- The chemical concerns some, but an official says it's safe and effective. NEWPORT NEWS - That heart- stopping roar you may have heard overhead Monday could mean fewer mosquito bites for the next two weeks. Langley Air Force Base deployed C-130 planes over Hampton, Poquoson and York County as part of a three-day mission to spray Hampton Roads with an insecticide that kills mosquitoes on contact. The planes whiz by at 200 mph and 150 feet from the ground to diffuse about a half-ounce of the chemical Dibrom per acre, said Mitch Burcham, pest control supervisor with Langley Air...