BrainStuff Classics: Are We in an Insect Armageddon?

A study found that bug biomass has been steadily -- and in some places, dramatically -- decreasing. Learn what may be to blame and what this could this mean for the future in today's classic episode of BrainStuff.

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Episode Transcript

Speaker 1 (00:01):
Welcome to brain Stuff production of I Heart Radio. Hey
brain Stuff, Lauren vogel Bomb here with a classic episode
from our podcast archives. In this one, we consider research
into the decline of insect populations around the world and
what that might mean for the future. Hey there, brain Stuff,

(00:22):
Lauren vogel Bomb here. When you hear the word armageddon,
you might imagine a battle thought at the end of
the world by humans. But it's possible that battle is
being fought right now. Only all the casualties are bugs.
Insects are vitally important to the functioning of the world's ecosystems.
They do most of the plant pollination, after all, while
providing food for the bulk of the world's birds, amphibians, reptiles,

(00:45):
and mammals. They're also essential in nutrient cycling, breaking down
the world's dead stuff, manure, and what have you to
make more dirt for us to grow our food in.
Every ecosystem on the planet needs insects, which is why
the apparent tanking of bug biomass is so alarming. A
study published in October seventeen in the journal Plos one

(01:05):
confirms the insect decline that many scientists and insect enthusiasts
previously suspected, and it turns out their suspicions weren't just validated,
but surpassed. In Germany, insect biomass is declined by roughly
seventy percent over a little less than three decades. We
spoke with co author Casper Hallman of the Institute for
Water and Wetland Research at Radbound University in the Netherlands.

(01:28):
In an email, he said declines in insects as a
group have been suspected for quite some time, indirectly through
declines in insect vorious birds, but around the globe only
a few data sets exist to inform us, and these
data are mainly concentrated around bees, butterflies and moths. Since
a group of amateur entomologists in Kerfeld, Germany, has been

(01:49):
collecting all kinds of insects from sixty three German nature
reserves between spring and autumn each year, following a highly
standardized sampling protocol. Over the years, realized that the tent
like traps specially designed to catch flying insects were yielding
a smaller and smaller catch each year, even though every
aspect of their sampling regime remained constant. Weighing the total

(02:11):
biomass of the yearly hall over time allowed them to
quantify exactly how big a hit these flying insects have
taken over the decades. They found an overall three quarters
decline in insects when they looked at the entire collecting season,
but in high summer, when insect numbers are at their highest,
the decline was even more noticeable. At These findings are
of course specific to Germany, and data are very scarce

(02:34):
for nature preserves in other parts of the world, but
the drop in insect populations is in no way limited
to Germany. The study authors speculate that their study locations
are representative of similar preserves around the world, and study
published in the journal Science detailed the decline in worldwide populations.
The reason it's important to compare these data to those
taken from other protected areas has to do with the

(02:57):
fact that agricultural or urban areas have relative little to
offer insects and are often outright toxic to them. Therefore,
it's tough to note based on data from these areas
whether insects are doing poorly in other places in the world,
in habitats where they should be thriving. That said, general
data sets on butterflies, moths, and most famously bees around
the world mostly point in the same dismal direction. Additionally,

(03:21):
the so called windshield phenomenon might not be data driven science,
but it seems that all over the world in recent
decades people have been noticing fewer squashed bugs on their
windshields than ever before. But what could be causing this
more than decimation of Germany's insects. While the research team
looked at whether changes in climatic conditions, the landscape or
the local habitat may have caused the decline, co author

(03:43):
Hallman says they were unable to explain it based on
these analyzes. Quote, Our best guests at this point are
the negative influences of land use surrounding the nature reserves,
particularly agricultural practices such as extensive use of pesticides and fertilizers,
as well as over decline in habitats sustainability in between
the reserves. But the effects of so many fewer insects

(04:04):
can already be observed in the decline of birds in Germany.
During the same time period, twelve million pairs of breeding
birds have disappeared, and the same trend has been observed
in other parts of Europe. So the next time you
see a bug in your house, reconsider squashing it and
maybe just escorted outside. It's kind of having a tough
thirty years of it. Today's episode was written by Jesselyn

(04:28):
Shields and produced by Tristan McNeil and Tyler. Playing. For
more than this and lots of other topics, visit how
stuff works dot com. Brain Stuff is production of iHeart Radio.
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