Preferred damselfly nymph habitat includes dense mats of submerged vegetation, such as chara, coontail, milfoil and pondweed. Damselflies can spend up to four years in the nymphal stage before making the transition to an adult. The nymphs undergo multiple molts or instar stages as they grow from minute creatures to 1.5-inch long mature nymphs. Lush vegetation that covers the shoal, or shallow zones, of a lake provide an abundant hunting ground for these carnivorous insects. Nymphs feed on scuds, mayfly nymphs, zooplankton and any other meaty food sources they can capture in their extendable mouthparts. These are not fast swimming predators, but stalk and ambush specialists. Nymphs are adept at matching their body coloration to the habitat they live in, so it is not uncommon to have multiple colors of the same species of damselfly in the same waterbody. Damselflies undergo an incomplete metamorphosis, which means there is no pupal stage such as found in midges and caddis. The fully developed damselfly nymph leaves the protection of its benthic habitat and swims to patches of emergent vegetation, like longstem bulrush, cattails or sedge grasses. The nymphs swim in a sinusoidal motion using their three-lobed caudal lamellae or “tails” to propel them through the water. Once reaching the plant stalks the nymphs crawl out of the water. Their exoskeleton dries and splits open allowing the adult to crawl out. Newly emerged adult bodies are soft and delicate and it takes up to several hours for their bodies and wings to harden. They then fly off and spend the rest of the open water season eating adult mosquitoes, midges and other small flying insects. Adults mate and females deposit eggs in emergent and floating vegetation. Females also crawl down emergent plant stalks and deposit eggs well below the surface. Adults live well into the fall season, but die off along with their prey with the arrival of freezing air temperatures.
It’s the nymphal stage that really attracts the attention of trout. One of the most intense and frenzied feeding periods occurs during the mature nymphal migration. Typical emergence occurs during the early summer season while water temperatures are still increasing, but prior to the onset of hot summer air temperatures. Overall, the hatch is short, often less than a couple of weeks in duration. Fully developed nymphs, in large numbers, swim from the lake bottom to within a few feet of the surface, then travel horizontally en route to concentrations of bulrush and cattail. During this migration the nymphs are fully exposed to trout cruising the shoals and edges of drop-offs. Fish pick off nymphs at will while never showing any signs of surface activity. Anglers see the swimming nymphs in the water or hanging from the stems of emergent plants. Pulling anchors at this time of the year often results in several nymphs falling into your boat or onto your float-tube. Things get even more interesting when masses of nymphs, emerging nymphs and newly emerged adults cling to the stems of rushes and sedge grasses. A gust of wind pushes the helpless insects into the water making for a very easy meal for trout willing to feed in water often less than four feet deep. At other times aggressive trout roll into bulrush stems to send the food purposely crashing onto the water. This is an amazing sight that leaves an angler shaking as they scramble to tie on an adult pattern. Fishing patterns tight to or into the bulrush or cattails is exciting and a real challenge when the trout decides to run even further into the forest!
Damselfly nymph emergences are best fished with floating, emerger tip or intermediate sinking lines. It’s important to try and imitate their swim up off the bottom of the shoal and then the migration high in the water column. A continuous hand twist or slow strip retrieve consisting of 4-to 6-inch long pulls, followed by regular short pauses, imitates the natural movement of these bugs. Often, actual damsels pause and slowly sink back down through the water column before getting back to the task at hand. It makes sense to position your fishing craft so that you are casting out and retrieving in the same direction that the nymphs are swimming. Better yet, one can anchor on the leading edge of a bulrush patch and cast right into the area where the real nymphs are swimming through. Make sure to tie on your nymphs with a non-slip loop knot, which adds lifelike movement to the fly.
Late fall is one of my favorite times of the stillwater fishing season. This is when the bigger fish school up and move into very skinny water to bulk up in preparation for a long, cold winter. In many clear-water lakes fall is all about sight fishing in the shallows. There are no insect hatches to rely on, so the trout go back on food sources that overwinter in the lake. This typically means scuds, leeches and juvenile damselfly, mayfly and dragonfly nymphs. I have noticed that in many nutrient-rich lakes damselfly nymphs make up a significant portion of the late fall diet. Often the damselfly nymphs are less than a half-inch long. For some reason big trout really search out the “baby” damsels. Overall, the most consistent way to catch these damsel feeding trout is to suspend patterns under an indicator. An indicator allows you to cast right up against or into openings amongst bulrush or cattail and present the fly within inches of bottom or at whatever depth you choose. A slight breeze blowing in the direction of your casts provides a subtle undulating motion that trout find hard to resist. However, there are days when the fish want more movement to the fly, so always try fishing the same patterns with a floating line and a 12-to 16-foot long leader. Casting into or parallel to the rushes or cattail stands, and retrieving the fly often gets the fish to chase after a fleeing food source. Think about your favorite stillwater fisheries—if they have abundant shoals and lots of emergent vegetation, there should be some good damselfly nymph fishing to be had at various times of the year.
Trout can get selective when feeding on the mature nymphs making their emergence migration swims. Realistic patterns that match the colouration of the real insect can make a difference between hooking the occasional fish or having a banner day. However, during the fall feeding time the nymphs can be more suggestive as long as the size is close to the real nymphs being eaten. There are many damselfly nymph patterns out there—some are extremely realistic and there is no question these patterns catch fish. Tying baby or juvenile damselfly nymphs can be as simple as using strung marabou fibers as this feather breathes and pulses when moved through the water. Here is the recipe for my Baby Damselfly Nymph.