US Butterfly Numbers Down By 1/3 Over Past Two Decades, Mirroring European Decline

[hatrack]

Butterfly numbers have dropped by one third in the last two decades in the US, echoing declines seen in Europe. These figures raise alarm bells for the health of other insect populations, because butterflies face similar environmental changes and are used as a proxy for studying insects in general. Much of what we currently know about declining insect populations comes from European monitoring programmes.

To find out if similar patterns were occurring in the US, Tyson Wepprich of Oregon State University and his colleagues turned to volunteers at the Ohio Lepidopterists, who have been collecting weekly data on butterfly sightings across the state over the last two decades.

“We analysed their data to estimate trends for 81 species over this time and found that many more are declining than increasing,” says Wepprich. “Overall, the number of butterflies you’d expect to see has fallen by 33%, or at a rate of 2% per year.”
Heading north

As temperatures increased, Wepprich and his team found that species from the south moved north into Ohio and were growing in number, while the number of northern species shrunk. “Insects are very sensitive to temperature, and these changes in some species suggest that they are responding to ongoing climate change,” says Wepprich.

EDIT

https://www.newscientist.com/article/2209171-butterfly-numbers-fell-by-one-third-in-the-us-over-last-two-decades/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=news

[Farmer-Rick]

1. It's more than just temperature increases

If I was just temperature increase you would just see increases in cooler areas and decreases in warmer areas. It would be a wash if the disappearing butterflies were moving into cooler areas.

As they note it's destruction of habitat. Now do we go back to paying a little to farmers for Not planting areas? The US Ag depts use to do that. It allowed small farmers to leave certain areas unplanted, uncultivated, and it served as habitat for all sorts of wildlife. We subsidize huge 1,000 acre farms right now. They plant all of it. There are no longer any strips left uncultivated for wildlife habitat. Yes, we paid farmers Not to farm. But it helped.

And then of course we have Round Up and deadly pesticides that we allow to be dumped on our food such as wheat, soy, corn, sugar beets and rice. And it's not just poured on once. Once a week a poisonous chemical is poured on all our food from almonds to grapes, strawberries to eggplants. All those chemicals are killing off our beneficial insects.