Speaker 1: Welcome to Brainstuff from How Stuff Works. Hey there, brain Stuff,
Speaker 1: Lauren Vogel. Bomb here. When you hear the word armageddon,
Speaker 1: you might imagine a battle thought at the end of
Speaker 1: the world by humans. But it's possible that battle is
Speaker 1: being fought right now. Only all the casualties are bugs.
Speaker 1: Insects are vitally important to the functioning of the world's ecosystems.
Speaker 1: They do most of the plant pollination, after all, while
Speaker 1: providing food for the bulk of the world's birds, amphibians, reptiles,
Speaker 1: and mammals. They're also essential in nutrient cycling, breaking down
Speaker 1: the world's dead stuff, manure, and what have you to
Speaker 1: make more dirt for us to grow our food in.
Speaker 1: Every ecosystem on the planet needs insects, which is why
Speaker 1: the apparent tanking of bug biomass is so alarming. Study
Speaker 1: published in October in the journal Plos one confirms the
Speaker 1: insect decline that many scientists and insect enthusiasts previously suspected,
Speaker 1: and it turns out their suspicions weren't just validated, but surpassed.
Speaker 1: In Germany, insect biomass is declined by roughly seventy percent
Speaker 1: over a little less than three decades. We spoke with
Speaker 1: co author Casper Hallman of the Institute for Water and
Speaker 1: Wetland Research at Radbound University in the Netherlands. In an email,
Speaker 1: he said declines in insects as a group have been
Speaker 1: suspected for quite some time, indirectly through declines in insectivorious birds,
Speaker 1: but around the globe only a few data sets exist
Speaker 1: to inform us, and these data are mainly concentrated around bees,
Speaker 1: butterflies and moths. Since a group of amateur entomologists in Kerfeld, Germany,
Speaker 1: has been collecting all kinds of insects from sixty three
Speaker 1: German nature reserves between spring and autumn each year, following
Speaker 1: a highly standardized sampling protocol. Over the years, they realized
Speaker 1: that the tent like traps specially designed to catch flying
Speaker 1: insects were yielding a smaller and smaller catch each year,
Speaker 1: even though every aspect of their sampling regime remained constant.
Speaker 1: Weighing the total biomass of the yearly hall over time
Speaker 1: allowed them to quantify it exactly how big a hit
Speaker 1: these flying insects have taken over the decades. They found
Speaker 1: an overall three quarters decline in insects when they looked
Speaker 1: at the entire collecting season, but in high summer, when
Speaker 1: insect numbers are at their highest, the decline was even
Speaker 1: more noticeable at These findings are of course specific to
Speaker 1: Germany and data are very scarce for nature preserves in
Speaker 1: other parts of the world, but the drop in insect
Speaker 1: populations is in no way limited to Germany. The study
Speaker 1: authors speculate that their study locations are representative of similar
Speaker 1: preserves around the world, and study published in the journal
Speaker 1: Science detailed the decline in worldwide populations. The reason it's
Speaker 1: important to compare these data to those taken from other
Speaker 1: protected areas has to do with the fact that agricultural
Speaker 1: or urban areas have relatively little to offer insects and
Speaker 1: are often outright toxic to them. Therefore, it's tough to
Speaker 1: note based on data from these areas whether insects are
Speaker 1: doing poorly in other places in the world, in habitats
Speaker 1: where they should be thriving. That said, general data sets
Speaker 1: on butterflies, moths, and most famously bees around the world
Speaker 1: mostly point in the same disabal direction. Additionally, the so
Speaker 1: called windshield phenomenon might not be data driven science, but
Speaker 1: it seems that all over the world in recent decades,
Speaker 1: people have been noticing fewer squashed bugs on their windshields
Speaker 1: than ever before. But what could be causing this more
Speaker 1: than decimation of Germany's insects. While the research team looked
Speaker 1: at whether changes in climatic conditions, the landscape, or the
Speaker 1: local habitat may have caused the decline, co author Hallman
Speaker 1: says they were unable to explain it based on these analyzes. Quote,
Speaker 1: Our best guess at this point are the negative influences
Speaker 1: of land use surrounding the nature reserves, particularly agricultural practices
Speaker 1: such as extensive use of pesticides and fertilizers, as well
Speaker 1: as over decline in habitat sustainability in between the reserves.
Speaker 1: But the effects of so many fewer insects can already
Speaker 1: be observed in the decline of birds in Germany. During
Speaker 1: the same time period, twelve million pairs of breeding birds
Speaker 1: have disappeared, and the same trend has been observed in
Speaker 1: other parts of Europe. So the next time you see
Speaker 1: a bug in your house, reconsider squashing it and maybe
Speaker 1: just escorted outside. It's kind of having a tough thirty
Speaker 1: years of it. Today's episode was written by Justlyin Shields
Speaker 1: and produced by Tristan McNeil. For more on this and
Speaker 1: lots of other depressing yet important topics, visit our home planet,
Speaker 1: how Stuff Works dot com