Sometime this month or maybe in early June it will be 'Duffers fortnight'!

This is a term coined many years ago by fly fishermen referring to the mass emergence of mayflies from our waterways when it was said that however basic their angling skills, any novice or 'duffer' could not fail to land a fish because trout indulge in a feeding frenzy and fling themselves at any fly on the water, live or artificial.

In Britain there are many species of mayfly, the largest being 'Danica', a most handsome and colourful insect.

All are 'upwinged' flies sporting three filamental tails. Fossil records reveal that they evolved over three hundred million years ago and have changed little since.

Larvae live under water for two years feeding on plant material. But, as mayflies famously only live for a day as adults, their mouthparts are useless as they have no need to feed.

Mayflies are unique among insects as they emerge from the water as 'sub-adults', rather dull in colour and fly weakly to bankside vegetation where they shed skins for a final time and become perfect very beautiful mayflies.

Mating takes place the next evening when swarms of both sexes rhythmically fly up and down until paired off.

Females then fly back to the river to deposit their eggs as the males die.

Eggs laid, females collapse onto the surface and become 'spent spinners', eagerly sucked down by trout. And trout are certainly not duffers!