Fly fishing flies: stonefly 2
Wednesday, 3 June 2015 | Simon
It’s useful before fly fishing stoneflies to understand something of their biology. Very much like mayflies, all stoneflies undergo incomplete metamorphosis, and experience only three major stages within their typical life cycle.
The first of these three stages is the larval one, when these insects are commonly referred to as stonefly nymphs. The nymph stage occurs entirely beneath the surface of the water. Stoneflies, unlike mayflies and caddis, have stringent requirements for their survival, including clean, cool, and well-oxygenated water. For this reason their populations tend to be strong only in northern environments, alpine environments, and otherwise clean rivers and lakes.
In general stonefly nymphs resemble those of the mayfly, but are typically somewhat larger. They have only two tails, and do not display visible gills along their abdomens. In terms of colour, their nymphs can occur in a range in which blacks, browns, yellows, and rusty oranges being the most common. The nymph's set of six large, powerful legs allow it to hug its often rocky environment for up to three years. It will do this before it is ready to hatch to a winged adult. We recommend you read all four of our fly fishing blogs on the stonefly to get as full a picture as you can.