Those many factors affecting mite reproduction

[Finman]

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The heat control of the hive depends on heat production, ventilation and evaporation of water.

When the hive has a good flow, hive must evaporate every day many kilos of water.
In Australia bees can live only on area, where they can get they get cooling water.

And you are going to mix somehow the life of colony. I bet that you will be worse bests than varroa itself.

Okay, you measure RH from hive, what then....You have 500 hives inside the radius of 50 miles. Keep hurry!



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[user 6228]

...
It does not see 80% humidity in the brood nest as being practically achievable when air change with the outside is possible.
Sure, you could seal them in and steam cook them, but what will happen is that a large number of bees will vacate the hive (possibly even abscond) and nectar evaporation will stop, existing nectar work in progress will ferment, and bees will get sick.
And you'd have to keep this up for months (varroa can live outside brood cells through the winter) to get varroa numbers to decline.

The paper explains a previously puzzling observation; it does not indicate a novel control method for use in temperate climates. Unfortunate but true.

I dont think the writer has got things quite correct in that regard. it is quite possible to have high temperatures and humidity if the hive is sufficiently insulated(roof and walls) to slow down thermally driven circulation. You will then ,if the bees are in the top, get a vapour and temperature stratification. It should be noted however that the bees will regulate the humidity down to 75% (according to other researchers)

Another research group has shown maximum Bee worker survival at 35C and 75% RH.

Most bee keeping practices put the bees in highly circulating conditions with cold conductive surfaces and the hot bees driving this circulation. The warm moist air is then condensed either on the hive walls, in the case of mesh floors on the mesh, or in top ventilation/entrances outside. This drives down humidity.


TYGMTSE note: thermal circulation is where the conduction cools the air so it descends at the periphery while the heat source is creating ascending air. The circulation hot to cold back to hot creates a cyclic dehumification effect.

 

[McNulty]

Hi derek,

have you got the links to the work regarding temp and humidity research?

Also, I see you have solid floors throughout the year (I think), do you have any links to research in this area?

I am a complete newbie in so many areas and so many opinions contrary to each other all appear to have merits. I am open minded to nearly all the ideas I read about at present so any hard science would be great, thanks.

 

[user 6228]

Hi derek,

have you got the links to the work regarding temp and humidity research?

Also, I see you have solid floors throughout the year (I think), do you have any links to research in this area?

I am a complete newbie in so many areas and so many opinions contrary to each other all appear to have merits. I am open minded to nearly all the ideas I read about at present so any hard science would be great, thanks.

pc network is in the middle of a backup at the mo... but one to hand is
Tolerance of two honey bee races to various temperature and humidity gradients - hossam F.Abou-Shaara

 

[McNulty]

thanks for that, good background info in a few of his papers