Salting roads in winter can tweak the physiques of butterflies the next summer.Text from Science News, with a tip of the hat to reader Bradley Ruben for bringing it to my attention. Photo from our yard.
Milkweeds and oaks, plants that caterpillars graze on, collected from alongside a country road carried higher sodium concentrations than the same species growing at least 100 meters from the splash and drift of deicing salt, says Emilie Snell-Rood of the University of Minnesota in St. Paul.
Monarch (Danaus plexippus) caterpillars raised on the sodium-boosted plants turned into males with extra thoracic muscles and females with bigger eyes and probably bigger brains than butterflies reared on the more distant foliage, Snell-Rood and her colleagues found.
A different butterfly, the cabbage white, echoed these his-and-hers effects when reared on a sodium-boosted lab diet, researchers report June 9 in the Proceedings of the National Academy of Sciences.
So is road salt good for butterflies? “I do not want that to be the take-home message,” Snell-Rood says. Instead, she says, the study demonstrates for the first time that road salt can alter how animals develop physically.
Related: The double-edged sword of salting roads in winter, and Cheese brine for icy roads.