Oxford Bees

Colony 08

Very high Varroa count for city centre hives

Submitted by will on Fri, 19/04/2019 - 06:34

I did a 24 hour Varroa drop count yesterday. This involves clearing the removable hive floor and counting the Varroa mites which drop out of the hive over a 24 hour period.

I counted

  • 15 Varroa on the floor of Colony 12;
  • 16 Varroa on the floor of Colony 4;
  • 30 Varroa on the floor of Colony 8.

These are very high numbers of mites for this time of year.

The modelling referenced by the National Bee Unit suggests that colonies starting the year with this many mites will be overwhelmed during the season. I'm not going to treat. I'll see what happens.

I did try to insulate 2 of these 3 hives before winter. The uninsulated hive had 16 mites. There isn't a noticeable difference in mite numbers between insulated and uninsulated which is counter-intuitive -- warmer internal hive temperature should encourage brood rearing which should give opportunities for mites to breed. This is a very small sample but I'm not seeing that correlation here.

Varroa fall is worryingly high for Spring

Submitted by will on Sat, 13/04/2019 - 19:38

I have seen a worrying number of Varroa bodies on the floors of my hives. This is particularly concerning at the start of the season because it suggests much higher numbers of the mites later in the season. If I was a conventional bee keeper I would treat the hives now. I'm not going to. We'll see what happens.

I periodically look at the removable floors in my out apiary in town. I've seen Varroa bodies on the floor of all the 3 hives there. I haven't been able to count the rate of fall yet but there were enough bodies to be a concern. There are also Varroa bodies in my hive in Headington. This afternoon I cleaned the hive floor and, 4 hours later, found 2 new bodies. This rate of floor is alarming.

The hives which contain colonies 8 and 12 were insulated with cork last Autumn. It wasn't the best job ever but it might have raised the temperature of the inside the hive so that more brood were raised. This would provide a great opportunity for Varroa to breed through the winter. I don't have evidence whether the insulation worked. I will try to count mite numbers to see whether there is a clear difference between insulated and uninsulated colonies. Colony 01 is uninsulated and has the very high mite count. Confusing.

Around the start of April there were also piles of dead bees outside the front of my hives in central Oxford. These were not fresh. It wasn't clear whether they died in the hive and were dumped by undertaker bees during the cold weather, or whether they crawled out. Either way it's not good news. Colony 8 had more dead than colonies 4 or 12.

I don't know what these bees died from. There were non-flying bees outside the hive on the ground. They could be suffering from a paralysis virus. There were no obvious signs of Deformed Wing Virus. I just don't know and I'm not likely to find out now.

The season has definitely begun

Submitted by will on Sat, 30/03/2019 - 10:44

All four hives which went into winter have survived. All four are now busy and apparently thriving.

There is dropped pollen on the base boards. There are dropped brood cappings. There is evidence that they're cleaning out old cells (the fine brown dust on the base board). There are also wax moth droppings -- showing that wax moth move in while the bees are in their winter cluster. I didn't see any ejected wax moth larvae. I did seem some dead Varroa.

There is lots of blossom around. The season is underway.

I set up an empty hive in my out-apiary in case any of the colonies swarm in April. I've replenished the water spot too. I haven't fed them this spring, although I did feed some of the colonies in Autumn.

All hives have over-wintered. Can they over-spring?

Submitted by will on Tue, 05/03/2019 - 16:14

All my current hives (A, D, E, G) are upright (after the recent windy weather) and sound. The hives are fairly heavy, which is reassuring. A peak through the door shows the floor to be fairly clear. Their colonies (1, 4, 8, 12) appear to be fine. They were flying when the weather was warmer; there is evidence of activity on the base board.

The base boards have darker chewed wax which usually means brood hatching. It's hard to know when this was fell because I've only occasionally looked. It does suggest that there has been a slow but steady rearing of brood.

I can't tell much difference between the hives which are insulated and those which are not. Two are; two are not. One of the uninsulated hives had evidence of some condensation but not much.

Last spring was devastating for my colonies. Brood rearing had started to increase in the warmer weather but then it became very cold. Colonies which had insufficient stores or few bees starved. I hope that there will be sufficient honey in the hives to keep them fed. I was careful not to take much last summer and 2 of the hives are insulated. We should know in a month.

November weather

Submitted by will on Fri, 30/11/2018 - 07:44

It's been windy and rainy recently. I checked yesterday on the 3 colonies in my out apiary. They're all upright (which is nice) and ticking over. There is evidence of brood emerging, with lots of Varroa mixed into the chewed cappings. The cold spring must have knocked back the Varroa but they built up again in the Autumn.

So far, so fine.

The Varroa finally appear

Submitted by will on Tue, 25/09/2018 - 05:51

The weather has turned colder, with only a few hours when it's warm enough for the bees to fly. Yesterday they were very busy in my out apiary.

My bee group remarked that their hives had a lot of activity at their entrances, with lots of orientation flights. They suggested that there had been a burst of young bees hatched in the previous days and these were getting to know the area. The drop off in brood rearing may also have been releasing nurse bees to fly.

There were a lot of chewed brood cappings on my hive floors showing that there have been lots of hatching. The flip side of this was that there were finally a few more Varroa bodies to count. The volume of hive floor debris made it hard to count accurately -- I would have needed to mix the debris with Methylated Spirits to see them clearly. I estimate that there were 2-4 dozen mites on the floors of colonies 8 and 12. There were only half a dozen or so on the floor of colony 4. I suspect that colony 4 had less because their dearth of stores may have reduced their number of brood.

All the hives look fine. All had strong defenses and plenty of flying bees. There was not very much pollen coming in, nor was there much pollen on the hive floors.

Wasps everywhere but none appear to be getting inside

Submitted by will on Sun, 05/08/2018 - 06:36

My hives are surrounded by at least half a dozen wasps which want to rob them. They zig-zag in front of the entrance; they crawl in under the Varroa screen; they wait at the edges and drink from the water tray. They want the honey but they can't get in.

All of the hives in central Oxford have small doors and strong guards. Three of the four have at least 20 bees visible on the outside of the hive entrance. One hive had fewer visible but appeared to be just as effective at guarding.

Having so many Wasps around makes it hard to open the hives. Once robbers get in they are more likely to return. They're as happy to gain entry from the roof as through the door. I think that they're also more likely to successfully return and re-enter the hive because they smell of the honey from that hive. Robbing can become a storm which only abates when the hive is moved out of range of the robbers. That's a lot of work just for a look inside.

Robbers notwithstanding, I took a very quick look inside the hives in central Oxford to check that none had run out of space. They all have sufficient space for the moment. They are also all dropping pollen, which suggests they're still laying and there  is forage for them. There is plenty of door activity at all the hives. I found no Varroa mites on the base board. I was some evidence of Wax Moth and some evidence of new comb.

Colony 1 in Headington is also faring well. There are some wasps, but fewer than in central Oxford. There is pollen being dropped and plenty of door activity.

Busy but steady across all hives

Submitted by will on Sat, 21/07/2018 - 20:06

Things seem to be going well in all my colonies. They're all busy at their entrances. There are wasps near the entrance to every hive but they don't appear to be getting in. The Varroa counts are very low and there's pollen on all the base boards.

Colony 1 still has ants infesting the base board so it's hard to be confident that I'm seeing the whole story. Certainly the bees are still removing and dropping crystallised honey -- presumably from last season. They are bringing in pollen which suggests they have unsealed brood. There are brood cappings which suggest that they also have emerging brood. All good signs. I saw what I took to be wax moth around the hives but I may have been mistaken.

Colony 11 is still vigorous. It has pollen and cappings on the base board. There was a smattering of wax platelets indicating new comb. I looked hard and found one solitary Varroa mite. It was alive.

Colony 04 is collecting pollen again which suggests that it now has brood again. I suspect that it took a break an unconfirmed swarming event in late June. There may be some wax moth in the hive but otherwise everything looks good. I found one solitary Varroa mite in this hive too.

Colonies 08 and 12 are doing fine. Bringing in pollen; keeping out the wasps. Colony 12 had about half a dozen Varroa mites, all dead.

I'm curious about why there are so few Varroa mites visible on the base board. The season is getting on and I would expect to see a lot more. I have ideas about what is going on which I'll put into another blog post.

Varroa drop not quite zero

Submitted by will on Wed, 13/06/2018 - 07:18

Colony 13 is dropping Varroa. They are also cleaning out old comb so there is a lot of debris on the hive floor. I found 2 or maybe 3 Varroa bodies.

This colony is new to my apiary, having been established elsewhere. I haven't really included it in my Varroa Zero post because it's new. Hives D and G are included. There were no Varroa on the floor of either this morning. There doesn't appear to much activity in Hive D at all. I shall have to check them.

Varroa drop zero

Submitted by will on Tue, 12/06/2018 - 05:50

I regularly examine the floors of my hives. The stuff which falls out of the hive tells a story about what the bees are doing. I always look for Varroa mites. I've found none on the floors of any of my hives for several weeks. I don't know why.

Mites on the hive floor can indicate how many mites are living in the colony. Varroa live for between 27 days to about 5 months (source: Managing Varroa, National Bee Unit, 2017). The mites require bee brood to reproduce so it's not surprising that there are fewer mites in the early part of the year. What is surprising is that I'm finding no dead Varroa at all in well established and very active hives.

We had difficult weather in spring. The temperature started to warm and then fell dramatically. This led to a number of colonies dying of complete starvation or isolation starvation. Dead colonies don't support Varroa. Live colonies do, but only in cells with brood. I wonder whether this has interrupted the mite life-cycle and knocked them back. I do not expect to find any colonies where Varroa are entirely absent.

I have 6 occupied hives. Three of these are new colonies. I expect to have lower drop anyway because they arrive only with those Varroa which cling on to swarming bees (during the phoretic part of mite life cycle). I have one established hive where there is an Ant infestation. It's possible that the Ants are taking away the mite bodies. That leaves two established colonies which have brood but are dropping no mites. That's a small number of hives, but striking anyway.

There will be more to say about this later.