A species of hymenopteran in the family Megachilidae. It is found in Europe & Northern Asia (excluding China) and North America by introduction. A tiny black bee associated with the flowers of various bellflowers (Campanula species). Common and widespread in much of England, but absent from Wales, Scotland and Ireland. It is commonly found in town and village gardens, and nests in old beetle holes or the exposed ends of thatch. Flies from June to early August. the abdomen is narrow and cylindrical, which is probably an adaptation to using small-bore beetle burrows as nest sites. The males have the final segment of the abdomen modified to form a two-pronged peg which is used to hold on inside flowers during the night or in poor weather, which gives a good method for recording the bees under such conditions.