Although I do not see many mayflies on the lakes and streams that I fish, I have fished farther north (in Ralph Cutter's angling back yard and other places a cross the west) and seen tremendous callibaetis mayfly emergences and spinner falls on many stillwaters, so I know these mayflies are just as important as he says they are for many people out there other than me. That's why I have decided to post the link to Cutter's Callibaetis Mayfly Article for you to read. This piece includes nice pictures and fishing information on all the important life stages of the most important stillwater mayfly there is for anglers. It is not a brief article but it is a good one, and about as through as it is possible to get on this subject. Here is the link to Cutter's article: http://www.flyline.com/entomology/callibaetis/