Data from: Planting of neonicotinoid-treated maize poses risks for honey bees and other non-target organisms over a wide area without consistent crop yield benefit

Neonicotinoid insecticides are routinely used as seed treatments on most
grain and oilseed crops in the USA, yet the extent and likelihood of
spread of insecticide residues during planting has not previously been
quantified. Honey bees, Apis mellifera, are highly mobile and highly
sensitive to neonicotinoid residues, presenting an opportunity to estimate
non-target exposures to neonicotinoids in mobile insects. We measured
neonicotinoid dust drift during maize sowing and used sites of maize
fields, apiary locations and honey bee foraging radii to estimate
likelihood of forager exposure. We performed a concurrent multi-year field
assessment of the pest management benefits of neonicotinoid-treated maize.
Our results indicate that over 94% of honey bee foragers throughout the
state of Indiana are at risk of exposure to varying levels of
neonicotinoid insecticides, including lethal levels, during sowing of
maize. We documented no benefit of the insecticidal seed treatments for
crop yield during the study. Synthesis and applications. We demonstrate
movement of neonicotinoid residues well beyond planted fields occurs
during maize sowing in Indiana. Based on locations of maize fields and
apiaries in the state, the likelihood of neonicotinoid exposure for
foraging honey bees is high. Other non-target organisms are also likely to
encounter neonicotinoid residues; we conservatively estimate that
deposition of neonicotinoid residues on non-target lands and waterways
will occur on over 42% of the state of Indiana during the period of maize
sowing. However, we also demonstrate that the risk to pollinators and
other non-target organisms may be rapidly and dramatically reduced without
yield penalties, by aligning use rates of neonicotinoid insecticides with
pest incidence.