As reported in The New York Times last night, agricultural aviators in the U.S. west will spray thousands of square miles of land that is at risk of grasshopper infestation with the chemical Dimilin, which prevents insects from molting. As reporter Kirk Johnson notes, Dimilin is likely a better alternative than Malathion, which was widely used up until the 1980s.
But how much better is it? At least one study has reported acute toxicity to Dimilin among juvenile rainbow trout and salmon — not to mention its broad-spectrum effects on insects of all types. In fact, the first line of the state of Maryland’s product description warns potential users that Dimilin is a restricted use chemical “Due to toxicity in aquatic inverterbrates.”
(Thanks to reader David Dalu for the NYT link.)