I came along in the evening to feed the queenless parent colony. It's recommended to feed only after the bees have stopped flying for the day if possible, otherwise all the foragers realise that there's a great new source of food coming in and all rush out of the hive trying to locate the source of it (unaware of course that the housebees are just bringing it down from the roof-space feeder!)
Bees are notoriously 'sleepy' after dusk - these ones were so slow that I had to brush them all out of the way before I could put the feeder down.
The recipe for spring feeding of sugar syrup is much more diluted than the autumn syrup - 1kg of sugar to 1 litre of water.
Even though they were all moving slowly, a few did come up within a few moments to start feeding.I won't be feeding the swarm colony yet. I'd like them to use up the last of their old honey stores in building up the foundation if possible - it's all been affected by the chemical varroa treatment I used so I need to make sure it's all completely used up if I want to even consider a honey harvest this year.
I won't be needing to use more chemical treatment now that we've created an artificial swarm. I can do some nifty frame manipulations over the next few weeks (if all goes to plan) and trick all the varroa into being exterminated (in theory, anyway!).
I wish I'd known that they were going to swarm so soon as I'm reluctant to use any chemical treatment unless it is necessary.
One spare hive body and a spare 
A quick puff of smoke at the entrance, to warn them that we were coming. It is possible that the workers would 'ball' the queen if the colony is unexpectedly disturbed. The queen rarely survives this scrummage so we always give the same few signs that an inspection is on the way (slide out the varroa floor, next blow a puff of smoke at the entrance, then gently drum fingers on the roof). I've no idea if this helps at all but bees are creatures of habit and routine so it makes sense to me!
There are plenty of these again but this isn't what we're looking for in this inspection, it's another swarm cell and I don't want to waste time knocking all those off right now (they could build another one up in 15 minutes anyway)
Here it is, just like I feared! A full-size queen cell right at the top of the frame and...
... sure enough, it contains a nice fat queen larva swimming in royal jelly! I couldn't get a better photo than this unfortunately, most of them were out of focus. So that's it then, time to create an artificial swarm immediately.
I marked this frame with the queen cell on it with a drawing pin so I'd know which one it was without having to handle it again. Queen larvae are notoriously fragile - because the cell's opening is at the bottom it's very easy for the precious larva to become dislodged and fall straight out. The next step is to find the existing queen and isolate her on one frame.
We've usually had no trouble finding Charlie before and thankfully she turned up very quickly.
She's even on an ideal frame for us too - it has to have brood in all stages of development but no queen cells at all.
This frame with the queen on goes into the spare nuc with the lid on, so there is no danger of losing her while we create her swarm.
The entire hive (known as the 'parent colony') is lifted from those black crates and moved 3 feet to the left, with the entrance at the same height and direction as before.
The new hive body is placed on the original site (this is the 'swarm colony') and filled with empty foundation frames.
In the centre I placed one empty frame of fully-drawn foundation so that the queen has room to continue laying eggs immediately, rather than wait for the workers to draw out cells on the new foundation. Ideally there would be two fully-drawn empty frames placed here with a space in between them, if they're available.
The frame with the queen on is removed from the nuc and placed into the centre of the new hive, along with all the bees on it.
The queen excluder is replaced...
... along with all the supers of honey.
Now to the parent colony which is now queenless. There were two frames missing from this brood box so we slid all the frames together and inserted new frames at either end (it is never advisable to split existing brood with empty frames).
The lid is replaced and the artificial swarm is completed now. A 'natural' swarm consists of the existing queen, all the flying bees, and as much honey as they can carry; we have now manually created this situation ourselves.
The swarm colony shown on the right here will behave as if it has just swarmed and set up a new colony, consisting of the existing queen, all the flying bees, and plenty of honey to start comb-building and brood-rearing straight away.
Of course the parent colony in the centre here is now in a very weak situation because it has lost all the flying bees (their main defense force). For this reason I cannot feed them for 2 days, giving them enough time to organise their defenses against honey-robbing.
Much as we had expected, not much change in the supers. We have previously found that when using this Thymol gel treatment before, all work in the colony seems to slow right down, no matter what the weather conditions. This may be because the smell of it dramatically affects the bees' communication.
They've taken most of the Thymol gel from the pack but the treatment isn't over yet. There are a quantity of mites still sealed safe inside the brood cells which will not have been affected until they hatch out.
This section of drone comb which was empty last week is not quite fully capped. I've got at least 10 days until those capped drone pupae on the left hatch out (along with all the varroa mites inside), so I can afford to leave this chunk for another week until I slice it off.
This was a distressing sight, and unfortunately not the only one we saw (and definitely not the last, I'm sure). It's a bee which has hatched out with deformed wings. It must have shared its development as a pupa with anything up to 10 mites, all of them parasites in its cell. We noticed 6 more bees with similar deformities.
We saw Bea quite easily and she seemed as healthy as ever. The brood pattern and all the cappings seemed in very good condition too - apparently these are the next warning signs to look out for if a colony continues to seriously decline.
Other than the few deformed wings, the health of the colony didn't seem bad. There were still a large number of clearly healthy bees and the signs of good housekeeping were there still. We closed up again, replacing the varroacide as it was.
These are swarm cells - signs that the colony is intending to swarm. They really meant it, too - there were over 20 of them in the hive...
... and every single one we could see inside had an egg in it already! This colony is really getting serious about swarming. Once an egg has been placed in a swarm cell it means you only have between five and eight days until the colony could swarm. We had to break off every single queen cell. This will not prevent the swarm from happening in future but it will delay it a bit. Now it's possible that they'll change their mind about swarming for the time being but at least now we have another week to prepare for it!
This drone brood comb was fully capped, as were many others in this hive, so I sliced it all off to see what level of mite infestation there was.
It's at times like this I'm very glad I wear latex gloves during inspections! This is a varroa mite clearly visible on the pupa here. I only found a couple of mites in all the drone brood I inspected so I'm confident that the level of infestation here is still moderately low (but that would change rapidly if the colony next door were to collapse - a large number of starving bees would come here in desperation, along with all their parasites!)
See the clear difference between the two colonies here!
The first hive, they've taken more fondant now - I've now sliced the pack open more than it is in the photo so it'll be easier for them to get at it. There were about 300 dead mites (that's about 75/day).
Similar situation with the fondant on the second hive - I've now sliced this pack open more too. There were far fewer dead mites here, only 60 (15/day).
The mite population increases by the rate of approximately 200% every four weeks, but this rate varies greatly as it is influenced by many other factors within the hive.
The table above shows at what point a dangerous level of infestation is reached, with the number of mites per day found on the varroa floor plotted against the month. Anything over 9 mites/day, no matter what time of the year, is considered a 'severe risk' of total colony collapse (this is, of course, when there is no treatment being applied - I hope to find considerably more dead mites than that now that I've applied the varroacide treatment).
As this table depicting varroa population increase shows [number of mites in the infestation plotted against number of days], anything but a very effective varroa treatment is almost pointless - if I only remove 80% of the infestation it will be right back at exactly the same danger level in two and a half months. This is why I have to use a number of treatments, and not just now but continually.
These are two small 'ekes' and two Thymol gel packs. It's not usual to use Thymol at this time of the year as it taints any honey in the hive but if I don't take immediate action the varroa population will massively increase in the next few weeks - the colony would be lucky to survive to mid-summer, let alone produce any honey at all!
I removed the supers, right down to the brood chamber.
The small eke went on next. This is used so that the Thymol pack won't get crushed by the supers.
Pack is opened and placed facing upwards.
I did the same on both hives, hopefully this will knock out loads of varroa before it's too late to save the colony. I'll keep monitoring the floors regularly - there should be a huge mite drop in the next few days.
Some very worrying signs on this varroa floor. It was cleaned only one week ago and now it is covered in dead varroa mites already!
We counted over 100 dead mites in total! I was only expecting to see one or two, a dozen at most. This is looking like a dreadful situation already - at least it was warm enough to look inside and examine the state of the colony.
The supers still contain some overwintered honey stores, but not much. They've taken some more of the fondant, but not a great deal.
The wax had built up heavily on top of the brood frames after all this time...
... but it was soft and easy to clean off in this warm weather.
The health of the colony actually looks pretty good. The bees seem the same as ever and the pattern of brood and stores seems fine.
We found this good long section of brace comb on this frame - it's ideal for 'drone brood removal', one of the means of removing varroa mite. Varroa prefer to breed in drone cells if it's available, so if we leave this brace comb here until it's full of capped drone brood, I can slice away a huge number of varroa in one go - and I only have to sacrifice some non-essential drone bees.
Another section of drone cell brace comb here and this one has larvae in. One week more and I should be able to chop this off too, along with all the varroa mites lurking inside (they only sneak into the cells shortly before they're sealed up, hiding behind the fat larvae, so I have to wait until after they're shut inside)
This is an encouraging sign - an adult drone bee (in the centre of the photo, with large eyes). Drones are usually only raised when a colony is strong enough to support them (they do no work at all and have huge appetites).
We were just on the very last frame thinking that things weren't as bad as we first feared then saw this in the picture above. A newly-hatched worker bee with a varroa attached. I really wanted to pick it off the poor thing!
On the same frame we saw this - two more worker bees with varroa attached (top middle and lower right). Varroa is evidently a massive problem for this colony but the productivity doesn't seem to be greatly affected yet. I'll need to look up just how long we've got until this colony faces total collapse because it doesn't seem to be beyond saving yet.
More varroa on this floor but not nearly so many - we counted 12 dead mites.
That's massively more than last year (we usually only found between 1 and 6 in a week) but far less worrying than Bea's colony.
Everything seemed to be pretty much identical to the first hive - a good amount of stores from winter and a bit more fondant taken in.
We cleaned up the brood frames like normal, very satisfying after building up for six months!
We quickly noticed that there seemed to be more bees in this colony but apart from that everything looked almost identical...
... there were even the same handy sections of drone cell brace comb for me to slice off next time!
We saw Charlie very easily (she's in the centre),
... and she seems full of vigour still (with a few traces of that blinking green smudge from about 10 months ago!)