Red-arsed bumble bee proves a surprise visitor

ON one of those days last week when the sun shone for a while I was sitting in a plastic chair in the vegetable garden with a basket of broad beans that I was shelling for the freezer.

I find this very satisfying work. And I like the way I can let my mind drift as my thumb extracts the beans from the furry interior of the pods.

It drifted to the subject of bumble bees. I planted a lot of broad beans this year and they flowered very well because we had some good weather in the spring. Then the weather broke and I got an average crop of beans rather than a bumper crop.

I have noticed over the years that my beans are pollinated almost exclusively by bumble bees. And I know that bumble bees will not fly in wind and rain. This was why the crop was not as heavy as it should have been.

In the middle of my weighty thoughts a bumble bee landed clumsily on my basket of beans and crawled up onto the basket handle. It was an amusing coincidence and I smiled — then I started to get rather excited. It was an unusual bumble bee. There are 18 species of bumble bee in Ireland, including the related carder bees. Most of them are a mixture of yellow, black, white or ginger. But this one was all black apart from a bright red back-side.

Bombus lapidarius (below) — I actually said it out loud, but bees are deaf, although they can sense vibrations, so the insect stayed on the handle of the basket. The correct English name for this species is the red-arsed bumble bee. Some squeamish writers have recently started calling it the red-tailed bumble bee. This is a shame and also inaccurate because bees don’t have tails.

In 2006 the National Parks and Wildlife Service published research on the status of bee species in Ireland. It concluded that the red-arsed bumble bee was vulnerable to extinction in Ireland. This was also the conclusion reached at a conference on bio-diversity in UCD held in April of this year. Other researchers have suggested that the only viable populations that are left are on off-shore islands or in places like the Burren.

The reason for this is usually given to be that hoary old cliché of biologists ‘changing agricultural practice’. Sometimes they are more specific and cite a change from hay-making to silage or else over use of insecticides.

But here I was sitting in the midlands, a long way from any off-shore islands or the Burren, with a real live red-arsed bumble bee sitting on the handle of my basket. Then the bee flew away and I finished shelling the beans and went in to use the internet.

I found out a lot of things about bumble bees. One was that those good people in the National Biodiversity Data Centre in Waterford have a Bumble Bee Monitoring Scheme. Ordinary members of the public are encouraged to participate in this scheme, though you might be better off organising things in the winter to be ready when the first bees are on the wing next March. They also have a bumble bee identification guide which you can access online or get in hard copy for a modest charge.

A few other bits of trivial information about bumble bees: only females can sting, and they very seldom resort to it. They can fly at up to 55 kilometres an hour and will range up to two kilometres from their colony to find nectar and pollen to feed their brood. Their colonies are small, usually less than 50 individuals.

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