Entomologists call it the windshield phenomenon. "If you talk
to people, they have a gut feeling. They remember how insects used to
smash on your windscreen," says Wolfgang Wägele, director of the Leibniz
Institute for Animal Biodiversity in Bonn, Germany. Today, drivers
spend less time scraping and scrubbing. "I'm a very data-driven person,"
says Scott Black, executive director of the Xerces Society for
Invertebrate Conservation in Portland, Oregon. "But it is a visceral
reaction when you realize you don't see that mess anymore."
Some people argue that cars today are more aerodynamic and therefore
less deadly to insects. But Black says his pride and joy as a teenager
in Nebraska was his 1969 Ford Mustang Mach 1—with some pretty sleek
lines. "I used to have to wash my car all the time. It was always
covered with insects." Lately, Martin Sorg, an entomologist here, has
seen the opposite: "I drive a Land Rover, with the aerodynamics of a
refrigerator, and these days it stays clean."
Though observations about splattered bugs aren't scientific, few
reliable data exist on the fate of important insect species. Scientists
have tracked alarming declines in domesticated honey bees, monarch
butterflies, and lightning bugs. But few have paid attention to the
moths, hover flies, beetles, and countless other insects that buzz and
flitter through the warm months. "We have a pretty good track record of
ignoring most noncharismatic species," which most insects are, says Joe
Nocera, an ecologist at the University of New Brunswick in Canada.
Of the scant records that do exist, many come from amateur
naturalists, whether butterfly collectors or bird watchers. Now, a new
set of long-term data is coming to light, this time from a dedicated
group of mostly amateur entomologists who have tracked insect abundance
at more than 100 nature reserves in western Europe since the 1980s.
Over that time the group, the Krefeld Entomological Society, has seen
the yearly insect catches fluctuate, as expected. But in 2013 they
spotted something alarming. When they returned to one of their earliest
trapping sites from 1989, the total mass of their catch had fallen by
nearly 80%. Perhaps it was a particularly bad year, they thought, so
they set up the traps again in 2014. The numbers were just as low.
Through more direct comparisons, the group—which had preserved thousands
of samples over 3 decades—found dramatic declines across more than a
dozen other sites.
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