The Douglas-fir tussock moth (DFTM), Orgyia pseudotsugata, is an important defoliator of white fir in California. Outbreaks of the native insect occur somewhere in the state about every 10 years. These outbreaks arise abruptly, but generally subside within one to two years. White fir is the primary host, but other tree species may be defoliated during outbreaks. Defoliation by DFTM may weaken, kill, or top-kill trees. Heavily defoliated trees may experience reduced growth for several years post outbreak and be more susceptible to attacks by bark beetles. Ninety percent of mortality occurs in trees that are ≥ 90% defoliated, while trees with ≤ 50% defoliation rarely die. Top-kill follows a similar trend.
If a particular use is restricted or section of the forest is closed to the public, the Forest Orders and other information will be posted here. Restrictions and closures may take place for many reasons including fire danger, public safety, wildlife protection, road and campground upgrades, etc..
Please be aware of these alerts and notices because many unexpected situations can present difficult challenges for forest visitors.
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