The group of international scientists from the United States and Canada has discovered that over the past 25 years, the number of butterflies in the United States has decreased by 22%. According to experts, important insects disappeared by a catastrophic speed. The research was published in the Journal of Science.
The team conducted the first national system analysis of the number of butterflies. It turned out that the number of these organisms in 48 states of the country decreased by an average of 1.3% per year from the beginning of the 21st century, while 114 species showed a significant decline in their population and only nine species increased their quantity.
The largest reduction of the observed number is found in the southwest of the United States (Arizona, New Mexico, Texas, Oklahoma), where more than 20 years, the butterfly population has decreased more than half.
According to the researchers, insect decline is due to the use of agricultural pesticides, climate change and losing their habitats.
Among the most alarming examples, scientists have identified the monarch butterfly, with the number from 1997 to 2022 decreased 120 times from 1.2 million to less than 10 thousand individuals.
According to the authors of the report, the situation can be saved by restoring the habitat, reducing the use of pesticides and creating favorable conditions for butterflies at local levels.