:shock:
I was fishing one of my favorite lakes this morning and was having pretty good luck with a olive size 10 mini wooly when this BIG yellow mayfly landed in an area were I had been fshing. I was eaten as soon as it’s feet touched the water! I will definitely not go fishing there again without dryflies in my box.
Years back, after a cool spring, a warm spell brought on three weeks of mayfly hatches during the one mid-June week we were on Basswood Lake. That included big yellow ones. Though I did not have a dry fly to match, the #4 Muddler I did have was a fair match as to size. I greased it up, tied it on, and got into Smallmouth Bass up to 18".
The Muddler can be a may fly, a hopper and even a minnow 
Some of the fun ended when a small pike chewed it beyond hope. I make sure to have a selection of Muddlers with me after that week.
On the ponds and smaller lakes around here, we get sparse hatches of big yellow mayflies sometimes as big as size 8. When these guys are coming off, EVERYTHING is after them. I’ve caught gills, bass, crappie, and cats on the same evening on the same fly, usuaslly a foam bodied hex dry does the trick, but I’ve also done well with a yellow hopper pattern in the right size with the kicker legs clipped off. I seldom catch the hatch right, and it’s always both sparse and localized, but I’m never without one or two of the flies just in case, and I’m always looking out for them when I’m on the water.
I never leave without a couple of hex patterns.
I did some research and it was a Hex! I’m loaded for them now. Thanks for the imput.
Greg 