Pesticide triggers a food chain cascade.

When it comes to pesticides’ effects on frogs, sublethal concentrations do not preclude lethality. That’s the conclusion of a new study published in the October issue of the journal Ecological Applications. After dosing wood frogs and leopard frogs with very small concentrations of the popular pesticide malathion, the researchers discovered that the chemical did not kill the frogs directly—instead, they died from the indirect effects of the pesticide on tiny zooplankton and the entire food chain. With amphibian populations declining around the globe, and pesticides implicated as one of the many causes, this study suggests the need to further investigate the indirect effects of these chemicals on ecosystems.