"Monarch population in the US has drastically declined to 90%, which is below its 20-year average, say environmental and food-safety groups. The population has reduced from 1 billion in the mid-1990s to around 35 million in 2013. The groups have asked the Fish and Wildlife Service to provide endangered species protection to the monarch butterfly.
The petitioners have blamed Monsanto Co.'s Roundup herbicide and Roundup Ready crops for the decline. Due to the increased planting of genetically engineered crops in the Midwest, where a majority of monarchs are born, a decline has been seen in the butterfly's population."
http://www.frenchtribune.com/teneur/1423548-provide-endangered-species-protection-monarch-butterflies