The loss of milkweed plants due to extensive herbicide use and changes in farming practices, such as the widespread adoption of herbicide - resistant crops, has been identified as a major contributing factor of monarch's decline in the eastern U.S. Disease, climate change, widespread insecticide use, and loss or degradation of nectar - rich habitat may also be contributing to declines. (xerces.org)
Monarchs rely on milkweed plants for laying their eggs and providing food for their young. (news.wsu.edu)
In corn production, for example, maintaining a few villainous milkweed plants in the middle of a cornfield may help minimize crop loss from the destructive European corn borer. (sciencedaily.com)