American Wigeon (Anas americana) Science Article 1
Nine fairways of a golf course located in Bellingham, Washington were treated with diazinon AG500 at a target application rate of 2.2 kg active ingredient (Al) per ha. The chemical application with a ‘boomless’ sprayer resulted in a variable distribution of diazinon residues on the turf (associated with a deep thatch layer) that ranged from 1.0 to 6.2 kg Al/ha. The diazinon treated turf was irrigated with 1.3 cm of water immediately following application. The postirrigation diazinon residue levels ranged from 100 to 333 ppm (i = 209; SD = 88; n = 8). These residue levels were higher than expected based on results of turf studies in other regions of the United States. Eighty-five American wigeon (Anas americana) died after grazing on one treated fairway on the day of application following irrigation. The brains of all 85 wigeon were analyzed for acetylcholinesterase (AChE) activity.
. J. Kendall, L. W. Brewer, R. R. Hitchcock, and J. R. Mayer, Journal of Wildlife Diseases, 28(2), 1992. pp. 26.3-267