New estimate doubles current estimates of insect biodiversity
A new estimate of insect diversity suggests there are at least 14 to 20 million species buzzing and crawling around the world.
It is double or triple other recent estimatesmost of which put the number at around 6 million species, researchers report June 29 in Proceedings of the National Academy of Sciences. Only about 1 million insects have been officially named and described.
Many insects are facing an “insect apocalypse.” The numbers are decrease For a myriad of reasons including pesticides, climate change, habitat destruction And light pollution. This new figure helps determine a basic approximation of how many different types of creepy crawlies exist on Earth, including many yet-to-be-discovered species that, like known species, could also be in trouble.
“It helps us understand how much we might lose,” says Laura Melissa Guzman, an entomologist and biodiversity scientist at Cornell University. “And that we must continue to study these insects to better protect them.”
Guzman and his colleagues analyzed the DNA of more than 1.6 million insects belonging to about 54,000 species captured in traps set in the Área de Conservación Guanacaste, a protected area and World Heritage site in northwestern Costa Rica. The region is a good place to start because it is well studied, Guzman says. Researchers have used traps and other methods to monitor insects in the region’s dry forest, rainforest and cloud forest ecosystems, from the ocean to the mountains, for more than 40 years.
The team focused on a subset of these insects: more than 11,000 specimens of parasitoid wasps spread across 388 species. Compared to charismatic and well-studied species like beetles, parasitoid wasps are diverse but massively understudied, Guzman says.
This wasp census allowed the team to leverage statistical methods to calculate how many species might have been missing, even among a large sample of more than a million insects. About 2,400 parasitoid wasps could inhabit the Guanacaste Conservation Area, along with more than 300,000 other insect species, the team concluded. From there, researchers increased their numbers to determine what might exist in the world.
Even the lower estimate of 14 million suggests there are millions of species left to discover. “It’s humbling how much we don’t know,” Guzman says. “And how much remains to be known.”