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

08/28/09

Bug Made Easy - Part 3

Stoneflies 101:
This is a brief overview of the stoneflies. Like the mayflies, stoneflies undergo
incomplete metamorphoses. Again, this simply means they start life as an
egg, change to a nymph and finally an adult. You will see shorty that
caddisflies and midges have another stage of life - the pupa.

Stonefly Nymphs:
Most of the stonefly nymphs are clingers but there are others called sprawlers.
Like the clinger mayfly nymphs they spend most of their life down between and
underneath rocks. For the most part, they are not available for trout to eat until
they move to the banks or crawl upon rocks to hatch.

All of the stoneflies that are important to anglers crawl out of the water to hatch.
They do this on the bottom of the stream.  During this time they are subject to
being eaten by trout. This is when the nymph imitation is most effective.

Stonefly Adults:
When the nymphs crawl on the bank or upon a rock, they emerge into adults.
The adults quickly fly off into the bushes and other stream side vegetation.   
The stoneflies mate and do not return to the water until they deposit their eggs
or otherwise accidentally get into the water. Some of the stoneflies drop their
eggs from the air but most of them actually dip to the water to deposit their
eggs. This is when we imitate the female adults.

Caddisflies 101:
Caddisflies undergo complete metamorphoses. This simply means the caddisfly
starts its life as an egg; then changes to a larva; changes to a pupa; and
finally changes to an adult. Caddisflies and midges have one more stage of life
to imitate than the mayflies and stoneflies.

Caddisfly Larvae:
The caddisfly larva comes in two basic forms - cased and uncased. To get a
little more technical, they come in five basic varieties - the free-living caddises,
net spinners, saddle case makers, purse case makers and tube case makers.
The larvae, uncased or the cased variety, out of their cases look like worms.
They are segmented and have six legs and of course, a head.

This will continue tomorrow with the Caddisfly Pupae:


Copyright 2009 James Marsh