Blog – bees, beekeeping & other sticky subjects

Foulbrood kits identify the disease and help analysis of foulbrood strains

Vita Bee Health’s foulbrood diagnostic test kits are routinely used by Britain’s National Bee Unit (NBU) to give fast results in the apiary when European or American foulbrood are suspected. And their usefulness doesn’t stop there.

Positive samples are then sent to the laboratories of the British government agency Fera Science Ltd where they are further analysed to see what strains of the disease are present. The results often show quite distinct geographical distribution of specific strains.

From 4,706 European foulbrood (EFB) samples taken over nine years, 30 EFB strains have been identified in Britain (a total of 45 when other countries are included). Sixteen strains are so frequent that they are subject to intense analysis. Their distribution often shows clustering and may point to how the disease spreads. The evidence suggests that one strain in particular will quickly spread around an apiary.

All this data can help to point towards more effect treatment and management strategies.

What is the secret of sunflowers?

Vita Bee Heath is sponsoring some Inside the Hive TV videos about honey bee health.

The varroa mite is thought to be the underlying cause of so many honey bee colony deaths. Vita Bee Health’s varroa-control treatments work well when administered properly but could there be other forms of help in the environment for the bees?

Here’s a video about the mystery of sunflowers and the varroa mite. Could there be a beneficial link for bees feeding off sunflowers even though the flower’s pollen is generally not thought to be the best for bees because of its relatively low protein content?

Those invading hornets

The media and others have been having a difficult time talking about hornets and showing the correct photo ID. It’s not that surprising because they are new insects come from other lands – and picture editors seldom sit beside the reporters. Here’s a quick referesher on some of the hornets.

Vespa crabro aka European hornet

Native across much of Europe and introduced to North America in about 1840, Vespa crabro is Europe’s largest native hornet. It is very distinctive because of its size and flash of yellow as it passes but it’s not seen very often (in Britain). It occasionally takes a bee or two but hardly ever poses a serious threat to honey bee colonies. (In contrast the common wasp [the yellow jacket in North America], Vespula spp., is much smaller, more numerous and sometimes attacks and destroy weak honey bee colonies.)

Vespa crabro workers c25mm long

Vespa velutina aka Asian hornet, yellow-legged hornet

Velutina is the hornet that arrived in pottery near Bordeaux in 2004 and has since spread at an alarming speed throughout France, around the north of Spain into coastal Portugal, into Italy, Germany and now seems to have been able to become established in the southern Netherlands. The tale of the fight back by the residents of the Channel Island of Jersey has become something of a legend on Facebook.

Velutina is now well established in parts of north-west Europe and eradication is deemed impossible, though many attempt to stop its spread into new territories.

Vespa mandarinia aka giant Asian hornet, murder hornet

Mandarinia is the one that the American media has delighted in dubbing the murder hornet – and British picture editors have been googling Asian hornet and, thinking they’ve found it, published an incorrect photo. It goes under various other names including the northern giant hornet and the Asian giant hornet. Whatever its name, it does look scary, as do its nest removers.

Vespa mandarinia is native to south and east Asia and was seen in the USA’s Pacific North West in 2019 and then in and Canada’s British Columbia. Nests were found and destroyed in 2021, but in 2022 there were no confirmed sightings and optimistic hopes that it may have been eradicated.

Vespa orientalis aka the Oriental hornet

Native to south-west Asia, Vespa orientalis has been spreading across Italy and was seen in Marseilles, France, in 2021 and Barcelona, Spain in 2022. On Malta, where it is now regarded as native, reports say it wiped out 70% of the island’s honey bee colonies. Vespa orientalis feeds on adult honey bees and larvae and plunders nests.

Vespa orientalis 25-35mm long

A confused and confusing swarm

Vita Bee Health’s guest blogger writes:

This afternoon, I cycled around my apiaries on the downland of north Hampshire, England, checking to see if the harvest was ready to be brought in. As usual, on my way back, I detoured slightly to visit a a wild colony that I have been watching for two years now. (I think the original colony may have died during the winter and a swarm reoccupied the nest this spring.) Instead of the usual to-ing and fro-ing, I was greeted by this heart-warming sight at almost exactly 4pm (very late in the day for swarming in these parts):

Needless to say, I stopped to watch what was happening. Bees were pouring out of the nest in the beech tree but few were taking to the air. They just gathered around their entrance — in a very loving heart shape. I watched for 45 minutes as they continued to gather — quite thickly, as they were buffeted by the strong breeze:

Then at last they took off, leaving the entrance almost free of bees. But not for long. They circled for about ten minutes. I watched to see where they might hang up — half wondering if it would be on my bike at the foot of the tree:

But they never did hang up and, instead, after about ten minutes, returned to the entrance — although some went to a false door (lower right).

I’ll try to make time to visit tomorrow to see if they make a second attempt to swarm. My best guess is that the queen could not or did not want to leave.

Causes of high Canadian winter losses

Winter honey bee colony losses in Canada have been enormous, much higher than normal even for a country with such cold winters. Losses of 50% have been reported by some beekeepers in the key beekeeping province of Alberta and up to 90% in Manitoba. Last winter was one of the harshest winters of recent years, especially in the Prairie provinces, but there were other underlying causes.

We have been asking our contacts in Canada what they think the causes might be and they suggest several possibilities but point to the varroa mite as being high on the list of suspects.

Mites have developed tolerance to amitraz-based treatments, so beekeepers would do well to pay even more attention to integrated pest management (IPM) principles, monitoring mite drops and using a rotation of different products to gain better control of mite populations.

There were reports in spring 2021 of high mite loads, even after spring treatments, and it becomes increasingly difficult to treat for mites during the honey flow. So, colonies were already damaged by mites going into the fall of 2021. Those who treated for varroa in the fall using formic and/or oxalic acid were often successful in saving their bees.

The summer of 2021 in Canada was very hot and dry. Honey crops were down by 25-60%. That also meant there was a lack of pollen sources for developing winter bees. Pollen supplements, such as Vita feeds could have helped the development of healthy winter bees. Those who did feed supplements appear to have been more successful. 

There was also something of an illusion of strong colonies going into winter. Some strong colonies probably had high proportions of summer bees but few winter bees, thereby giving the impression that colonies were strong. They weren’t. Colonies like this are likely to keep their populations until mid-March in the following spring and then they perish.

Anecdotal reports also suggest that nosema may have been a factor. One beekeeper who had lost 60% of his colonies, recalled that his colonies had several million nosema spores when he tested them last July. He hadn’t used Fumagilin-B (now available in Canada) but he says he will now.