I photographed this bee-fly Bombylius major on a sunny bank neat Thorsgill wood in Teesdale last week.
These furry little flies that mimic bees are parasites of mining bees and several of them seemed to have just emerged from their underground nursery in bees' nests.
Their first actions on emergence are to feed on nectar, darting from blossom to blossom with incredible speed, rarely stopping to settle and usually just hovering in front of a flower, sucking up nectar with that long and deadly-looking proboscis.Violets and primroses, both flowering at this site, are popular nectar sources.
Few flies look so menacing but they are totally harmless - unless you happen to be a mining bee.
When mining bees dig their new tunnels and provision them with pollen for their developing larvae a bee-fly will hover close to the ground near the entrance,flicking eggs into the tunnel entrance with its tail. When the eggs hatch the larvae will eat the mining bee host's own larva.
You can find more information, a bee-fly ID guide and a video of the insect laying eggs at http://www.brc.ac.uk/soldierflies-and-allies/bee-flies