I photographed this flying insect in my garden - it was investigating holes in the soil, perhaps with a view to using them as a nest. I think it is some sort of sawfly but I haven't been able to identify it from books or the Internet. Can anyone help with this please?
Not a sawfly but (it might surprise you) a bee. It is a species of Nomada, commonly called Nomad bees or wasp bees (for obvious reasons). They have a very interesting life history - the females lay their eggs in the nest burrows of solitary bees where there larvae then feed on the food provisioned for the solitary bee larvae (cleptoparasitism this is called). The holes being investigated were probably the burrows of solitary bees
I would say this one is Nomad goodeniana which is a cleptoparasite of several of the larger and common species of Andrena.