Diazinon Dissipation from Vegetation, Occurrence in Earthworms, and Presence in Avian Gastrointestinal Tracts Collected from Apple Orchards Following D-Z-N super( registered ) 50W Application

Avian exposure to diazinon was examined in 1989 in apple orchards in Washington State and Pennsylvania. Data were derived on diazinon application rates, and vegetation samples were collected and examined for diazinon residues. In addition, the accumulation of diazinon by earthworms and diazinon presence in the gastrointestinal tracts of birds were determined. The data revealed that diazinon concentrations were highest in apple leaves, but residues of the pesticide were found in all areas of the orchards. Consistently high diazinon concentrations were found in earthworms, with mean residue concentrations of 10.54 and 0.39 mu g/g in worms in Pennsylvania and Washington State, respectively. Diazinon was present in the gastrointestinal tracts of 24 of 25 birds examined, covering 19 different species. Highest concentrations were found during the study in Canada geese, killdeer, and American robins.