Dead Fly Mystery Solved

While we were in Dorset, we noticed many flies that at first appearance were just resting on leaves but on closer inspection were dead. They were attached in an invisible way to the leaves as if in a trance. 
I have now found the answer. They were infect by Entomophthora muscae, a fungus that releases millions of spores; if they land on a fly hyphae grow into its brain to control its crawling activity. The fly crawl upwards until it latches onto something high – eg one of the upper leaves of a nettle.There it adopts the pose in the images above while the fungal hyphae permeate its body, stick its feet to the leaf and digests its internal organs. The fungus then produces sporangia which erupt from the fly’s body and distribute its spores into the air.
Truly the stuff of science fiction.