Something to watch out for
27th July 2010, TuesdayBombus ruderatus is one of several bumblebee species that used to occur on Romney Marsh but which now appear to be extinct here. When entomologists started to search for it about 10 years ago there was a great deal of confusion because, as it was so rare, few of the surveyors had actually seen it and it looks superficially similar to the garden bumblebee Bombus hortorum. It came close to being eliminated from the list of Biodiversity Action Plan species, when, fortuitously a surviving population was found in the Ouse Washes and was proved to be a good separate species by DNA analysis.
Both species have two yellow bands on the thorax, but in hortorum the posterior band is narrower than the anterior one, whereas in ruderatus the bands are of similar width, and the hairs are shorter and neater. Sometimes ruderatus has a completely black form, distinguished from other all black bumblebees by it’s long face.
The good news is that this bumblebee has benefited from payments to farmers to grow pollen and nectar mixes and it is starting to spread from its refuges in the Fens. This means that there is a possibility of the bee recolonising the RX areas, so if you see a bumblebee with two yellow stripes of equal depth on the thorax I would be very interested to hear about your sighting.