When Susan Weller traveled to Ecuador to study tiger moths in the 1980s, she found plenty of insects. A decade later, Weller, now director of the University of Nebraska State Museum, returned to conduct follow-up research. But the moths she was looking for were gone.
“Just in that time frame, areas I had collected had been transformed. Forests had been taken out. … brand new cities had sprung up. I tried to go back and collect from other historic collecting sites, and those sites no longer existed. They were parking lots,” she says.
Around the globe, scientists are getting hints that all is not well in the world of insects. Increasingly, reports are trickling in of unsettling changes in populations of not only butterflies and bees, but of far less charismatic bugs and beetles as well. Most recently, a research team from the US and Mexico reported a startling decline between 1976 and 2013 in the weight of insects and other arthropods collected at select sites in Puerto Rico.
Some have called the apparent trend an insect Armageddon. Although the picture is not in crisp enough focus yet to say if that’s hyperbolic, enough is clear to compel many to call for full-scale efforts to learn more and act as appropriate.
“I would say the insect decline in biomass and diversity is real because we see things repeated across different sites across different groups,” says Weller. “But is it an Armageddon? That part is more difficult to tease out.”
“We do know we have some declines, some very worrisome declines,” echoes David Wagner, professor of ecology and evolutionary biology at the University of Connecticut and author of a chapter on insect biodiversity trends in the 2018 Encyclopedia of the Anthropocene. “The bigger question is, ‘Why?’” he says. “And that’s so very important. You can’t fix something until you understand what the problem…