About Osmia caerulescens (Linnaeus, 1758)
Female Osmia caerulescens are 10 to 11 millimeters long, dark blue-black with a metallic sheen, and sparsely covered in brown hairs. On the hind margin of each abdominal segment, the brown hairs form a narrow, dense, flattened band. The dense pollen-collecting scopa brush on the underside of the abdomen is jet black. Males are slightly smaller at 9 millimeters, have a more slender build, are distinctly metallic green, and are covered in pale hairs. Osmia caerulescens lives in a wide variety of habitats, including woodland and private gardens. This species is mainly distributed across the Palearctic realm, found across most of Europe, Asia, the Middle East, and North Africa. In Great Britain, it occurs mainly in England and Wales, becomes more restricted to local areas further north, and reaches as far as central Scotland. It is also found in India. The presence of Osmia caerulescens in North America may be the result of human introduction. In North America, its range extends from Minnesota to Nova Scotia, and south to Illinois and North Carolina.
