A new study by zoologists from the University of Basel and Lund University in Sweden revealed that spiders play a crucial role in maintaining ecological balance by munching astronomical number of insects on a global scale.
The study, published in the journal the Science of Nature, showed that spiders remain of the most important predators of insects, killing up to 800 million tons of preys every year.
"Our calculations let us quantify for the first time on a global scale that spiders are major natural enemies of insects. In concert with other insectivorous animals such as ants and birds, they help to reduce the population densities of insects significantly," said lead author Martin Nyffeler, from the University of Basel, in a press release. "Spiders thus make an essential contribution to maintaining the ecological balance of nature,"
For the study, the researchers used two calculations based on different models. Their calculations consistently showed that the global spider population, weighing about 25 million tons, consumes around 400 to 800 million tons of prey each year.
Among the astronomical amount of prey, insects and springtails remain the top snack for the spiders, accounting for over 90 percent of their annual prey consumption, Other spiders, especially large tropical spiders, sometimes feast on small vertebrates, such as snakes, frogs, lizards, bats and fishes.
The researchers also found that spiders living forest and grassland kill more insects than their counterparts in desert regions, Arctic tundra and agricultural areas.
The eating habits of spiders can be compared to that of humans that consumes around 400 million tons of fish and meat every year On the other hand, whales in the world's oceans devour about 280 to 500 million tons of prey annually,
Spiders are considered to be one of the world's most species-rich and widespread groups of predators. At present, there are over 45,000 species of spiders. These eight-legged creeps have a population density of up to 1,000 individuals per square meter.