Nosema Cerana in Scotland

[greengumbo]

http://planetearth.nerc.ac.uk/news/s...ookieConsent=A

Interesting. About 77% of hives sampled had N.cerana.

[Jon]

N ceranae was detected in NI about 2 years ago.
I wonder did the survey distinguish N Apis from N Ceranae through DNA testing or was this microscope work.
They are notoriously difficult to tell apart under the microscope.

Ruary will likely chip in!

[greengumbo]

Hi Jon - just read the full paper and they did a combination of microscopy and species specific PCR. They also sequenced a sample of the N.ceranae to confirm.

Nice wee study.

[Jimbo]

I wonder what the % found were in the East of Scotland compared to the West. My sample came back as negative for any Nosema. Same for a few of our Association members. In the West we don't have large importation or movement of colonies where as the East has more commercial beekeeping so more chance of colony movement. Which is another possible explanation for the difference in colony loses from West to East and may not be due to pesticides. There has been a suggestion that bees affected with high Nosema loads and treated with Oxalic acid also tend not to make it through the winter.

[Jon]

Thanks GG. Found the link to the paper.

There has been a suggestion that bees affected with high Nosema loads and treated with Oxalic acid also tend not to make it through the winter.

The Oxalic seems to hasten their demise according to some and I have certainly lost a few myself within a couple of weeks of Oxalic treatment but these were very small anyway and had little or no chance.
There seems to be a big problem locally with much smaller than normal winter clusters. I suspect nosema may have something to do with that and we had N Ceranae confirmed here 2 years ago.

[gavin]

G84 had three samples - two negative and one PCR-positive but without spores seen microscopically. Might that be yours Jimbo?

It seems surprising that Mull (supposedly isolated from imported bees since Varroa spread across the west) has PCR positive samples. OK, there was an importation in the SW of the island but that was isolated and died out. Pity that Colonsay doesn't seem to be represented as it is probably more certainly isolated in terms of live bees.

[Jimbo]

Nope! I'm clean and have the letter to prove it! but I know who had the PCR positive sample and it was from an area to where bees where brought into the area a few years ago

[gavin]

Interesting. I wonder if our Mull members can see a similar pattern.

[Ruary]

Nope! I'm clean and have the letter to prove it! but I know who had the PCR positive sample and it was from an area to where bees where brought into the area a few years ago

I do winder about the sensitivity of a PCR screening, I had cause to send a sample of Nosema apis to USA, and the first sample which was dried sludge on a slide glass showed 'no dna'. A second sample which was similarly packed with dries spoes gave a similar result, but was then run through PCR which showed that the sample was apis and not cerana. How many bees were taken in the screening, there would need to be enough to be sure that one infected bee was in the sample?

[Ruary]

They are notoriously difficult to tell apart under the microscope.

Ruary will likely chip in!

Well here goes, Fries when he first described cerana stated that it required electron microscope to see the difference, but this has now been altered and with experience it is possible most times to differentiate under optical microscopy. The first case in Ireland was seen by Pat Maloney of Teagasc who thought the spores 'looked different' and has the sample sent for PCR analysis.
No other sample from the South has, to my knowlege, been sent for PCR confirmation.
Ruary