title: Pesticides and honey bees: nectar and pollen contamination in alfalfa treated with dimethoate.
abstract: Medicago sativa L. (Leguminosae) sprayed with O,O-dimethyl S-(N-methylcarbamoylmethyl) phosphorodithioate (dimethoate) had only 0.5 ppm of dimethoate in pollen one day later, but 3 ppm in nectar one week later, and 1 ppm in nectar two weeks later. As little as 1 ppm added to syrup fed to caged workers of Apis mellifera L. (Apidae) inhibited cholinesterase and reduced survival. Bees given a choice between treated and untreated syrups showed no preference; this suggests that the levels of dimethoate found in nectar are toxic and not repellent.
mesh_terms: D000818:Animals; D001516:Bees / Q000378:metabolism*; D002802:Cholinesterases / Q000378:metabolism; D004117:Dimethoate / Q000032:analysis* / Q000633:toxicity; D004326:Drinking; D004355:Drug Stability; D006722:Honey / Q000032:analysis; D000455:Medicago sativa / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis*; D011058:Pollen / Q000032:analysis*
chemical_list: D010573:Pesticide Residues; D002802:Cholinesterases; D004117:Dimethoate