Thread: Dwv

**Bumble** · 15-06-2012, 01:13 PM

Originally Posted by Jon

I think there is some evidence that bees can adapt.

The Primorsky strain of honey bee in East Asia has coexisted with varroa mites for about 150 years and this strain has developed considerable resistance. Some US breeders specialise in 'Russians'

I imagine that the bees which have least resistance to varroa and virus will be eliminated quite quickly from the population allowing hardier strains to coexist to some extent with the varroa mites.

There has been work done on strategies which help bees live with varroa such as grooming, uncapping affected pupae, and general hygienic behaviour. Prof Ratnieks is working on this at Sussex University. At an amateur level Ron Hoskins in Swindon is also looking at how some bees can damage varroa mites by biting their carapaces.

Prof Ratnieks uses liquid nitrogen to kill a patch of brood, then sees how quickly and efficiently the bees deal with it, I think Ron Hoskins has been trying to breed bees that will groom off varroa. In my mind these are physical traits or characteristics that might be useful, same as the dented varroa that might be less good at clinging onto bees.

I was wondering more about an innate immunity to strains of DVW that might have built up over generations, which is why I mentioned measles and humans. I wondered if there might be a genetic marker of some sort.

**The Drone Ranger** · 16-06-2012, 04:13 PM

There was a study done on breeding foulbrood resistant bees
They found that bees who removed infected larva early were able to survive longer
Bees who did nothing less so
Bees who removed larva late when loaded with infection were most likely to collapse

I'm sure they factor that in to the recent study.
I have seen it suggested that killing a patch of brood and seeing if bees remove them is something we all might try.
I suspect it would not tell us as much as we think.
Dead is one thing, infected another, and parasitism something else

**Calum** · 16-06-2012, 09:07 PM

I have seen it suggested that killing a patch of brood and seeing if bees remove them is something we all might try.

Yup here in Germany thats a catergory you can check for queen selection.

So a friend of mine has some nucs we made up together with DWV. We could treat with AS - which I am loathe to do as it will not do the open brood any good, and as the queens are very young carries an increased risk of doing them in. Any suggestions -Apivar / Apilife treatmens less agressive on the bees?

**Stromnessbees** · 22-06-2012, 11:15 AM

I recently received a request by Reg Godwin and Glyn Davies for queens from varroa free colonies. They would be used in a new study that examines the link between DWV and queen failures.

I replied that I would be happy to support the research as long as the collected data would also be checked for a possible bias from neonicotinoid pesticides, as they are also a strong contender for affecting queen performance.

According to Reg no question about possible exposure to these pesticides was included in the record sheets yet, and he would pass on my concerns.

I have not had a definitive answer about the final set of records yet, but I suspect that this study will be conducted without checking for a bias from neonics.

In my experience, any scientific study has to inlcude data that could produce a strong bias, or else the results cannot be relied upon.

Likewise, one could conduct a study to see if, for example, eating chicken promotes lung cancer: if it isn't recorded whether the participants are smokers or not, the study becomes worthless.

I recommend that anybody else who is asked to supply queens for this study should request that neonic data be included in order to make sure there is no more money wasted on incomplete research.

**Calum** · 22-06-2012, 12:07 PM

Hi
nope thats wrong, as long as all test groups are subjected to the bais in equal terms/levels it can be ignored. Bais imples that one group is subjected to influences that another group have not been subjected to and that this effect has not been recorded/controlled. (although where effects are compounded this could become an issue -but then the number of factors by bees becomes unreal).
I'd start by asking for queens that are sisters from the same graft and mating area to start with....

Likewise, one could conduct a study to see if, for example, eating chicken promotes lung cancer: if it isn't recorded whether the participants are smokers or not, the study becomes worthless.

But they all breath air. Was it GM chicken?

**Jon** · 22-06-2012, 01:52 PM

I replied that I would be happy to support the research as long as the collected data would also be checked for a possible bias from neonicotinoid pesticides, as they are also a strong contender for affecting queen performance.

Really. The only person I have heard state that is Graham White and latterly yourself quoting him.
His evidence was based on the fact that some of the new mated queens from his ten colonies were superseded early.
I wonder how he eliminated possible nosema from his conclusions as nosema has been associated with early supersedure for decades.
I remember him posting about it on the old bbka forum.
Roger Patterson highlights queen mating problems but he has always been careful to keep an open mind re. the causes as I have discussed it with him many times.

My thought for the day is that neonicotinoids are a strong contender for inducing climate change as it has rained all day and I got wet earlier.
Some may say that a low pressure area is over the UK and Ireland, but in the interest of avoiding bias I think we can't yet rule out Clothianidin for making my socks wet.

**Adam** · 22-06-2012, 04:26 PM

My assumption is that early queen failure - or queens that just stop laying but remain in the hive - is caused by Nosema and not a varroa vectored thing. In my case, as I haven't seen any dysentry, then N. ceranae is suspected. Last Autumn I treated with Fumidil B and Hivemakers thymol emulsion as a treatment for Nosema and this year I have not had any early failures. Not proof enough I know.

**Adam** · 22-06-2012, 05:03 PM

Originally Posted by Stromnessbees

I recently received a request by Reg Godwin and Glyn Davies for queens from varroa free colonies. They would be used in a new study that examines the link between DWV and queen failures.

I replied that I would be happy to support the research as long as the collected data would also be checked for a possible bias from neonicotinoid pesticides, as they are also a strong contender for affecting queen performance.

According to Reg no question about possible exposure to these pesticides was included in the record sheets yet, and he would pass on my concerns.

I have not had a definitive answer about the final set of records yet, but I suspect that this study will be conducted without checking for a bias from neonics.

In my experience, any scientific study has to inlcude data that could produce a strong bias, or else the results cannot be relied upon.

Likewise, one could conduct a study to see if, for example, eating chicken promotes lung cancer: if it isn't recorded whether the participants are smokers or not, the study becomes worthless.

I recommend that anybody else who is asked to supply queens for this study should request that neonic data be included in order to make sure there is no more money wasted on incomplete research.

Doris, you are in the fortunate position of not having varroa unlike (most of) the rest of us. Would you refuse to supply if there was no 'neonic bias' adjustment as you wish?

**Stromnessbees** · 22-06-2012, 05:19 PM

Originally Posted by Adam

Doris, you are in the fortunate position of not having varroa unlike (most of) the rest of us. Would you refuse to supply if there was no 'neonic bias' adjustment as you wish?

I would, yes.

It's just good practise to include questions about general colony health (e.g. signs for Nosema etc.) in the data sheet for every queen examined. The proximity to neonic treated crops nowadays has to be one of them, as it could significantly influence the results.

This doesn't need to make the study more expensive, as I say, it's just another question on the sheet.

If it's not included then this might be an indication that the researchers don't want to find a connection even if there is one.