Varroa breakthrough

[neilr]

An interesting article in The Guardian last week reports exciting news about a beekeeper from Swindon who has bred varroa resistant "cleaner" bees. Here's hoping his efforts and the consequent research proves successful. The following link should take you there. My bees gulping up syrup (with fumidil B) at a good rate of knots just now and I'm using Apiguard with good effect. All the best, Neil.

Here's the link: [url]http://www.guardian.co.uk/environment/2010/aug/25/honeybees-virus-superbee-saviour-swindon

[gavin]

That's three times now Neil! I suppose that I was hesitating before commenting, as folk might think that I was just attention-seeking again having been on Radio Scotland on Wednesday lunchtime on this story. 12:40, Scotland Live, my son tells me it is on i-Player.

It is great news, but as Ron himself says it is just a step on the way. 11 years ago John Harbo and Jeff Harris published a key paper on the genetics of the traits shown by bees resistant to Varroa and I wrote this on Bee-L:

http://community.lsoft.com/scripts/wa-LSOFTDONATIONS.exe?A2=BEE-L;bBfoFA;200011172349500000C (http://community.lsoft.com/scripts/wa-LSOFTDONATIONS.exe?A2=BEE-L;bBfoFA;200011172349500000C)

Prior to that there were continental beekeepers describing some of these traits. The 'Suppression of mite reproduction' has since been realised to be something subtly different: 'Varroa sensitive hygiene'. In other words the ability of bees to identify and remove pupae infested with reproducing Varroa. This is one of the main mechanisms for resistance, but there are others.

I've given talks on this in Dunblane and Glasgow, and at the first of these I met a man who had gone cold turkey regarding Varroa treatments. Some of the story is in the Scottish Beekeeper and John sometimes posts here under a pseudonym but has been keeping his head down lately. I've tested his bees in my apiary and while he has been able to withdraw any kind of treatment for 4 years, in my hands they got rather too mitey for my liking, especially at a time of threat from foulbrood when I should have been removing stress from the bees. We started this but haven't taken it very far:

http://www.scottishferals.org.uk/

So, there is a degree of Varroa resistance all around us. Some of the mechanisms are well known, whereas others are just John's observations and not yet written down. As I'm a geneticist by profession I tried to get funding for a proper project on this, but failed. There is huge potential to select for these traits in our bees and the best way forward is probably to form local breeding groups, as they have done in Swindon. My own priority now is to try to save local stocks of Amm in Tayside, and then, once we have mating sites and strains secured, turn again to breeding for Varroa resistance. If you are interested in doing something similar in the Lothians, there will be a bee breeding workshop in Fife in November which might help.

best wishes

Gavin

[Jimbo]

Hi Gavin,

I agree with you about there being a degree of varroa resistance. A number of years ago I was talking to John Tyler from Largs who noticed some of the varroa mites under the mircroscope had dents and cuts. He put this down to the bees biting the mites and damaging them. He was going to look at hygene behaviour and possibly breed from the bees with the highest behaviour. He also said he had stopped varroa treatment is some of these colonies.
It would be interesting if other beekeepers when they are counting varroa mites to also look closely at the actual mite to see if they see any damage. I will be looking this year when doing my varroa treatments although I am not seeing a lot of mites this year.

Jimbo

[gavin]

Thanks Jimbo. Do you (or does anyone else reading this) know if John Tyler is still going down this route?

I'm pretty sure that the VSH trait and the biting and grooming are quite separate traits. One of the colonies from t'other John were very hygienic in that they assiduously ripped out sealed brood that they didn't like, but the Varroa numbers still climbed through the season. Some of the samples from his floors from colonies that seemed highly VSH had undamaged mites on the floor.

That means that combining the two maybe necessary for high levels of Varroa resistance. There are other things the bees seem to do which are less easily seen that may also reduce the levels of Varroa in the hive, and the biting and grooming might be a behaviour that is triggered by circumstances and not something always switched on.

Gavin