Thermomite: a new weapon against varroa

[JamezF]

I've bought a few chemicals over the years (with good, peaceful, reasons), that I half expected to cause a knock in the door.

Potassium nitrate is always a good one

James

 

[Ian123]

That's really interesting .. so the idea is that raising the temp of the brood nest to 42 degress for a period of 6 hours does not harm the bees but kills virtually all the varroa mites ?

There was that oven thing about years ago that you put the whole hive into and cooked them, I can only wonder why it didn’t catch on

 

[B_north]

I never tried the unit and it doesn't seem to be something a commercial keeper would use but, sometimes someone somewhere takes an idea and makes it better. It sure would be nice.

 

[JamezF]

There was that oven thing about years ago that you put the whole hive into and cooked them, I can only wonder why it didn’t catch on

If it's anything like our oven it'll be because no-one understood the controls. Each of the main and top ovens in ours has seven different options where it's not "off" and I have no idea what most of them actually do.

James

 

[pargyle]

I think it's a fair bit more complex than that. Humidity appears to be a factor as well and perhaps the genetics of the bees too. The second part of the article is worth reading, certainly.

My overall impression is that a) far more research is required before it's possible to say what might constitute a genuinely efficacious thermal treatment across a range of conditions (assuming it's possible at all) and b) even if we can, it may be impractical to implement such a treatment successfully at reasonable expense.

My feeling is that with a "passive" heating system such as that in the original post, it will be difficult to maintain an appropriate temperature over the time required in hives of different types of construction and it may be that some users find it just doesn't work for them. An "active" system on the other hand would require power, which may be ok if you can provide a mains connection or have a portable generator, but with even a fairly heft car battery it will eat through them quite quickly and doesn't really lend itself to, say, treating a dozen colonies in a single apiary all at the same time.

I think the research is worth doing though, because there's always the possibility that a viable method for treatment could emerge.

James

Yes - having read the next months article from Randy Oliver it is clear that it's a fine line between heat and humidity and the 'sweet spot' where there is an effective mite removal (not necessarily a kill rate) is difficult to achieve in real life conditions. It is a concern that the mite levels returned to a pre-treatment level very quickly. Jt is also a concern that even a very modest variation above the active temperature appears to affect the sperm in queens and the ability of drones to produce fertils sperm.

There are clearly risks attached, it's not an easy treatment to administer, it's not a highly effective treatment as it stands - there's more development required.

What I do find interesting (and it has some synergy with my TF regime) is that higher temperatures and humidity in a hive do inhibit the ability of varroa to thrive. I spent several years measuring the in-hive temp and RH in my highly insulated LDH. My obs were that the bees often maintained temps in excess of the 34 degrees commonly accepted as 'normal'. RH was often in the high 70's and low 80's. Under these conditions the ability of varroa is seriously inhibited,

Perhaps highly insulated hives create conditions that are conducive to inhibiting varroa reproduction ? Bees may wish to see higher hive temperatures and humidity levels than is traditionally recognised as the norm.

I love the fact that heat treatment for varroa is a totally 'natural' treatment but I rather fear that it is not yet the silver bullet although I wait with interest any developments.

 

[JamezF]

Perhaps highly insulated hives create conditions that are conducive to inhibiting varroa reproduction ? Bees may wish to see higher hive temperatures and humidity levels than is traditionally recognised as the norm.

It's an interesting idea. If we were to assume that wood and poly hives don't provide the same level of insulation as a cavity in a tree, for example, perhaps bees might have some sort of concept of "not ideally warm, but good enough (or 'as close as we can get without excessive effort')" that means they maintain a slightly lower temperature in a standard hive. (I include poly hives because many have large areas that are nowhere near as thick as looking at the tops of the walls might suggest.)

Someone must surely have done some research into that. It feels like the sort of thing Tom Seeley might have done.

James

 

[Amari]

I used to take the old camera film containers and pack with powder from fireworks or cut open cartridges. You made a slit/cross in the lid and glued it down, you then cut a banger just below the length of the fuse and shoved it in the top. There then followed a process of wrapping with foil and duct tape until all but a few mm of the banger fuse was exposed. The resulting boom and cloud of shredded foil was impressive

I wonder if bangers are still sold? The best brand was The Cannon @ 2d each. Wrap a lump of mud around the base, light the fuse and chuck it into a stream = a most satisfying underwater thud.

 

[Erichalfbee]

If it's anything like our oven it'll be because no-one understood the controls. Each of the main and top ovens in ours has seven different options where it's not "off" and I have no idea what most of them actually do.

James

After 10 years I discovered that my oven has a bread proving temperature that I can use for bread and to warm honey

 

[Garry R]

A poly hive's advantage is that (in my opinion) you don't get cold spots in the hive hence no condensation even though the humidity would be high provided you have an insulated roof (hot moist air rises). We go back to Bernard Mobus' research on this and the adage that damp can kill bees but cold won't. So perhaps poly hives do provide better conditions for natural varroa control as regards higher temperature and higher humidity. If the bees find it too hot surely they will fan - any comments?

 

[Moobee]

I initially thought the title said Thermite - a new weapon against varrora!

The inventor could be in cahoots with the creator of those concrete hives.

Whaaaat? Concrete hives????

 

[Moobee]

Meanwhile, in Canada…..
https://www.cbc.ca/news/canada/brit...U researchers found that,is in its third year

 

[jenkinsbrynmair]

I wonder if bangers are still sold? The best brand was The Cannon @ 2d each. Wrap a lump of mud around the base, light the fuse and chuck it into a stream = a most satisfying underwater thud.

I found a half hundredweight can of calcium carbide in the loft above my aunty peggy's stable (they had a shop and sold it to miners for their laps to use in 'damp free' mines. great fun, either packing it into the holes in a big lump of clinker (plenty to be found on the river bank near to where the tinplate works used to be) then chucking it into a pool in the river or packing some into a lidded metal container, punching a few holes in it and doing the same - the resulting explosion would also stun any fish in the vicinity.
Being a mining community, there was also quite a few detonators lying around, which sometimes were the cause of some nasty accidents, as one of my neighbours (who was in school with me) Steve 'two fingers' Mackey will attest.

 

[jenkinsbrynmair]

There was that oven thing about years ago that you put the whole hive into and cooked them, I can only wonder why it didn’t catch on

maybe invest in a BFO microwave so it can be done in less time?

 

[Ian123]

maybe invest in a BFO microwave so it can be done in less time?

Lunch?

 

[MillMeadow]

Whaaaat? Concrete hives????

There's a few designs around. I wouldn't be surprised if they would crack after a dose or two though.

 

[madasafish]

I wonder if bangers are still sold? The best brand was The Cannon @ 2d each. Wrap a lump of mud around the base, light the fuse and chuck it into a stream = a most satisfying underwater thud.

We did that. Good for catching trout as it stunned them



Back on topic, my experience of heating hives or rather nucs - in the winter to melt wax is that the heat loss through wooden sides is very high.(High enough in my case to make melting wax with a limited steam output (wallpaper stripper) was very high. And the wax did not flow well but solidified inside teh nuc!

So I suggest heating a hive to c 40C for several hours in cold winter weather is likely to be problematic with wooden hives. And a fan driven method with thermostatic control would be needed.

As I vaped my colonies at c 10C - a warm winter's day = that makes the process dubious in winter in colder climes : like almost anywhere outside S England or areas warmed by the Gulf Stream

 

[Moobee]

There's a few designs around. I wouldn't be surprised if they would crack after a dose or two though.

View attachment 34884

What mad person thought that up? Britains strongest man?? It’s hard enough lifting full supers as it is.

 

[MillMeadow]

What mad person thought that up? Britains strongest man?? It’s hard enough lifting full supers as it is.

Someone concerned about security!

If you had some way to secure the roof with an inset lock it would be safe from everything except the most determined thief.

Other than those long hives that are fixed/ built into the ground they'd be the safest hives around.

The weight of a full super has taken me back abit I admitt

 

[Sutty]

What mad person thought that up? Britains strongest man?? It’s hard enough lifting full supers as it is.

Could discourage theft though - hard to nick a sealed up hive if the floor is concreted to the ground