Imported bumblebees pose 'parasite threat' to native
bees
By Victoria Gill
Science reporter, BBC News


Between 40,000 and 50,000
bumblebee colonies are imported into the UK every year


Bumblebees imported from Europe carry
pathogens that pose a threat to native honeybees and bumblebees in the UK,
according to scientists.


Between 40,000 and 50,000 bumblebee colonies are imported into England each
year to assist with crop pollination.


For a study in the Journal of Applied Ecology, scientists bought 48 colonies
- hives containing up to 100 bees each - from three producers in Europe.


They found 77% had parasites that could infect native bees.


Lead researcher Prof William Hughes, of the University of Sussex, said
commercial production and importation of bumblebees had been "going on for
decades".


"We couldn't grow tomatoes in this country without these bumblebees," he
said.



And with the decline in pollinating insects in recent years, food producers
are increasingly reliant upon imported bees.


"Over a million colonies are imported globally - it's a huge trade," said
Prof Hughes. "And a surprisingly large number of these are produced in
factories, mainly in Eastern Europe.


"We sought to answer the big question of whether colonies that are being
produced now have parasites and, if so, whether those parasites are actually
infectious or harmful."
Undercover science

With his colleagues from the universities of Leeds and Stirling, the
researcher set out to buy colonies "in exactly the same way a farmer would".


Precious pollinators



The team then screened the bees for parasite DNA.

"We found quite a number of parasites within the bees," Prof Hughes said.


The imported bumblebee colonies carried a range of parasites including the
three main bumblebee parasites (Crithidia bombi, Nosema bombi and
Apicystis bombi), three honeybee parasites (Nosema apis,
Ascosphaera apis and Paenibacillus larvae), and two parasites that
infect both bumblebees and honeybees (Nosema ceranae and deformed wing
virus).


The team also found parasites in the pollen food supplied with the bees.


The scientists say that current regulations governing bumblebee imports are
ineffective.


In England, for example, the non-departmental public body responsible for the
protection of the environment, Natural England, issues licences for the release
of non-native bumblebee subspecies.


But this study found parasites in both native and non-native subspecies that
were commercially reared in Europe, and no licences are required to release
native subspecies into the environment.


Natural England said under current regulations it was "not possible to impose
disease control conditions or environmental safeguards on the release of
imported bumblebees which originally descended from British bumblebees".


"It is therefore of particular concern that this research has revealed that
imported bees - descended from British stock - have been found to be carrying
disease," its statement added.

Many bee species are already showing significant population
declines”

End Quote Prof William Hughes University of Sussex

"Our licensing regime stipulates that where non-native
bumblebees are used, they must be disease free, only used within polytunnels or
greenhouses, using hives from which queens cannot escape, and that all hives and
surviving bees must be destroyed at the end of their use."


But the researchers say that regulatory authorities need to strengthen
measures to prevent importation of parasite-carrying bumblebee colonies,
including checking bees on arrival in the UK and extending regulations to cover
imported colonies of the native subspecies.


Prof Hughes said: "If we don't act, then the risk is that potentially tens of
thousands of parasite-carrying bumblebee colonies may be imported into the UK
each year, and hundreds of thousands worldwide.


"Many bee species are already showing significant population declines," he
said.


"The introduction of more or new parasite infections will at a minimum
exacerbate this, and could quite possibly directly drive declines."


The British Beekeepers Association said in a statement: "Defra (the UK
Department for the Environment, Food and Rural Affairs) must take urgent steps
to tighten regulations together with practical steps to ensure that imported
bumblebee colonies are not heavily laden with pathogens.


It continued: "[Regulations must ensure] that these bees are not released
into the environment at the end of the season putting our native pollinators at
enhanced risk."


A Defra representative responded to the study, saying: "Imported colonies of
non-native bees are required to be screened for parasites and disease.


"We will continue to work with Natural England to ensure that growers who
break the rules are punished."