A U.S. study suggests the common insecticide malathion can decimate tadpole populations, killing them indirectly at doses too small to kill them directly. University of Pittsburgh researchers wanted to determine the environmental impact of the use of malathion — the most popular insecticide in the United States. The scientists discovered gradual amounts of malathion that were too small to directly kill developing leopard frog tadpoles instead sparked a biological chain of events that deprived them of their primary food source — bottom dwelling algae, or periphyton, which tadpoles eat. "As a result, nearly half the tadpoles in the experiment did not reach maturity and would have died in nature," the researchers said.

Study: Insecticide decimates tadpoles