They include the general loss of open spaces that mean fewer flowers and leaves for them to eat, as well as changing agricultural practices that have reduced the number of butterfly-friendly plants along the edges of crop fields. The growing use of pesticides by farmers and home gardeners probably plays a role. So does climate change, which produces higher temperatures that can dry plants out and make them inedible.

Source: Los Angeles Times March 12, 2019 22:41 UTC