Imidacloprid is one of the most used insecticides in the world. It is the active ingredient in agricultural, household and lawn and garden products. It is in the neonicotinoid class of insecticides, a systemic that acts as a neurotoxin in insects. It selectively targets insects while proving much less toxic to mammals, both humans and pets.
Neonicotinoids are a group of systemic pesticides that are taken up by a plant and transported to the tissue in all its parts: the leaves, roots, stems and flowers as well as the pollen and nectar. The pesticide is applied to plant roots in the form of a drench or seed coating, or sprayed on its foliage.
Trade names for insecticides containing imidacloprid include Gaucho, Admire, Merit, Advantage, Confidor, Premise and Winner. It is the active ingredient in many Bayer Advanced products.
Researchers have found imidacloprid persists in the soil ranging from 40 days in unimproved soil to 140 days in soil recently amended with organic fertilizer; in nonagricultural soil the time can range to almost three years.
Imidacloprid breaks down quickly in sunlight and sunlit water; however, at a much slower rate without light. In soil it binds with organic matter. The EPA warns against applying it in soils that are permeable and where leaching is high because of the potential for the insecticide to run off into surface water and leach into ground water.
In addition to lingering in the soil, imidacloprid is toxic to pollinators and, in particular, highly toxic to bees. The harm is certainly unintended, but data suggest that imidacloprid residue can accumulate in the pollen and nectar of treated plants, thereby exposing pollinators to the insecticide.
Researchers have found imidacloprid residue in nectar and pollens. Bees and other pollinators consume this residue in the nectar and pollen they feed on. It has been documented that imidacloprids can persist for months, even years, after it has been applied to the soil. Newly planted and untreated plants may absorb the chemical from soil treated the previous year.
Studies cite imidacloprid as a possible contributing factor to colony collapse disorder among honey bees. There is a growing consensus that low dose exposure to imidacloprid contributes to colonies’ inability to maintain a healthy immune response to bee parasites and diseases. Ongoing research shows links between pesticide exposure and decline in the bee population. Certainly we need more research to fill in the many knowledge gaps. In the meantime there is good reason to use imidacloprid with great care, if at all.
Be aware of other neonicotinoids in lawn and garden insecticides that should be used with care. They include clothianidin, thiamethoxam, acetamiprid, thiacloprid and dinotefuran. They are the active ingredient in some well-known brands like Ortho, Green Light and more.
We need pollinators for the reproduction of 90 percent of flowering plants and one third of human food crops.
Locally tomatoes, blueberries, melons and strawberries are among the crops that need native bees and honey bees for pollination. Bees pollinate approximately $10 billion worth of crops each year in the U.S.
As you know the number of honey bee and native bee pollinators has decreased in our environment. However, we can help bees and other pollinators thrive in our yards with pollinator friendly practices.
Limit the pesticides you use in your yard and garden. Practice IPM, Integrated Pest Management, and use pesticides only as a last resort to target an identified pest. Choose carefully. Apply only to a specific pest in a targeted area. Follow label instructions. Spray just after dawn when bees are not active.
Provide safe food by planting a pollinator friendly garden with flowers that bees feed on. (Remember: Bees are attracted to blue, purple and yellow flowers.)
Provide nesting spots and water. Leave some spots of bare ground for ground nesting bees. (70 percent of native bee species nest in the ground.) Add a nesting box. As possible, allow a tree snag to remain standing.
Add a little buzz to your yard. We can support our own need for food by helping the bees.
Reach DEBBIE MENCHEK, a Clemson Master Gardener, at firstname.lastname@example.org