Federal researchers have added new evidence to the growing case that agricultural pesticides blowing into California’s wilderness areas have played a role in mysterious declines in frog populations.
Traces of the common pesticides Diazinon and chlorpyrifos showed up in more than half the Pacific tree frogs sampled in Yosemite National Park, but in only 9 percent of the frogs tested at sites upwind of agricultural areas, report U.S.