The insect life above earth suffers as a result of the introduction of earthworms to northern North America. Bug abundance, biomass, as well as species richness were all shown to be affected by this. According to their findings, changes in insect populations may have underlying reasons that have hitherto gone unnoticed.
Northern North America has had essentially no earthworms at all after the previous ice period ended roughly 10,000 years ago. It’s possible that soil and crop transfer from Europe have brought them to the United States in recent decades. In the intervening years, they have scattered and altered the soil ecology dramatically. Many scientists have yet to explore what effect this invasion has had upon human life on Earth.
The research was carried out in a forest in Calgary, Alberta, Canada, where worms are either present or absent. Bug vacuum samplers were employed to collect terrestrial insects, and the scientists analyzed the captures. A considerable difference was found between regions that had intrusive earthworms and those that did not, in terms of insect population, biomass, as well as species diversity. There was a 61% reduction in insect populations, a 27% reduction in bug biomass, and an 18% reduction in biodiversity in areas with the greatest earthworm organic matter.
Insects, on the other hand, seem to be affected by the earthworms in ways that are yet unknown. If earthworms are eating the nourishment, it’s probable that beetles & fly larvae may have a harder time decomposing dead plant matter because of the reduced habitats.
As the bulk of bugs is herbivores, a possible explanation for the documented drop in insects might be that soil characteristics have changed, resulting in a shift in the flora. Plant diversity or distribution did not change much in this instance, according to the scientists.
Future earthworm types are improbable to have the same harmful impacts on natural ecosystems in Europe, where they have traditionally co-evolved with earthworms.
The study was published in Biology Letters.