An aerial black fly suppression operation has been scheduled for Thursday May 29th on the main stem of the Susquehanna River, a portion of the lower Juniata River, Swatara Creek and Conewago Creek. This aerial operation is scheduled to begin at 0700 in Selinsgrove and continue South throughout the day. The operation will include flights in Northumberland, Snyder, Juniata, Dauphin, Perry, Cumberland, Lancaster and York Counties.