Insect decline is being driven by losses among the locally more common species, according to a new study published in Nature.
Insect decline is being driven by losses among the locally more common species, according to a new study published in Nature. Led by researchers at the German Centre for Integrative Biodiversity Research (iDiv) and the Martin Luther University Halle-Wittenberg (MLU), the meta-analysis of 923 locations around the world notes two significant trends: 1) the species with the most individuals (the highest abundance) are disproportionately decreasing in number, and 2) no other species have increased to the high numbers previously seen. This likely explains the frequent observation that there are fewer insects around now than ten, twenty, or thirty years ago.
Researchers at iDiv looked at long-term trends of land-based insects, such as beetles, moths, and grasshoppers, and found that decreases in the number of the formerly most common species have contributed most to local insect declines. Common or abundant insect species are those species that are locally found in the highest numbers, but which species these are differ among locations. The study’s findings challenge the idea that changes in insect biodiversity result from rarer species disappearing.
The study follows the recent sounding of alarm bells about insect loss, as researchers note dramatic declines in the total number of insects in many parts of the world. However, little is known about the general trends among locally rare and abundant species over long periods. “It was obvious this needed exploring,” says Dr Roel van Klink, lead author of the study and senior scientist at iDiv and MLU. “We had to know whether observations about declines in total abundances of insects differed among common and rare species, and how this translated into changes in the overall insect diversity.”
Read more at German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig
Photo Credit: simardfrancois via Pixabay
