The relentless march of the bark beetle continues, but two new agencies have joined the forces arrayed against the tiny pests that threaten to destroy as many as 80 percent of the Rim country’s ponderosa and piñon pine trees.
The Tonto Natural Resource Conservation District and the Regional Payson Area Project have taken on new roles in combating the bark beetle’s infestation of ponderosa and piñon pine trees caused by forest overgrowth and extreme drought.
The conservation district has mounted a campaign to inform not only the public, but also Arizona’s congressional delegation of the “causes, effects and consequences” of the infestation.
“Our involvement is going to be public awareness,” said John Dryer, supervisor-vice chairman of the conservation district, an agency that normally limits its activities to stream bank stabilization and erosion protection.
Conservation districts were initiated in the 1930s during the Dust Bowl. They are staffed by volunteers and funded through state land departments.
Besides providing factual information on the bark beetle, the messages the conservation district wants to convey include what limited treatments are available and how to prepare for a worst-case scenario a wildland fire in an area full of dead and dying trees.
“Pine-Strawberry Fire Chief Paul Coe told me that everybody needs to make sure their homeowner’s insurance policies are real good and up to speed,” Dryer said. “If a fire starts down Pine Creek Canyon next summer with all those dead and dying trees, it’s going to show no mercy.”
The Regional Payson Area Project (RPAP) has joined the fray by incorporating steps to reduce the magnitude of the bark beetle infestation into its recently completed Fire Risk Reduction Plan a document that represents a first step in the implementation of the 10-year project designed to provide a protective ring against wildfires around the Payson regional area.
Payson Fire Chief John Ross said part of the project’s focus will be on removing bark beetle-killed and infested trees.
Stating that the regional Payson area “is in, or will soon be in an insect epidemic,” the document advocates a “highly aggressive approach to the identification and timely removal of beetle-killed trees ... in order to mitigate the effects the current insect epidemic has on forest fuel composition and arrangement.”
RPAP, a coalition of area communities, agencies and businesses formed in 2001 to address issues of forest health and wildlands fire hazard reduction in Northern Gila County, is funded by grant money. It also includes homeowner education meetings and classes, fuel reduction assistance to homeowners, and forest thinning utilizing a restoration-based approach.
“Part of our master plan is to create a healthier forest by thinning the existing forest and taking out the bug-killed trees,” Ross said. “Once that’s done, what remains is the forest as we had 100 years ago. The trees and brush that exist after we thin and treat these areas will have more nutrients, more sunlight and more water to be healthier so they’ll be better able to defend themselves against this bark beetle infestation.”
Once a tree becomes infested, it is too late to save it, according to information released by the conservation district.
“The bark beetle kills a pine tree in 48 hours,” Dryer said. “It’s got to be cut down in sections and hauled off, or it can be covered with plastic but that’s not real successful.”
While there is no effective insecticide treatment for infested trees, Rim country residents can pre-treat the trees they most want to save with annual applications of one of two insecticides carbaryl or permethrin. Since the entire surface of the trunk and large limbs must be sprayed to within a few feet of the top, large trees need to be treated by professionals.
“The only company that can do the application is Tree Pro,” Dryer said. “They’ve ordered a heavy-duty sprayer that will spray up to the tops of the big trees.”
Tree Pro owner Shane Owens said the sprayer has arrived but had to be sent to the Valley for minor adjustments. It should be available beginning next week.
“We’re offering a warranty that assures homeowners we’re not spraying trees that have already been infested,” Owens said. “We’re spraying it with a product (carbaryl) recommended by the U.S. Forest Service and the state land department.”
Dryer said spraying entire forest areas with carbaryl is simply not economically feasible.
“We’re going into our sixth dry winter,” he said, “and until the drought ends, we’re just going to have to put up with those little bitty bastards.”
Frequently asked questions about bark beetles
What do bark beetles do?
The direct effect of bark beetle attack in living trees is tree mortality or sometimes top-killing. In an urban situation, this can be undesirable as the attacked trees may have great value, could become a hazard if not removed, and be expensive to remove. In the forest, beetles can influence resource management in many ways, some positive and some negative. Bark beetles are a natural part of our southwestern forests. They have evolved with Ponderosa pine for millennia. In a sense, they function as nature’s thinning agents, removing the sick, old or weakened trees. Effects of beetles on wildlife species depend on the species involved. Dead trees provide habitat for many species which utilize snags for nesting, roosting or foraging. Clumps of dead trees create openings which create habitat for others. Extensive mortality may create habitat for some but may also reduce it for others. Presence of dead trees, especially in large numbers, can also increase fire hazard.
How do I know if my tree is affected?
Evidence of attack varies some by species and is discussed later in these notes. In general, if a tree has red boring dust in the bark and small round entrance holes, or pitch tubes, it may be infested. It does take a good number of attacks to kill a tree so just a few pitch tubes or holes on one side usually won’t kill a tree. Usually by the time the pine needles change color to reddish brown, the beetles are gone.
Why do we see them kill some trees and not others?
Bark beetles are usually associated with stress factors such as drought, disease or injury. Bark beetle populations may increase when one or more of these stress factors is associated with highly susceptible stand conditions (i.e., dense stands).
What can we do about them?
In the long term, preventive strategies are most effective in reducing tree losses. Unacceptable losses can be avoided in most cases by maintaining thrifty, vigorous trees. Thinning dense stands of Ponderosa pine so that crowns are no longer touching, will relieve competitive stress among the remaining trees, making them less susceptible to attack. Proper treatment of pines infected with dwarf mistletoe (a parasitic plant) and removal of trees severely damaged by lightning or construction activities, may also reduce the likelihood of a beetle attack.
In urban settings, avoiding damage to tree trunks and roots can also be effective. Once a tree has been successfully colonized by bark beetles, it cannot be saved. In some situations, removal of infested trees prior to emergence of brood is recommended in an attempt to protect surrounding trees. However, the overall effectiveness of this strategy is unproven.
Further, in most forest situations, it is not feasible to locate and remove all trees prior to emergence. Ips beetles may complete one generation in one month during the summer. If trees are cut, they must either be removed from the site, or if left, the bark should be stripped off to kill the developing beetle brood. Covering the wood with clear, heavy plastic is also effective.
Trees can also be protected from attack by bark beetles during particularly hazardous times through the application of pesticides. The entire bole (trunk) of the tree must be covered in order to provide protection. Carbaryl (Sevin) is registered for this purpose for several beetle species in pine. Formulations of this product provide up to two years of protection.
Source: USDA Forest Service