.......................  ......Fly Fishing Yellowstone National Park

08/27/09

Bug Made Easy - Part 2

The Mayfly Hatch:
Near the end of the year or second and even third year in a very few cases, the
mayfly nymphs hatch. In other words, they turn into a fly. They do this by:
1. Swimming to the surface and shedding their nymphal shucks.
2. Crawling to the bank or up rocks or plants to emerge.
3. In some cases, emerging on the bottom and swimming to the surface as a fly.

You need to know which way this activity occurs, when it occurs and where it
occurs for all the mayfly species you may encounter. Most of them swim or float
to the surface (aided by gas bubbles) and hatch into a fly. During this time they
can easily be eaten by trout. This is when we fish an emerger pattern or a fly
that represents the nymph changing into a fly with wings. If it crawls out of the
water to emerge, we don’t need to imitate the dun. The dun will never touch the
water. Slate Drakes. Mahogany Duns do this.

When the mayflies hatch they fly off to the trees or bushes for a short time.
They stay there for a few hours but up to two or three days depending on the
species and the weather conditions. During this time, almost all, duns change
into what we call a spinner. They actually shed their thin shucks, their tails get
longer, and their wings get clearer. In layman terms, they become sexually
mature .After they become a spinner, the males will usually congregate out over
the water. They typically dance up and down, supposedly to attract the females,
who join them shortly afterwards. Then they mate and the males drop dead -
similarly to the way a lot of us older men will probably die.  

In most cases, or with most species, the females fly back to the trees, their eggs
develop or ripen, if I get by with calling it such. After a few minutes or hours,
again depending on the species and weather, they fly back out over the water
and deposit their eggs.

1. Some drop them from the air
2. Some dip to the water and drop them
3. Some dive to the bottom and paste them to rocks and plants.

You need to know which way or you simply do not know what your doing when
you imitate the egg laying process. After depositing their eggs, the females die
and fall to the water or if they dive to deposit their eggs, they rise to the surface
and float off.

If they drop their eggs from the air you do not need to imitate the female
spinners at all as an egg layer. You may imitate them dead in what we call a
spent position with the wings flat but not dipping to the water or diving under the
water.

If the mayfly dives to deposit her eggs, you need to be fishing a wet fly to
imitate that activity.

Copyright 2009 James Marsh