In some parts of the world, insects are disappearing at a rate of one to two percent every year. What does this mean? Areas of severe decline could lose as much as a third of all their insects in two decades.
This news is one part of a special package of 12 studies in Monday’s Proceedings of the National Academies of Sciences written by 56 scientists from around the globe.
We’re already seeing “death by a thousand cuts,” says David Wagner, a University of Connecticut entomologist and author of one of 12 reports on what some describe as the “insect apocalypse.” And those “cuts” include climate change, insecticides and herbicides, human population growth, light pollution, invasive species, and deforestation, reports CBC Canada.
PNAS Special Issue
The collection of papers in the special issue delves into everything from how the public perceives news of insect declines to evaluating the geographic, ecological, sociological, and taxonomic perspectives of relevant threats.
It is a big undertaking and some authors liken the issue of declining numbers to trying to put together a jigsaw puzzle. Scientists still don’t have all the answers so they have trouble grasping its enormity and complexity and getting the world to notice and do something.
And this presents an interesting conundrum because researchers aren’t equipped with enough data to say that the rate of loss is greater than with other species. The world has “spent the last 30 years spending billions of dollars finding new ways to kill insects and mere pennies working to preserve them,” says University of Delaware entomologist Doug Tallamy.
Insects – the fabric of the Tree of Life
Even though many people “hate bugs,” insects play a vital role in pollination and natural decomposition, while also being essential to the food chain. Insects “are absolutely the fabric by which Mother Nature and the tree of life are built,” Wagner said.
Matthew Forister, an insect ecologist at the University of Nevada, Reno, who also contributed to the report, says, “But it’s clear insects have a possibility to rebound. It’s grim, but it’s not too late.” As an example, Forister, who studies butterflies in the western U.S., points to two species representing very different situations.
For 30 years, the public has been aware of the decline in honeybees and Monarch butterflies, and there have been efforts initiated to increase that awareness. The gulf fritillary, generally found in southern portions of the U.S., Mexico, and Central America is now flourishing in California because people there cultivate its host, the passion vine, a popular ornamental plant.
However, populations of the large marble butterfly, which thrives on invasive mustard plants, crashed, likely due to a triple whammy of climate change, habitat loss, and pesticides.
It goes without saying that a multitude of issues, including deforestation and loss of forests by wildfires, drought, and extreme weather events are impacting insects, just as they impact other species. The PNAS special edition aims to use scientifically grounded assessments of insect population trends while suggesting specific actions that may help insect populations and species survive.
