This mayfly landed on the spokes of my umbrella when we were out walking by the river Tees in the rain at the weekend and walked through a mating swarm. When mayflies hatch from their aquatic larvae they often appear in very large numbers and there are swarms along most of our local rivers at this time of year. Mayflies are weak fliers, merely dancing up and down in the air, and the main purpose of their flight is courtship. The males wait for females to stray into the swam, then grab them and mate with them in flight. We watched several successful 'captures' with the pair locked together and falling out of the air into the vegetation below.
Once the male’s purpose is fulfilled the females head for water, fluttering just above the surface to lay eggs - and so providing a feeding bonanza for trout that leap to catch them. Those that escape the attentions of fish are often snapped up by swallows skimming across the water. The life of an adult mayfly can be over in a single day, lasting just long enough to produce eggs that will perpetuate the species.
I haven't identified this species yet but it does have this distinctive pale blue eye stripe.
A second slightly different mayfly, possibly the same species but the other sex, landed into the umbrella.
More pictures of mayflies here.