Insect Identification Made Easy

Quite often I will have beginner fly fishers come in to the shop asking for a Mayfly. Now mayflies are a huge group of insects that run the gamut of size and colour. They range anywhere from a tiny size 24 Trico to a giant size 8 Green Drake, and everything in between. So how does the novice know what insect it is they are seeing on the water that is driving the fish crazy, making them greedily eat every bug in sight, except the artificial tied to the end of their line? Actually identifying the four major and abundant aquatic insect groups that are of importance to the fly fisher is easier than it would seem.

MAYFLIES:

Mayflies are the darlings of the flyfishing world and are very abundant in most trout streams. When mayflies “hatch” and come floating down stream they are easy to identify as they look like little sailboats, that is they hold their wings upright and together over their backs. Traditional dry fly patterns such as the Cahill and Adams imitate these insects. All the angler has to do is note size and if possible body colour and these patterns, tied to match, should fool the fish.

CADDISFLIES:

One of the most abundant of aquatic insects, due to their tolerance of less than ideal water conditions, caddis flies are a little easier to imitate. Even though they can range from very large and orange, to very small and black, a size 12 or 14 Elk Hair caddis in tan will usually work. These insects hold their wing over their backs in a v, what I like to compare it to is a pup tent. These insects get very active on cloudy days and in the evening when the sun is off the water. They will skate across the water and high floating patterns like the Elk Hair caddis or the Goddard caddis imitate them quite well.

STONEFLIES:

While stoneflies also have a large size and colour range the ones most associated with trout fishing are usually quite large. They also lay their wings over their backs but in a flat position. Since stoneflies migrate to shore to hatch it is not until they return to lay their eggs that fly fishers usually imitate them. The female flies very clumsily over the water, dipping her egg sack into the water to release her eggs. The two main imitations are the “Salmon fly”, which are generally dark with some salmon orange coloration on their bellies. This is usually a large dry fly #4 through #8. The second is the Golden Stone, a little smaller, #8’s and #10’s in, you guessed it, a golden brown colour.

MIDGES:

The smallest and most frustrating of the aquatic insect is the midge. Often seen in clouds over and on the water these bugs drive both the fish and fisherman crazy. They can be found hatching 12 months of the year wherever you find open water. The Griffiths Gnat is probably the most popular midge imitation, in sizes #18 through #24; even at this small size this fly imitates a cluster of these tiny insects.