ONBG meeting, 16th Nov 2017 – insulation, honey and mites

On a winter’s evening a dozen folk gathered at the Victoria Arms in Oxford to discuss, you guessed it, bees and beekeeping.

Jack had brought along the heat-vision FLIR camera he used to photograph his hives’ heat profile in a previous post. Brian and I have borrowed it to see where our hives, which are different styles, lose heat during winter – more on that in a future post.

People brought up some interesting questions and stories…Santa had a great tale about collecting her first swarm. She went to Banbury library where it had been reported, hanging on a wall. She suited up and lots of interested bystanders watched, some taking pictures with their phones. She was very nervous and unsure of the procedure, but her husband helpfully pointed out that this was a very public spectacle and she now had to go through with it or she would end up all over the internet. So she went ahead, and caught the swarm, which is still alive in one of her hives.

2018 natural beekeeping conference

We mentioned this upcoming event in the Netherlands: it looks like a good opportunity to network and learn new things. It is likely to cost ~€300 for the weekend, not including accommodation and travel.

Honey

The question arose of exactly how and when to harvest honey from a Warré or TBH.

A number of new members have asked this recently, so in 2018 we intend having a meeting where we go through the process of judging a surplus, harvesting comb and extracting honey using the crush and strain method. In short, if there is a sufficiently large surplus, with Top Bar Hives you can take just a comb or two as and when, whereas with Warrés you generally take off a whole box at once, at the end of Summer, and only if it is filled with honey and there is at least another box filled also. There are a lot of exceptions to this – for example some years the bees don’t have any excess to harvest, and a newly establishing colony should not be harvested from in its first year – which is why we might spend an entire meeting on this subject.

Mixed white and dark capped honey cells on the same comb. Source: Oxfordshire hive in 2013.

Santa described how her honey combs can look different. Some patches of honey cells seem dark – is this OK? Yes, it is. It simply indicates that the bees in her hive are not a pure strain – they have different fathers, and different preferences in the way they cap their honey. Bees with A.m.m. (black bee) or Buckfast genetics like to make a cap with an air gap between the wax and the honey behind – this looks white. Bees with Italian heritage place the wax cap directly against the honey surface, resulting in a dark cell. Basically, any capped honey should be fully mature and OK to eat.

Honey colour can vary with the blossom it was collected from. In our area, we sometimes see plugs of solid white crystalline honey in cells, if ivy or rape honey is allowed to cool for a few weeks (i.e. if they are not in the heated brood area.)

Overwintering: heat retention and mites

The idea of heavily insulated hives has long been a core principle of natural beekeeping, but is now spreading rapidly through the conventional beekeeping community too, thanks to the work of Derek Mitchell which has prompted a rethink on how insulation has no downsides, only upsides. (Eric remarked there’s a parallel with how people who keep horses find they spend 30% less on winter feed if the horses wear blankets.)

Our TBH and Warré hives seem to need far less stores to survive winter (well under 10 kg) than the BBKA recommends (typically 20kg). It varies with insulation, strain of bee, size of colony and local forage patterns, but one little-mentioned edge is that our low-intervention style, with few inspections, allows the bees to follow their instincts and build “brace comb”. Brace comb connects combs right to the edge of their cavities, adding extra support and reducing draughts and thus, heat loss. Every time you inspect a comb or frame, you need to cut away this brace comb to pull the main one out. Like culling drones, the bees are going to re-do the work involved to optimise the nest as they see it, so you are wasting their effort every time.

Will H opened debate on the conventional wisdom that colonies with a high mite load will die after 2 years: he has two hives, two years old and of feral origin, dropping hundreds of mites a week. I suggested he leave them alone, and if they don’t survive, repopulate from a swarm – I’ve become more hard line about ruthless natural selection over the years. I’ve seen the 2-year limit mentioned, but research shows colonies tend to keep mites under control indefinitely if they are allowed brood breaks (typically by swarming, for feral colonies), rather than being stimulated to lay continuously by feeding. In rural Oxfordshire, I also see brood breaks due to nectar dearths in June-July, and this helps reduce mite levels; but this may not be true for Will’s urban hives. Note: Will’s high mite drop hives were still going a month later according to his blog. I’ve made a note to update this page in a few months to report if they pulled through.

Will, Ann W and Faith have all noticed colonies with crawling bees (indicative of DWV spread by varroa mites) in spring, which seemed to clear up after a few weeks. So it’s not that our bees are totally unaffected by varroa; but Oxfordshire bees seem to have evolved coping mechanisms for Oxfordshire mites. According to a researcher Will asked, by late spring there are enough brood to have some uninfected; this spreads out the mite / virus load. In other words, the viral load concentrates in winter.

Our winter survival surveys show that our group has some losses every year, though generally from queen failure and never, it seems, from mites. Our winter deadouts are consistently marginally less than conventional beeks’. An argument could be made that this is because we don’t weaken our bees with miticides.

Something to consider

Talking of mites… did the arrival of varroa in the UK in 1992 – 1993, have an upside?

True, it wiped out most of the hives in the country in just a few months. Going by BBKA membership stats, half the beekeepers of the time gave up the craft.

But, it brought home the dangers of unrestricted importation of bees; and how migratory beekeeping spreads pests; and probably gave the residual feral population a breathing space to bounce back, with reduced flooding of areas by foreign drones. Local bees have a wider gene pool than inbred strains from breeders, who are still searching for varroa resistant strains of their stock – and local bees have fewer pressures on them as their breeding rhythms, etc, are tuned to local conditions, so they show more resilience to new factors.

Most beekeepers I know in this area, even conventional ones, use primarily local stock now. It’s tough, it’s well adapted and it just works. Even the BBKA promotes the use of local bees. One might think that perhaps varroa has, by now, killed off the more unfit colonies.


Many thanks to all who came on a chilly Winter night!

Next meeting: TBA

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1 Response to ONBG meeting, 16th Nov 2017 – insulation, honey and mites

  1. Pingback: Infrared images of hives in winter | Oxfordshire Natural Beekeeping Group

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