Sandy, if you can cary a book whilst fishing then you are not wading deep enough Interesting point about fly sizes, LDO's here are a #12 IMO, larger than on the northern English rivers and some of the spring Stoneflies are simply enormous. Interesting letters from Ollie Edwards & Steve Rhodes on this point in this months FF&FT.
you'd be amazed where it fits.
agree with the LDO synopsis sometimes even a 10!!
There are very small BWO's at the height of summer 18-20
the yellow mays are a size smaller than down south too(16)
The one to really try and spot is the tiny iron blue that hatches in April
it's about a 20 and is often the cause of the fish not taking the march browns
they are very hard to spot in amongst the bigger flies but they start slightly earlier in the day
and I have found the trout key into them first and can miss the march brown/large dark olives
have yet to see a trout take a stonefly
despite the fact it would be the best hatch if the river were in the US.
They DO take the nymphs though.
Just wait till you get to the micro caddis
cheers
sandy