This must be one of the most challenging seasons for bees in a long time. This week last year all the colonies were making preparations for swarming but this year they must be at least 2-3 weeks behind. On a day when the temperature got up as high as 15 degrees Celsius this week, I inspected them all and topped up the emergency fondant. I just give small blogs at a time to keep them going as very little nectar is being stored. After 2 days of heavy rain showers for part of the day the temperature has plummeted. I meet a customer walking her dog in the woods today and she asks how the honey is coming along and I have to tell her that it isn’t. At least not so far. I notice a field of OSR on the other side of the village just coming into flower so hopefully we will get better weather and a harvest in June.
On warmer days the swallows fly low picking off flies and one nearly collides with me in the apiary. Luckily it misses my face but it startles me as it speeds past. Blue tits and great tits peck around the hives removing bees.
A Slow Introduction.
Having lost queens in the past following introductions I take it very slowly and control their release. Previously, I’ve taken the tab off the cage release hatch on placing queen in the hive, and introductions have sometimes ended in supercedure after the queen has been laying for only a week or so. I have a colony whose queen cannot have been mated well last year as there were only a couple of frames of brood with a patchy palm-sized area of worker and drone brood on each side. A friend needed a home for 2 nucs with last year’s queens so I took them on and united the nucs and took one of the queens in a cage with a few workers to the colony that I had made queenless 2 days previously. It is amazing how the sound of the hive changes as soon as they get a new queen. When I opened the hive to place the cage there was such a roar typical of the queenless state. By the time I’d shut up the hive they had settled down.
I’d filled the cage feed compartment with fondant and left the tab in place so that they couldn’t release her for at least 3 days. 3 days later when I pulled off the tab I noticed that there were a lot of bees around the cage. I waited another 3 days before I checked on her release because I wanted the wee bee apprentice to get some beekeeping experience and I’d waited till her visit. Connie comes every week after school and we haven’t had much time looking at bees so far this year.
Last week she asked if we could make pollen slides and amazed me by asking if the spiky mallow pollen grains were from the daisy family because she remembered how they are covered in spikes too. I explained that Malvaceae family plant pollens are also spiky and quite large and I told her how impressed I was that she had remembered all the work we had done on pollen last year. I’d collected various pollens and preserved then in alcohol so Connie made several slides herself from those as well as from the house plants. I only needed to remind her of a couple of the steps, otherwise she did everything herself inlcuding labeling and sealing the coverslips in place with clear nail polish. She has a microscope at home to enjoy examining her slides under.
The queen had not been released after 6 days! I discover that the fondant had set to rock hard and it was taking a long time for the bees to release her. I open the cage and release the queen but we wait and watch to see if she is accepted or balled by the bees and killed.
With great relief we notice her acceptance and instantly she has acquired a retinue. A week later she has laid up one frame on both sides and it seems like all is well. I checked also to see if emergency queen cells had been made after I’d removed the original queen and there were none. I also looked every day, after the new queen’s release, just to check that she wasn’t lying outside the hive.
Inside The Hive TV With Dr Amiri: Viruses.
Last weekend I listened to a fascinating presentation by Dr Esmaeil Amiri from the University of North Carolina. You can subscribe to Inside The Hive TV to hear it yourself but it focussed on queens and how we can best keep them healthy by firstly keeping drones healthy.
There are around 30 different viruses affecting honey bees and some are more virulent and damaging than others. RNA viruses are more problematic than DNA viruses. Some take longer than others to kill bees with acute bee paralysis virus (ABPV) taking 2-3 days from infection to death.
Inside the hive older bees transfer the viruses to larvae via trophallaxis as royal jelly carries viruses. This has implications for trade in royal jelly, pollen and wax which all carry viruses. With black queen cell virus (BQCV), deformed wing virus (DWV) and sacbrood virus (SBV) there is vertical transfer from the queen to her eggs. Some viruses spread horizontally by bees contacting other bees in the hive. Viruses can also be picked up from flowers, and from the robbing of weaker colonies by stronger colonies.
What was worrying was learning that drones spread DWV to queens during mating. One might think that affected drones are too poorly to fly and mate but this is not so as Dr Almiri’s study discovered. His unmated queens had low levels of DVW compared with higher levels in mated queens. He found that the ovary masses were lower in infected queens and explained that fighting viruses takes a lot of energy from queens, as does virus replication.
It was interesting was learn that 2 days after emerging, queens have the weakest immune systems at any time in their lives and it takes 4 days for the immune system to mature. This means that they are vulnerable to infection via infected royal jelly and are generally quite fragile at this stage.
The situation with honey bee viruses is not unlike our own with covid-19. Bees and viruses evolved together but when we move bees from one country to another the genetics are different in each virus, so we introduce new strains and put our bees at risk.
We all know that varroa infestation is the game changer in the spread of the more virulent form of DWV and it is even more important to monitor varroa levels even if one is moving towards treatment free beekeeping and raising hygienic bees. After varroa treatment, it takes 2 months for the bees to be healthy again after having DWV according to Dr Amiri. He reminds us that DWV tends to kill bees during winter and he advises against uniting colonies late in the season. There is good evidence for not uniting small colonies to get them through winter because if they are small at the end of the season they make be sickly and weak from viruses.
Having been inspired by Steve Riley’s work on selecting for hygienic bees that chew up infected pupae, I was alarmed to read the latest paper on pupal cannibalism spreading DWV (see below). I asked a couple of scientist friends if I should be worried by this report, and if it would affect what we are trying to do with selection of bees with this trait. I’m relieved and reassured by the answers and I will carry on observing and selecting for hygienic behaviour but will also keep an eye out for further research.
It seems that this is a small study sample and one of at least 100 pupae would draw a more reliable conclusion. Althought it is possible for DWV to be passed by pupal cannibalism and then trophallactically to other workers, or even to the brood, the mites remain the biggest source of transmission. This is how the virus was traditionally transmitted, prior to the introduction of varroa mites in the west. If a colony expresses a sufficiently high level of hygienic trait, then the population of mites will be reduced over time. This should reduce the transmission rate of DWV.
As long as we try to kill mites as fast as we can, we actually help to select for more virulent mites and more virulent viruses, that can reproduce faster than we can get rid of them. If the virus only passes from bee to bee, without mites, then nature will select for a low-virulence strain for DWV, that does not kill its host as rapidly, so it can remain in the population. A highly virulent strain that cannot easily move to a different colony will cause its own demise when it kills off its own host. Varroa has allowed viruses to spread between hives much faster and more efficiently.
Before the arrival of varroa on Hawaii they had multiple strains of DWV present in the bee populations, but these were not considered a serious threat. After the recent arrival of varroa, they quickly saw the most virulent form of DWV became the most common one.
There is not a lot of detail about colony history in this paper. What is the overall mite level in these colonies? What level of VSH behavior were being expressed? And if you follow these same colonies over time, how would the levels of mites and viruses change? The best colonies that express the ideal level of hygienic behavior maintain <1% mite infestation level. Focusing on this one virus neglects the other potential benefits of VSH behavior… reduced physical/metabolic damage to bees with lower mite level, as well as reduction in other viruses and pathogens that are vectored by mites.
This paper describes some observations in a lab setting, but until we see some larger scale field studies that follow colonies for several seasons, any behavior that naturally reduces mite infestation is probably going to be more beneficial overall.
Avery Mather’s Guest Blog: Challenges.
Avery lives in Grantown-on-Spey near the mountains where the climate is harsher than just 20 miles downhill in Nairnshire. He has been keeping bees for around 3 years now and is continually reading and learning, but, as we know, every year throws up something new and challenging for us all in beekeeping.
This up and down weather has been so difficult in so many innovative ways. This one was new to me, and very puzzling.
I aim to keep two colonies over the winter (wife not keen on me becoming a bee farmer). Early this ‘spring’, I lost one of those colonies to nosema – where do they get these things? – and couldn’t recover it. The surviving colony was looking pretty good though. During the short period of warm weather, a few weeks ago, they had brood and stores, and they were flying, bringing in pollen. Fondant off, syrup on (yes, that was a bad idea).
Then hail, snow, wind and frost again – the full fury of a Scottish summer. I might have put fondant back on but it’s cold and wet and I don’t want to open them again if I can help it. All’s well though – they have some stores and the syrup, and the weather will be fine tomorrow. Uhu?
Three days ago, the weather’s still miserable but there are a couple of bees out on the flight board, looking very dozy. Ah well, a few optimists dipping their toes in the water. Next day, hundreds of bees; dead on the ground outside the hive. Look in the entrance; hundreds of bees are dead on the floor. Starvation? Opened up. Hundreds of bees are dead on top of the frames, some blocking access to the feeder, which still had plenty syrup in it. Bad beekeeping – another lesson learned. Confessed my crime to my beekeeping buddy.
However, I had a last hope in mind, so I didn’t go down into the frames.
Next morning – the sun’s out – and I dash back and forth, just in case any bees emerge. Noon – yes! Quite a few. Mind you, some of them are crawling about over the dead bees outside. Not surprising if it was starvation. Try to rescue a few (I’m a sop), hive transferred to a new stand and floor (devoid of corpses), syrup off, some of the dead bees swept quickly off the top of the frames, fondant put directly on frames, my patent double-glazed quilt on. Let’s feed the survivors and keep them cosy for a few days. Whew! Maybe this can be rescued.
This morning it’s warm and sunny (of course it is) and the bumble bees are roaring in the bird cherry. I go and have a look at Hotel Disaster. Many more bees are out but most of them are staggering about on the grass. Damn! It looks like CBPV type one after all. Maybe it never was starvation and chilling.
But – some of the bees have a white fungus on their wings. They seem to be trying to fly, but can’t. Double whammy of CBPV and DWV? No, the wings don’t look deformed – just that white fungus. Trawling books and websites for something similar. Nothing. And then… fondant! It’s fondant. It’s warmed up so much in the sunny morning – assisted by my brilliantly effective double glazing – that the fondant’s melting and dripping down. That’s not so bad but, even so, the ones with fondant on their wings can’t fly.
Insulation comes off: sure enough, fondant everywhere. Fondant put on a cut-out square of plastic windbreak to hold it up but still allow access (I’m going to do that next winter too, should have thought of it before). I leave off the insulation and close up again. Nothing else to do for the moment.
But hang on. What about the ones who were staggering about but didn’t have fondant on their wings? Unfortunately, I think they’ve got CBPV after all – and starvation – and chilling – and FWD (‘Fondant Wing Disease’) and IBD (‘Idiot Beekeeper Disorder’). Just shoot me now.
Still, nothing else to do but sweep up the corpses and hope for the best. Unless anyone has any other ideas.
Thank You, Avery.
We wouldn’t learn much if everything worked out well all the time in beekeeping. It is especially useful for all of us when beekeepers share their bad experiences as well as the ones that went well. Not everyone is confident enough to do this. Thank you, Avery.
Cloudy Wing Virus.
I have seen bees with cloudy wing virus (CWV) before and the wings are opaque having lost their transparency. I’ve also seen “FWD”; some fondants are softer than others but I always place them over a queen excluder now to reduce the risks of this happening.
Very little is known about CWV but apparently 15% of managed colonies are naturally infected. The transmission route remains unknown and diagnosis would require expensive PCR testing. Adult bees infected with CWV have a shortened lifespan but it is not considered much of a problem. Next time I see one I’ll photograph it.