Articles- Fly Fishing Fundamentals

One of the greatest satisfactions of the angler is to attract a fish successfully with an imitation of its preferred food. Many kinds of flies have been created to imitate the shape and color of real insects. In Fly Fishing Equipment and Techniques, the author states, "it is certainly not necessary to know every intricacy of the life cycle of an insect to enjoy fly fishing, but some knowledge of entomology...can provide essential background information that will make your approach more systematic and successful" (Ruel 42).

Virtually every type of freshwater habitat contains some form of aquatic insect. Found in rivers, lakes, and small ponds, they all represent food to the fish. These insects spend a large part of their lives in water and lay their eggs on or in the water. After hatching, the larvae or nymphs crawl around the lake or stream bed or swim freely, feeding on aquatic organisms and breathing through gills. At the end of this phase, which can last a few days to several years, the insects swim to the surface or crawl up on dry ground to emerge into their adult form. Then, they complete their life cycle by mating and producing eggs for the next generation.

Mayflies are an important group of insects, partly because of their wide distribution in the water and the very concentrated emergence period that takes place. The mayfly has a simple life cycle of a nymphal stage and an adult stage. Most species of mayfly have about a one-year life cycle. Mayflies become most vulnerable to fish during their emergence. Fish begin to feed heavily at these times, and they also feed heavily on the adult mayflies. The adult mayflies rest on the surface of the water and wait for their wings to dry (Ruel 45).

Caddisflies are abundant in most lakes and rivers. They have a complete life cycle. This life cycle includes an egg, larva, pupa and the adult. During the larval stage, they build protective cases out of vegetative debris or sand in which they live in. When it is time for emergence, the larva seals the opening of the case and waits until the metamorphosis is complete. Then the pupa emerges from the case, swims to the surface and flies off quickly as an adult caddisfly. Fish often feed on caddisflies as they emerge from the pupal case underwater, just before they appear on the surface. They also feed heavily on adult caddisflies that linger on the surface of the water depositing their eggs (Ruel 47).

A third order of aquatic insects that is important to fly fishers is the stonefly. This type of insect is only found in rivers and streams. It has a simple life cycle of nymph and adult. The nymph crawls among the rocks of the river bottom until it reaches maturity. The nymph then crawls out of the water onto the rocks or the shore and sheds its nymphal case (Ruel 49). "Stonefly nymphs are of particular interest to fly fishers because they are an important source of food for trout; the adults, however, are not" (Petralia 115).

Another important food source for fish are the midges. Midges are a small aquatic insects that are found in waters with rich nutrients. "Although they are very small, their great abundance compensates for their size, and they are an important source of food for fish" (Ruel 45).

Terrestrials insects are yet another source of food for fish. These insects complete every stage of their life cycle on dry ground and only become prey to fish when they fall or get blown by the wind into the water from shore. The most common terrestrial insects consumed by fish are crickets, caterpillars, grasshoppers, ants, and beetles.

Although insects are the major interest to fish, other creatures are also consumed. The most common are small fish such as minnows. "Minnows can easily become big meals for fish. But, minnows are not a food that fish look for and key in on. They are a secondary food for fish. Minnows can quickly become prey if and when the situation presents itself" (Ruel 47).