Threats to Monarchs from Pesticides
Another persistent risk to monarchs comes from neonicotinoids, or neonics, a class of insecticides widely used in agriculture and landscaping. Monarchs near agricultural land are often exposed to neonics when crops are sprayed with this substance. While initially marketed as less harmful than other insecticides, neonics are now known for their devastating impacts on pollinators and beneficial insects. Research on bees reveals that neonics affect the brain and reproductive system, deplete their energy, and prevent them from expelling parasites.
In spite of their threat to wildlife, neonics use in the US has increased substantially in the US over the past 20 years. They have been banned in the European Union since 2018. While the US federal government has not restricted their sale, a number of states have moved independently to do so, including Colorado, Nevada, Maryland, Connecticut, Maine, Vermont, Massachusetts, New Jersey, New York, and Rhode Island.
California has passed a law that bans over-the-counter sales of lawn and garden neonicotinoid pesticides by 2025, limiting their use to trained professionals on land used for agriculture.
Pressure from consumers and conservation organizations has led some large retailers to label plants treated with neonics. If you buy plants at a nursery be sure to ask if any pesticides have been applied to the plants.
Neonics have contributed to the near extinction of almost 25% of California’s 1600 native bee species.
