A Difficult Decision.
I’ve been rescuing animals since my childhood on the farm and I hate it when they don’t surive. Most often now neighbours bring me sick bumble bees but I’ve had birds, hedgehogs, hares and rats over the last 29 years. Alice the small brown and white rat was the main success story and she lived happily with me for a couple of years till the end of her life. Alice was wandering the streets of Elgin confused and malnourished when she was discovered by a rabbit rescuer. Caraline also rescued guinea pigs but drew the line at rats and brought Alice to me. As soon as I clapped eyes on the skinny wee fragile animal I couldn’t refuse to take her in.
But, I digress and must tell you about my sick bees. I’ve written previously about the colony that has had Chronic Bee Paralysis Virus (CBPV) for 2 years. One of my mentors was with me when I first noticed bees tumbling out of the front entrance acting like they had been poisoned. Lab tests proved negative to poisoning and I realised that the bees had CBPV. They carried on to survive over 2 winters but now the are not building up but dwindling. In fact, they also have Deformed Wing Virus (DWV) though sugar roll tests shows low varroa burden. I normally only use organic acids but last autumn used Apivar (Amitraz), then oxalic acid sublimation in December.
The colony is now dwindling rapidly and sick bees are falling off the combs and dying on the floor. The brood is chilling and dying because they don’t have enough healthy nurse bees to care for them. Chalk Brood (Ascosphaera Apis) is flourishing and the colony will slowly die. The brood frames are normal otherwise and a full disease inspection shows no other disorder.
Recent UK by Budge et al on CBPV can be viewed below.
https://www.nature.com/articles/s41467-020-15919-0
What to do With a Sick Colony?
I could leave this sick colony to dwindle further and die over time but is this good management? For a start, the bees are suffering and they also might infect my healthy colonies. They might leave their hive and move in next door.
I decide that the time is right to destroy the colony but I am sorry because the queen is laying vigorously and looks healthy. I discuss the situation with a mentor who suggests that I save the queen and make up a nuc. This is what I do and I place the queen on a healthy frame of sealed brood in a 5-framed nucleus box with stores, another healthy brood frame and empty drawn combs.
The foragers are vigorously flying to dandelions and bringing in huge pollen loads and I want them to return to the queen in the nuc so I remove the parent hive 20 feet away and place the nuc on its site.
Preparing to Euthanase the Colony.
I find a solid floor and place an old towel on it before selecting all the remaining brood frames that will go into the brood box on the new solid floor. The remaining bees are now in this box and the healthy flyers return to the parent hive. I shut up the entrance when I see no activity at the entrance and I pour in a cup of petrol through the hole in the crown board. The fumes quickly kill the bees. I replace the roof and hear a roar (like the noise the colony makes after sublimating with oxalic acid). It lasts no longer than a few seconds fortunately.
Cynthia my bee-buddy helps me and provides moral support. It’s not something either of us has done before. She drops by after inspecting bees at the nearby distillery and we have a cup of tea (socially distancing) after the deed is done.
Within the hour I have cleaned up the dead bees wrapping them in the towel and double bagging the combs and bees. I’m surprised how quickly the smell of petrol dissipates and it’s gone by the time I come to blow-torch the woodwork.
Results.
I won’t know for a few weeks if this has been successful in reducing infected bee numbers and allowing colony build up again, but yesterday there were no dead bees on the nuc floor, and the little 5-frames super on the brood box was full of bees.
Wild Bee Colony.
Another disappointment this week was discovering the wild bee colony inactive on a very warm still day of around 18 degrees Centigrade. I was hoping to see loads of pollen going in but there were only a few bees flying in and out. As on the last visit, the bees were defensive. This wild bee story can be found in Bee Culture magazine, April.
The Good News.
It was really warm here for a few days and so I got out the solar wax extractor. I had to brush off a couple of years’ worth of dust first. I store up old frames and burr comb in airtight containers till I have enough to process. Waiting for hot weather is the main constraint here in the Highlands.
I’ve used my friend Kate Atchley’s nifty tip of lining a loaf tin to collect melted wax.
Mining Bee.
I was sitting in the garden near this plant and noticed the smallest of bees with pollen baskets almost larger than itself. This was one of the highlights of my week. So, it wasn’t all gloom and doom. Scout bees are sniffing round one my 5 bait hives so next week promises to be interesting.
Hi Ann sorry to hear about the bees it must be so hard having to destroy them. Glad you had some moral support later. All the best to the new nuc may they thrive. I always felt like a sort of neighbour to the wild bees so again sorry they seem to be dwindling.
Hopefully all will be well now.
Thank you, Susan. It is a shame about the wild bees but they may pick up again. The bees with DWV are from the wild bees rescued from fallen tree River Nairn 2016.
Hi Ann. I admire how you were mindful of the health threat of the failing colony to the nearby colonies, and how you are testing whether you can use the failing colony’s queen without passing on the CBPV. I look forward to learning more about this. It must have been hard to kill the workers in the failing colony, but you minimized their suffering, and you reduced the likelihood of health problems in your other colonies, so I think you have done well for your bees.
Hello Tom, thank you for your supportive comment. It was a difficult decision to make and a hard thing to do but it was over very quickly for the bees. So far, there are no dead bees on the floor of the nuc, or outside, but only time will tell if I have done the right thing there keeping the queen.
Thanks Ann for sharing your challenging and sad bee story. I thank Jane too for her honest sharing a few weeks ago. We all can learn from each other’s experiences.
I hope the nuc will come through and your apiary will flourish.
Thanks, Anna. It is a sad story but it feels more positive than letting the bees carry on dwindling and potentially spreading disease. I agree about Jane’s blog and the benefit of learning from such experiences.
Hi Ann,
I hope it is not too late to comment on this article.
I have a strong colony that has been losing bees to CBPV since April. I took a sample to SASA and am awaiting them being used in the current CPBV research thorugh St Andrews university and David Evans.
I have been completely uncertain as to what to do about this colony so have left it alone.
Very recently, the virus has now spread to all my other colonies, killing the one next door and infecting those further away. It has also spread to a neighbouring apiary, not mine, about 1.5 miles away. This is extremely worrying and difficult.
I now think I should have culled the first colony quickly, although the advice at the time from SASA was that the virus would likely stop after a few weeks. It has been hard to find any advice as to what to do. I do not know where the virus came from.
Hello Sue,
It is never too late to comment on anything in Beelistener. Thank you for getting in touch. I am sorry to hear your discouraging news. Well these viruses are just around now anyway, since there is so much movement of bees, and often cause trouble when colonies are stressed. However CBPV manifests in big strong crowded colonies where it spreads quickly. It has been associated with commercial beekeeping and imported queens but it is something that we hobbyists are seeing more of in our apiaries.
My “go to” reference book is “Honeybee Veterinary Medicine” by Nicolas Vidal-Naquet. The advice is: clear away dead bees from the hive and around, perform a shook swarm (so bees are on fresh comb and brood frames are destroyed) and re-queen the colony.
I was like you and waited to see what happened. However 2 years on and the problem recurred so I euthanised the nurse bees and sacrificed the brood on the assumption that the foragers were still able to fly and looked well enough. I suppose I did a version of a shook swarm in that I put the queen on a frame in the new hive, on original site, and let the flyers return before I finished off the others in the original hive that I had moved to the other side of the apiary.
With hindsight I would have done a shook swarm and re-queened as soon as possible after discovering the problem. Initially, I thought they had been poisoned which is why I sent the sample to SASA. It was the end of summer and not a great time for a shook swarm but hindsight is a wonderful thing!
You can still do shook swarms as the weather is good and if you give them a 1:1 sugar syrup they can draw out the comb easily.
Thank you Ann for such a prompt reply. I really appreciate you taking the time.
My neighbour beekeeper, who has many years of experience, has already tried a version of what you suggest. He shook out the hive 50 yards away and then put a new box, new frames etc for the returning bees and gave a new queen. He says it has not helped. I see flying bees laden with pollen come back to the hives and then start to falter and shake and eventually fall off the landing boards. It is so upsetting. But it means some flying bees are already infected and so must transmit into the new box. But I’m guessing that didn’t happen in your case and performing your version of a shook swarm cured it completley?
I have 5 hives now that are affected and don’t have enough equipment to do this to all of them. And I don’t have any spare queens to requeen- another reason for learning how to raise more queens, I think!
So I am wondering if the strain of virus that has appeared here is more virulant than the one your colony had, if it didn’t spread to your other hives after 2 years. Whereas here it has spread, in the past few weeks, to 10 other hives I know about. Is it likely, do you think, that there could be different strains?
Thanks again for sharing your experience. I might get help, and hopefully a queen, to try at least one shook swarm – something I’ve never done before -and see if it makes any difference.
It would not be true to say that it has completely disappeared. I carried out the manipulation last year and the colony did fine over winter and showed no signs till last week (almost exactly the same time of year that I first noticed it 3 years ago). Only a few bees are affected and I have just re-queened this week. My colonies are not close together and certainly not in a line. I clean my hive tools in washing soda solution between inspections, and bee suit after a day’s work. I always wear disposable gloves which I wash in washing soda solution between inspections as well. It will be interesting to get the results back from the lab. Perhaps we do not have the same virus as I have not had it confirmed due to cost. I am going by bee behaviour and appearance.
Thanks Ann. I am sorry to hear the virus has reappeared. I hope it is a mild bout.
I follow the usual biosecurity procedures too in my inspections, so I hope I have not transmitted it. I can’t have done so with regard to my neighbours apiary, so it must be mostly to do with bee to bee contact.
Until the sample I took to SASA is tested firther, I also don’t know for sure what this is, but whatever it is, it is horribly infectious.
Thanks again for your time and support.
Hello Sue, I agree with you that it seems mostly to do with bee to bee contact and transmission. I’ve been checking the hive entrance every day and there are only a few crawling bees to be seen now and again, and nothing like it was initially. So I think that it is never going to go away completely but I can take action if it gets too bad again. I do worry this week though with the torrential rain and confinement that it may increase.