Are imported Bumblebees a threat?

[Bumblebeebob]

I already knew that some commercial greenhouse producers (of Tomatoes & Strawberries) use Bumblebees to pollinate their produce but what i didn't know was that some are importing around 10,000 colonies of a Mediterranean species (Bombus Terrestris dalmatinus to do the job. I found this article on the web, by someone who researched this for his PhD, which basically says they could replace our native species because they are ecologically superior, being superior learners & their breeding output is higher. There is the danger they will hybridise with our own native Bumblebees. Another case of a foreign introduction endangering our own native wildlife?
I wish people would consider the long term effects before embarking on these courses of actions. Commercial pressure again.

http://www.biology.qmul.ac.uk/research/s...m/Tom.html

[eucera]

This is an interesting post. Tom Ings's research at Queen Mary has had quite an impact.

The figures you quote for importations are, I'm afraid, some way out now. I attended a meeting last summers with various researchers and also the 3 big suppliers of commercially reared Bombus. Between them they import some 50 000 colonies of bumblebees into the UK for the fruit and glasshouse trade. The majority are B. terrestris dalmatinus, and one supplier also imports B. terrestris terrestris (the form on the near continent). Technically speaking, all imports of an "alien kind" of bumble (and both these sub-species fall into that category) are illegal under the terms of the Wildlife & Countryside Act. However, banning importation would put our fruit and tomato growers at a massive commercial disadvantage compared to our near-European competitors.

It is possible to import only B. terrestris audax (our sub-species), but, because it is less productive, the costs would likely be about 10x the cost of using the alien ssp. Defra (who sent a rep to the meeting I attended) are aware of the situation

The big increase in winter bumble activity in the last few years may well be a sign that the interbreeding is already happening and that B.t. audax is in danger of being hybridised out of existence (cf the White-headed Duck). Certainly, biosecurity is somewhere between non-existent and poor in many cases, and the imported bees are allowed to fly freely. Queen excluders are fillted to the boxes, but they do not exclude the smaller males from escaping. Instructions for the safe disposal of colonies have been poor. I even know of one commercial fruit grower giving old colonies to his/her workforce to enhance dwindling populations in gardens. There was also a case of an "eco-friendly" garden supplier providing active colonies (now withdrawn I believe).

You are right though... commerce wins out over the environment.

[Bumblebeebob]

Thanks for expanding on this eucera, I don't have a great deal of knowledge of Bees but I do find them fascinating creatures.

[Paul mabbott]

The link doesn't work.
Let's get one thing straight, though: Bombus terrestris is the species whereas B. terrestris dalmatinus will be a sub-species or form - presumably one better adapted to the warmer conditions of the Mediterranean. It would probably interbreed with the native form and the genes which allow it to live in warmer drier conditions will help B. terrestris to survive when climate change becomes severe in the British Isles.

Originally Posted by Bumblebeebob

I already knew that some commercial greenhouse producers (of Tomatoes & Strawberries) use Bumblebees to pollinate their produce but what i didn't know was that some are importing around 10,000 colonies of a Mediterranean species (Bombus Terrestris dalmatinus to do the job. I found this article on the web, by someone who researched this for his PhD, which basically says they could replace our native species because they are ecologically superior, being superior learners & their breeding output is higher. There is the danger they will hybridise with our own native Bumblebees. Another case of a foreign introduction endangering our own native wildlife?
I wish people would consider the long term effects before embarking on these courses of actions. Commercial pressure again.

http://www.biology.qmul.ac.uk/research/s...m/Tom.html

[Bumblebeebob]

Very strange, try this link.

Tom

[eucera]

Actually, most bumbles are cool adapted, and B. terrestris dalmatinus is no exception. It isn't strictly a Mediterranean subspecies as such, but is found in the hills and mountains of the Balkans and in central Anatolia. Bumbles are really rather scarce in the Mediterranean proper and form only a small percentage of the bee fauna. It is also true to say thet the breeders are continually selecting the biggest and most productive strains of those they keep in domsetication

I am not sure that we should be deliberately introducing genes from the Med in the expectation that climate change will work against our own subspecies. Would anyone advocate the introduction of Mediterranean butterfly subspecies to prepare the native fauna for climate shock?

The UK and Irish bee fauna has very few things that are distinctive, and the buff-tailed form of B. terrestris is distinctive enough to allow its tail-colour to provide us with a vernacular name. It would be a shame to lose it.

[Paul mabbott]

Quite so; I didn't mean to suggest that we should actively encourage sub-species introduction or cross-breeding but there could be worse things and that the mixing in of a few genes is not as bad as losing the whole species.

Originally Posted by eucera

Actually, most bumbles are cool adapted, and B. terrestris dalmatinus is no exception. It isn't strictly a Mediterranean subspecies as such, but is found in the hills and mountains of the Balkans and in central Anatolia. Bumbles are really rather scarce in the Mediterranean proper and form only a small percentage of the bee fauna. It is also true to say thet the breeders are continually selecting the biggest and most productive strains of those they keep in domsetication

I am not sure that we should be deliberately introducing genes from the Med in the expectation that climate change will work against our own subspecies. Would anyone advocate the introduction of Mediterranean butterfly subspecies to prepare the native fauna for climate shock?

The UK and Irish bee fauna has very few things that are distinctive, and the buff-tailed form of B. terrestris is distinctive enough to allow its tail-colour to provide us with a vernacular name. It would be a shame to lose it.

[Hobjob]

Why are bumble bees better at pollination in glass houses and on soft fruit than the good old bee and hives?

[eucera]

Good question!

1) Many greenhouse crops (eg tomatoes, peppers, aubergines) require the anthers to be "buzzed" before they will release their pollen. Honey bees are incapable of doing this but bumbles are capable.

2) Growers are increasingly worried about honey bee problems (disease, susceptibility to pesticides etc.). Keeping honey bees can be a burdensome business and there is less support than there used to be. Using bumbles is seen as an insurance policy

3) Insect for insect, bumbles are more efficient pollinators of many crops than Honey bees.

[Hobjob]

Originally Posted by eucera

Good question!

1) Many greenhouse crops (eg tomatoes, peppers, aubergines) require the anthers to be "buzzed" before they will release their pollen. Honey bees are incapable of doing this but bumbles are capable.

2) Growers are increasingly worried about honey bee problems (disease, susceptibility to pesticides etc.). Keeping honey bees can be a burdensome business and there is less support than there used to be. Using bumbles is seen as an insurance policy

3) Insect for insect, bumbles are more efficient pollinators of many crops than Honey bees.

Thank-you.
Fascinating