In recent months a debate over whether a global insect apocalypse is underway has raged in the mainstream media and among researchers. To assess the range of scientific opinion, Mongabay interviewed 24 entomologists and other scientists working on six continents, in more than a dozen countries, to better determine what we know, what we don’t, and, most importantly, what we should do about it.
This is part two of a four-part exclusive series by Mongabay senior contributor Jeremy Hance. Read Part I, “A global look at a deepening crisis” here.
Tyson Wepprich, a postdoctoral research associate at Oregon State University, was only supposed to be looking at the presence or absence of butterfly species in Ohio. But news of insect decline, in blockbuster studies from Germany and Puerto Rico, changed his plans. His team is now also looking hard at overall abundance — and the early results aren’t good.
“The trends are similar to those in long-term European butterfly monitoring where abundance, summed across all species, is declining at around 2 percent per year,” he says of the team’s unpublished work, and “about twice as many species are declining rather than increasing.”
Wepprich’s ongoing research is just another sign that something may be seriously amiss with the world’s insects — something some entomologists have privately suspected, but which they are only now beginning to prove and publish about.
“I used to think of conservation as policies to save rare species from extinction,” Wepprich says, but adds he now believes conserving abundance must also be a part of any successful environmental strategy.
A “typical malaise [trap] catch in the good old days” before insect decline swept Western Europe, as described by researcher Hans de Kroon. Malaise traps are the typical traps used to capture insects over time. Image by the Entomological Society Krefeld.
Insects: A conservation black hole
Despite the fact that arthropods make up most of the species on Earth, and much of the planet’s biomass, they are significantly understudied compared to mammals, plants, birds, amphibians, reptiles, fish and much else.
The IUCN Red List, for example, has assessed just 8,131 insect species regarding their extinction risk,