Deformed Wing Virus

[MuswellMetro]

Despite an almost Zero drop of Varroa i have a colony that has about 10% of the drones with deformed wing virus

it had a VERY HIGH Varoa load in august 2011 and it was treated with vet prescribed Apivar (Amitraz) under EU cascade2 in September 2010and March 2011, Apiguard August -September 2011 and Oxalic Jan 2012

I was doing a bailey change onto new comb but had to AS split due to 32 queen cells some capped on the 2nd April!!!

But now have two broodless brood boxes as theclipped queen still flew later that day

any veiws whether further Varroa treatment would be worth while...the last tacky board drop was one mite in a week on both boxes

also the vector for DWV is the varroa but does it reside in the old wax (ie do i have a better chance of getting rid of it in the queen side of the AS

so hive clean/oxalic/thymol?

 

[drstitson]

presumably a heavily infested hive has a much greater chance of the queen getting parasitised by mite(s) and hence infected by DWV herself, thus producing affected offspring?

i don't think the wax acts as a reservoir - virus will need to be iside bee or mite.

 

[MuswellMetro]

presumably a heavily infested hive has a much greater chance of the queen getting parasitised by mite(s) and hence infected by DWV herself, thus producing affected offspring?

i don't think the wax acts as a reservoir - virus will need to be iside bee or mite.

thanks Dr S...got a new job yet?

I wonder whether i have imported the DWV with the queen as it appeared after i re queened with an imported Queen ( i normally try to buy local or UK queens)

Biology is not my strong point as being bought up my Plain Quaker Grandmother i was not allowed to take biology lesson as i might learn things like Darwinism that went against her beliefs

 

[drstitson]

Yes - only 3 days technically unemployed. Although the work isn't as regular as before that does give me a bit more free time and the lab(s) are miles better equipped. More difficult work though as previous place was progressively deskilled with big cancers being done elsewhere.

amazing to think all those early biologists and geologists were men of the cloth!

 

[alanf]

I wonder whether i have imported the DWV with the queen as it appeared after i re queened with an imported Queen

There is evidence that DWV can be transmitted by queen to offspring.

http://aem.asm.org/content/72/1/606.long
http://www.virologyj.com/content/3/1/16

Might be worth getting back to whoever supplied the queen, others could be affected.

 

[DanBee]

Have a look in the drone brood with an uncapping fork and see what proportion have mites. Make sure you get 100 or so at pink eye stage. More than 5 mites is a sign of trouble brewing. You might be seeing the results of reinvasion.

Although I don't disagree with the point about DWV transmission, it's going to be a difficult one to prove until you can replace the queen, and significant apparent DWV would indicate problematic mite levels now...

 

[mbc]

DWV was around before varroa came to our shores and can exist without it. Its my opinion that once a hive is heavily infested with varroa then the varroa can cause the virus incidence in the whole colony to be elevated for quite some time afterwards (even if the varroa have been contoled). This could be the case with this hive and it may be that a decent spell of weather- causing lots of old bees to die (from hard work) and new "clean" bees( hopefully) to replace them- will reduce the problem. Many hives recover from what appears to be bad DWV without beekeeper intervention.

 

[Polyanwood]

presumably a heavily infested hive has a much greater chance of the queen getting parasitised by mite(s) and hence infected by DWV herself, thus producing affected offspring?

This is foxing me out of my socks.

I wonder what the DWV transmission mechanism was pre varroa? I know of no evidence that DWV can be transmitted from infected queen, via the egg to the larva and then the emerging bee...I would be pleased to know if this is a proven transmission path.

I thought viruses can only live for only very short periods of time outside living tissue, so not looking likely at all that there will be a reservoir of DWV in the wax, so do you reckon that brood food is likely to have DWV and that is how it is passed on?

 

[The Cumbrian]

I wonder what the DWV transmission mechanism was pre varroa? I know of no evidence that DWV can be transmitted from infected queen, via the egg to the larva and then the emerging bee...I would be pleased to know if this is a proven transmission path.

I can't claim to know much about the subject but the paper:

Detection of Deformed wing virus, a honey bee viral pathogen, in bumble
bees (Bombus terrestris and Bombus pascuorum) with wing deformities
Elke Genersch a,¤, Constanze Yue a, Ingemar Fries b, Joachim R. de Miranda c

Says

There are two main transmission routes. Oral transmission between bees is thought to propagate the inapparent, persistent infections whereas pupae infected through injection by the vector V. destructor sometimes
develop into adult bees showing wing and other morphological
deformities,

 

[Fenman]

I have a colany that I suspected of robbing out a feral colany nearby early this year my bees had shown no varroa drop this spring but now a brood cycle later have DWV bees dropping out of front enterance, which local Robin clears up very quick, so was a job to pick up still no indication of bad varroa infestation, one hive on its own seperate from out apiries.