Deformed wing virus

Deformed wing virus (DWV) is one of the viral diseases associated with Varroa mite infestations. Although the disease is also found in colonies not infected with Varroa, it appears to be both more common and more destructive in colonies where mites are well established.

Other things can cause an occasional case of deformed wings and a diagnosis is impossible without laboratory tests. However, if you see a young bee with distorted, misshapen, twisted, or wrinkled wings, there is a good chance you are seeing the results of deformed wing virus.

In untreated hives, the Varroa mite population skyrockets in late summer and early fall. The mites had all spring and early summer to build up and now, when the drones are being evicted and the honey bee population is shrinking, the number of mites may overwhelm the number of bees. When the viruses also become concentrated in the remaining bees, symptoms are more likely to be apparent to beekeepers.

Bees with deformed wings do not live very long. The one shown below wandered out of the hive this morning and was fluttering her misshapen wings and running in a circle when I found her.

Rusty

A honey bee with severely deformed wings

Comments

Gary
Reply

Have you ever used powdered sugar to treat varroa mites?

Evan
Reply

I have noticed some drones with DWV but have not noticed any workers. I opened up a few drone cells and have noticed a couple mites here and there but by in large most of them appear clean. This is the hives second year after going the first year treatment free (caught a swarm last spring).

Rusty
Reply

Evan,

Since you know mites are in there, you should consider some management technique, such as removing drone brood or breaking the brood cycle. Those mites will move from your drone brood into your worker brood in the fall, so be on the alert.

Jon
Reply

Hi Rusty,

I found a couple of mites on some drone brood I inspected a little over 2 weeks ago. I have done a powdered sugar dusting on both of my colonies the past 2 weekends (both are newly installed nucs, 1st week of May). I only left the mite boards in for a couple of hours on both hives for both treatments. Combining both sugar treatment numbers: hive 1 mite board had 14 mites and hive 2 had 9 mites after sugar dusting. Again, I didn’t leave the mite boards in for 24 hours, just for a few hours as the temps in East TN now are upper 80’s and about 80% humidity. I’m sure my mite numbers are higher.

Yesterday I noticed about 8 worker bees outside one of the hive boxes walking around with deformed wings.
Contemplating my next steps and wondering how concerned I should be over these bees with deformed wings. Would you continue powder sugar dusting or a different approach? Also is there any treatment for DWV outside of lowering the number of Varroa?

I would like to stay away from chemical treatments, as naive as that may sound, but am not opposed to a soft treatment if absolutely needed (Api Life Var, Apiguard, can’t get Hopguard2 in TN yet).

Any advice would be greatly appreciated.

Thanks,
Jon

Rusty
Reply

Jon,

Your mites counts were high. Even if you hadn’t seen DWV, I would say you were in trouble; the DWV confirms it. So, what to do? According to Randy Oliver, who has experimented extensively with powdered sugar, it will do the job as long as you dust every frame every week. This gets old after awhile and it’s disruptive to the bees. What I’ve always done is use one of the soft treatments, as you suggest. I rotate between ApiLife Var (thymol), MAQS (formic acid), and HopGuard (hop beta acids). Rotating lessens the chance of developing resistance. If you can’t get HopGuard, you can use the other two or also oxalic acid (not listed in the US, but readily available in the form of wood bleach).

There is nothing you can do for DWV. It rarely transmits between bees except through the bites of mites, so it will not move from bee to bee unless you have mites. The bees that already have it are doomed.

Mites are a part of beekeeping life these days, so you have to develop strategies that you can live with. In addition to those mentioned above, you can remove drones from the hive (drone trapping) and you can sequester the queen for a few weeks to break the brood cycle. Making splits also helps as it also breaks the brood cycle.

Jon
Reply

Thanks Rusty,

I like what I’ve read about Apilife var so that is the route I will likely go. Unfortunately it’s hot and humid right now here in TN so that makes the use of a fumigant a little tricky. I’ve been told Hopguard 2 should be available here in the fall and thats another soft treatment that sounds promising based on your articles and what others report. For now I will continue to dust with powdered sugar. Also supplementing sugar syrup w/HBHealthy. I’ve ready several of Randy Oliver’s articles about dusting and was very glad to find that it definitely knocks the mites off. How thoroughly it works is yet to be determined in my opinion.

Do you have any experience with or info about fogging with FGMO for varroa control? Would be interested in your thoughts on this.

Thanks again, as a new beekeeper your site has been extremely helpful.

We are definitely on an uphill climb but I believe beekeepers are passionately stubborn enough to keep climbing. It also doesn’t hurt that honeybees are an incredible little creature with an amazing ability to persevere in spite of so many obstacles.

Thanks,
Jon

Rusty
Reply

Jon,

I don’t have any personal experience with FGMO, but here is an article written my one of my associates and it includes interesting photos.

David
Reply

I just noticed 7 or 8 wasp on my garden walking. They all have one wing and the other is small or shriveled. These are definitely wasp and has it been reported about wasp having this problem. As far as honey bees I’ve only seen 3 all season…

Rusty
Reply

David,

Interesting about the wasp wings. Where do you live? Is this a local thing or widespread?

David
Reply

I live 20 or so miles north of Philadelphia and my neighbors and friends from surrounding communities said they have been seeing them too. I’m not sure how widespread it is, but the bee populations this year are as low as I ever saw. In fact only 3 that I can recall on my flowers.

Rusty
Reply

David,

That is scary. Are you having unusual weather? Or did you have an early or late spring?

David

Had a hard long winter, late spring and a lot of rain… It’s below average temp right now…

Craig
Reply

Penn State is doing much of the research on CCD and other bee problems, at the Center for Pollinator Research.

This might be of interest to them or they may have some info on it. Many wasps are also pollinators and this could indicate that DWV has jumped species or that there could be an environmental issue at work.

The director’s name is Dr. Christina Grozinger.

Their number is 814-865-2214.

Email is cmgrozinger@psu.edu

Elisabeth Gillmore
Reply

This morning I went out to watch the bees and noticed that bees were dragging out dead pupa with deformed wings and they didn’t have any mites on them. I did a sugar role test last week and saw no mites. If they do have deformed wing virus is it treatable? I have pictures if you would like to look at them.

Rusty
Reply

Elisabeth,

I wouldn’t expect dead pupa to have mites on them. The mites will move on to live bees so they can extract their hemolymph. Deformed wing virus was around long before varroa mites, but it used to be more isolated and unusual than it is now because the mites help it to spread. Like most viral diseases, deformed wing virus is untreatable. If you are confident that your bees don’t have mites, then there is nothing more to be done. The bees are doing what they are supposed to be doing by removing deformed or damaged brood.

Jane Danikas
Reply

Can you see the mites with glasses? I have dwv I think. I don’t see any mites. I looked at the bees with a loupe I can see grains of pollen with it. I have no mites.

Rusty
Reply

Jane,

Varroa mites are big enough to see without magnification, but that’s not the problem. First they are seldom on the adult bees, and even when they are, they can hide between the segments where they are difficult to spot. You need to do a sugar roll test in order to estimate your mite load. Although you can have DWV without mites, it is unlikely.

Jane Danikas
Reply

I have DWV. I don’t see any mites. I used a loop I can see grains of pollen. I should be able to see mites but I don’t see any thing. How can I help my bees.
Thank you.
Jane

Rusty
Reply

Jane,

To help your bees, do a proper test for mites (Sugar Roll Test) and then treat, if necessary.

Jane Danikas
Reply

What is a sugar roll test? how to do it? Are my bees going to die if I get rid of the mites.Im still finding 10 bees a day out side on the ground.I have treated twice should I keep treating?my friend and I are ready to give up on bees but I want to keep trying at least 1 or 2 more times not defeated yet.Are Russian bees stronger to this virus?

Rusty
Reply

Jane,

1. I gave you the link to the sugar roll test in the previous e-mail to you.
2. The link explains how to do it; just follow the directions. It will not hurt your bees.
3. I don’t know if your bees will die if you get rid of the mites, but they will probably be better off. By the way, ten bees per day is nothing. On a normal summer day, a healthy colony will lose 1000 or more. You just notice them more in the winter because they die closer to home.
4. You say you have treated twice. Read the directions of the product you are using to know if you should treat again or not. Directions are usually on the side of the package and should be followed to the letter. Since I don’t know what you used, I can’t answer the question.
5. I don’t know that Russians are more resistant to DWV. I haven’t read anything one way or the other.

Graham White
Reply

Professor Klaus Wenzel published a paper in the last issue of The Beekeepers Quarterly which reviewed the most current research on bees, DWV, varroa and neonicotinoids. He elucidates the work of Dr De Prisco’s team in 2013 which confirmed the following:

1. Deformed Wing Virus and Nosema Cerana are ‘endemic’ – present at all times, in just about every single honeybee colony on the planet. Varroa is also present in just about every colony.

2. In healthy, robust colonies, these pathogens (DWV and nosema) are normally benign – like the coldsore virus in humans, they are always present but they do not normally manifest.

3. Similarly, although varroa is a nuisance, there are very few records of varroa, on its own, killing healthy colonies.
However, varroa has become more ‘lethal’ since the 1990s; a mite count of 2,000 or more was generally not lethal in 1998, but a mite count of just 500 is usually a sign of imminent colony death in 2016. How can this be?

3. De Prisco’s experiments found that when neonicotinoids were added to the equation, all became clear as day.
When colonies were exposed to field relevant doses of clothianidin (used on 200 million acres of US crops) – the replication rate of Deformed Wing Virus DNA in those colonies was increased by a FACTOR OF 1,000. The situation with Nosema was the same; it changed from a benign, hidden fungal pathogen into an explosive disease which killed the colony.

The varroa burden of the control colonies and the neonic exposed colonies was the same. In the control colonies, the bees continued to thrive, despite the varroa burden. In the neonic exposed colonies, DWV and Nosema suddenly appeared and grew exponentially, as did the varroa count.

Dr Wenzel concluded that exposure to even the most minute dose of neonicotinoids destroyed the bees natural immune system defences, and catalysed the explosion of DWV and Nosema, turning benign, hidden pathogens into colony killers.

He also stressed that it was ‘biologically impossible’ for varroa mites, on every continent, to simultaneously evolve to become 4 times more lethal than they were just a decade ago. It just does not add up, until you add in the neonicotinoids/ immune suppression factor, which turns varroa into a colony killing virus carrier (DWV).

Confirmation of this hypothesis comes from studies of bumblebees, which are dying at a much higher rate than honeybees in areas where neonicotnoids are present. Bumblebees are NOT parasitised by varroa but they are dying from DWV, Nosema and other infections in uncountable numbers – because their exposure to neonicotinoids destroys their immune systems – just as in honeybee colonies. This is the crucial insight which reveals that Varroa is merely an ‘accomplice’ – an accelerating factor – in the death of bee colonies; but the real killer is immune system suppression by neonicotinoids.

The Wenzel paper is published in the Spring 2016 edition of Beekeepers Quarterly. The De Prisco study is available online here: http://www.pnas.org/content/110/46/18466.abstract

ABSTRACT:
“Honey bees are exposed to a wealth of synergistically interacting stress factors, which may induce colony losses often associated with high infection levels of pathogens. Neonicotinoid insecticides have been reported to enhance the impact of pathogens, but the underlying immune alteration is still obscure. In this study we describe the molecular mechanism through which clothianidin adversely affects the insect immune response and promotes replication of a viral pathogen in honey bees bearing covert infections. Our results shed light on a further level of regulation of the immune response in insects and have implications for bee conservation.”

Graham White
Reply

The Klaus Werner Wenzel paper is available free online here:
http://www.moraybeedinosaurs.co.uk/neonicotinoid/Neonicotinoid_Insecticides_Causing_Bee_Losses.pdf

“Recent research has clarified certain biological phenomena, which previously we could not explain. Generally, it is the sub-lethal effects of systemic pesticides, mainly Neonicotinoids, which damage or destroy the bees’ immune response. As far as the Varroa mite is concerned; there is no scientific proof that Varroa causes the collapse of honeybee colonies, as claimed by the agro-chemical lobby and many official institutions in Germany. Varroa mites clearly live as parasites in honeybee hives, where they may weaken bee larvae, but they do not kill colonies. They may contribute to bee deaths indirectly, by infecting bees with viruses and bacteria via their bites. However, such endemic infections may already exist within the colony, as was proven for the potentially deadly DWV, since both the eggs and drone sperm can already be infected with the virus. Such endemic infections in the past could also explain why DWV is to be found in almost every beehive worldwide. DWV exists chronically and covertly within healthy bee colonies, but DWV only becomes virulent and deadly when direct immune suppression is triggered by NN (Di Prisco et al. (21):”

Jane Danikas
Reply

Time for the bee keepers to file a class action law suit for their losses

Jane Danikas
Reply

I had it last year; I know what it looks like. It depleted my hive. I’m just hanging on; hoping it can make a come back. Queens not laying much, hardly anyone left to take care of the brood. Took one hive off better chance if hive is smaller, not so many robbers and a lot warmer.

Valeria
Reply

I am based in Auckland, New Zealand. I think my girls are in big trouble. They have been doing sooooo well since I got them last November. Treated November with Apivar and March with Bayvarol. The climate is considered temerpate in Auckland over winter, and they have raised drones all winter. The activity has been very high, so much pollen and full abdomens coming in, lots of orientating bees every lunchtime. But over the last few days there have been a lot of newly hatched with deformed wings. About 20 discarded per day, at least. And I don’t have any Apivar cos I thought I had until 1 st September to start treatment. So won’t have that til Thursday ass I had to buy online. And hope the weather is OK to put it in. What are their chances of surviving this? I haven’t seen any mites on any bees coming in or out (I look at the foragers closely and catch drones and look with my 3.0 spectacles) But I haven’t opened for 4 weeks because it’s been cold and as I say, from the entrance everything looked great. Your experiences in bringing a hive back from DWV appreciated. Or should I order another nuc now? Thanks

Rusty
Reply

Valeria,

Mites are not something that you would normally see on your bees. Most mites, up to 80 percent of them, can be hidden inside of capped brood. I never see any mites at all until I treat, and then I see them drop off in great numbers.

Since you have temperate winters and you have brood all year long, you can raise a lot of mites between treatments. With no winter brood break, you need to treat before you put on honey supers and then again after you take them off.

That said, if your last treatment was in April, that was only four months ago, so I’m surprised you are seeing so much deformed wing virus. Did you check the expiration dates on the packages? Did you follow all the directions?

It’s not obvious to me what’s going wrong. Still, if you treat soon, you may be able to overcome it because your bee populations will be building up for the season. Normally, once the mites are under control, the virus disappears because the bees don’t transmit it themselves.

My guess is that your bees will make it, but do write back and let me know how it goes.

Valeria
Reply

Thank you so much for your reply, Rusty, I will certainly update you in about a month. I was neglectful after my last treatment as I did not sugar shake to determine efficacy. Maybe the remaining mite load was still too high. I did follow all treatment instructions and left it in for correct amount of time, as per local beekeepers’ advice so carelessly presumed all would be OK. Today, when I put the new treatment strips in I will try to do a sugar shake so I know how bad it is before and then will definitely do one after the treatment period. Again, my sincere thanks for your advice and this blog.

David
Reply

It was 2 years ago I wrote about DWV in my area..I appreciate the replies. The problem now here north of Philadelphia is no honey bees, none. I haven’t seen one bee this year, and only 3 bees last year..Truly concerned..
No Monarch butterflies for 2 years either..

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