PITTSBURGHAmphibian populations living close to agricultural fields have become more resistant to a common insecticide and are actually resistant to multiple common insecticides, according to two recent studies conducted at the University of Pittsburgh.
In a study published today in Evolutionary Applications, the Pitt researchers demonstrate, for the first time, that tadpoles from populations close to farm fields are more resistant to chlorpyrifosone of the most commonly applied insecticides in the world, often sold as "Dursban" or "Lorsban." In addition, a related study published in February shows that tadpoles resistant to chlorpyrifos are also resistant to other insecticides.
"While we've made a lot of progress in understanding the ecological consequences to animals that are unintentionally exposed to insecticides, the evolutionary consequences are poorly understood," said study principal investigator Rick Relyea, Pitt professor of biological sciences and director of the University's Pymatuning Laboratory of Ecology. "Our study is the first to explore how amphibian populations might evolve to be resistant to insecticides when they live in places that have been sprayed for many years."
The Pitt researchers used newly hatched tadpoles collected from nine populations of wood frogs living at different distances from agricultural fields. They tested the frogs' resistance when exposed to chlorpyrifos, which is used against insects, and Roundup Original MAX, which is a common herbicide used against weeds.
Relyea and his Pitt collaborators exposed the tadpoles from each of the nine populations to environments containing either no pesticides, chlorpyrifos, or Roundup. After 48 hours, they measured how well the populations survived.
"Wood frogs living close to agricultural land were more likely to have been exposed to pesticides for many generations compared to those living far from agriculture; the latter fro
|Contact: B. Rose Huber|
University of Pittsburgh