An less beat of wings, a more fragile ecosystem. The butterfliesicons of beauty and lightness, they are disappearing from the United States at a worrying pace. A study published on March 6 on Science reveals a 22% decrease since 2000with some species in decline up to 50%. The phenomenon, attributed to insecticides, climate change and loss of habitatscould have disastrous consequences not only for biodiversity, but also for the balance of the entire planet.
A worrying decline
The analysis, conducted by the ecologist Collin B. Edwards And colleagues, it is the largest ever built on the US territory. The researchers combined data from 35 programs in Citizen Scienceanalyzing over 12.6 million butterflies surveyed in 76,000 investigations. The result is alarming: between 2000 and 2020, the total abundance of butterflies decreased by 22% of 554 species analyzed.
Data from About 76,000 Butterfly Surveys conducted by Various Groups Showed That Their Numbers Dropped by 22% from 2000 to 2020 in The Opiguous United States. Scientist ACTRUSTED The Decrease to Habitat Loss, Pesticide Use and Climate Change https://t.co/yttckz6qlt pic.twitter.com/1u1zhenera
– Reuters Science News (@reuterscience) March 7, 2025
The declines proved to be spread throughout the territory of the United States, with two thirds of the species that have recorded falling drops to 10%. Even more worrying is the ratio between the decreasing species and the increase: for each species that grows, there are 13 that decrease. Second Nick Haddadentomologist of the Michigan State University And co -author of the study, “we see no signs of slowdown”.
The causes of the decline
Three main factors are contributing to the disappearance of butterflies:
The most affected areas are those of South-west of the United Stateswhere the number of butterflies has decreased by more than half in the last 20 years.
A signal for nature (and for man)
Butterflies are not just fascinating creatures: they are environmental health indicators. Their decline suggests that other pollinating insects, fundamental for agricultural production, could also be at risk. “The butterflies warn us that our ecosystem is in danger,” he explains Anurag Agrawal, Evolutionist ecologist of the Cornell University. “Their loss is a signal that the health of our planet is worsening.”
Not everything is lost. Scientists point out that there are solutions to reverse the trend. Here are some actions that can make the difference:
Haddad concludes with a message of hope: “Each of us can do something, even just planting flowers in your garden. Small gestures can have a great impact ”.
