title: Insecticide residues in pollen and nectar of a cucurbit crop and their potential exposure to pollinators.
abstract: Neonicotinoids are systemic insecticides widely used on many pollinated agricultural crops, and increasing evidence indicates that they move to some extent into pollen and nectar. This study measured levels of neonicotinoid residues in pollen and nectar from a pumpkin crop treated with formulated products containing imidacloprid, dinotefuran, and thiamethoxam using different timings and application methods. Environmental conditions have a significant effect on overall residue levels; nectar residues were 73.5-88.8% less than pollen residues, and metabolites accounted for 15.5-27.2% of the total residue amounts. Foliar-applied treatments and chemigated insecticides applied through drip irrigation during flowering resulted in the highest residues of parent insecticide and metabolites, which may reach average levels up to 122 ng/g in pollen and 17.6 ng/g in nectar. The lowest levels of residues were detected in treatment regimens involving applications of insecticides at planting, as either seed dressing, bedding tray drench, or transplant water treatment.
authors.affiliation: Department of Entomology, University of Maryland, College Park, Maryland 20740, United States.
authors.forename: Galen P
authors.initials: GP
authors.lastname: Dively
authors.forename: Alaa
authors.initials: A
authors.lastname: Kamel
mesh_terms: D000691:Anabasine / Q000009:adverse effects / Q000031:analogs & derivatives / Q000032:analysis; D000818:Animals; D001516:Bees / Q000187:drug effects*; D028464:Cucurbita / Q000737:chemistry*; D005506:Food Contamination; D005638:Fruit / Q000737:chemistry*; D007306:Insecticides / Q000008:administration & dosage / Q000009:adverse effects / Q000032:analysis*; D008396:Maryland; D008954:Models, Biological; D010573:Pesticide Residues / Q000009:adverse effects / Q000032:analysis*; D057048:Plant Nectar / Q000009:adverse effects / Q000737:chemistry*; D011058:Pollen / Q000009:adverse effects / Q000737:chemistry*; D054817:Pollination
chemical_list: D007306:Insecticides; D010573:Pesticide Residues; D057048:Plant Nectar; D000691:Anabasine