There seems to be a lot of confusion in the classification of Cahills.....and I confuse easily so I just keep it simple. If it is a light colour, hatches from mid May to the middle of July, and has a mottled wing, and two tails.... it's a cahill. Here are a few of the different ones that I have found over the years, that all seem to key out as Cahills. One thing that I have noticed over the past couple of years is that as the hatch progresses later into the summer Cahills tend to get lighter in colour.
The first four are all duns and the last is a spinner.
