I have to say LIz, I'm afraid I was thinking exactly the same thing. I have no
intention of opening either of my hives until it's much warmer for a longer
period than we've had so far this "spring" and there's either lots of activity,
or clearly none.
On 19 Mar 2018, at 09:18, liz leaper
<lizzieleaper@xxxxxxxxx<mailto:lizzieleaper@xxxxxxxxx>> wrote:
I don't understand why everyone is even looking in their hives when it is so
cold?
On Mon, 19 Mar 2018 at 09:07, Helen Nunn
<helenmaynunn@xxxxxxxxx<mailto:helenmaynunn@xxxxxxxxx>> wrote:
I have one or two observations - I opened one of my (modified TBH) hives last
week (before it snowed!) to find a good amount of stores throughout the colony,
ie some honey on nearly every comb, plus some brood on the middle two combs,
and towards the end furthest from the entrance solidly honey. They had
obviously stored more than they needed for winter. There were 17 top bars.
This is a TBH, but double-walled with featherboard for insulation on the
outside, and with Warre-type quilt boxes plus a pillow in the eke. (See
oxnatbees.wordpress.com/2014/03/27/adding-warre-features-to-a-top-bar-hive/<http://oxnatbees.wordpress.com/2014/03/27/adding-warre-features-to-a-top-bar-hive/>)
The floor is open mesh but with a bottom board which is raised beneath the
floor, and over winter the debris from chewing off wax cappings has made a
carpet over the mesh, effectively insulating the floor. Ventilation still
happens because at the ends, beyond the follower-boards, the mesh is clear.
Going into winter I thought this hive had not really prepared with adequate
stores, but it seems their motto was better late than never. I have not fed
them. In fact I just removed three bars of honey.
My other similar hive has a bigger colony, but I couldn't inspect them as they
were completely propolised-up. What I did manage to see was that the six-or-so
bars nearest the entrance were empty of bees - they were all down the further
end on the remaining 12-or-so bars.
Helen
On 18 March 2018 at 17:05, Paul Honigmann
<dmarc-noreply@xxxxxxxxxxxxx<mailto:dmarc-noreply@xxxxxxxxxxxxx>> wrote:
First, sorry for not yet commenting on your earlier post on survey results.
It's on my to-do list...
To "advantages of warm hives" Derek Mitchell (the expert everyone quotes) would
add "vastly less fuel needed to maintain optimum humidity / temp for honey
manufacture in summer". Ie it's not that they are WARM hives but WELL INSULATED
and it helps in all seasons.
Re: disadvantages. Through the windows I've sometimes seen bees in a loose
cluster with some wandering around comb when the books say they should all be
in a tight cluster. Presumably that uses more energy than simply clustering,
but I'm guessing not much more as the bees seem to thrive in well insulated
hives, and they never seem to use as much winter stores as the BBKA say they
need (maybe 5-7kg not 20kg). Also in general I would say the bees I see have
relatively small winter clusters, nothing near the size you hear of in
conventional books (a winter cluster covering several frames). So despite the
brood rearing being earlier / easier than in a cold hive, one can say "it
works".
A minor advantage of Warres is that OSR honey is said to still be liquid after
2 years, i.e. easily eaten by the bees, instead of crystallising in weeks and
this is thought to be due to the honey being kept continuously warm.
Perhaps the most telling experimental proof of warm hives' benefits is that
Gareth reckoned his bees struggled in TBHs but thrived when he switched to
Warres. He knows his stuff and has lots of hives. Warres are definitely better
insulated than TBHs, but they differ in other ways too (vertical structure vs
horizontal) so this isn't a controlled experiment. However, assuming that
Gareth lives in a marginal area where bees struggle - and I would say rural
west Oxfordshire is not ideal as there are long nectar dearths and a lot of
monocropping - it shows that something about the hive types makes a positive
impact. Gareth is now experimenting with other hive types like the
einraumbeute<http://www.dheaf.plus.com/framebeekeeping/modified_einraumbeute.htm>
to see how they modify the bees' behaviour, but he keeps returning to heavily
insulated ones, i.e. Warres with extra thick walls or double walls.
Paul
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On 18 March 2018 10:51 AM, Will H
<whanrott@xxxxxxxxxxx<mailto:whanrott@xxxxxxxxxxx>> wrote:
I've heard Paul say on several occasions that insulation is good for hives
because it ensures a warmer hive. I would like to develop a better
understanding of the advantages and disadvantages of hive insulation. I'm
writing to the group for views. Please pitch in.
So far...
Advantages of warmer hives:
* lower energy requirements over winter limits risk of starvation leaves
colonies in better condition in the spring
* winter brood rearing will provide younger workers who can help the colony
increase in spring
* Varroa mites may preferentially infest brood cells at cooler
temperatures, so higher temperatures may inhibit Varroa reproduction[1]
* fewer cold surfaces may reduce condensation which limits mould and
spoilage by yeasts
* bees are able to move around the hive to access stores during the colder
months
Disadvantages of warmer hives
* warmer brood nest may stimulate winter brood rearing which increases
energy requirements and may leave colonies at greater risk of starvation
* winter brood rearing provides a host for reproduction of Varroa whose
numbers will be greater in spring
* winter brood will be heavily infested by Varroa because there are fewer
of them. This may lead to disabling levels of Deformed Wing Virus. I already
see noticable numbers of crawling bees in spring because of this. These new
bees are wasted effort for the colony
* condensation may be useful for metabolising honey over winter. Bees may
need to fly for water when none is condensing in the hive and risk being lost
You'll see that some of the advantages have -- as I see it -- a corresponding
disadvantage. Furthermore, I wonder whether discussions about warmth may be
conflating better insulation with reduced ventilation. It may be that better
insulation is good but worse ventilation is bad but you can't have both.
All comments are welcome.
Thanks
Will
[1]: From "Biology and control of Varroa Destructor", Rosencrantz et al 2009:
"Depending on the test system Varroa mites prefer temperatures between 26 and
33 °C (Le Conte and Arnold, 1987, 1988; Pätzold and Ritter, 1989; Rosenkranz,
1988), which are significantly lower than the normal temperature in the brood
nest of approximately 34.5–35 °C (Becher and Moritz, 2009; Rosenkranz and
Engels, 1994). Varroa mites are able to discriminate temperature differences of
about 1 °C (Le Conte and Arnold, 1987). It was assumed that Varroa females
preferably invade colder brood cells at the periphery of the brood nest;
however, there is no solid evidence for this hypothesis and the preference for
low temperature may, at least in part, be due to the artificial test conditions
in a laboratory temperature gradient (Dillier et al., 2006)."