New research links neonicotinoid pesticides to monarch butterfly declines
By Jonathan Latham, PhD
USDA researchers have identified the neonicotinoid insecticide clothianidin as a likely contributor to monarch butterfly declines in North America. The USDA research is published in the journal Science of Nature and was published online on April 3rd (Pecenka and Lundgren 2015).
Monarch butterfly populations (Danaus Plexippus) have declined precipitously in North America in the last twenty years. This decline has commonly been linked to loss of milkweeds (Asclepias species) from farmer’s fields. Monarch caterpillars are dependent on milkweeds. The ability of farmers to kill them with the Monsanto herbicide Roundup (glyphosate) has therefore led to this herbicide being considered as a major contributor to the decline of the monarch butterfly.