Conservationists warn of monarch butterfly decline

Conservation experts this week announced that a record low number of monarch butterflies returned this year to wintering grounds in the mountains of Mexico and their annual migration is at “serious risk of disappearing.”

Monarchs, which migrate from Mexico across North America and back every year, have been in serious decline since the 1990s.

Experts believe the widespread use of glyphosate weed killer, sold as Round-Up, in connection with genetically engineered glyphosate-resistant corn and soybeans, may be destroying once-widespread milkweed, which monarchs rely on exclusively for reproduction.

“This news raises a disturbing question that can no longer be ignored: Are our actions causing the rapidly dwindling population of monarchs?” said Peter Lehner, executive director of the Natural Resources Defense Council. “We must urgently review the widespread use of glyphosate, which may be wiping out milkweed plants, essential for the Monarchs’ survival. It would be heartbreaking if we inadvertently destroyed in just a few years the millennia-old miracle of the Monarchs’ unique migration.”

The NRDC said Mexico estimated the winter population of monarchs at 33.5 million individuals. The estimate is a huge drop from a high of 1 billion in 1997 and down from a long-term average of 350 million over the last 15 years.

The decline also also epresents the ninth consecutive yearly measurement below the long-term average, according to the nonprofit enviromental group.