HATCH GUIDE:
Damselflies
By Brian Chan
We knew something was up as my fishing
partner and I drove up the increasingly snow
covered road to Peterhope Lake on a mid-
November day. 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 sit-uation 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,
reaching 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 the maze
of bulrush stems. Anchoring at the first good
pod of bigger fish, we set up with floating lines
and indicators and started suspending and wind
drifting micro leeches and scuds, both go-to fall
patterns. The first fish landed in my boat, as long
as it is big enough, will get throat pumped. And our
first this day was crammed with still 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 the adult. The
nymphs undergo multiple molts, or instar stages,
as they grow from minute size to 1.5-inch long
mature nymphs. Lush vegetation that covers a shoal
or 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 am-
bush specialists. Nymphs are adept at matching
their body coloration to the habitat they are in, and
it’s 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 that found in midges and caddis. The
fully developed damselfly nymph leaves the protec-
tion of their benthic habitat and swims to patches of
emergent vegetation like longstem bulrush, cat-tails
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 and 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
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