Forest officials in southern Arizona are trying to keep bark beetles from destroying endangered squirrel habitat.
The Coronado National Forest says it plans to treat 300 acres of Douglas fir trees with a product that repels bark beetles.
The treatment involves placing capsules containing anti-aggression pheromones among the trees. Officials say the capsules send a signal that ward off male beetles looking to reproduce.
The treatment is scheduled for early spring. Forest officials say they should be able to tell if it worked by late summer 2018.
They say they saw success with the treatment after a wildfire in 2011.
Officials say wildfires in 2004 and earlier this year charred much of the critical habitat for the endangered Mount Graham red squirrel. About 600 acres remain.