Hatches Made Easy:

Cream Cahill (Maccaffertium species ) - Duns and Spinners


As mentioned in the previous article, the duns vary in appearance. However, all
of the species are quite different in appearance from most other mayflies. The
picture below is typical of a Cream Cahill. They are fairly easy to recognize.

I'm not certain that the fish I have caught on dun patterns were taken by the
trout for a spinner or a dun. As I mentioned before, I have not found them
hatching. I assume many if not most of them hatch during the evening. If this is
correct, fishing the dun pattern during the day would not be any more effective
than any generic imitation.

I have seen Cream Cahill spinners depositing their eggs at different times of the
day, even in the morning. I have watched brook trout eat them while they were
darting around on the surface of the water - I assume, laying eggs.

If you discover any of these mayflies
depositing their eggs, I would
suggest that you try a fly that
matches the spinner. You should
fish it on the same type of water you
see them. Most likely that would
be the runs and riffles. Clinger
mayflies deposit their eggs in the
same fast water they hatch in.
If you discover spent spinners
on the surface in eddies or the ends
of riffles and runs, I would suggest
you try a spent spinner imitation. I
have never found a concentration
of them.

Coming Up Next:
Cream Cahill (Maccaffertium species) - Fly Pattern Colors

Copyright 2008 James Marsh
This Cream Cahill spinner shows the wing
markings typical of the Maccaffertium
species. It has a white body very unlike the
normal brown or rust color of most