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
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…

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