Mayfly time

Words by:
Barry Grantham
Featured in:
May 2021

May is my favourite month for fly fishing on our Lincolnshire rivers. During the later part of the month we get the mayfly. Anglers call the time when mayfly are hatching ‘Duffer’s Fortnight’, but this is not always the case. The trout can sometimes still be finicky with their feeding. By Barry Grantham

The mayfly is known for its short life and emergence in vast numbers. The winged mayfly has large eyes and short stiff antennae coming forward. They do have a mouth but it serves no function as once the mayfly enters the winged stages it does not feed.

I find the life-cycle of the mayfly fascinating. There are four stages: egg, nymph, subimago and imago.

The egg: the female lays its eggs on the water. The eggs can vary in size and be different shapes, oblong or round. After laying the eggs on the water surface they sink to the water’s bottom and lay there until hatching into a nymph in about two weeks.

The nymph: the nymph’s life can be as long as two years, depending on its environment. When the growth of the nymph is complete it makes its way to the surface. There its skin splits down its back and wings appear. The nymph is now called a subimago.

The subimago: the subimago flies from the surface of the water to some bankside vegetation for shelter. It sheds its skin – again this usually takes place overnight. Anglers sometimes call the mayfly at this stage a ‘spinner’ instead of the imago.

The imago: mating takes place above the water with swarms of males as dusk is approaching. The males and females mate in flight. As soon as the process has finished the female lays her eggs. The female will either deposit her eggs by dropping them onto the water or by flying low over the water and touching the water’s surface with her abdomen and washing her eggs off. The female then dies and falls to the water with wings outstretched. The angler calls this the spent mayfly.

Coming up to mayfly time, I like to use a mayfly nymph casting upstream and letting the nymph come towards me in the current, lifting and lowering the rod tip to make the nymph rise and sink in the water.

As the mayfly is hatching, I like to use an emerging imitation. Basically it is a mayfly imitation which seems to be emerging from its nymphal skin. This again is cast upstream and allowed to drift back with the current. The most exciting time for myself as an angler is when the spent fly drifts down the river after laying its eggs. The trout rise and feed franticly taking the spent fly off the water’s surface.

The tackle I like to use when fishing the mayfly is a tip to middle action split bamboo rod of my own making and mate this up with a silk line. I always fish as traditionally as I can when fly fishing on rivers. A split bamboo rod is the perfect tool for accurate presentation on small streams – you can cast short lines a lot easier than you can with modern carbon fibre rods. A silk line is a joy to use. The one that I use was made for me by a friend. It has a nice fine taper at the front and it turns over perfectly placing the mayfly gently on the water.

There are plenty of mayfly patterns available. For the nymph pattern I use a pattern invented by the late Richard Walker. For the adult dry mayfly there are many patterns to choose from. My favourites are: Brown and Green Drake, Grey Wulff and the Adams.

My thanks to my very good friend John Boulton for his photographs of the mayfly nymphs and adult.

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