Public-health officials know that the insecticides that kill mosquitoes, in order to prevent Zika and other diseases, also are fatal to honeybees, butterflies and imperiled species, says Ensia in describing an emerging interest in minimizing environmental harm. “We’re just at the beginning stages, trying to figure out what we need to focus on,” said Patricia Bright, senior science adviser for the U.S. Geological Survey.
An estimated 2.5 million bees were killed in South Carolina this summer by an aerial spraying campaign against mosquitoes that might spread Zika. Tests by the U.S. Fish and Wildlife Service in recent years said the pesticides used against mosquitoes also are highly toxic to butterflies and caterpillars.
In the short run, experts suggest that insecticides be sprayed less often and only at dawn or dusk, when butterflies are not foraging. And they say there may be little value in spraying large areas outside of towns. Under development are genetically modified mosquitoes to stop the insects from multiplying, and agents that use bacteria or growth-regulating substances to stop mosquito reproduction. “One thing is clear,” says Ensia, “community action will become more important,” with precautions such as making sure the backyard is not mosquito habitat.