Scientists have warned of an ‘insect apocalypse’ in recent years, given the sharp decline in particular regions, particularly in Europe. A new study suggests that these warnings have been exaggerated and are largely not representative of what is happening to insects.
Georgia University of Agroecology professor Bill Snyder sought to find out if the so-called “insect apocalypse” was actually going to happen, and if so, it had already begun. Some scientists say that all insects can occur only 30 years before extinction, so this is a very important and timely question for agriculture and conservation.
Snyder and a team of researchers from UGA, Hendrix College, and the US Department of Agriculture used more than 5,300 data points for pests and other arthropods at surveillance sites representing 68 natural and managed areas, more than 68 natural and Managed areas were represented. Fall throughout the United States.
Some groups and sites showed an increase or decrease in abundance and diversity, but many remained unchanged, with net abundance and biodiversity trends generally unchanging from zero. This decrease of overall growth or decline was consistent with arthropod feeding groups, and was relatively similar to heavy disturbances at natural sites. These results were recently published Nature Ecology and Development.
The idea for the study began last year with a cross-country road trip from Snyder in Washington State to their new home in Georgia.
“I had the same observation with a lot of people. We had our drive across the country — you don’t see many pests on your car or windshield.”
When he went to his home in Bishop of Georgia, it seemed like a different story.
“I noticed that the light outside was filled with insects, as much as I remember as a child,” he said. “People have this perception – it seems [there are] Less bugs – but what evidence? ”
There is some alarming evidence that European honey bees have a problem, but Snyder was curious if insects are in decline everywhere. “We depend on insects for so many things,” he said. “If the insects disappear then it would be really, really bad. Probably the end of human existence.”
He was discussing the topic with Matthew Moran, another biologist and friend at Hendrix College, and recalled the US National Science Foundation’s network of long-term ecological research (LTER) sites, which were established in 1980 and monitored 25 A network of locations was included. In each of the major regions of the country.
The LTER data of NSF are publicly available, but have not previously been gathered in a single dataset to examine evidence of widespread scale density and biodiversity changes through time.
Arthropod data sampled by the team included grasshoppers in the Conza prairie in Kansas; Ground arthropods in the Seviletta desert / meadow in New Mexico; Mosquito larvae in Baltimore, Maryland; Macrointegrate and crayfish in North Temperate Lakes in Wisconsin; Aphids in the Midwestern US; Crab burials in Georgia coastal ecosystems; Tick at Harvard One in Massachusetts; Caterpillar at Hubbard Brook in New Hampshire; Arthropods in Phoenix, Arizona; And stream insects in the Arctic in Alaska.
The team compared the samples with human footprint index data, including several factors such as pesticides, light pollution, and the built environment to see if there were any overall trends.
“No matter what factor we looked at, nothing could explain the trends satisfactorily,” said Michael Crossley, a postdoctoral researcher at the UGA department, the study’s UMO department and lead author. “We just took all the data and when you look, there are as many things as going down. Even when we broke it down into functional groups, there wasn’t really a clear story like that of hunters Decreasing or increasing vegetarian people. ”
“This is an implication for conservation and for scientists, who are calling for more data due to under-sampling in certain areas or certain insects. We have taken the opportunity to use this wealth of data that has just Has not been used until, ”explained Crossley, an agricultural entomologist who uses molecular and geospatial tools to understand insect ecology and evolution and improve management outcomes. “There should be even more data sets that we don’t even know about. We want to continue the canvas to get a better idea of what’s going on.”
Good and bad news
To answer Snyder’s broader question, “Are there overall declines?” No, according to the study. “But we’re not going to ignore the small changes,” Snyder said. “It is worthwhile to distinguish between the two issues.”
In particular the pest species that we rely on for major ecosystem services of pollination, natural pest control and decomposition remain unaltered for degradation in North America, the authors note.
In Europe, where studies have seen dramatic insect declines, according to Snyder, insects may have a larger, longer-term effect than the US, which has a lower population density.
“Taking deep breaths is not the worst thing in the world,” Snyder said. “There have been a lot of environmental policies and changes. Many of the pesticides used in agriculture are now doing narrow work. Some of those effects look like they are working.”
When it comes to conservation, there is always room for everyone to pitch in and do their part.
“It’s hard to tell when you’re a single homeowner, you make an impact when you plant more flowers in your garden,” he said. “Maybe some of these things that we are doing are starting to have a beneficial effect. It could be a hopeful message that the things people are doing to protect bees, butterflies and other insects Really working. ”
Insect apocalypse? Not so fast, at least in North America
Michael S. Crosley et al, US Long Term Ecological Research Sites Has No Pure Pest Abundance and Diversity, Nature Ecology and Development (2020). DOI: 10.1038 / s41559-020-1269-4
Provided by the University of Georgia
Quotes: ‘Pest Apocalypse’ Cannot Happen in America (2020, August 11) Retrieved August 12, 2020, from https://phys.org/news/2020-08-insect-apocalypse.html
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