Mayflies

When resting you can view this species four partially transparent wings held vertically. Projecting from the end of the abdomen are two or three long filaments. In their nymph stage, the Mayfly has rows of leaf like gills along the sides of the abdomen along with two to three feathery tail appendages. A Mayfly, dependent on species will live anywhere from three months to upwards of three years underwater. Upon reaching maturity the Mayfly emerger rises to the water surface, sheds its skin and transforms into a flying dun. Continuing the life cycle, a dun exists for roughly one day, again shedding its skin to become a spinner. The spinner is a sexually mature Mayfly, it does not eat and  lacks functioning mouth parts. Lasting as little as a few hours, the sexually mature Mayfly mates in a swarm above the water. The females die after depositing their eggs in the water.

Every point in the life cycle of the Mayfly is important fish food. As nymphs, in the early morning and early evening behavioral drift occurs. As the nymphs disengage from their underwater perch the Trout actively feed  on the bounty. Prior to a hatch, nymphs disengage from the rocks below as emergers, anglers throw an emerger pattern often behind a dun in order to fool the weary Trout. In prime hatch time Trout become less discerning and throwing a Mayfly dun where a Trout is actively feeding will yield a bounty. Finally note that fishing cripples and spinners is also an option. The cripple is an emerger that was unable to shed its skin thus preventing its transition to a dun. Finally after depositing eggs the spinner falls back to the water becoming a valuable protein source for a Trout.

Caddisflies

Aquatic in both larval and pupal forms these insects resemble moths. The larvae are soft bodied with a hard horny covering on their head. The larval thorax has three distinct segments each bearing a pair of legs.  Larvae reside in tube form cases constructed of leaves, sand, twigs or bark. The case is unique to a species and can be used to determine the identity of the builder. The larvae feed on plants and animals in the stream. The majority of the caddisflies life is spent as a larva. The insect has a two week pupal stage followed by a month long adult life.There are more than 750 species in North America and they make an important food source for Trout.

Stoneflies

This insect is up to two inches long, recognized by its clear membranous wings and two long antennae. A Stoneflies’ gills are located behind each leg. There are about 300 species in North America; they prefer clean, cool and flowing water. In the nymph stage they reside in flowing waters, while still found in quiet pools under stones, leaves and bottom debris. Each species feeds on either plants or animals as well as serving as a food source for Trout.

Scuds

These crustaceans are distributed in ponds, deep water and large lakes. They have a body that looks flattened sideways. When in streams they are found in slow moving waters and the areas immediately near weed beds. Further note the Scud avoids light and stays near the bottom.

Terrestrials

In the summer months, especially in nutrient poor streams and where the stream course flows through grassy fields, the Trout will feed on these juicy protein filled snacks. Grasshoppers, beetles and ants are all common terrestrials. On the Green River in Utah, you may see Cicadas or the Mormon Cricket on a good year.

Dragonflies and Damselflies

Anyone who has walked along the bank of a pond or slow moving drainage in the summer will recognize these flying insects. Dragonflies are larger and hold their wings at horizontal position when they rest. Damselflies are smaller and hold their wings upward and backwards. Adult versions of both of these insects are not important sources of food for Trout. This being said their nymph life form is a very important source of food for pond dwelling trout. They are dull colored and interesting looking; the Dragonfly nymph has large eyes, the Damselflies have three leaf shaped gills at the back of their abdomen. Fish patterns near stalks emerging from the water, this is where the nymph transforms into an adult.

Leeches

Leeches are found in calm, shallow and warm waters where there is abundant debris on the bottom. Leeches avoid light on the bottom, some are bloodsucking other carnivorous and then there are scavenger species. Movement happens in a process referred to as “looping” where they attach the mouth sucker or the tail sucker to a surface. Wooly Buggers fished on a two inch strip retrieve mimic this movement. Feeding on leeches makes for large Trout.

Midges

Often resembling mosquitoes these insects are seen flying over the surface of water. They mate in swarms often forcing the angler to wear a mask to prevent the annoyance of the midge swarm, some even bite. Larva’s bodies are bent when resting, common imitator patterns are the Griffith’s Gnat and Zebra Midge.

Information about area streams and ponds.