Dibrom

The insecticide being used is Dibrom, which officials say is Environmental Protection Agency approved and routinely used to combat mosquito-borne disease.

Sold as Dibrom, naled is an organophosphate, a category of chemicals that also includes malathion; both are widely used to control mosquitoes.

Beekeepers should cover their hives during the application of the Dibrom.

The similarly effective Dibrom continues to be used effectively outside the Delta, where mosquitoes have not developed a resistance to organophosphates.

That liberal use of that class of pesticide inadvertently lent mosquitoes a resistance to what elsewhere has proved to be the most effective weapon against them: a chemical known as Dibrom.