PARIS: Half of the million species of animals and plants on Earth that face extinction are insects, and their disappearance could be catastrophic for humanity, scientists said in a “warning to humanity.”
“The current insect extinction crisis is deeply worrisome,” said Pedro Cardoso, a biologist at the Museum of Natural History in Finland and lead author of a review study published on Monday.
“However, what we know is just the tip of the iceberg,” he told AFP.
The disappearance of insects that fly, crawl, dig, jump and walk on water is part of a mass extinction event, only the sixth in the last 500 million years.
The last one was 66 million years ago, when a wandering space rock annihilated terrestrial dinosaurs and most other life forms.
This time we are to blame.
“Human activity is responsible for almost all decreases and extinctions of the insect population,” Cardoso told AFP.
The main drivers are habitat decline and degradation, followed by pollutants, especially insecticides, and invasive species.
Excessive exploitation: more than 2,000 species of insects are part of the human diet, and climate change is also wreaking havoc.
The decline in butterflies, beetles, ants, bees, wasps, flies, crickets and dragonflies has consequences far beyond their own disappearance.
“With the extinction of insects, we lose much more than species,” Cardoso said.
“Many species of insects are vital providers of services that are irreplaceable,” including pollination, the nutrient cycle and pest control.
‘Critical points’ of biodiversity
These “ecosystem services” are worth $ 57 billion (52 billion euros) per year in the United States alone, according to previous research.
Globally, crops that require insect pollination have an economic value of at least $ 235-577 billion annually, according to the UN biodiversity scientific panel, known as IPBES.
Many animals depend on abundant insects to survive.
A sharp drop in the number of birds in Europe and the United States, for example, has been linked to the collapse of insect populations decimated by the use of pesticides.
Scientists estimate the number of insect species at approximately 5.5 million. Only a fifth of them have been identified and named.
“The number of threatened and extinct insect species is unfortunately underestimated because many are rare or not described,” Cardoso said.
The Red List of Endangered Species of the International Union for Conservation of Nature (IUCN) has evaluated only about 8,400 million species of insects that are known to exist.
Between 5 and 10 percent of all insect species have disappeared since the industrial era began about 200 years ago.
Half of the native species of plants and vertebrates are found exclusively in about three dozen “critical points” of biodiversity that cover 2.5 percent of the earth’s surface.
“These critical points probably harbor a similar percentage of endemic insect species,” said the study entitled “Scientists’ warning to mankind about insect extinction,” published in Conservation Biology.
A quarter of a century ago, conservation scientists issued a “Warning to Humanity” about the collapse of Nature. In 2017, they issued a second warning, signed by 15,000 scientists.
The new study, entitled “Scientists warning humanity about insect extinction,” was published in the journal Conservation Biology.