Parasitic Wasp (?Sp)
Actual size 5mm, Lancashire, UK

Canon EOS 300D and MP-E 65mm, f/16, 1/200 with fill in flash

The long ovipositor can clearly be seen (the 'stinger' at the end of the abdomen). This family does not sting, but uses the ovipositor to inject eggs directly into a host (such as an insect grub) which the wasp lava then eats from the inside out.