On Thursday evening I attended a talk given by Professor Dave Goulson, founder of the Bumblebee Conservation Trust and probably the UK’s leading expert on bumblebees. I have read his book A Sting In The Tale so had a pretty good idea what he would have to say but it was fascinating and educational nonetheless.
I must confess I have a real soft spot for bumblebees – they are charming creatures but they are also incredible insects which play a vital role in our ecosystems, helping to pollinate the majority of crops in the UK, not to mention our wild flowers. Unfortunately they are under real pressure, as a result of habitat loss, pesticide use and disease.
Here are some of the stand out points Professor Goulson made:
The UK has lost around 97% of its hay meadows and unimproved grasslands, replaced by intensive agriculture of arable crops or single species silage fields. This has had a devastating effect on those bumblebee species that are adapted to meadows, such as the Short-haired Bumblebee (extinct but currently subject to a reintroduction programme) and the Shrill Carder Bee (seven, possibly now just six populations in the south of England).
Overzealous use of pesticides is another key factor driving bumblebee declines, as well as declines in other species of pollinators. Apparently it is not unusual for crops in this country to have over twenty different pesticide, fungicide and fertilizer treatments applied in a single growing season, a third of which are known to be extremely harmful to bees. If you grow vegetables in the garden, there is no way you would use that many chemicals and then eat what you had grown, yet this is the way we farm.
Modern neonicotinoid pesticides – currently subject to an EU moratorium and therefore prohibited from use – are extremely toxic to all insects. The lethal dose of a typical neonicotinoid, which would kill a bee on 50% of the occasions it was exposed, is just 4 nanograms or 4 billionths of a gram. A teaspoonful could therefore kill one and a half billion bees. This is 6 or 7 thousand times more toxic than DDT. And by the way, only 5% actually ends up on or in the crop – about 94% ends up in the soil and in our watercourses.
Like honeybees, bumblebees can be sold and shipped all around the world in order to provide pollination services. Unlike honey bees, there are few if any controls or restrictions on this practice, meaning diseases, infections and parasites can be transmitted to native bumblebees, as well as other species of pollinator. Where native bees have no evolutionary response to those infections, there is the possibility of extinction, as is currently the case in South America where the world’s largest bumblebee is close to disappearance.
However, it is not all doom and gloom. The Tree Bumblebee reached the UK naturally in 2001 from the continent and has now spread all the way into Scotland. Its success is probably down to the fact that it can thrive on garden flowers and makes good use of nest boxes we put up in our gardens for the birds.
And there are plenty of ways we can help make a difference for our bees, be it through planting our gardens with them in mind, cutting out pesticides, getting involved in meadow restoration projects, pressuring our local authorities to do more for bees and other pollinators or just teaching our kids the value of bees.