I was out for a run just now,the path at Whiteabbey passes by an area of wetland,and I saw the first hawthorn fly of the year, they have that distinctive dangly bit that hangs down when they fly.
They hatch between late April and mid May, the trout love them, the big brown trout always seem to come up for them at Kernan Lough where I normally fish.
I suppose it is because they are the first big land based insects that hatch after the winter months, they must be too good to resist for the fish.