NatureAlley

Thanks for your response, James. As far as I am aware from research I was involved in sideways heat shock proteins, HSP70 being a dominant one, are produced temporarily in all kinds of organisms, including humans, as a result from stress (such as heat exposure) and their function has been related to relieving the stress that triggers their production. HSP production drops back gradually after the stress factor has been removed. So you are correct to be cautious, it is not a mutation, it is merely a temporary conditional expression. I am convinced HSP are are not something to worry about. Varroa selection is more dangerous if a treatment is allowing more resistant individuals to survive based on their genetic make-up. Yes, the thermal box I built is very much like the Varroa controller but I looked at many other concepts, even the (patented) solar hives. After this initial inventory I decided on the 'brood only' approach. I think it was at least in part through trial and error that I got to where I am now (many of the best and lasting inventions and 'scientific progress' happen by accident or by making mistakes, unfortunately). There are differences with the commercial instrument, such as the way warm air is circulated and also in my 'contraption' the temperature and relative humidity are not set values but can be varied. As a hobbyists who likes a DIY challenge for now I am happy if the approach temporarily brings down varroa numbers in such a way (by about a month) that chemical treatment during the time when there is still nectar flow can be avoided. And should it be unsuccessful ... I will have a box to warm up the honey frames before harvesting. .. No guts no glory. Good luck with the project! Jan

As a biologist I am interested in physical treatment instead of chemical.. I am a hobbyist, and being retired I do have time but even so squashing each individual Varroa specimen manually is no option . Inspired by the equipment for hyperthermia treatment as it was developed at the University of Tübingen in the 80's and by the results claimed I looked at equipment and prices. The price of a decent instrument that ensures homogeneous temperature distribution and controlled humidity (in EU about €2500 for a 20 frame unit) is in my opinion prohibitive for hobbyists and I agree with PeterS that so far it seems not ideal for commercial application. But I found the idea interesting enough to home build a box for ~ 20 frames, just for personal use. Interesting exercise the past few months.... it turned out to be not so easy to achieve a homogeneous temperature throughout the box so that all frames are treated the same and not one area ends up 'well done' and an other area 'rare'; I would not be surprised if half-baked treatment might result in dead larvae/pupae as well as Varroa in the hotter areas whereas Varroa might survive in the cooler areas. There is another potential risk although I do not think it has ever been looked into seriously: that Varroa surviving the treatment may develop to be more heat tolerant which would get us back to the issue of resistance. So it seemed appropriate to improve the initial build. With a lot of tweaking and rebuilding the variation is now within 0.3° throughout the box during treatment and temperatures can be controlled reliably. Afterwards I did understand the €2500 a bit better..... The thermal box treats brood, so its predominant use is in spring varroa control or at least as long as there is brood. In the meantime (after consulting with a seasoned beekeeper who was friendly enough to teach me the ropes) I decided to use oxalic acid/glycerine strips this autumn. I still struggle with the question "How to perform a relevant test run with the thermal box?"; it will be impossible to achieve with any degree of reliability the way a biologist in a lab would be able to, especially with only two hives. Anyway, it was fun building, I look forward to spring when real testing can be done!

Most people accept every science based fact as long as it suits them, except when t comes to climate change.

So recognisable!

I have no experience yet, but thought give it a try. Did you perhaps heat the wax up way above the melting temperature? It looses its yellow colour that way and bees may not recognise it anymore as 'their' wax. Your foundation layer looks a bit pale. Might be just the picture...