This is an ichneumon wasp feeding on hogweed near Lambrok Stream.
There are more than 2,500 species of ichneumonids in the UK. It is believed they make up an astonishing 10% of all our insect species and it takes an expert to identify any of them except the most obvious. This one looks like Alomya semiflava but it’s hard to be sure.
Most ichneumonids are parasitoids: the females lay their eggs on or in the body of other invertebrates and the larvae eat the host, eventually killing it. An ichneumon larva usually pupates just before its host dies, and the newly hatched adult eventually emerges from the carcass.
Despite their ferocious appearance, the adults of most species of ichneumon wasp feed on nectar or aphid honeydew. Some are so short lived that they do not feed at all and a few are predators, feeding mostly on arachnids.
 A female ichneumon wasp lays her eggs on or in the body of other invertebrates
 She has a long ovipositor, which look very intimidating
The header picture is of a male; the females have long ovipositors, which look very intimidating, that they use to pierce the defences of the prey insects and place their eggs exactly where they want them.
Header picture: SMH;