Red-tailed Mason Bee (Osmia bicolor)

An early season Mason be, seen from March to July, it's easily confused with the Red Mason Bee (Osmia bicornis) which I believed it was when I took the photo.

This is a male, and as you can see, it's not too dissimilar.

The female O. bicolor is both more distinctive with a black head and thorax, and an abdomen of deep crimson red and truly fascinating.

She creates her nest in empty snail shells, into which, once she's turned the shell over and over to inspect it for suitability, she builds up to to 4 or 5 individual cells, using chewed leaves, particles of earth, and chalk (or similar) to divide them.

Once completed, she then disguises the shell by covering it with twigs and other debris.

This is not my video, but it's a must watch, to see how she does this: