Special to The SUN
The spruce beetle infestation grew about 34,000 acres on the Rio Grande National Forest (RGNF) in 2015, as detected by the forest health aerial survey.
A total of 588,000 acres have been infested since 1996. The amount of new areas infested by the bark beetles is down significantly from the previous year. The rate of annual spread will continue to decline on the RGNF because most of the spruce-fir forests have been infested.