Oxford Bees

A Hive

No crawling bees outside Hive A

Submitted by will on Mon, 07/05/2018 - 07:19

For at least the last 2 years there have been flightless bees crawling around outside Hive A. These bees were clearly suffering from Deformed Wing Virus or another disabling virus. This year there are none.

The cause was explained to me by a researcher at University of Salford. All winter the Varroa mites feed from worker bees. They accumulate DWV virus particles. In spring, when brood production increases they rush in to infest the new brood and transfer more virus to them. These bees show visible signs of DWV -- deformed wings or an inability to fly.

The absence of crawling bees can be explained in several possible ways.

  1. There are fewer Varroa mites in the hive. I usually check this by looking at the removable floor of the hive. I've found dozens of ants on the floor so I don't know whether they've been taking the Mite bodies away. I don't think that this is what's happening.
  2. The overall number of virus particles has fallen in the hive. It was very cold in April this year. This should have stopped the bees rearing brood. Virus is removed from the hive by bees or mites leaving the hive. If more mites died during April then it might explain some of the reduction.
  3. There are fewer brood this year. This seems most likely. The activity at the hive entrance is quite slow. I did look inside the hive and found only one frame of brood which was capped. I may have overlooked uncapped brood but it points to there being fewer bees and fewer brood. They're taking longer to build up this spring.

On reflection I think that Colony 01 is smaller this year which would mostly explain the absence of crawling bees.

Four hives still ok

Submitted by will on Tue, 20/03/2018 - 21:40

Three hives in the out apiary appear healthy. It's still too cold for them to fly but there's detritus on on the removable screen beneath the brood nests.

It's less clear how Hive A is in Headington. The Ants are active on the removable board. There's some evidence of activity. The hive still has supers on because the brood nest moved up. It always appears to be very big so I assume that it's strong. Let's hope that's still true in a fortnight.

Submitted by will on Sun, 15/10/2017 - 20:28

I visited my out-apiary today and examined the removable hive floors for evidence of recent activity.

Three hives (D, F and G) show evidence of recent brood emergence. There were also hundreds of dead mites. Hive D had been especially prolific. There was also crystallised sugar which suggests that old honey is being eaten or cells are being cleaned out.

One hive (C) was so wet with condensation that it was impossible to tell what had fallen to the floor. There must have been wax and pollen. Presumably mites but it was hard to tell. The hive is ventilated but I assume that there has been a strong honey flow and the ventilation has been insufficient.

One Hive (E) was in crisis but activity seems much reduced. Fewer mites and fewer hatchings. This might mean that the crisis has abated or that the colony is in deep trouble.

The overall picture is that foraging is still strong during the warmer parts of the day. Brood rearing is strong which is supporting very high levels of mites. This picture is matched by Hives A and H in Headington. A is dropping lots of mites. Both A and H are bringing in large amounts of pollen. H is building lots of comb (which A doesn't need to do).

The Varroa population models suggest that colonies risk collapse when total mite numbers is greater than 1,000. I would only be confident that hive H has fewer than that.

What happens next? This is where my commitment to no-treatment beekeeping is tested.

Five different honeys

Submitted by will on Wed, 30/08/2017 - 05:30

I harvested 5 different honeys this season. It's been a privilege to compare them and see the differences.

There were 2 from Hive A. The first was a spring honey, collected in April and harvested in May. The likely nectar source was Horse Chestnut which flowers around this time and is in a nearby park. The second was some old, dark honey which I removed from deeper in Hive A. I'm not sure when it was harvested. It was less distinctive than the other honeys. The bees were very reluctant to clear from the super, perhaps because the frames had been used for brood at some point.

There was a peculiar honey from Hive E. It seems to have been collected in a single nectar flow but the comb was bizarrely wonky, almost making a star shape. The honey was dark and viscous with a flavour described as caramel or stewed fruit. I wondered whether it might have been from Honeydew. The bees were very defensive around that time which may have been related.

There were 2 supers of honey from Hives C and D. I took one from Hive C in June which was light and tasty. It appears to have been collected in May so Hawthorn may have been a large part of the nectar. The second was from Hive D, harvested in July. It had a slight minty taste.

Comparing the honeys showed their differences. The colour varied significantly; the clarity varied according to the granulation of the honey; the flavours were very distinctive. The favourite honey seems to have been the spring honey from Hive A, probably from Horse Chestnut. The dark honey from Hive E split opinion.

In trying to write about the flavours, I'm reminded how difficult it is to describe flavour except by simile: all flavours are described as being like some other flavour. This makes a merry-go-round of the description. I can say with confidence that these all tasted very much like honey.

Submitted by will on Sun, 25/06/2017 - 08:22
two colours of honey in one jar

I recently took some honey from Hive A. Most came out as comb but there were also a couple of jars.

Yesterday I returned to Hive A. Some time ago I had put some broken comb pieces onto the crown board. In the usual way the bees had built a large slab of comb around it it and started to fill it. I cleaned up the crown board and then hung the crunched comb in mesh bag overnight.

The honey drained into a jam funnel and into a jar. After filling one jar I started top up a half empty jar which contained honey mentioned in my first paragraph. The two honeys didn't mix, leaving a contrasting layer.

I'm not sure why there is a difference in colour. The lighter honey probably was made during a nectar flow and may be largely monofloral - perhaps from the Horse Chestnut trees which flower around here in spring. The darker honey was there for quite a while and may have been hotter and from a wider variety of plants.

Small bees, or, the vicissitudes of photography

Submitted by will on Sun, 25/06/2017 - 06:02
comparing 2 honey bees while they're cold from the fridge

The bees which I've just collected as a swarm for hive H appear small compared to those from established hives. I've found it difficult to provide a photograph to show this. It was obvious when I caught the swarm: these were tiny bees. I've been wrong before so I decided to compare.

I caught 2 bees - one from hive A and one from hive H - on their way out to forage. I put both briefly in the freezer in different sized boxes. The bee from hive H was in a tiny box. It slowed down but was largely unaffected. The bee from hive A was in a bigger box and appeared completely dead and curled up. I photographed them side-by-side but it showed nothing useful. The bee from hive H flew away quite quickly. After a few minutes the bee from hive A revived and also flew off.

The freezer didn't work. I tried the fridge instead. Two new bees in two identical boxes on the same shelf of the fridge. That worked and I got my photograph but I'm not certain which bee was which. Conclusion: I can't tell the difference in size between the two bees.

There is a difference in the coloration of the abdomen which is interesting. In an earlier post I wondered whether the colony in hive E - which came from the same feral colony - were dark bees. I concluded that they were not. This difference in colouration hints that I may have been correct before.

Deformed Wing Virus appears to be seasonal in Hive A

Submitted by will on Wed, 31/05/2017 - 06:40

For at least the last 2 years I have observed a definite pattern in Hive A. In spring there are lots of crawling bees outside the hive. Some are clearly affected by Deformed Wing Virus (DWV); others maybe by another paralysis virus or by exhaustion.

They crawl around near the hive. If you launch them into the air they fall back to earth. They never make it back to the hive and have probably been ejected by the other bees. The Sparrows eat some of them. The others presumably die out of site.

By mid-May they have all disappeared. Mite drop on the hive floor has diminished so much that I've started wondering whether Ants are removing them.

I don't have an explanation. Maybe there is greater transmission of viruses when the bees are confined to the hive during the early spring build up. Maybe these bees have been in the hive for a while and are only ejected in spring.

I'm going to write to a DWV researcher to ask whether seasonal expression of DWV and other diseases is usual, and if she has an explanation.

More wonky comb

Submitted by will on Wed, 31/05/2017 - 06:03

Hive A has delivered another super of honey. Unfortunately it is crooked and cross-combed.

The bees built the comb relatively quickly. I'm not certain why it isn't straight. Strong nectar flows induce the bees to build on several frames at once and I think this encourages straight comb.

There are a couple of options for extracting the honey. It can be cut out into plastic boxes or pressed using an apple press. Neither option returns reusable comb which is disappointing.

Sparrows

Submitted by will on Tue, 02/05/2017 - 14:09

For the second year running the Sparrows are foraging.

There were quite a few bees crawling near my home hives in a state of moribund helplessness. There was no chance that they could get to the hive entrance and even if they did I doubt whether the guards would have let them back in. Some may have been exhausted, but most either had deformed wings or paralysis. No way back.

Their distress has attracted a few sparrows who feed on them. They perch on nearby fences; they perform a fluttering swoop to grab a bee on the ground; they fly off quickly.

This arrangement probably suits all. The sparrows get a meal. The bees are put out of their misery. The grass is cleared of bees which sting bare feet.

The bird which I saw today was a male House Sparrow.

Hive A dropping one Varroa mite per hour

Submitted by will on Sun, 23/04/2017 - 21:40

I've been looking at the removable floor of Hive A. There is a steady fall of Varroa mites there. I checked three times and the average is about one mite falling per hour. Some were still alive; a few were clearly immature.

This rate of mite drop puts the colony at severe risk of colony collapse, according to the BeeBase document "Managing Varroa".

I have seen quite a few crawling bees around the hive. Some have deformed wings, but not all. I'd be more concerned if this hadn't been the same last year.

We'll see what happens to the colony. My expectation is that it will not collapse, and that this rate of mite drop is seasonal and bearable.

If this colony survives this round of severe Varroa infestation then I'd say they have developed tolerance