This year around North Yorkshire in the rivers to the east of York I reckon we have had the best mayfly hatch for probably 20 years, They have been emerging since the end of May ( which is early for round here ) and were still hatching last night. Some evenings the hatches have truly memorable with great columns of spinners. I wondered what the general experience had been in other parts of the country?.

I am not sure if i just picked the right days to fish this year but on my club waters on the itchen i have seen some hatches of biblical proportions, one day in particular there was so much natural food on the water it was tough to keep sight of the mohican mayfly i was using.. it has been persistant too.. i have seen good hatches from about the second week off may right through to last week...

i was wondering if anyone had observed a biannual fluctuation, we know that ephemera live as nymphs for 2 years... well i had noted that last years hatches were no where near as prolific as the year before or this years.. it stasnd to reason that if this year has good hatches then in 2 years time the progeny of this year should be hatching... if last years hatches were more sparse then next year there will be fewer nymph to hatch...


or am i just talking rubbish

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Who knows?


Most entomologists would say the hatches comprise a mix of one and two year old adults.

For example this article by Mutsunori Tokeshi.

I have never noticed a definate 2 year correlation between good hatches. What amazes me is that in the last 3 years I have seen huge floods with enormous sediment shifts. In the last winter extremely low temperatures for weeks on end. Then a cold late spring and we end up with a huge hatch thats 2 weeks early by normal standards,,,,