An operational aerial application of parathion to sunflower fields resulted in greater or equal spray deposit in wetlands adjacent to or surrounded by sunflower fields than in the sunflower fields. In another application, when the applicator attempted to avoid contamination of the wetlands, parathion still drifted into wetlands in detectable amounts; in 2 of 4 comparisons, spray deposit in wetlands and sunflower fields did not differ. Weather during both spray operations was ideal for North Dakota, Le., wind speeds