For the second year in a row, the number of monarch butteflies spending the winter in Mexican forests has declined, said Alejandro Del Mazo, Mexico’s commissioner for protected areas. The monarchs covered trees on 6 acres this year; in 1997, when a long-term decline began, they covered 44 acres, said the science news site Physorg.
Increased use of herbicides on U.S. crops has reduced the availability of milkweed, the food source of monarch caterpillars which eventually turn into the colorful butterflies. A variety of programs have been created to help the butterfly. Among them is the Monarch Butterfly Habitat Exchange, launched last week by the Environmental Defense Fund and Smithfield Foods, which pays landowners to create or preserve habitat for the insects.
The Interior Department is due to decide by June 2019 whether to list the monarch butterfly as an endangered species. The department’s Fish and Wildlife Service is conducting a so-called species status assessment of the butterfly.