larvae, pupae and adult) are killed by prolonged freezing (more than a day or so). Make sure the supers cannot be entered by mice, as they can do their share of damage.


‘Zero treatment’ beekeeping

Is it possible to go completely treatment–free? There are some well known beekeepers out there who present convincing evidence that they are using no artificial treatments, and have surviving, productive bees.  There seems to be a bias towards these beeks living in warmer, drier climatic areas.   Whether the techniques being used would work in NB is unknown.  All beekeeping is local.  What works in BC almost certainly cannot be relied upon to work in the east, and even what works in Maine may not be completely reliable.  Think of the differences in temperature, humidity and freeze-thaw activity between Saint John, Fredericton and Edmundston.  Every microclimatic zone has its own best management approach. Locally-adapted beekeeping requires finding out what that is.


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