Could Biological Control be the next (viable) weapon in Varroa IPM?

[Neils]

After an interest day listening about Varroa where, if there was a buzzword (or TLA) it'd probably be "IPM".

After listening to the guy from Vita in particular, I get the distinct impression that new chemical treatments aren't likely to be forthcoming and that in some respects we were "lucky" (depending on your point of view I guess) to get Apistan and Bayvarol in the first place. While resistance to thymol based treatments is still thought to be unlikely, it was conceded that it was possible.

A talk by Dr Dave Chandler I found particularly interesting though as he drew parallels between greenhouse agriculture and Beekeeping and the current use of "biological IPM" there to deal with pesticide resistant pests or with crops where the use of pesticides wasn't ideal.

What's biological IPM? Basically the use of "agents" that predate on the pests you want to be rid of, either using other bugs or in the case of varroa, Fungi.

Apparently Varroa is particularly vulnerable to certain types of fungi which appear, in most cases, to be harmless to bees and to us. There are some studies already done apparently, but I've not yet had a chance to track them down.

Given funding here has apparently been pulled, but continues in the US, EU and elsewhere is this our next best chance of remaining on top of Varroa?

[Trog]

Sounds very interesting, Nellie. What types of fungi are being investigated?

[Neils]

Here's a link to the Chilean Study (http://www.scielo.cl/scielo.php?pid=S0718-58392009000400008&script=sci_arttext&tlng=en) that was mentioned, they can probably explain it better than I. The posh term is entomopathogenic Fungi, in this particular study it's a type of Beauveria, but there's another type beginning with M which I didn't get a chance to write down before the slide changed :)

Here's a USDA Study (http://www.coloss.org/publications/B%20bassiana%203%20treatments%20JAR.pdf) also using Beauveria

Another one (http://www.springerlink.com/content/54406n2726244677/)based on using Metarhiziumanisopliae, now I know why I couldn't remember it.

I think Gerding's report (the first one) reported around 66% efficacy after 21 days but with "some" bee death, so I don't think it's a silver bullet just yet. Again that's going from my notes from the talk rather than me reading the actual study but I believe these are all field studies.

[gavin]

Hi Folks

David Chandler (no relation I think!) and Rothamsted collaborators were on the track of this - and Eric's friend Norman Carreck was involved - but Defra pulled the funding on the whole honeybee group.

The Americans have been active - see this optimistic article but also note the date. Seven years later is anything in commerce?

http://www.ars.usda.gov/is/AR/archive/oct04/bees1004.htm

Also the NZ bee researchers are looking.

The Americans settled on the fungus Metarhizium anisopliae. Not sure which ones the other groups have focussed on.

Some have hinted at a need to get conditions just right to make it work in the real world.

But yes, it does have some promise.

Gavin

Oops, thanks Nellie, you beat me to it.

[Neils]

Again, going from my notes and recollection from the talk.

I believe you're right that UK funding has ceased.

Research is apparently going on in the EU as well.

The main challenge apparently, apart from the obvious one that we need to not affect the bees (or us!) is that fungi typically like cool, damp conditions and bees like warm, dry ones.

There was a mention that the UK research thought, with a bit of extra funding than what they had before it was cut, that they were 3-5 years away from something that could be considered close to a marketable product.

I'll also apologise in advance for the plethora of posts that might well follow as I start to digest today's conference a bit more. Wish/hope IBRA make copies of the slides available.

[Jimbo]

Hi Nellie,

Was there any mention of how the Fungi could be applied if it were to become commercially available?

[Rosie]

They talked about adding it to pollen and also making it up into patties.

In the past there was great hope for the American study but I remember seeing pictures of the bees being almost as badly affected as the mites so that particular fungus and delivery method turned out not to be very practical.

I noted that Dr Chandler was very aware of the dangers of introducing alien species to any particular region and was keen to point out that he had only been working with native fungi that were already in the environment but at a low level. He said that it could work if delivered to the target at the effective concentrations which would then gradually diminish to the normal, harmless background levels.

I hope the other researchers have the same responsible approach.

Rosie

[chris]

In the past I've read of trying to develop viruses to *attack* varroa, and mite eating mites etc.
I somehow feel (which is nothing like a scientific know) that biological control is dangerous. I read somewhere that upwards of 80 mites are connected with bees and the hive. Do we know the roles they play or how the hive environment is organized? Do we know what chain reactions may be set up?

[Neils]

Hate to break it to you, but it's a widespread practice already, outside of beekeeping, but I do get the concerns. I think when it's looking at introducing either new or vastly increased numbers of elements into a colony then that does need to be carefully studied. I think mention's already been made of at least one study where the fungi being used was just as effective at killing the bees as the Varroa. I guess there's always that question of how do you know something that appears to benign actually is though.

[chris]

Hate to break it to you, but it's a widespread practice already, outside of beekeeping, .

I am aware of that Nellie, but that doesn't justify its use in another field.

[Neils]

Perhaps not but personally I think it's got to be an avenue worth exploring, it's considerably cheaper to develop than a chemical based treatment and, one would hope, might satisfy the "natural" lot who currently choose not to treat.