DRAGONFLIES

Class - Insecta, Order - Odonata, Suborder - Anisoptera, Family - Aeshnidae

Common Names:

Dragonflies, Darners, Gomphus, Skimmers

General:

Not to be mistaken for it's cousin the damselfly, the adult dragonfly cannot fold its wings along it's back. Dragonflies are usually much bigger and thicker bodied than damselflies. Both are very predacious in both the nymph and adult stage. Nymphs will feed on almost any creature in the lake including very small fish.

Most of our Interior dragonflies are 'Darners' of the family Aeshnidae. I have seen a few 'Gomphus' dragonflies of the family Gomphinae and some Common Red Skimmers but not enough to include as a major component of the following discussion. Gomphus are also known as 'Clubtails' and the adults generally have a distinctive club-like shape at the end of the tail. The Red Skimmers are smaller than many of our regular dragonflies and adults have a definite reddish color.

Life Cycle:

Adults mate in flight and can often be seen flying in tandem. The fertilized female 'oviposites' her eggs into woody vegetation or in some cases over open water or burrowed into the lake bottom. Metamorphosis is incomplete and when the eggs hatch they are just a smaller version of later stages. Therefore, all non-adult versions are simply referred to as nymphs. These nymphs live and grow in the lake and molt their shells 10 to 12 times before they are ready to hatch into adults. The nymphs crawl onto the shore or shore line vegetation to hatch into adults. The adults live for a few weeks to several months before mating. Most of our local dragonflies take one to two years to complete a generation but this can be as long as four years. This longer life cycle requires that most hibernate in the lakes during the winter months. Hibernation is usually done in the deeper water and this brings about spring and fall migrations to and from the shallow waters.

Appearance:

Dragonfly nymphs have large bulbous eyes and generally have a thick, cigar shaped body. In cross section, the abdomen is somewhat triangular shaped, being flat on the bottom and slightly ridged on the top. The legs of a dragonfly nymph are fairly pronounced in comparison to most other aquatics. Dragonflies do not go through a pupa stage. The immature forms look much the same but are just different in size. Adults develop two pair of wings and the abdomen lengthens and narrows for flight.

Size:

Many Darner nymphs get up to 40 mm in length (1.5 inches) when ready to hatch into adults. Broods of all sizes less than that will be in a lake.

Colour:

Shades of black and light green are the two most common colors for dragonfly nymphs in our lakes. However, they do come in other colors including darker greens, grays, and a reddish brown.

Movement:

Dragonfly nymphs mostly crawl along weeds or the lake bottom in search of prey. However, when disturbed or otherwise in a hurry, they can use a "jet propulsion" system to rapidly propel themselves. The nymphs have internal gills for which water is sucked into the body and then expelled. This expulsion can be quite rapid to provide an emergency means of locomotion.

Habitat:

Since they are highly predacious, the dragonfly nymphs will stay near available food sources. These are generally found on the shoals or the shoal drop-offs into deeper water. When not feeding they tend to hide under submerged logs and rocks or among the bottom vegetation. They usually prefer pollution free water that is well oxygenated but certain species will live in the more stagnant ponds.

Importance to Fly Fishing:

Dragonflies are the fourth most important source of food for trout in the Interior lakes. They comprise about 7% of the total feeding samples examined. For dragonflies I haven't found a significant difference between feeding samples of those fish caught during the day to those caught in the evening or darkness hours.

The feeding samples at 7% are somewhat misleading. Dragonflies are good at hiding and staying out of reach from the feeding trout. If it can find a dragonfly, the trout will often take it in preference to many other available foods. Likely this is because of the its large size. One dragonfly nymph ready to hatch is equivalent to about 25 Chironomid pupa.

My records on the success of fly patterns indicate that the dragonfly pattern accounts for 13% of fish caught on all types of flies. If attractor flies are eliminated and we only consider flies that imitate aquatic bugs, the success of the dragonfly increases to 19% of all fish caught on imitator flies. Naturally these number relate to how I fish but it does serve to point out that the trout will often take the dragonfly if they can find one.

Hatches:

The main hatches of the dragonfly from nymph into adult peaks about mid July with lesser hatches both before and after that time. At lower elevations, some species will start to hatch as early as late May. To hatch, dragonfly nymphs migrate to the shoreline and crawl out on the land or up shoreline vegetation. This 'hatching' migration and often the hatching itself often occurs in the evening or at night. By early morning the new adults are taking flight. Except for the migration portion of hatching, these combinations don't fair well for the fly fisher.

Adults:

The adults are very seldom found in feeding samples. This is partly because the nymphs crawl out of the water to hatch. Even when an adult falls into the water the trout seldom seem to feed on them. I'm not really sure why this happens but if any other food source is available the trout will simply ignore adult dragonflies.

Nymphs:

The nymph of the dragonfly is by far the most important stage to the fly fisher. I prefer to tie flies imitating this nymph with the large bulbous eyes that are characteristic of the dragonfly. I believe the fish 'key' on certain aspects of a fly as to what it represents. For dragonfly nymphs I firmly believe that the eyes are this key. I never tie the dragonflies without large eyes and a well-shaped head. I also prefer a dubbed body trimmed to shape but yarn bodies will also work.

Usually the fly imitation is fished on or near the lake bottom. The retrieve can be still, or an inching motion to represent the nymph crawling, or short to moderate pulls to represent the dragonfly using it's emergency jet propulsion system to escape the oncoming predatory fish. A sinking line or weighted flies with a dry line both seem to work.

Migrations and Availability:

Most of the Darner species live longer than a year and hibernate in deeper water during the winter. As soon as the water begins to warm and the ice goes off in the spring, the dragonflies will awake and begin their migration to shallower water for feeding. This spring migration starts right after ice off, will peak within a week or two and then steadily decline. The migrations for hatching peak about mid-July. The nymphs are exposed during this period and available to the trout. In the fall the dragonflies will return to deeper water for hibernation. These fall migrations occur over a longer period of time than the spring migration and usually don't start until the water has cooled considerably.

A hint for fishing these migrations is to use a large imitation of the nymph in the spring and for the summer hatch. By large, I am suggesting one, to one and a half inches in size. For the fall migration, the large nymphs have all hatched and it is time to use smaller flies to represent the size of the following generation. These flies should probably average one quarter to two thirds of an inch in length. Also fish the spring and hatching migrations from deep to shallow water and reverse this (shallow to deep) in the fall.

Recommended Fly Patterns:

Nymph:

• Bob's Deadly Dragon
• Gomphus
• Dragon Nymph
• Bottom Walker
• '52 Buick

Be sure to read other articles by Ron Newman

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