Nosema ceranae — emergence & hope
This week Vita begins lab tests in Greece for a new treatment for Nosema ceranae, the second greatest threat to honeybees after Varroa in some countries. Earlier tests have proved promising, so it’s time to go further and perhaps try it in the field later, at a time of year when the threat is greatest.
Coincidentally, I was reminded of my introduction to Nosema ceranae yesterday while walking across the Berkshire countryside in England and stumbled across an apiary I remembered from a few years back. (Public footpaths across agricultural land are common throughout England and Wales, so it is possible to explore the countryside and get into all sorts of nooks and crannies.)
It was 2009 and I was leading a group of local beekeepers in a spring apiary inspection of about a dozen hives. The apiary was beautifully situated in a clearing in front of a patch of woodland that faced onto a wide expanse of arable land. The bees were in a very poor state, but there were no obvious signs as to what was wrong.
We ‘ummed and ahhed’, but came to no firm conclusions on the day. Nosema apis (the older version) was considered, but since there was no evidence of dysentery on the front of the hives, it was discounted. Similarly there were no signs of excessive Varroa populations or of either American or European Foulbrood. We left the apiary mystified. We didn’t then know much about the new version of Nosema ceranae that was emerging and proving to be a killer in other countries. On reflection, we now think the new variant was the culprit.
The elderly, experienced beekeeper was distraught. I offered him a spare colony from my own apiary to help him rebuild and he gladly accepted. But the problem was how to collect it. He was an agricultural worker and had a vehicle that because it used discounted agricultural (red) diesel was prohibited from travelling on public roads except «on rare and very limited occurrences». He tried plotting a route of 30 kms across English countryside avoiding public roads, but failed. I had visions of him churning up fields and gardens on his way to me. I was relieved when he eventually he turned up in a borrowed car using the public highways.
Since 2009, Nosema ceranae has gained a much higher profile and is now thought to have been the cause of the deaths of huge numbers of colonies in Spain in 2001. It has probably been around for 20 years having jumped from the eastern honeybee (Apis cerana), but wasn’t identified as being distinct from Nosema apis until 2007. Whereas Nosema apis has seasonal peaks and falls and is relatively easy to identify and therefore control, Nosema ceranae is less obvious, can be virulent all season and reaches parts of the bee that Nosema apis cannot.
VitaFeed Gold has proven very effective in boosting honeybee immune systems, particularly in colonies affected by dysentery. The new potential treatment under test could provide a very effective tool in tackling Nosema ceranae directly. Vita will report back on progress.
Vita’s Guest Beekeeper Blogger