Mining bees and a Bee-fly

Today whilst out gardening I noticed that in a corner of the garden there seemed to be lots of bees. They looked quite wasp like on first glance but on closer looking I realised they were bees. There were at least 20, probably more, flying around and they seemed to be enjoying the spring sunshine. As soon as the sun moved away from that section they disappeared again. I tried to find where they were coming from and discovered they were actually emerging from holes in the ground. I grabbed my camera and headed to try and get a photo, which I managed once one of them landed for long enough!

On further investigation I have worked out that these are mining bees, bees that nest in the ground, on there own, but all in close proximity forming a group. Although I'm not exactly sure what type of solitary mining bees they are, they belong to the genus Andrena, but I'm not sure which, jacobi, haemorrhoa? Can anybody identify it specifically for me?

Mining bees are common in spring, and as it's early April that fits. Apparently these are very beneficial bees and aid pollination. They can sting but are unlikely to do so. Unfortunately I have nothing in flower at the moment, last year I'm sure my sage was in flower by now, which they seemed to like, but it seems a bit later to flower this year. Hopefully soon there will be some food for them in the garden.

While I was watching and waiting to get a photo I noticed that one of the bees looked a bit bigger, and then when I looked closer I realised it was actually a different bee, as it had a peculiar long 'nose', and darker almost moth like wings. Just as I was going to try and get a photo of that too it flew off. So I didn't manage to get a photo today of that species but I'm hoping it will return. I have never seen this bee before, so had to do some searching to see what it was. It's a bee-fly.

It's just the right time of year for the bee-fly (Bombylius) they become active in March/April, their nose as I called it, is actually called a proboscis that is used for drinking nectar, it's like a large drinking straw! Interestingly these bee-flies are parasitic to the ground nesting bees, which is exactly what I also have in my garden in the same area I spotted the bee-fly. As I didn't get a photo today here is a link to a great website, Insectopia.co.uk  with a great photo of a bee-fly, so you can actually see what I'm trying to describe. Has  anyone else every seen one?