A recent study published in the journal Science of Nature suggests that on Earth, spiders feed on 800 million tons of prey each year, twice as much as humans.
Uncomfortable with these numbers? The civic duty of our arachnids is however crucial. More than 90% of the spider’s diet consists of insects and springtails, which are part of a class of small pancrustacean arthropods. By devouring several hundred million tons of these tiny parasites each year, spiders play a vital role in maintaining ecosystems. They are shadow workers:
» Our calculations allow us to quantify for the first time the food ingested by spiders on a global scale to the point of considering them today as the main natural enemies of insects. “, explains the biologist Martin Nyffeler of the University of Basel in Switzerland who participated in the study. » Together with other insectivorous animals such as ants and birds, spiders help reduce insect population densities significantly, helping to maintain the ecological balance of nature. « .
With more than 45,000 listed species and a density of up to 1,000 individuals per square meter, spiders are among the most varied and widespread predators. Based on previous estimates based on different terrestrial biomes (including forests, grasslands, croplands, and other areas), the team estimated that there were around 25 million tons of spiders. all species on Earth. Taking into account the different densities of spider populations and based on their dietary requirements per unit body weight, the researchers calculated that spiders consume 800 million tons of prey each year. For comparison, humanity consumes 400 million tons of meat and fish per year. Cetaceans in the world’s seas engulf between 280 and 500 million tonnes of biomass each year.
» We hope that this estimate and its significant magnitude will help raise awareness of the important role spiders play in sustaining nature. “says the researcher who recalls that spiders, which turn out to be formidable predators, “ are themselves also on the menu, being the prey of thousands of other animals « .
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