This insect (about 20 mm long overall) is a female ichneumon fly one of many species in the UK. It predates on other insects by inserting an egg into, e.g. a larva, using its long ovipositor at the end of its abdomen. The egg then develops and consumes the larva - pretty grisly!
Close-up and macro
Wildlife and nature
baxster, blondiebee, bppowell and 6 more