Neonicotinoids, or "neonics" for short, are neurotoxic pesticides that kill insects by blocking nerve impulses, causing lethal paralysis. Neonics are used on dozens of crops and are the most widely used insecticides in the world. Neonics may be applied to plant seeds, the soil, or sprayed directly onto foliage. As systemic insecticides, neonics are absorbed through the roots or the leaves, and move throughout plant tissue, contaminating pollen and nectar.
Neonics are highly persistent, and remain present in plant tissues long after applied. Research also shows neonicotinoids can persist in the soil several years after the last application, affecting plants that were not the original targets. The consumption of neonics dissolved in pollen or nectar is one way bees can be exposed to neonicotinoids. Bees may also be exposed by direct contact with sprayed plants before the pesticide has been absorbed. Although bees have received most of the attention, they are not the only species group potentially harmed by neonics. A single corn kernel coated with a neonicotinoid is toxic enough to kill a songbird.
Although ingestion or contact with neonics can kill bees directly at high enough doses, smaller doses can cause “sub-lethal” impacts. In honey bees these include problems with flying and navigation, reduced taste sensitivity, and slower learning of new tasks, which all impact foraging ability. Bumble bees exposed to sublethal amounts of neonicotinoids exhibit reduced food consumption, reproduction, worker survival rates, and foraging activity.
Neonicotinoids are found in hundreds of products sold over the counter under various trade names. Many of these are designed for individual home and garden use. One of the most toxic neonicotinoids to our native bees – imidacloprid - is commonly applied to gardens, flowerbeds, shrubs, and trees in urban and residential areas. Neonicotinoids are also applied on a broader scale by farmers producing crops and ornamental plants.
Declining pollinator populations have been documented across the world, posing a real threat to crop production and to the integrity of native ecosystems. Although there are multiple drivers of this phenomenon, including habitat loss and pathogens, systemic insecticides are recognized as key factor in pollinator decline. A taskforce convened by the International Union for Conservation of Nature (IUCN) reviewed over 800 published studies on systemic insecticides, concluding that neonicotonoids "are causing significant damage to a wide range of beneficial invertebrate species and are a key factor in the decline of bees." The report also noted that neonicotinoids are present in the environment “at levels that are known to cause lethal and sub-lethal effects on a wide range of terrestrial (including soil) and aquatic microorganisms, invertebrates, and vertebrates.”
Pollinators matter. They are worth protecting. Let's take the needed steps to save them.
How You Can Help
Ensure your garden isn't harming the very bees you attract! See our list of nurseries that have pledged not to supply neonic-treated plants and help us scout out more neonic-free nurseries.