Weizmann Institute of Science researcher: 'Arthropods have been described as "the little things that run the world" because of their central role'

Weizmann Institute of Science researchers have found that arthropods are just as important to the environment as humans and farm animals as they have a biomass of about one billion tons, according to a recent study led by Professor Ron Milo.

The researchers calculated the total collective weight of terrestrial arthropods through data gathered from thousands of observations from 500 survey sites around the world, according to the study published on the Israeli-based institute’s website. The study showed that arthropods are critical in the ecological processes, and if they were gone, it would be catastrophic. Arthropods are virtually found everywhere including on our bodies and in our food. They pollinate crops, turn over soils and sustain a large amount of different types of predators that that feed on them.

“Arthropods have been described as ‘the little things that run the world’ because of their central role in multiple ecological processes. We must take them into account if we’re to fully understand humanity’s impact on the planet and the possible consequences of climate change,” Dr. Yuval Rosenberg said. Rosenberg led the study in Professor Milo’s lab located at Weizmann’s Plant and Environmental Sciences Department along with Dr. Yinon Bar-On.

Though tiny, arthropods have a far-reaching impact that impacts the future.

“Quantifying arthropod populations establishes a baseline against which we can measure future changes to the arthropod communities and how these changes, in turn, could affect global processes," Rosenberg said.

Arthropods' biomass also belongs to creatures living underground that include springtails and mites, according to the study. These are responsible for fertilizing soil and critical to underground ecology. They prey on other organisms as well. The estimate is that there are 10 quintillion arthropods living underground.

The study also revealed that social insects that live in colonies account for half of the mass of arthropods found underground. Termites and ants are 40% and 10% of this. Arthropods located aboveground have the most biomass found in tropical forests and include butterflies, ants, spiders, beetles and grasshoppers.

“The health of our ecological systems depends to a great extent on the condition of arthropod populations,” Milo said. “They are a massive force when it comes to regulating vegetation. Thousands of species of birds, reptiles and amphibians depend on them for food and, ultimately, arthropods help break up and recycle dead plants and animals, as well as their excrement.”

Participants in the study included Weizmann Institute of Science’s Plant and Environmental Sciences Department members Amir Fromm, Meital Ostikar, Aviv Shoshany and Omer Giz. They hope to promote what Rosenberg called a "holistic, quantitative understanding” of how arthropods contribute to the ecology worldwide.