Skin-crawling action

It is a classic Weedon's World of Nature scenario. There is Weedon pottering around the garden admiring the beauteous bounty of Nature in blooming July glory. He naturally has a quick look at his favourite, ever-plumper Cinnabar moth caterpillars, each happy one of which is busy devouring a Ragwort to an unrecognisable mess. But one does not look too happy at all, in fact it is twtchy, lifting its head and swinging round. Aha, thinks Weedon after a closer look, it is fidgeting because a little aphid has accidentally landed on its back.
But a closer look reveals that the landing was no accident, and this is no innocent aphid. The tiny creature which won't go away is a teensy ichneumon and its business is egg-laying. And it won't leave until it has pierced the caterpillar's skin many times to lay its eggs, which will hatch within the moth larva and eat it alive from the inside.
It makes your skin crawl! Further inspection of another clump of Ragwort found two more of these microdevils pursuing their natural aim of taking advantage of the fat grazers. Now I must go and itch – enjoy the shots:

Getting ready for action, caterpillar flailing hopelessly.

Close-up of the parasite.

Then the ovipositor is injected under the skin.

Closer for the ghoulish...
Nikon Coolpix 4500.