Potential exposure of honey bees to neonicotinoid seed treatments in US rice.

This article focuses on the presence and levels of neonicotinoid insecticide residues in rice (Oryza sativa) tissues and the associated exposure risk to honey bees (Apis mellifera) in rice production systems in Arkansas and Mississippi. The study found that thiamethoxam and clothianidin, two neonicotinoids used as seed treatments and foliar sprays for controlling rice water weevil (Lissorhoptrus oryzophilus), were infrequently detected in rice flag leaves, pollen, and grain, with residues generally higher in flag leaves than in pollen or grain. Honey bee foraging activity in rice fields was low, with more bees observed during mid-day than morning or evening, and the overall low frequency of neonicotinoid residues in pollen suggests limited risk to managed honey bees from these insecticide applications in rice. The findings indicate that current insecticide seed treatments and foliar sprays targeting rice water weevil pose minimal exposure risk to honey bees in commercial rice production.