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Thermal Control of Varroa and SHB - Blog version - Pictures and graphs removed

Updated: Mar 4, 2020

For the full article with pictures and supporting graphs, visit (removed for blog post) Presents:

Thermal Treatment Review

Mites, Small Hive Beetles, and MORE??? :-)

Beekeeping Stories: An adventure in Integrated Pest Management

An article and review by Mike Immer for

Please be sure to get permission from and credit the author and source when


Special thanks to Sophia A. Immer for some assistance making graphical sense out of

my junky spreadsheets! (removed for blog post)

Article Summary/Overview:

Thermal treatment equipment and methods vary. The thermal boards from are simple and require little to no custom or

non-standard equipment.

Thermal treatment on 30 test colonies showed the greatest effectiveness on both

varroa mites and small hive beetles (SHB) on single brood box configurations.

Thermal treatment was still effective for varroa mites on double deep brood boxes

configurations but was less effective for small hive beetles (SHB).

Thermal treatment was more difficult and less effective for varroa mites and made

almost no difference for small hive beetles (SHB) in triple deep configurations.

Additional, more anecdotal information offered: general health and hardiness of

bees observed to be better and support the proposed additional benefits of reducing

the viral and bacterial load bees may be experiencing with mites being the primary

vector for the additional diseases. Testing to continue on this topic.

Pros: Kills mites on the bees, in the hive, even under capped brood

Kills or forces out small hive beetles (SHB)

Less safety equipment is required/more comfortable

Safer than oxalic acid sublimation/dribble

More studied and proven than essential oils and powdered sugar methods

Less temperature dependent than some treatment methods

Can be used with supers

Durable and reusable

Can be integrated with other pest management methods if needed

Length of treatment ensures impact on mites as foragers come and go*

Affects mites on bearded bees with temperatures that kill or sterilize mites

Recent studies indicate that heat can also reduce viral and/or bacterial loads

No need to buy and store harsh chemicals or worry about expiring products

~$350 US per unit

Cons: Length of treatment (roughly 2.5-3 hours) and yes, listed as both pro and con

Requires monitoring for 15-30 minutes until treatment temp is reached

Requires power (nearby outlet or generator)

Only available for Langstroth style 8 Frame, 10 Frame and Nucs

Custom bottom board required to treat plastic/foam insulated hives

Recommended operating temperature minimum 70 degrees Fahrenheit

(Meaning most treatments done in daytime when foragers are out)*

Effectiveness varies based on configuration of hives l

(Meaning most effective on singles, least effective on triples)

Doubles and triples often require tape over any gaps between boxes

~$350 US per unit - and yes, this is listed as both pro and con

*Note: Reiterating the biggest complaint about the process and product, the

treatment time. This may actually be a positive in regards to overall effectiveness.

Most foragers will be making trips back into the hive to deposit any gathered

resources over this period of time and will be exposed to the raised hive

temperature. The temperature to sterilize mites is actually lower than the full

treatment temperature, and less exposure time can still effectively reduce or

eliminate mites in a given hive/colony.

Returning foragers may also beard up with the other bees trying to regulate the hive

temperature, and thus be exposed to temperatures that can kill or sterilize mites

they already had, or those they may have picked up while robbing out a collapsed

hive, open feeding, or just being out foraging in the trees, flowers, etc.

Records/Data: See my somewhat rudimentary spreadsheet data and cost

comparison at the end. One or two hives being tested wouldn’t be a large enough

sample, so I used 30, in the same yard. Further, more scientific studies could

eliminate more variables by standardizing further and providing a control. (removed for blog post)

Disclaimer: I am not a scientist or a professional researcher, data analyst, or even a

spreadsheet guru. I’m an “ok” writer I suppose, but I know there are errors here and

there in this article correcting would have put publication of this information off

EVEN LONGER. The curse of a perfectionist with very little time I guess!

That said, I know there are unaccounted for variables, and likely anomalous data

due to my own terrible handwriting, the weather, etc. J But certain trends and

generalities can be gained from the data I’m offering as it relates to the small scale

testing that I did on thirty of my own colonies in the summer and fall of 2018.

Thumbnails (below) are of the larger graphs at the end of the document: (removed for blog post)

The Rest of the Story - for those that like to read

First of all, I am not what you would call a strictly, treatment free beekeeper.

By strictest definition, treatment free beekeeping advocates discourage ANY type of

activity that intervenes in the process of bees developing their own survival traits

against pests like varroa and small hive beetles. Some would argue that anything

beyond observing them in the wild could be considered intervention. So I won’t get

into that.

Although I applaud treatment free or chemical free beekeeper’s determination and

intent in some ways, and I LOVE the idea of treatment free beekeeping…I like the

idea of keeping bees alive even better!

Even so, I try to keep a “no judgment” attitude in my little bee company as I try to

help whoever I can, without condemning “mite bombs” and the increased potential

for small hive beetle proliferation, and spreading of other diseases etc.

I just try to be as responsible a beekeeper as I can be, and take care of my bees, and

my customer’s bees, as well as I can.

That said, and even though I use things like Apivar, oxalic acid sublimation/dribble,

patties, test other methods etc., I DO like to limit the use of harsh chemicals when I


In fact, I tend to favor more natural and organic treatments whenever I can… IF they

are effective.

So, in thinking about this mysterious new thing called “thermal treatment” what

could be more natural and chemical free than strait up heat? Right?

I’ll go ahead and risk sounding (unintentionally) like a review of the specific type of

thermal treatment equipment I tested, but this article is more than that.

Hopefully I will be able to relieve some of the immediate concerns beekeepers seem to have beyond the general “newfangled-ness” (if that’s a word) of these computer

controlled devices.

A lot of beekeepers have never heard of thermal treatment.

In fact, I’ve received lots of private messages about this topic, so thought I’d go

ahead and write up my experience and elaborate a bit for whoever is interested.

When I first came across thermal treatment, I had NO IDEA what it was, how it

worked, it’s intended use etc. other than it was a relatively new and chemical free

alternative treatment for honeybees to rid them of the nasty little varroa mites that

have been causing such difficulty and disease.

It turns out that the bees themselves do a version of “thermal treatment” when they

swarm, raising the hive and their own body temperatures before they go, etc.

Fascinating, right? Did you know that? I didn’t until I started my research!

I did a ton of reading, and it turns out that the concept isn’t necessarily new, but

overcoming some of the challenges during the studies and finding a way of

simplifying the process IS new.

To boil down a LOT of research, some of which was conducted in other countries,

thermal treatment simply involved heating bees up to determine at which

temperatures mites were affected, and at what temperatures would the bees, brood,

wax, queen, etc. be able tolerate?

You can imagine how many bees “gave their lives” in this type of research. It’s kind

of sad to think about.

You can imagine, there were significant difficulties encountered in rounding up

bees, moving them, containing them for treatment, building cabinets for treatment

and monitoring, and then putting survivors back, and determining queen viability,

managing variables, laboratory versus field studies, etc.

Moreover, there was lot of measuring and recording of data to determine what

temperatures and timeframes were required to kill mites in various states and

various places within the hive. For instance, finding ways of killing mites under the

capped brood, where they are protected from many other treatments!

By the way, this is the real breeding ground for varroa mites, that many other

treatment methods don’t reach. This one very good reason that oxalic acid (OA)

vaporization (more accurately called sublimation) and fogging aren’t very effective,

at least when brood is present! That is also why several treatments are necessary.

The every four days, or every seven days, for three or four treatments with OA? That

is intended to get into the cells that were capped, and hatched, etc. over the

treatment period! That may be something else you didn’t know too!

So, before we get into too much detail, I think the simple goal of all of this, beyond

healthier bees, should be stated:

Use heat to destroy/control mites, and have healthy and productive bees.

Without going into the “law of unintended consequences” and a bunch of other stuff,

let me outline some of the reasons I landed on one particular product to test with.

1. I didn’t want to utilize ANY non-standard beekeeping hive equipment. If it

required custom frames or foundations, I had no interest in trying it.

2. I wanted use ONLY standard Langstroth deeps, mediums and even a few

shallows, in ten and eight frame configurations as these are the most

common, and would provide the best test for my own purposes based on

what equipment and bees I had available.

3. Portability is important as I also didn’t want to have some kind of bulky

enclosure or cabinet to move around, or a process that could only be used at

night, or anything like that.

Why? Like most beekeepers, budget always plays a role. All of my equipment at the

time consisted of standard, Langstroth deeps, mediums, and shallows, with a mix of

plastic frames, plastic foundations, wooden frames, and even some foundationless

frames. And I also had very few telescoping lids by this time, as I had switched to

migratory lids.

After doing some looking, I chose the “Mighty

Mite” thermal treatment boards.

I spent a lot of time at their website reading through their documentation before

deciding to go this direction. The information they shared matched up pretty nicely

to other studies I’d read, and even used some of those studies as sources.

Since I had both eight and ten frame equipment, I went ahead and ordered one of

each. This would allow me to treat two hives at a time, which it turns out was hugely

beneficial to me as I had already determined I wanted to test thirty hives.

This particular piece of equipment met my needs for simplicity, no custom

beekeeping woodenware, etc. and it was simple to install.

But there were (and are) some requirements to consider.

1. You need a power source, either a standard outlet nearby, long enough to run

extension cords, or a generator.

2. You need to make sure the ambient temperature is 70 degrees or higher.

3. You may need some tape for any gaps, and an extra super to set on top of the

provided foam lid to hold it down while providing adequate ventilation.

4. Notably absent from these requirements? Chemical resistant gloves, eye

protection suitable for fog/vapor/sublimation, and a respirator.

Since I was running mostly singles, I started with a couple of those and decided to

test it’s effectiveness on the doubles and triples I had, last. Since customers had been

asking, and I was investing the time and money into testing these devices, I was

determined to keep records as well as I could.

(Assuming my chicken scratch, glove and wind hampered notes can be trusted, I’ll

provide what I was able to translate into spreadsheet data at the end!)

It’s important to note that the following experience as a first time user of thermal

treatment, although common, isn’t necessarily representative of a typical treatment.

I’m just relating what I did, how I did it to some extent, and why.

But it makes for an entertaining story that can save time for users of this product

who, having read this, will know better what happens, and what parts of the process

will continue on WITHOUT the intense scrutiny I’m describing.

And yes, I did a mite wash and counted nine on the first hive prior to treatment.

As you can imagine, I was very cautious with my first treatments to be very sure I was doing this correctly. And I remember, my goal was to test this process, so starting with a “before” alcohol mite wash was an important step.

I reviewed the instructions and got to work.

I slid the thermal board/heating plate into the fully open entrance easily. It fit nicely and sat solidly on the bottom board, covering the screen on the first hive. (I had a mix of both screened and solid bottom boards.)

Following the directions closely, I placed the sensor on

top of the middle frame of the bottom brood box, which was easy enough given that

I was starting with singles. Then I made sure the connection to the control unit was good.

I put the provided insulation board on top instead of the migratory lid, and then placed an empty medium on top of the foam insulation board to hold it in place, and placed the migratory lid back on top of the empty super, leaving it gapped, or open by a couple of inches to make sure it was well vented. And since my first test was on a single, I didn’t have to worry about taping/sealing any gaps between brood boxes etc.

I put the specially provided entrance reducer on the front. It was designed so that it

had just enough room for the cable to the heating element on one side and only

enough room for a bee or two at a time to make their way in and out of the opening

at the other side.

This special reducer was intended to keep the heat in and make it harder for

the bees to work against the process while the hive was getting up to

treatment temperature.

Nervously, I plugged in the control unit last, and three lights blinked as the

computerized controller did a “Power On Self Test”. I was one button push away

from starting the process. So, I gave it one last look and started it up.

What was going to happen??? Would all of my wax melt? Would my bees pile up dead? Would my queen abscond, stop laying, or worse let, lose viability or die???? Scary stuff, right? :-)

I watched, intently while the blinking blue light indicated it wasn’t yet up to the correct temperature.

A few bees started piling up a little at the much smaller entrance as it took fifteen to twenty minutes to switch from blinking blue to blinking green

indicating the hive had reached treatment temperature.

I pulled the entrance reducer out a couple inches and stood back to watch…and

watch…and watch…

The green light blinked red a few times indicating that the temperature in the brood

nest had reached a tenth of a degree higher than the target, and the thermal board had turned off and stopped heating for a while. As the temperature came back down

to the ideal 106 degrees, the green light resumed it’s blinking.

The beard on the front of the hive got bigger, and bigger as more and more bees piled out in a futile attempt to lower the hive temperature.

And more and more foragers were coming in to deposit the resources they had gathered.

It made sense on seeing this why ventilation is SO important. Imagine how much oxygen the bees use to try and cool down their hive into the normal range! If the hive was sealed too tightly, asphyxiation would be a risk!

This cycle continued…and continued…and continued…for two and a half hours!

That’s a LOT of time, right?

But not to worry! I was only sticking around for the full cycle because it was my

first time using it.

As I gained more confidence and experience I was able to start the process, and once

the entrance reducer was pulled away, I could walk away, go do other things (like

start a second hive’s thermal treatment process, and just let the treatment complete

on it’s own.

Please note that it is CRITICAL to make sure the ventilation is correct, and to

remove the entrance reducer once the hive reaches treatment temperature. So set

an alarm on your phone or something! (That’s what I did).

While observing the process, and watching the bees beard more and more, I also

noticed something else that was fascinating…

Small hive beetles were LEAVING the hive, right out the front entrance, and

right into direct sunlight!

But more about SHB later.

When the treatment concluded, the controller switched automatically to a solid

color to indicate it was done. I started the process of removing the thermal

treatment equipment.

Even with heavy bearding going on, being a single deep configuration, it wasn’t

difficult to lift the lid, empty super, and foam insulation board off, in order to

remove the sensor.

I carefully slid the thermal board out of the entrance, and to my amazement (and my

concern) it looked like someone had taken a pepper shaker to the board! There

were a few dead bees, a few puddles of wax (from comb hanging down below the

frames) and there, dead on the board, surrounded by varroa, were a dozen or two

small hive beetles!

A two for one SCORE!

My beekeeping buddies had been referring to the thermal treatment as a “bee microwave” and scoffed at it’s use!

But I have to admit, I was as impressed as I was concerned at this point.

Yes, I was impressed at its obvious effectiveness, and at the same time I was

concerned about the brood, the queen, and the colony as a whole.

There wasn’t a giant puddle of wax. But those bees had bearded out like crazy!

Had I done something wrong?

Were they going to go back in?

Had I forced them to abscond?

I had all kinds of questions at this point, mostly around potential damage to the

colony as a whole.

Had I ventilated it properly?

Had I killed off the queen?

Damaged her fertility?

I resolved to monitor the other hive I started VERY closely as well because it was an

eight frame!

Despite my concern I was committed to testing the equipment, the process, etc.

myself, on my own hives, before I could speak to it, or at some point potentially

recommend it to others.

Why risk it? Why try something scary and new like this?

It made sense to me from a biological, mammalian perspective, to compare the

thermal treatment of a colony to how a human might get a fever.

We get a fever to rid our bodies of infections. So I wondered… since varroa is a

vector for other diseases, could the same thermal treatment that killed of the varroa

ALSO help reduce or eliminate some of the diseases brought by the varroa?

What if heating up the bees also reduced the diseases they already had, either from

varroa, or just in general?

I found myself wishing I had the equipment and knowledge to test for viral or bacterial load in the hives, to do a before and after test for that as well!

In any case, giving an entire hive a ‘fever’ made sense to me from this perspective, so I forged ahead, and started two more hives.

I checked back on the first two hives while the second pair started running and the

bearding lessened. Over time as the bees were allowed to succeed in their task of

cooling the hive, they simply made their way back inside.

Somewhat surprisingly their behavior hadn’t become any more aggressive. In fact, the opposite occurred.

Perhaps it was because they had to focus on cooling and ventilating the hive so much that I was less a bother to them.

Maybe, they were just enjoying a bee sauna!

By the time the third and fourth hives had reached their treatment temperature, I did what any beekeeper would…

I glanced at the first two hives and saw they were getting back to normal and then went inside. I took off my bee suite, got a drink, toweled the sweat off, and cooled down some, confident that the process would complete successfully without my monitoring it constantly.

Truth be told, I DID toss a veil on and go check a couple of times prior to completion,

wanting and to see how the first two were “recovering” from the treatment. But

everything continued as expected. The other hives returned to normal, went about

their business, and before my alarm went off to check the second set of hives, I had

decided to do a “post treatment” inspection.

I even went digging through the first few hives in fact, just to make sure the queens were still alive. And they were!

The third and fourth hives treated completed and reacted the same way, bearding to

an extent that I wondered if the bees outside the hive were getting any benefit from

the heat. And…they were.

I was able to find out with further research that the brood nest was the most

important part of the hive to treat, as new bees hatching would be healthier and

mite free. Even if the bees on the outside of the hive weren’t up to the full 106

degrees, they were getting temps close enough in the heat streaming out of the hive

that the mites on them were becoming sterile.

This begs the question: Why don’t mites, exposed to heat when the bees are flying

around in triple digit heat, die out?

A couple of thoughts occurring to me involve the position of varroa, on the underside of the bee, between the plates where it feeds on the fat body organ protect the hidden mite to some degree.

Even if sterilizing some of the mites outside of the hive from external temperatures was happening, the breeding mites INSIDE the hive, UNDER the capped brood, would likely be outpacing the mites dying outside the hive by a significant ratio.

This is likely similar to the reason OA treatments aren’t very effective when brood is

present. Even if you manage to kill ALL of the mites on the bees themselves, and

even those in the open brood cells, the mites UNDER the capped brood are still

going to outbreed the ones that are killed off!

This is also why OA might have a really good knock down, and a week to ten days

later, the hive still has a significant mite load when you do your mite wash. They are

on the new bees that hatch out!

To get back to and continue the story, similar results presented themselves from

significant mite drops, through hive beetles dying and scurrying away and a small

but varying number of dead bees.

The dead bees I understood were likely old and weak bees, or bees that the varroa had been feeding on the longest.

By now, I guess I was noticing that none of my hives so far had what I would call a higher mite count than others. But it is common practice to treat the entire bee yard, as a unit.

And I had customers with mite counts with thirty, fifty, and some even higher. In fact, by the time I got around to editing and finishing this article, the largest mite count I had ever seen (on a hive that successfully wintered) was 127!

Keeping in mind that I am not a strictly treatment free beekeeper, I managed these bees pretty carefully. Full disclosure, all of these bees had been treated with OA sublimation (4 treatments 1 week apart) early in the spring. So I wouldn’t have expected a horrendously high mite count either.

Back to the story. I called it a day, having treated the first four of thirty, with the intention of treating all of them over the next few days. Simple math put my burden at three treatments per day for four days, and an extra treatment on the fifth day. Plus, I was going to be comparing results toward the end of the week on double and triple deeps!

Days two and three were singles, with similar results, and I was still bemoaning the

time it took to do the treatments. But I kept at it.

By Day four, I was into the doubles.

The warm up process took a little longer, and I had to start using tape, as the

directions indicated, to cover where the first and second deeps met. In a few cases it

took two warm up cycles to get up to the mite kill temperature, and with larger

hives, there were larger beards to contend with.

It got a little more complicated inserting and removing the temperature sensor, and care had to be taken to either brush away or smoke away some of the bees piled up on the outside when tilting back and then lowering the second deep brood box to minimize the number of bees squished. Remember, the sensor goes on top of the middle frame, in the bottom brood box! In a double deep, that can be dead center of a brood nest that extends upwards into the second deep!

I eventually realized that giving them time to cool down a little and start dispersing on their own after the treatment ended made the process easier. But then we were talking about more time!

With bigger brood nests came larger mite counts and bigger mite drops. But with

larger hives and more places to hide, less small hive beetles were dropping and


By the fifth day I was wishing I had a couple more thermal boards (and that the

treatment was faster)! I only had a couple of triples left to do. After a couple warm

up cycles and lots of tape I was able to get them to work. And although it was still

somewhat effective on the mites, there were zero hive beetles dead on the board. I

think the small hive beetles just made their way up into the top and waited it out!

I was quickly realizing that the MOST effective configuration for this treatment for

BOTH varroa and small hive beetles was a single deep brood box.

The next most effective configuration was a one and a half story or a double deep, both of which seemed just as effective for varroa, but were slightly less effective for small hive beetles. And the last, triple deep configuration seemed a little less effective for mites, and almost completely ineffective for small hive beetles.

Naturally, more testing and observation was in order in regards to small hive

beetles, but before I went on to do that testing, I wanted to conclude testing on the

intended pest, the mites. So I watched and waited another couple of days.

I had been pre-warned that the bees might start opening up infected brood chambers with dead mites in them, and might pull larvae from them. And I did see some of this as the bees cleaned up their hive. So I didn’t worry too much about it and let the bees do their thing.

I couldn’t help myself, and pulled a frame or two after a few days, and was a little shocked at how the brood pattern had changed.

Some of the brood frames were solid patterns, and looked great before the treatment. Now some of them looked spotty, as some of the larvae had been pulled. The queen hadn’t laid eggs back in the frames I looked at, so I just put them back and crossed my fingers for improvement when I came back to do another mite wash on the 7th day.

I wanted there to be a full week between the time I treated the hive and when I retested.

So, seven days later, I was back to hives one through four! And then the next set of hives the next day, and so on!

I was using quite a bit of alcohol and killing another 300 bees per hive to test this process, and again, the brood patterns were starting to look spotty.

Even while doing the follow up mite counts I was wishing the treatment process was faster (and that I had more boards available for use) but I was no longer questioning the


And I was confident it wasn’t killing off queens and healthy brood, but I had to wait another couple of weeks to see the full effects.

I’ll note that NONE of these hives had an extremely high mite count to begin with, but still, I got significantly reduced mites and zero hive beetles in hives one and two.

The same mite count was true for all four of the hives from day one’s treatment, but

I did see ONE hive beetle scrambling around in hive six, which could have been a

recent arrival.

Since hive beetles do most of their encroachment at night, I didn’t worry too much

about the single beetle. Rather, I felt I had discovered a great method for getting hive

beetles out of a hive once they had already taken up residence, so that mechanical

methods for keeping hive beetles out would be more effective.

I added some guardian entrances to the mix for those colonies to see if I could keep

the hive beetles from getting back in. I also screened off any other gaps and vents, and tossed in a some swiffers in, more to establish a count of beetles inside the hive

and gage their numbers than as a means of controlling them. I’ll write more about guardian entrances at another time perhaps. Some find them gimmicky, but they seem to work nicely, without the messy traps and poisons you might otherwise add.

I have to take a moment and mention that the results were impressive enough that

despite the ribbing I was getting from my friends that were more experienced and

larger scale beekeepers, I had to mention it to them.

Naturally, they were expecting my thermally treated bees to die out, lose viability,

etc. They were still expecting it. So I didn’t say much more, or go into any more

detail about how extensively I was testing them. I just scribbled out my notes and

continued on.

The mite washes continued, for the all of the thirty hives in my education and

testing yard.

At the 14 day mark, all of the singles had a LOW mite count, and every now and then I saw a beetle or two. More accurate numbers are noted in the graphs and data at the end of this article.

Also, all of the doubles had a much lower mite count, and fewer hive beetles than previously seen. And of the two triples I treated, the mite count had dropped dramatically as well, the highest being 6 mites, and the lowest being 4. They had been in the 18 and 11 mite count range prior to treatment.

Now, who could say if those remaining mites were sterile or not? Or if they had

come from other places? But it was improvement for sure.

By the time I got to the 21 day mark, the mite counts were about as low as I would

have expected with multiple rounds of OA, and use of mite strips!

Again, more detailed information can be found at the end of this article, but I was very happy with the results, if not the time it took to get those results!

Also observed, was a change in the demeanor of SOME colonies. Some of them with

higher mite counts became noticeably calmer. Of course, there were a couple that

were generally angry and no change in behavior was noticed. But it is worth

mentioning because, setting other environmental and conditional factors aside

(dearth, losing a queen, etc.) you could imagine bees that are healthier, behaving

better than those under stress.

Overall, I was pleased, with everything except the time it took to do the treatments.

For all intents and purposes, I was done with my own series of tests, when I

repeated the treatment in the fall, with similar results.

What I considered the ‘ultimate’ test was to come.

What would these bees look like over the next year?

Would the queens burn out early?

Would they survive as well as the hundred or so OTHER hives they were going to get tossed in with?

All of my hives were thermally treated in Missouri, (eastern side of the Kansas City

Metropolitan Area). The bees they were going to Texas with had not had any

thermal treatments, and my bees would go back to a more typical treatment


A good friend wanting to take bees to the great state of Texas? You know, where it stays warmer year round, rarely gets cold enough to kill off moths, where mites and SHB are a problem year round?

That Texas.

Intimidating, right?

I decided I would help him, and we would take eighteen of my hives for good measure!

The trip was a great adventure, perhaps to share another time. But the relevant part of the thermal treatment story is in the way we combined my singles, with many more of his singles, into a yard with 100 total.

My eighteen had a fall thermal treatment in addition to the summer thermal

treatment I detailed previously. His eighty two had not. My eighteen had screened

vents in the lids (to keep SHB out), his eighty two did not.

And, truth be known, all hundred in this yard as well as the other hives in other

yards had received at least one blast of oxalic acid before we loaded them up (it was

cold and they were relatively broodless before we left the KC area).

But a month or two later, we did a few mite washes on his and a few mite washes on mine.

Of course it wasn’t a completely thorough count, but my hives had lower mite counts!

Zero in a couple of cases, compared to his!

Bragging rights among friends was good enough for me, but it helped further my appreciation for another tool in the beekeepers bag.

More work was to be done with these bees, and when we started doing splits, the viability of the queens would show.

If the queen’s viability, in eggs, in laying, etc. had been impacted, it would show in

how well they brooded up, how well the colonies survived, and how well they held

up in general to the splits.

We were ROUGH on these colonies, splitting and chopping them up mercilessly, over

numerous trips.

Even though we had a few dead outs that were most likely robbed out from some

more established colonies near by (we weren’t aware of them when we placed our

hives) they performed just as well, or even slightly better in a couple of cases, than

the ones that had not had any thermal treatments.

They were chopped so hard over the next few visits that they were eventually

absorbed into the overall production, in the hectic, muddy, and difficult Texas

beekeeping experiment.

And the time and speed didn’t allow for any more thermal treatments, or observations.

But for my purposes, I was satisfied. The boards worked exactly as advertised, and

even exceeded my initial expectations, controlling small hive beetles as well.

I don’t have the equipment or expertise to determine bacterial/viral loads, so

determining the effectiveness in this regard would have to wait.

Reflecting on the use of these innovative devices, I have to mention again that NOT

having to wear a respirator, eye protection, and rubber gloves was a relief! Since the

thirty hives I initially tested with were close enough to use extension cords, I didn’t

even have to breath exhaust from a generator.

And I should mention that I use a ProVap 110, roughly a $500 tool to be able to

sublimate OA and treat hives quickly, so spending some extra money on better tools

makes sense to me.

At this point, the only thing remaining for me to evaluate is something I failed to

evaluate in another product that I reviewed a while back. Durability.

How would the equipment hold up?

How many treatments could I do with a given thermal board?

A few hives?

One season? Two?

Well, I’m happy to say that both of my initially purchased thermal treatment

boards from have lasted through roughly a hundred treatments, and are into their second season treating hives. I’m confident enough to use them for customer’s hives now.

And, although they are showing signs of wear, remember that I transport and use

them frequently. I rent/loan them out occasionally. They don’t necessarily get

maintained as well as they should.

They have gotten rained on.

They are getting dirtier and dirtier with the dead mites,

hive beetles, and sick or aging bees that drop on them and get scrapped off.

So, while they no longer look new, and some of the cords and connectors are

starting to pull away, they work just as well as they did when they were new.

And, they are not exclusive in regards to their use. Meaning, on a particularly sick

colony, or a colony for a customer that I might not see again until spring, I can toss

in some apivar. I can hit them with OA for a quick knock down. I can use feed based

treatments, put in beetle traps, use mechanical methods for keeping beetles out or

even trapping them. I can EVEN use them with fancy, new, insulated foam and

plastic hives (carefully and with a wooden bottom board) and nucs.

So, they are much more versatile, portable, and cost effective than the large cabinet

heaters or the wire/heat element embedded foundations or custom frames that

some others have come out with. To me, they are simple, letting heat rise naturally

to convectively heat the entire hive, instead of fans or forced air.

My only thoughts for potentially improving the process would be around speed and

ventilation requirements:

1. An optional or included fan/blower mechanism could both improve oxygen and the ventilation and potentially speed up the process, although some thought should be given to the idea of temperature shock for the brood, perhaps?

2. Additional sensors could be added with a way to quickly place them (perhaps a shim or board of some sort, or embedding sensors into an insulated lid) to further ensure the temperature throughout the hive rather than just in the center.

Conclusions: The more I integrate this treatment method into my pest management

regime, the more impressed I am. And as I continue to learn and grow as a

beekeeper, I try to stay up to date on other studies and techniques and innovations

or gadgets that are out there.

Remember my assumption about fevers in mammals compared to creating a ‘fever’

in a colony with thermal treatment earlier in this article?

I recently saw a reference to specific studies for thermal treatment in reduction of

viruses and bacterial diseases.

It again makes me wish I had the time, the equipment, and the funding to evaluate and document this more scientifically myself! I might be sending off samples to a laboratory next season to try and determine some of this!

In another note, a late update if you will, I was told that Dr. Samuel Ramsey is

studying thermal treatment, and is using these same boards.

If you don’t know who he is, find out! Excellent videos and articles describe his huge contribution to understanding varroa mites and debunking a number of strongly and wrongly held beliefs. In any case, I’m certain his evaluation will be much more credible and helpful than mine.

If you like the story, information, and thoughts I shared, and it resonates with you, I

encourage you to try thermal treatment and share your experiences with me!

If you like my reasoning in going with the thermal board instead of the custom

enclosures, or heated frames, or lids with moving parts, and you want to order a

“Mighty Mite Killer” from, please let them

know you were referred from and take a minute to give us a like

on Facebook and follow us on YouTube by searching for BeeResQ!

When I started this study, on my own, and gathered this data I had NO financial interest or obligation. Since completing the study, I have become an affiliate of sorts, so that I will receive a small referral bonus from the manufacturer. So, IF you do decide to order one (or more) of these units, PLEASE remember to tell them sent you.

Beekeeping can be expensive, and when I go out and buy products to test for my customers, it’s out of my own pocket. So any help, even a like or two on a facebook page, is appreciated! :-)

ALSO! If there is a (beekeeping related) product YOU are curious about, but don’t

want to test, let us know. Maybe we can go buy and test them for you.

Currently on the list for additional testing are:

Apimaye Insulated Hives (additional testing in 2020)

Better Bee Synthetic Comb (testing planned for spring 2020)

PermaComb Plastic Comb (testing complete - review pending)

Take care!


See additional DATA for Review below: (removed for blog post)

Summer Mite Numbers: (removed for blog post)

Fall Mite Numbers: (removed for blog post)

Summer Small Hive Beetle Numbers: (removed for blog post)

Fall Small Hive Beetle Numbers: (removed for blog post)

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