Location: Safford Ranger District, Coronado National Forest
The Frye Fire Burned Area Response (BAER) process has recommended that 300 acres of unburned Douglas-fir forest be treated to reduce the impact of Douglas-fir bark beetles which can severely damage or kill surviving trees. This vegetative type is the primary habitat of the endangered Mount Graham Red Squirrel (MGRS). During the Nuttall Fire in 2004 867 acres of MGRS habitat were destroyed. The Frye Fire destroyed an additional 463 acres leaving only 590 acres of critical habitat for the squirrel.
There is a high probability for a post-fire response by bark beetles, especially the Douglas-fir beetle, which could further degrade the remaining habitat and the potential survivorship of the MGRS. Previous success with MCH pheromone (MCH) on the Safford Ranger District, and on the Wallow Fire in 2011, indicate that the effects of bark beetles can be reduced by the use of this product. Based on the previous success approximately 300 acres of unburned Douglas-fir will be treated within the area of the Frye Fire.
MCH (methylcyclohex) is designed to interrupt the reproductive cycle of the bark beetle by reducing the interest in the treated area to the male beetle. The treatment process involves the use of bubble capsules containing the anti-aggregation pheromone to repel beetles from uninfested areas. MCH duplicates the natural pheromone put off by the male bark beetle which sends a signal of “no vacancy” to other male beetles entering the area.
The MCH process involves the placement of plastic packages containing the anti-aggregation pheromone in the stand to be treated in the early spring. MCH is more effective when it is applied before beetles begin to fly and attack trees. This process begins when ambient air temperature exceeds 65 degrees Fahrenheit. The MCH capsules (1,000mg) are applied at a rate of approximately 20 per acre. The objective of the treatment is to place the capsules in a pattern that will result in a cloud of MCH sufficient to affect beetle behavior when beetles are searching for host trees.
Monitoring will occur in the late summer of 2018 to determine the effectiveness of the treatment. A second treatment will most likely occur in the spring of 2019 to assure the maximum effect of the MCH product on beetle invasion.
Closures: The majority of the Frye Fire area remains closed to public. Detailed information regarding this closure may be found at https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fseprd552786.pdf
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