Factors influencing the toxicity of Headline® fungicides to terrestrial stage toads.

Amphibians are susceptible to exposure from contaminants via multiple pathways. Pyraclostrobin fungicides have been shown to be toxic to terrestrial amphibians at environmentally relevant concentrations; however, these studies did not account for factors that may influence exposure and effects, such as fungicide formulation, age of the individual, exposure route, and physiological state of the individual. We examined Headline® and Headline AMP® fungicide toxicity to adult Anaxyrus cognatus and Anaxyrus woodhousii by direct overspray, as well as acute toxicity of Headline AMP to juvenile A.

Occurrence of current-use fungicides and bifenthrin in Rainwater Basin wetlands.

Wetlands in the Rainwater Basin (RWB) of Nebraska are commonly in close proximity to or embedded within row-crop agriculture. Several fungicides and bifenthrin are applied aerially to corn throughout the RWB during tassel stage. Thus, aerial spray drift and runoff may result in pesticide contamination of wetlands.

Terrestrial exposure and effects of Headline AMP(®) Fungicide on amphibians.

Recent studies have demonstrated that a pyraclostrobin-containing fungicide (Headline(®) Fungicide--Headline(®) Fungicide and Headline AMP(®) Fungicide are registered trademarks of BASF) is toxic to amphibians at environmentally relevant concentrations. However, these studies were performed in a laboratory setting of a worst-case direct exposure in clean media. Interception of spray by the crop canopy and ground cover used by animals for security cover will influence exposure.