Discussion about a diy varroa heat treatment

[A7M3D]

Hi
I want to experiment with heat treatment for varroa
This will be done either inside the hive or i will take the brood frames and put it in an insulated box with constant temprature between 40 and 47 C
I just want to ask if anyone experimented with this
And also if some one can recommend a good heater and temprature controller for this
 

[Ben Framed]

Hi
I want to experiment with heat treatment for varroa
This will be done either inside the hive or i will take the brood frames and put it in an insulated box with constant temprature between 40 and 47 C
I just want to ask if anyone experimented with this
And also if some one can recommend a good heater and temprature controller for this

Welcome to Beemaster! One of our members, Live Oak has experience with heat treatment. I have not seen a post by him here for quite a while. If no one else tags along that can help you, you might send a PM to him. He may be in a position to help guide you. He was always kind in answering my questions via PM or here publicity.

I build my own OAV vaporizer. I used the inkbird PID controller for temperature stability. It is VERY accurate. I have not dug deeply into this method you are asking about, but I have wondered if a simple heating pad may get hot enough to serve the purpose? That may be a good place to start your journey of research? Wishing you the best. 

[yes2matt]

Best thermostat for the DIYer is an inkbird.

https://www.ink-bird.com/products-temperature-controller.html

I use the ITC-1000 on a couple different projects (poultry) and I like that you can set the differential range quite narrow. The more expensive units look like they would be easier to plug n play.

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[.30WCF]

I built an incubator out of a refrigerator one time. Hatched 407 of 500 quail eggs. I used a thermostat out of an old chicken house, and (2) 100 watt light bulbs as the heat source.
I was at work when they started hatching, and my wife was carrying baskets of quail chicks to the brood boxes.


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[TheHoneyPump]

Here is a question on the opposite end of the scale, how cold.  What is the LOW temperature needed to kill varroa?

[FloridaGardener]

For sure. 
I hope.

[Ben Framed]

Here is a question on the opposite end of the scale, how cold.  What is the LOW temperature needed to kill varroa?

And a good question. I have not heard this asked or discussed. You have my interest.

[TheHoneyPump]

I may be thinking too simply on this, because I have never considered this before. If you want them hot, perhaps consider the simplest heater is the honeybee. Just screen in and close off the entrances of the hive. It will not be long they will be running hot and freaking out inside the hive. Frantically running all over every nook and cranny inside. Making the whole hive temperature rise considerably. No need for fancy heaters or insulation wraps. Just put long temperature probes in and block them in for a day or two. Open/close vents to keep them hot and control the temperature exactly where you want it.  Put a PID controller on a vent flap if you want to get fancy.  Perhaps that approach is too simple. ( Highly recommend the queen is caged and removed for such things )

On the other hand, I am most interested in what lower temperature the mite can survive.  What low temperature kills the mite. Saying "frozen" solid isn't good enough or an acceptable. I want an actual number.  For example the honeybee dies at body temperature of 4 degC.  What low temperature does the mite die.

[Ben Framed]

Everything you say here makes perfect sense to me. I obtained my first bees via cutouts. I was taught  on videos the importance of making sure newly vacuumed bees have adequate ventilation on the trip home or they may overheat and die.  The PID set us as you suggest should work for the heat side of things.

As far as the opposite is concerned; As I said earlier, you have my full attention. From what I understand, Varroa Destructor originally came from a warmer climate. Asia if I remember correctly. It may very well be that cold could be their weakness. As we know bees keep varroa plenty warm, even in the colds of the North. Mr HP what is your ideas on overcoming? Thanks.

[TheHoneyPump]

Everything you say here makes perfect sense to me. I obtained my first bees via cutouts. I was taught  on videos the importance of making sure newly vacuumed bees have adequate ventilation on the trip home or they may overheat and die.  The PID set us as you suggest should work for the heat side of things.

As far as the opposite is concerned; As I said earlier, you have my full attention. From what I understand, Varroa Destructor originally came from a warmer climate. Asia if I remember correctly. It may very well be that cold could be their weakness. As we know bees keep varroa plenty warm, even in the colds of the North. Mr HP what is your ideas on overcoming? Thanks.

For example; forced but controlled chill of the whole hive.  No re-fridge unit needed up here.  -16 degC last night.
Let say the bee can take 5-6 degC and recover just fine, we know this.  But perhaps the mite dies at 10 degC. A hive chill treatment to 8 degC could potentially wipe out every mite.  (Remove the queen first of course).

Also, alot of us run solid bottom boards.  If mites are tossed off in grooming they can climb back up into the cluster.  But what if the bottom board is cold, how cold does the bottom board have to be for the mite to be killed when dropped.

I think we have alot of advantages, and potential opportunities, in northern beekeeping.  We just need some substantiated target numbers to experiment with.

Am not meaning or wanting to hijack this thread started on heat, hyperthermic treatment.  I just threw the question in there in case someone browsing through knows the numbers for cold, hypothermic treatment.  No intention to distract from the OP.

[Beeboy01]

I would think making a DIY varroa heater for a hive would be complicated. The president of our local club was talking them up three years ago, turns out he was the area vendor for a manufacturer of a hive heater. I'm not naming any product names because of some problems that the club had with the equipment. I never tried one even though the club had them available to the members.

 Apparently the lethal temperature zone for varroa is close to the lethal temperature for the bees and some club members cooked their hives resulting in total hive loss as well as queen death.
 
  The biggest problem I would think a DYI would face is the different size or volume of hives found in most bee yards and the location of the temperature sensor or sensors, more would be better for more accurate control. You would need to determine the dwell time needed to cook the mites and deal with temperature decay as the hive cools during the treatment.

  A one shot treatment that kills both the phoretic and brood mites is a plus for a varroa hive heater but still seems to be risky. Building a DIY might just be reinventing the wheel and the money you save could cost more in the long run with dead hives.

I've moved over to OAV treatments which has shown to have timing constraints to be effective.

[yes2matt]

I would think making a DIY varroa heater for a hive would be complicated. The president of our local club was talking them up three years ago, turns out he was the area vendor for a manufacturer of a hive heater. I'm not naming any product names because of some problems that the club had with the equipment. I never tried one even though the club had them available to the members.

 Apparently the lethal temperature zone for varroa is close to the lethal temperature for the bees and some club members cooked their hives resulting in total hive loss as well as queen death.
 
  The biggest problem I would think a DYI would face is the different size or volume of hives found in most bee yards and the location of the temperature sensor or sensors, more would be better for more accurate control. You would need to determine the dwell time needed to cook the mites and deal with temperature decay as the hive cools during the treatment.

  A one shot treatment that kills both the phoretic and brood mites is a plus for a varroa hive heater but still seems to be risky. Building a DIY might just be reinventing the wheel and the money you save could cost more in the long run with dead hives.

I've moved over to OAV treatments which has shown to have timing constraints to be effective.

In an incubator that is 40-80 liters, I would use a computer fan (or if my source voltage was 12vdc I would put two 5vdc fans in series) to forcibly circulate air thru the space.

If I had a hive that had a screened bottom board, I can imagine a heating and circulation unit that blew up thru the screened bottom with a thermometer/stat built to plug the hole in a solid inner cover (top).

I know that bees are masters at metering and controlling temperature and circulation in their own hive and I don't know if I would be comfortable actually doing this to them.

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[little john]

Here is a question on the opposite end of the scale, how cold.  What is the LOW temperature needed to kill varroa?

I think this is a non-starter ... because the bees won't play that game.  When the temperature falls, the bees will begin to cluster.  As it falls further, the cluster will tighten - in order to improve it's insulation characteristics, and so keep the core warm. But at the core will also be at least some Varroa mites.

Those bees on the periphery of the cluster might drop their mites - that's always possible - but in order to guarantee an effective mite kill, you're going to need to prevent the bees from clustering - and that's a tough one.

Regarding heat - yes it's do-able, especially with the assistance of a fan, and with appropriate temperature control (recommend cascade-PID control).  The limiting factor however, is the time taken for each treatment - you're looking at hours per hive, rather than a few minutes per hive as when using an inverting band-heater OA vapouriser or similar.
LJ

[Ben Framed]

This is proving to be interesting discussion, which I am enjoying.

[yes2matt]

LJ

Good to see you sir.

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[little john]

LJ

Good to see you sir.

Very kind words - thank you.
LJ

[Ben Framed]

> HP For example; forced but controlled chill of the whole hive.  No re-fridge unit needed up here.

> LJ When the temperature falls, the bees will begin to cluster.  As it falls further, the cluster will tighten - in order to improve it's insulation characteristics, and so keep the core warm. But at the core will also be at least some Varroa mites.


For discussion sake, looking at HPs words of forced but controlled chill,  (perhaps by a small fan of some sort), the clustering bees may not have a choice but to comply if the forced cooler air is introduced, cooler air forced through the finest crevices of their best effort of cluster?  I will add, I am pleased you are posting here also LJ! Thanks!