This bee is a slightly larger than a honey bee and is fairly distinguishable, especially for a solitary bee, with a deep reddish thorax and a shiny black abdomen that appears to be hairless.  Its head and legs are also entirely black.  This bee has a strong association with coastal habitats; it can often be found nesting in the soft vertical cliff faces in Scilly.  There are two generations; the spring generation males emerge in Feb and females linger into May. the summer generation emerges late June until late August.