I love Fireflies
I really want to see them.. but...
Why Are Fireflies Disappearing??
Nobody knows for sure. But most researchers blame two main
factors: development and light pollution.
Most species of fireflies thrive as larvae in rotting wood
and forest litter at the margins of ponds and streams. And as they grow, they
more or less stay where they were born. Some species are more aquatic than
others, and a few are found in more arid areas—but most are found in fields,
forests and marshes. Their environment of choice is warm, humid and near
standing water of some kind—ponds, streams and rivers, or even shallow
depressions that retain water longer than the surrounding ground.
The problem is that in America and throughout the world, our
open fields and forests are being paved over, and our waterways are seeing more
development and noisy boat traffic. As their habitat disappears under housing
and commercial developments, firefly numbers dwindle. Logging, pollution and
increased use of pesticides may also contribute to destroying firefly habitat
and natural prey.
Human traffic is believed to disrupt firefly habitat as
well. While scientific studies have only been done for the past few years, there’s
plenty of anecdotal evidence in areas that were once full of fireflies—and much
of it goes back generations. Some areas once had so many fireflies that they
profited from running firefly tours in marshes and forests—but since human
traffic has increased, firefly populations have gone down.
Too Much Light At Night
Scientists don’t know enough about fireflies to tell for
sure. But the signs are indicating light pollution as a major factor in the
disappearance of fireflies all over the world.
Both male and female fireflies use their flashing lights to
communicate. Some species synchronize their flashes, sometimes across large
groups of thousands of insects. All species speak a language of
light—scientists believe they use it to attract mates, defend their territory,
and warn off predators.
Human light pollution is believed to interrupt firefly flash
patterns. Scientists have observed that synchronous fireflies get out of synch
for a few minutes after a car’s headlights pass. Light from homes, cars,
stores, and streetlights may all make it difficult for fireflies to signal each
other during mating—meaning fewer firefly larvae are born next season.
Where fireflies once had uninterrupted forests and fields to
live and mate, homes with landscaped lawns and lots of exterior lights are
taking over. The reduction of habitat and the increase in lighting at night may
all be contributing to make fireflies more rare.
Fireflies are fascinating creatures that light up our nights
and bring a sense of magic and mystery to our environment. If they disappear,
it will be a great loss to habitats and generations of people all over the
world.
Help me...
Turn off outside lights at night.
Fireflies use their flashing lights to signal each other,
attract mates and warn of danger. While the science is still preliminary, it’s
likely that human light pollution can disrupt their flashes—making it harder
for fireflies to find mates and breed. This leads to fewer fireflies mating and
smaller numbers in subsequent generations. You can make your yard a haven for
fireflies by turning off exterior and garden lights, and drawing your blinds at
night so that interior light doesn’t brighten your yard too much.
Let logs and litter accumulate.
Some species of firefly larvae grow up in rotten logs and
the litter that accumulates beneath the forest canopy. To encourage their
growth, plant some trees on your property. If you have trees in your yard,
consider leaving some natural litter around them to give firefly larvae a place
to grow.
Create water features in your landscape.
Most species of fireflies have one thing in common: they
thrive around standing water and marshy areas. Ponds, streams and rivers can
all provide good habitats for fireflies, but even a small depression full of
water can cause them to congregate. Build a small pond or divert a small stream
to run through your property, and it’s more likely you’ll see fireflies at
night. Chemically treated swimming pools aren’t a good substitute; fireflies
are believed to eat the smaller insects, grubs and snails that thrive in
natural ponds and streams, and these don’t live in chlorinated environments.
Avoid use of pesticides.
It’s likely that chemical pesticides and weed killers may
also have a negative effect on firefly populations. Fireflies and their larvae
may come into contact with other insects that have been poisoned, or they may
ingest the poisons from plants that have been sprayed. Avoid using pesticides on
your lawn and you may boost firefly populations.
A notable example of how overspraying has affected a local
population is the extinction of the dusky seaside sparrow who was native to the
salt marshes of Merritt Island in Florida. Its habitat was sprayed with DDT to
control mosquitoes and human development quickly changed the ecosystem so much
that the bird could not compensate and went extinct.
Many communities over spray for mosquitoes at night just
when fireflies are active, flashing and mating. Such over spraying can wipe out
firefly populations. These same communities often do not implement more
effective control of mosquitoes, such as neighborhood programs to reduce
standing water, especially in swimming pools, and usage of mosquito larvacides
to prevent the growth and development of mosquitoes in drainage ditches. By
encouraging broad spectrum mosquito control efforts and discouraging spraying
at times when fireflies are active, communities can actually save money and
effect better control of mosquitoes, causing less impact to firefly species and
other small animals.
Use natural fertilizers.
While no conclusive studies have been done, it’s possible
that chemical fertilizers may have a harmful effect on firefly populations as
well—especially since many harmful chemicals in pesticides are also found in
chemical fertilizers. Using natural fertilizers may make your yard a more
healthy place for fireflies.
Don’t over-mow your lawn.
Fireflies mainly stay on the ground during the day, and
frequent mowing may disturb local firefly populations. While you may feel that
you need to keep your lawn mowed for aesthetic purposes, consider incorporating
some areas of long grasses into your landscaping. Fireflies prefer to live in
long grasses, and doing this may boost their population in your yard.
Plant trees.
Fast growing pine and native trees provide a good habitat
for many species of fireflies. Naturalist Terry Lynch, who has studied fireflies
for many years, recommends Pine trees because they provide shade and the low
light area provided by a canopy actually increasing the amount of time
fireflies have to find a mate. Also, the litter produced by pine trees, if left
to accumulate, provides a good habitat for earthworms and other small animals
which firefly larvae feed upon.
Do NOT introduce earthworms to you yard.
What’s so bad about a worm? For many of us, seeing
earthworms under rocks, on sidewalks after rainstorms, and in our gardens is just
a fact of life. Few of us think to question the presence of worms or their
impact on fireflies.
The truth about earthworms is this: they are not native to
any of the northern United States or Canada. Any worms that were here
originally were wiped out during the last glaciation. It would be pretty hard
for a creature that lives in the upper topsoil to survive the crushing weight,
scraping, and sedimentary deposits of a mile-thick hunk of ice.
The impact of earthworms is not limited to plants. The
reduction in plant diversity and leaf litter affects the habitat and food
availability of insects such as fireflies, which affects the food chain on up,
reducing the food available to reptiles, amphibians, birds and small mammals.
The earthworms we currently have in the region are of
European origin (which are the same species that you can pick up at a bait
shop) and were introduced by settlers ~300 years ago and have been on a human
aided journey west since then. These non-native earthworms are contributing to some
ecological effects in these glaciated areas that for the last ~12,000 years
developed earthworms free. There are native earthworms along the East coast of
North America but these populations are small and localized. Current research
in that area is showing that these non-native earthworms are having negative
effects on native earthworm species also.
Talk to your neighbors.
If you live in a suburban area in close proximity to others,
what you do in your own yard will help—but you can create even more habitat for
fireflies by enlisting your neighbors in your efforts. Tell your neighbors
about your concern over dwindling firefly populations and what they can do to
help. If you convince even one or two people on your street, you could help
increase firefly habitat in your area even more.
Fireflies are disappearing all over the world. But there are
a few things you could do to help—and every little bit counts. Allow some room
for wildness on your property—low-hanging trees, forest litter, and long
grasses all create welcoming environments for fireflies. Ponds and streams are
crucial to firefly populations, and you can further encourage their numbers by
reducing the amount of light in your yard at night and by cutting back on
chemical fertilizers and pesticides. Follow these tips, and it’s possible you
could see a resurgence of fireflies in your area.
