One of a group of medium-sized, predominantly black, Lasioglossum bees which require care in identification and which are unlikely to be easily recognised in the field. This is a species which is distributed throughout the northern regions of both the New and Old World, although it is montane in the southern parts of its range.

One of four brown bumblebees known from the British Isles; two of which, B. muscorum and B. humilis, are declining greatly and were  included in research undertaken by the Bumblebee Working Group. The biology of these two species is very similar. Both are associated with extensive areas of tall, but open, flower-rich grasslands, especially those which have many flowers with long corollae, such as clovers, dead-nettles and yellow-rattle. B. muscorum is the more northerly distributed species… Read more

The inner spur of the hind tibia of the female is diagnostic for this bee in Britain, the teeth being broad and rounded apically, rather than narrow and pointed.

One of two small Osmia bees frequently occurring in gardens as well as woodland clearings and edges. The males of both O. leaiana and O. caerulescens are extremely hard to distinguish, being about 6mm long, shining metallic green and having bright ginger hairs when fresh. The best character is microscopic: look at the downward-sloping front surface of the first gastral tergite. It is shining in O. caerulescens and matt with reticulation in O. leaiana… Read more