Of Mites and Men

E23 is a winter bee, born late in fall as the last of the major brood cycles.  She is fed differently than her summer sisters.  She eats more and eats more pollen than the bees of August.  She is bred to survive the cold of winter.  Stalking her colony is a tiny destroyer which will suck the life from all it touches.

When E23 first climbs out of her cell she is already infested with four of them.  As she sits on the comb, preening her still soft fur her hind leg catches on something.  She instinctively gives it a flick.  A red dot the size of her mandibles lands on a capped cell and immediately the legs begin wiggling.  She wastes no time in firmly biting it and tossing it to the hive floor.  What she does not know is that two more cling to her back and one is on the move.

Up her abdomen the parasite crawls, making her wings twitch as it passes.  On the way it stops to puncture E23 and drink several times.  At the base of her thorax it slides around and wedges itself into the armor plating that forms E23’s skeleton.  Now no bee can remove the mite.  It will not stop feeding until it is ready to breed or E23 is dead.This bee has a varroa mite attached even in death.

The third mite is waiting patiently for a chance event it knows must come.  A drone bumbles by in the nest and the mite reaches out and catches on as it passes.  The drone is already carrying five others but the mites do not fight over it.  They will feast on him first and others as convenient.

E23’s wings don’t work quite right.  She can’t get the right one to close and is unable to take a orientation flight.  The guard bees are reluctant to let her back in when she tries to enter.  The hypocrites carry pests of their own.  The mites are everywhere. 

E23 finds that as she walks the cells of capped brood not all smell right.  Instinct drives her to open a cell, tearing open her sister’s bed.  The larva inside is nearly formed but even its eyes are still white.  The red specks stand out clearly on the pale carcass.  The mites are buried in the larva flesh and remain that way when the mortuary bees drag it away.

The foragers of E23’s colony are dying.  This is expected as they knew they would not live through the winter.  As they die their attackers leave the dead and search for new victims.  E23’s original mite finally left its place at her thorax.  E23 was checking a larva and the mite just slipped away to the bottom of the cell.  Not to worry.  Four more have taken her place.

She can barely walk now and the dead are left in a pile at the front of the hive.  The mites leave the dead and crawl back into the hive hunting for new hosts.  New bees are not being born.  They are dying under their cells, sucked to death by groups of mites in concert.  It isn’t too much longer until E23 dies as well and the colony falls silent.  The last few drones to hatch eat their fill of honey, which the mites care nothing for.  Then they leave for better parts, other colonies.   With them goes the crawling death.

 

The view from the House

The greatest threat to honeybees today is not a pesticide or poison.  It's not a rat, a skunk, or even an angry neighbor.  It is a mite. A tiny insect so small it appears as a red speck on a bee.  Given the chance it will kill them all.

 Varroa or V-Mites as they are sometimes called, are best observed under a microscope.  They are also best observed dead, preferably in mass quantities indicating that a colony has been effectively purged of mites.  If you take a close up look at one you will see an round shaped body with tiny legs.  It resembles a tick.  It feeds like one too.  This is the greatest enemy of the honeybee and the beekeeper.  American Honeybees have few defenses against the mites and the mites will literally bleed them to death before moving on to new hosts.

You might wonder how such a balance can exist in nature.  It does not.  Man introduced the mite and the western honeybee.  Like a blind date gone horribly wrong the results have been disastrous. Varroa are native to Asia where the Asian bee, _Apis Cerana_,  is able to co-exist or at least survive the infestation.  Accidentally introduced into America, they have devastated the feral bees in America and caused a seismic shift in beekeeping.

Before Varroa bees were more or less left alone.  The theory was that they'd done all right by themselves for 30 million years and they would be ok for a few months with no checkup.  Feral bees were everywhere.  The "art" of finding feral bees involved walking straight forward in the woods until you ran into a tree.  Odds are it had a bee colony in it.  Post varroa beekeepers must constantly measure the mite levels, treat and search for treatments.  Failure to do so will result in the death of the colony.   The feral bees were for the most part slaughtered.

When the varroa first arrived, beekeepers found a pesticide which combated them,  Apistan.  Apistan (fluvinate) was so effective that surviving mites couldn't be found.  After the crash of thousands of mite infested colonies and the bankruptcy of many beekeepers, we breathed a collective sigh of relieve.  And confidence.  Fluvinate was a kind of triumph of technology over nature, proof that we could put the genie back in the bottle.  That was not true.

The survivors might have been hard to find, but they were present and highly motivated to find each other.  Their offspring bore a natural tolerance to fluvinate.  Beekeepers didn't help.  They treated year after year with Apistan, often leaving the treatment strips in long after the killing dose wore off.  What was thought to be the war on mites, won, was in reality just the opening skirmish.  Resistant mites bred together and in hives with weak levels of fluvinate a resistant mite appeared.  Again hives began to crash, and again we searched for new chemicals to win the war, and we found them.   New comers to the battle lines included Check-Mite (and now Check Mite II), acids of several sorts, and more types of gadgets than one can list. 

To understand the battle you have to know your enemy, so first we must take a closer look at the mite.  Varroa adults can transfer by contact with bees or even from flower to bee as necessary, and so a mite free colony can get a gravid female mite brought in quite easily.  Drones skip from one hive to the next and as we shall see, Varroa prefer drones.  Therefore much of the blame can be placed on the man of the hive (no surprise there).  The female mite, once in the broodnest, will climb off onto the comb and seek open brood which are about to pupate.  Current theory (and it makes sense) is that the brood are located by the pheromones they produce which signal workers that they are ready to be capped. Into the cell the mite crawls, and waits.  She crawls down into the bottom of the cell where she is safe from any workers who pass by to check.

Once the cell is capped over the pupa will spin a cocoon in which to undergo its metamorphosis, and the mother mite will be certain to be inside the cocoon.  There she will lay eggs, many eggs.  She lays them on the walls of the cocoon.  When they hatch the new mites are trapped with their food source.  They rapidly begin to feed.

Varroa are vampiric, drinking the bee's "blood".  As the bee grows the mites feast upon it.  This has a number of effects on the bees.  The most common one is "K-wing", where the wing of a bee juts out at an angle, but legs can be missing or malformed, abdomens twisted and scarred.  The worker hatches bearing healthy mites that are ready to reproduce.  The mother mite will slip out and try to find another cell to reproduce in.  Her daughters stay with their ride.  As long as the bee is alive it's fit to eat and they will stay with it until something jucier comes along or an open cell calls to them with a fresh meal.  Why do varroa prefer drones?   Drones take longer to hatch than any other bee, a full four days longer than workers.  Laying on a drone means the mites can complete nearly two cycles of reproduction before the hapless drone emerges (if he ever does).  The mites that emerge will be fully prepared to continue the infestation. 

The bees don't ignore the varroa.  Hygenic bees are bees that clean themselves (and others) often.  They will bite and discard mites, a highly desirable trait.  To counter this mites wedge themselves into the plates in a honeybee's body.  Safely out of reach they can feed for as long as necessary to breed.

Beekeepers have chosen many methods to battle the mites, chemicals, acids, powdered sugar, and a technique called "Drone Baiting".  In drone baiting, drawn drone comb is placed in a colony in the heart of the brood nest.  How do you get drawn drone comb?  With frames of drone foundation, sized so that the bees will naturally draw thousands of drone cells on a single frame.  In a strong colony the queen will lay in these quite quickly.  The beekeeper knows this, and ten to twelve days afterwards he will remove the drone brood, which has just been capped.  The varroa have chosen these drones to reproduce, and many of the females are currently safely sealed under wax, feasting on the hapless bees.   The beekeeper bags and freezes the frames, killing the drones and devastating the varroa.  The frames are then re-introduced, where workers will clean them out and prepare the trap once more.

 

Other beekeepers have sought different ways.  Some noticed that not all feral bees died out.  In fact, as time went on there was a very slow return of feral bees.  Studying these bees led those beekeepers to conclude that the size of the cells was what counted.  Smaller cells produce smaller bees.  Smaller bees (at about 4.9 mm) are capped sooner, and hatch sooner.  The change in timing is also devastating to the varroa, which are not prepared for the earlier capping and emergence.  This is called "Small cell Beekeeping", and focuses on "regressing" your bees so that you have only small bees, drawing small cells.   Finally you have "Natural Cell" beekeeping, where the bees are encouraged to draw their own comb.  This comb will be of mixed cell size.  Some storage cells are huge and deep.  Some drone cells are monsterous.  Some worker cells are average, and many are tiny.  The colony naturally utilizes the range of bees produced in this method.

Foundationless frames or frames with starter strips of foundation allow the bees draw the frames without foundation, so the cells are whatever size the bees want to make them.  The beekeeper can rotate the old frames out so that the bees have the chance to draw new, different sized cells if they desire.  This doesn’t mean that chemical treatments shouldn’t also be considered.   Avoiding the mite killing pesticides for now is preferable and leaves more options than one would expect.  Powdered sugar, integrated pest management, essential oils and vaporized acid all can play a part. 

We haven't seen the final chapter in this war.  There will be no final chapter as long as there are mites or bees.  Men will continue to try and poison and prod and force things to operate their way, and nature will continue to one up them, finding a way to survive toxin and technique.  The bees will keep trying to do what they do, in spite of both man and mite in their eternal pursuit of honey.

The Hive at Home

Vast papers have been written on the subject of varroa.  Many schemes concocted to deal with them.  Some feature gadgets that blow sugar or oil into the hive.  Others use scented oils to inhibit the mites.  Still others blast the hive with chemicals until it nearly glows at night.  For all this many efforts fail.

You can classify most treatment methodologies into one of two categories:  Pesticides and Natural.  Despite the impact of pesticide based treatments one shouldn’t consider them all bad.  It’s true you don’t want the pesticides in your honey.  It’s also true that pests become immune to the cides in time.  What we have now battled varroa long enough to understand is that said resistance is not forever.   Over the years of non exposure the mites tolerance for these foreign chemicals drops.  At times a chemical treatment may be the only thing that can save a colony.  Take one look at the prices and you’ll rapidly conclude that maybe there _are_ better ways to deal with varroa. 

Don’t Treat

I don’t consider this an option for a normal hive on full foundation drawn comb.  I list it anyway because year after year beekeepers decide to try this treatment strategy.  It is an excellent method of leaving the beekeeping hobby without collecting money for any colonies you have raised.   Mite “crash” as it is called is nearly assured.  I don’t recommend this.

Small Cell

Small cell regression revolves around the theory that since a smaller bee is uncapped sooner it disrupts the mite’s breeding cycle.  Capped a day sooner, emerging a day sooner, the mites timing is thrown off.  The foundation of small cell is allowing the bees to draw natural comb.  That means no foundation, or only starter strips.  Once the bees have drawn a full broodnest of natural comb and raised a cycle of brood, the outside comb is removed and fresh frames are inserted.  The smaller bees then get to draw new comb and will theoretically draw it even smaller.  After two complete cycles of drawing fresh frames the cells should measure roughly 4.9mm.  Some beekeepers successfully use this method year after year but getting there can be hard.

Natural Cell

Natural cell builds on small cell but is less focused on the size of the resulting cells and more focused on getting the bees to draw fresh comb.  The fresh comb may in fact be smaller and it will certainly have less disease and potentially chemicals built up in them.  What to do with all those frames you are pulling?  You can melt them down for wax or use them to hold honey if you are using the same size frames in the brood nest and in your honey supers.   A common figure cited is that bees spend eight pounds of honey to draw one pound of wax.  There’s no scientific backing for this, and the bees behavior doesn’t support it.  They don’t recycle wax unless they are forced to or in emergencies.  Those wax cappings on the bottom boards are never re-used unless the bees are desperate.  What is not disputed is that bees that have drawn comb to work with take off faster and collect more honey because they can concentrate on storing rather than drawing wax.

Acids

Oxalic and Formic acids both rely on vapors that don’t harm the bees but kill the mites.  Be careful with acids, particularly Formic acid.  Ants sting with it, people etch with it, and it kills lung cells quite effectively.  Used correctly Oxalic acids are quite effective.

Powdered Sugar, Sucrocide

One is something you get at the store, the other is one you don’t (unless you shop at bee supply stores a lot).  Powdered sugar, dusted over all the bees and brood in a hive has acceptable to poor varroa killing properties.  It might be good for knocking down the varroa count of a low infestation but you need heavier guns for heavier problems.  Sucrocide is that heavier gun.  A liquid sugar you spray over the bees with a garden sprayer, application is very labor intensive – you spray every bee, every frame. 

Oils and Screens

Essential oils in grease patties form a miticide that some beekeepers swear by, and others at.  I’ll render no judgment either way and you should be open to options as well.  Integrated pest management is using screened bottom boards to allow mites to fall out of the hive (and hopefully die).   Screened bottom boards with collection trays also provide a way to get a mite drop count from a hive.

Nuc ‘em till the glow (and shoot them in the dark)

Don’t rule out chemicals completely.  A time may come when you need those chemical poisons to save a colony.  In that case the best advice is what the state apiary inspectors have said for years – Know what pesticides work in your areas and which don’t.  Don’t use fluvinate if your mites are resistant, it just prolongs the process.  Don’t use any chemical other beekeepers near you already know to not work.  I won’t cover how to use pesticides.  The labels are the best source of information and the only way to use them.

Conclusions

Read, study and always be on the lookout for the next thing down the pipe.  You haven’t seen the final chapter in the war on mites and neither have I.  The best a beekeeper can do is prepare for the battle, know his enemy, formulate a plan and follow through.  The rest is up to the bees.  They will do their part.