A meta-analysis of 800 peer-reviewed reports out last week, suggests that seed treatments might be more harmful to pollinators and other insects than originally thought.
A specific class of pesticides, called neonicotinoids, are often applied to the outsides of seeds in order to protect them at early growth stages. Scientists with the international Task Force on Systemic Pesticides say the data indicates such pesticides, which are soluble in water so that the plant can absorb it, are killing off invertebrates, including pollinators.
At Iowa State University, Dr. Mary Harris with the Department of Entomology explains that treated seeds are rough on the exterior, and to keep them flowing through farm equipment during planting season, a dry lubricant like talc is usually added to them. Dust from the dry lubricant then travels into the air, and settles on plants just as pollinators are foraging for food after the winter.
Harris says it's not uncommon for producers to use treated seed preemptively, and questions whether that's the best path forward.
She says, "I would like to see us return to a scouting program where we know what we have in the field and if we don't need to apply, if we don't need to plant treated seeds, we don't. It would save cost on the seed treatment and it would save, it would retain the efficacy of this valuable insecticide."