Hatch Guide: Damselflies

Words by Brian Chan

We knew something was up on that cold, mid-November day, as my fishing partner and I drove up an increasingly snow covered road to Peterhope Lake. Not a tire track to be seen and certainly no evidence of anyone recently launching a boat. So, why would anyone want to fish with a good eight inches of snow on the ground and ice pushing out from the back bays of the lake? Because this situation was perfect—no competition, flat calm water, and a bright, sunny morning meant we could cruise the shallows and the edges of the longstem bulrush patches, searching for big rainbows.

It wasn’t long before we spotted dark shapes swimming slowly along the marl bottom, and other groups of fish disappearing into a maze of bulrush stems. Anchoring at the first good pod of bigger fish, we set up with floating lines and indicators and driftied suspended micro leeches and scuds, both go-to fall patterns. Every time I fish, the first trout to hand (as long as it's big enough) will get throat-pumped, no matter if caught during spring, summer, or fall. And our first this day was crammed with live, immature damselfly nymphs. A quick pattern switch made for an extremely productive morning bite.

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 adult. The nymphs undergo multiple molts, known as instar stages, as they grow from minute size to 1.5-inch long mature nymphs. Lush vegetation that covers a shoal or the shallow zones of a lake provide an abundant hunting ground for these carnivorous insects. Damsel 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 their habitat habitat and it’s not uncommon to have multiple colors of the same species of damselfly in the same lake or reservoir.

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, such as longstem bulrush, cattails and sedge grasses. The nymphs swim in a sinusoidal motion using their three-lobed caudal lamellae (tails), to propel them through the water. Once reaching the plant stalks, nymphs crawl out of the water to emerge. 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 of the lake. 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 or frenzied feeding periods occurs during the mature nymphal migration. Typical emergence occurs during the late spring and early summer season while water temperatures are 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 or cattail. During this migration the nymphs are fully exposed to trout that are 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 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, which provides an easy meal for trout that feed in water that is often less than four-feet deep. At other times aggressive trout roll around or onto bulrush stems to purposely knock these damsels into the water. This is an amazing sight that leaves one scrambling to tie on an adult pattern. Fishing patterns tight to, or even into, the bulrush or cattails is exciting, but a real challenge when the trout decides to run even further into the forest.

Damselfly nymph emergence swims are best fished with floating, emerger-tip, or intermediate sinking lines. It’s important to imitate the damsel nymph’s swim off the bottom of a shoal and the migration high in the water column. A continuous hand twist or slow, strip retrieve consisting of four-to six-inch long pulls, followed by regular short pauses, imitates the natural movement of these bugs. Often, these insects 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 you cast out and retrieve 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 your nymphs on with a non-slip loop knot to add more lifelike movement to the fly.

I like to fish damsels whenever I can, but the late fall timeframe might be my favorite. This is when bigger fish school up and move into very skinny water to bulk up for winter. In many lakes fall is all about sight fishing in the shallows. There are no insect hatches to rely on so the trout go back to food sources that overwinter in the lake. This typically means scuds, leeches and juvenile damselfly, mayfly and dragonfly nymphs. In nutrient-rich lakes damselfly nymphs make up a significant portion of that late fall diet. Often the damselfly nymphs are less than half-inch in long. For some reason big trout really search out these “baby” damsels. 

Overall, the most consistent way to catch trout on damsels is to suspend patterns under an indicator. An indicator allows you to cast right up against or into openings in the bulrush or cattails and present a fly at whatever depth you choose. A slight breeze blowing in the direction of your casts gives your fly a subtle, undulating motion that trout rarely resist. However, there are days when the fish want the fly moving faster, so always try fishing the same patterns with a floating line and a 12-to 16 feet long leader. Casting into or parallel to the rushes or cattail stands and retrieving at a desired pace often get the fish to chase what they believe to be a fleeing food source. Think about your favorite stillwater fisheries--if they have abundant shoals and lots of emergent vegetation there's some good damselfly nymph fishing to be had . . . at various times of the year. So, enjoy the spring migraton, but don't forget about baby damsels in fall, right when all those big trout are packing on weight for winter.

Trout get selective on mature damsel nymphs during that insect’s emergence migration swims. Realistic patterns that match the coloration of the real insect can make a difference between hooking the occasional fish or having a banner day. However, during fall feeding time, nymphs can be more suggestive as long as the size of your fly matches the actual insect. There are many damselfly nymph patterns to choose from. Some are extremely realistic and there is no question these patterns catch fish. Tying your own 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.