The Silence of the Bugs
By Curt Stager
Curt Stager is a professor of natural sciences at Paul Smith’s College and the author, most recently, of “Still Waters: The Secret World of Lakes.”
Fifty-six years after Rachel Carson’s
“Silent Spring”
warned of bird die-offs from pesticides, a new
study published
last fall documented a 76 percent
decline in the
total seasonal biomass of flying insects netted at
63 locations in Germany over the last three
decades.
Losses in midsummer, when these insects
are most numerous, exceeded 80 percent.
“Silent Spring”
warned of bird die-offs from pesticides, a new
study published
last fall documented a 76 percent
decline in the
total seasonal biomass of flying insects netted at
63 locations in Germany over the last three
decades.
Losses in midsummer, when these insects
are most numerous, exceeded 80 percent.
This alarming discovery, made by mostly amateur
naturalists who make up the volunteer-run
Entomological Society Krefeld, raised an obvious
question: Was this happening elsewhere?
Unfortunately, that question is hard to answer
because of another problem: a global decline of
field naturalists who study these phenomena.
because of another problem: a global decline of
field naturalists who study these phenomena.
Most scientists today live in cities and have little
direct experience with wild plants and animals, and
most biology textbooks now focus more on
molecules, cells and internal anatomy than on the
diversity and habits of species. It has even become
fashionable among some educators to belittle the
teaching of natural history and scientific facts that
can be “regurgitated” on tests in favor of
theoretical
concepts.
direct experience with wild plants and animals, and
most biology textbooks now focus more on
molecules, cells and internal anatomy than on the
diversity and habits of species. It has even become
fashionable among some educators to belittle the
teaching of natural history and scientific facts that
can be “regurgitated” on tests in favor of
theoretical
concepts.
That attitude may work for armchair physics or
mathematics, but it isn’t enough for understanding
complex organisms and ecosystems in the real
world.
Computer models and equations are of little use
without details from the field to test them against.
Are we in the midst of a global insect Armageddon
that most of us have failed to notice? Here’s
another
data point: A decades-long decline in plant-
pollinating hawk moths has been reported in the
Northeast, but its causes and consequences are
uncertain because we know so little about the
ecology of these insects. In days past, compiling
such information would have made a respectable
life’s work for a Linnaeus, Humboldt or Darwin.
Now such creatures are often ignored because
studying them seems unlikely to generate
publications, headlines or grants that provide
academics with tenure and prestige.
that most of us have failed to notice? Here’s
another
data point: A decades-long decline in plant-
pollinating hawk moths has been reported in the
Northeast, but its causes and consequences are
uncertain because we know so little about the
ecology of these insects. In days past, compiling
such information would have made a respectable
life’s work for a Linnaeus, Humboldt or Darwin.
Now such creatures are often ignored because
studying them seems unlikely to generate
publications, headlines or grants that provide
academics with tenure and prestige.
This leaves us with little more than anecdotal
evidence to work with. A recent story in The
Telegraph noted that automobile windscreens
in Britain are no longer heavily caked with
splattered insects. It reminded me of the tiny
wings, legs and antennas that used to smear the
front of my car after midsummer drives during
the 1970s. Nowadays, a drive through northern
New York, where I live, yields barely a blemish.
Is it because cars are more streamlined? Not
likely. Last July, I examined parked vehicles in
Saranac Lake and found little or no bug debris,
even on license plates or the blunt fronts of vans.
evidence to work with. A recent story in The
Telegraph noted that automobile windscreens
in Britain are no longer heavily caked with
splattered insects. It reminded me of the tiny
wings, legs and antennas that used to smear the
front of my car after midsummer drives during
the 1970s. Nowadays, a drive through northern
New York, where I live, yields barely a blemish.
Is it because cars are more streamlined? Not
likely. Last July, I examined parked vehicles in
Saranac Lake and found little or no bug debris,
even on license plates or the blunt fronts of vans.
What’s behind the decline? Probably not climate
change, according to the researchers in the
German
study who also monitored local weather during
the
survey. What about collisions with vehicles?
Despite my experience and the dashboard
observations in Britain, one study published in
2015 estimated that hundreds of billions of
insects
are being killed in North America by cars and
trucks every year. The study’s authors called for
additional research to determine whether what
they found is “contributing to the substantial
declines of pollinating insects occurring on a
global scale, thus putting the ecological
functioning of natural areas and agricultural
productivity in jeopardy.”
Cars were probably not the culprit in the
German study, though, because it focused
on nature reserves where road carnage is
minimal. For some experts, the process of
elimination leaves pesticides among the likely
suspects.
German study, though, because it focused
on nature reserves where road carnage is
minimal. For some experts, the process of
elimination leaves pesticides among the likely
suspects.
Rachel Carson quote on the use of pesticides
and their negative impact on living creatures
Why care about this new silence of the bugs? An
across-the-board decline in flying insects, if true,
means that an entire sector of the animal kingdom
is in trouble, representing an immense diversity
of life-forms, from butterflies and beetles to
hoverflies and damselflies. The eminent biologist
Edward O. Wilson, who has spent much of his
life studying ants, has warned: “If all mankind
were to disappear, the world would regenerate
back to the rich state of equilibrium that existed
ten thousand years ago. If insects were to vanish,
the environment would collapse into chaos.”
So there it is. Could it be that whatever might be
causing these insect deaths could be a threat to us
too?
causing these insect deaths could be a threat to us
too?
The widely reported decline of honeybees in the
United States pales in comparison with the
drop-off of bugs in Germany, if not in scale, then
in the loss of biodiversity. Insects represent the
vast majority of all animal species. Because they
are pollinators and a vital part of the food chain,
their absence would strike deep at the roots of life
on earth.
United States pales in comparison with the
drop-off of bugs in Germany, if not in scale, then
in the loss of biodiversity. Insects represent the
vast majority of all animal species. Because they
are pollinators and a vital part of the food chain,
their absence would strike deep at the roots of life
on earth.
I’m a lake scientist, and my colleagues and I have
been struggling to explain our own mystery: a
restructuring of plankton communities in lakes
worldwide in recent decades, which we’ve
documented by examining sediment cores extracted
from lake bottoms. This could signal problems for
water quality, fisheries or other aspects of lake
ecology. Had we not taken the core samples, the
geographic scale of this change might remain
undetected, because funding and rigorous field
monitoring of plankton composition in lakes has
often been lacking.
Some experts have attributed the plankton shift to
climate change, others to nitrogen pollution from
agricultural runoff, but we need more long-term
field studies to confirm the cause and anticipate
its effects. The German insect data suggest
another possibility. Could agricultural chemicals
be poisoning aquatic organisms, including
plankton and insects that begin their lives as
aquatic larvae? We simply don’t know.
climate change, others to nitrogen pollution from
agricultural runoff, but we need more long-term
field studies to confirm the cause and anticipate
its effects. The German insect data suggest
another possibility. Could agricultural chemicals
be poisoning aquatic organisms, including
plankton and insects that begin their lives as
aquatic larvae? We simply don’t know.
In Britain, the news report about car-insect
collisions was based on a study that relied on data
from volunteers who monitored gridlike
“splat-o-meters” on their license plates. We need
more of this sort of scientist-directed
crowdsourcing. Citizen scientists and a few
field-research-oriented college communities
like my own at Paul Smith’s College in the
Adirondacks of New York are turning their yards,
gardens, lakes and forests into long-term monitoring
stations. Online clearinghouses like iNaturalist,
Budburst and the North American Breeding Bird
Survey compile and archive field data for others
to use, and show that many species are changing
their ranges and migration habits in response to
climate change.
DDT truck
coming around every Spring and Summer
and spraying the neighborhood for mosquitoes
In the United States, research scientists associated
with a network of more than two dozen long-term
ecological monitoring centers have also been
conducting more detailed field research for several
decades. But these efforts are still not enough to
keep track of a rapidly changing world. We need
new crops of professionals trained in field biology
and ecology to focus on important but less
charismatic or commercially valued creatures
than songbirds and honeybees.
In 1996, an editorial in Conservation Biology
warned that “naturalists are dying off,” and asked:
“Will the next generation of conservation
biologists be nothing but a bunch of computer
nerds with no firsthand knowledge of natural
history?”
Two decades later, we are beginning to realize
how lucky we are that dedicated expert and
amateur naturalists remain to observe and record
the distinctive flash of a firefly or the soft
clatter of dragonfly wings. But we need more
of them, and soon.
how lucky we are that dedicated expert and
amateur naturalists remain to observe and record
the distinctive flash of a firefly or the soft
clatter of dragonfly wings. But we need more
of them, and soon.
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