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Goldspotted oak borer inspections continue


Pat Boss (left) and Don Patterson yellow band a tree suspected of being infested with Goldspotted oak borer on Hemstreet Place on Thursday, May 16. Photo by Marshall Smith

The current count of Goldspotted oak borer infested trees stands at 11, with the majority of those in Idyllwild. On Friday, May 18, crews removed a large infested oak in Pine Cove in the 23000 block of Pine Needles Lane. Because of the size of the oak and proximity to a residence, a crane had to be used as part of the removal process.

The present CAL FIRE GSOB program pays for 100 percent removal of diseased GSOB trees. Funds are federal dollars, called a State Fire Assistance grant, and are awarded to Riverside County for hazardous fuel reduction, according to CAL FIRE Forester Chief Gregg Bratcher. There are two caveats important to local property owners: if CAL FIRE removes the trees using designated grant money, all wood must be taken away from the site. No firewood would be left for landowner. Also, grant funds, unless reauthorized, end in September, after which, landowners would be responsible for cost of infested oak removal. Removal costs, depending on tree size, location and necessary equipment can range from $1,500 to $3,000.

As local oaks begin growing new leaves, Mountain Community Fire Safe Council Goldspotted oak borer inspection teams have another element to check on their inspection forms — canopy health. Comparative leafiness of an oak’s crown, thin and spotty compared to other oaks in the same area with more robust canopies, is one indicator of an ailing tree. FSC Teams have already inspected 212 oaks on 44 area properties.

Last week, Pat Boss and Don Patterson inspected two black oaks on Hemstreet Place. The older and larger of the two, showed sufficient markers, including thinning canopy and at least five D-shaped exit holes, that the team marked it for subsequent CAL FIRE inspection. The tree was old, around 200 years thought Patterson, already hollowing out on one side and showing signs of overall general weakness. The smaller tree, although adjacent, showed no obvious signs of Goldspotted oak borer infestation. Boss estimated the candidate tree is less than a mile from the oak across from the American Legion that was removed, and is arguably part of that same micro zone of infestation.

A cutter removes a limb from a Pine Cove GSOB tree on Friday, May 17. Photo by Marshall Smith

But Boss noted Goldspotted oak borer beetles are not known to fly long distances or move too far from a tree that is still productively hosting them. So how this tree became infected, whether from firewood brought in, or from nearby beetles is unknown.

What is known is that older, larger black oaks, already in a weakened state, are strong candidates for Goldspotted oak borer occupation. Local property owners with black oaks should check tree canopies, a more obvious indicia of tree decline, than others used by FSC inspection teams. If your tree canopy looks thin and is not fully filled out, contact the GSOB hotline to arrange an inspection.

Forest Service Entomologist and lead GSOB researcher Tom Coleman advises concerned property owners who want to learn about current science in combatting Goldspotted oak borer should consult “Pest Notes” at www.gsob.org. At a recent Idyllwild GSOB education session, the “take home” message on one of the featured slides was: “read the GSOB Pest Note; there is no silver bullet for managing GSOB; ground surveys can be very effective for detecting GSOB; current insecticide research has been effective in the lab (but not yet in the field); grinding or tarping firewood can eliminate GSOB populations (if the tarping is secure and won’t develop holes); leave wood on site for two years before moving it (two years is the length of time GSOB can survive in firewood) and bio-control research is ongoing.”

University of California Riverside’s Mark Hoddle, who works with Coleman on Goldspotted oak borer research, was asked about bio-control and whether there are current native California enemies effective against the beetle. Goldspotted oak borer predators found in Arizona (“parasitoids”) that attack the beetle’s eggs and larvae and seem to hold it in check are not effective in California, according to Hoddle, in stemming the advance of Goldspotted oak borer.

“Parasitism levels appear to be low in Arizona, based on the limited surveys we have done. This low level of attack is unlikely to be sufficient to effectively control GSOB in California,” Hoddle believes. “Native [California] oaks have not co-evolved with a wood boring beetle like GSOB [as oaks have in Arizona] and they [California oaks] might therefore be very sensitive to this kind of attack. So a combination of low levels of parasitoid and predator activity and host plant resistance [in Arizona] in combination may be what holds GSOB at low levels.”

Regarding if and when Goldspotted oak borer enemies from Arizona could be introduced into California, Hoddle said, “No natural enemies will be introduced from Arizona to California until we have run safety tests on bio-control agents that we think have the potential to be useful. These studies will take years to complete in quarantine if we start them.”

Tree removal is the most effective way to currently stop spread to additional trees. Some insecticide sprays have shown effectiveness in laboratory tests. And firewood from a diseased tree must be tarped and sealed in such a way that beetles cannot emerge for a two year period. During that time, firewood should not be moved.

For a GSOB inspection, call (951) 659-8328.

Goldspotted oak borer town hall meeting on Jan. 19


Editor’s note: The reporter in this article had $49,000 of tree-removal costs during the 2003 bark beetle infestation. Fortunately, Southern California Edison paid for all but $10,000 of the removal costs, since the very large pines threatened power lines. The Goldspotted oak borer, recently identified in Idyllwild, could cause similar if not greater tree loss and property damage for Hill homeowners.

A meeting important to Hill land and homeowners, one that could impact their land and home values, takes place from 2 to 4 p.m., Saturday, Jan. 19, at the Idyllwild Town Hall.

Forest Service scientists and CAL FIRE incident leaders in this investigation will discuss the recent discovery of one Idyllwild tree evidencing infestation by the Goldspotted oak borer, and what options are available to the community at this point.

Speakers include Gregg Bratcher, CAL FIRE Forest Battalion Chief, Tom Coleman, U.S. Forest Service entomologist and lead Gold spotted oak borer scientist, Tom Scott, UCR conservation biologist, Kevin Turner, UCR Goldspotted Oak Borer Program Coordinator and Edwina Scott, Mountain Communities Fire Safe Council executive director.

It is important for part-time homeowners from San Diego County to attend since that county is the present site of the greatest tree loss caused by this invasive beetle. Firewood imported from San Diego County is the likely cause of the Idyllwild infestation. Scientists involved with the investigation of the Idyllwild incident identified firewood brought from San Diego County as having evidence of oak borer infestation.

In San Diego County alone, this insect has already killed 90,000 oaks. Once it is ensconced in an area, there are no current treatment options available to stop its further spread.

To prepare for the meeting, there is web site information to use as a primer. That information is found at www.gsob.org, and includes how to identify infested trees, how citizens can report that infestation as well as diagnostic questions that will help scientists better understand how long the infestation has been in a particular area and where it may have come from. Also included is a section on “Best Management Practices” for preventing the spread of Goldspotted oak borer through the movement of logs and firewood.

In a section called “Early Warning System,” University of California scientists are asking woodland owners to help monitor the condition of their oaks and immediately report signs of declining health, leaf loss in tree crowns and other signs of impending oak mortality.

Experts explain oak borer concerns and local action
What: The presence of the Goldspotted oak borer in Idyllwild: An opportunity to learn what we can do the stop the spread of this invasive property damaging pest.

When: Saturday, Jan. 19, from 2 p.m. to 4 p.m.
Where: Idyllwild Town Hall, 25925 Cedar Street

Speakers will include:

  • Gregg Bratcher, CAL FIRE Forest Battalion Chief
  • Tom Coleman, entomologist, U.S. Forest Service
  • Edwina Scott, Mountain Communities Fire Safe Council
  • Tom Scott, a conservation biologist at the University of California, Riverside
  • Kevin Turner, Goldspotted Oak Borer Program Coordinator, UC Cooperative Extension

Goldspotted oak borer private land inspections begin


Ron Perry and Doris Lombard inspect a black oak in Pine Cove. Photo by Marshall Smith

Mountain Communities Fire Safe Council has begun dispatching teams of volunteers trained in spotting signs of Goldspotted oak borer infestation. Executive Director Edwina Scott said the teams received their survey sheets on Friday, April 5, and then began responding to inspection requests from private landowners.

Inspection teams formed primarily from FSC’s Woodies component received Goldspotted oak borer spotting training from key scientists involved with mapping the spread of the highly invasive oak predator. FSC presently has five inspection teams.

On Monday, April 8, a team composed of Doris Lombard and Ron Perry inspected a property in Pine Cove. The property owner had attended a
January Goldspotted oak borer information meeting held at Town Hall. There she had signed up to have her oak-studded property inspected. With flashlights, magnifying glasses, markers, paper clips (to measure depth of exit holes) and detailed survey sheets, Lombard and Perry inspected two oaks on the homeowner’s property. The inspection revealed possible infestation when the team discovered characteristic D-shaped exit holes on both trees.

Kevin Turner (at left), GSOB project coordinator, trains Woodies at Help Center on Friday, April 5. Photo by Doris Lombard
Perry and Lombard logged the property location, the GPS coordinates and detailed descriptions of the inspected oaks (species, tree breast height diameter and crown rating – fullness, apparent leaf health, or lack thereof of the tree canopy and exit holes. If bark is already missing, FSC teams can then look for frass, staining or larval galleries).

The morning of the inspection was very foggy, with heavy drizzle, making inspection difficult. Lombard and Perry plan to return to inspect additional oaks on this homeowner’s property.

The next step in the FSC protocol is for scientists to visit trees the FSC teams have identified as Goldspotted oak borer candidates. Then scientists, during subsequent visits, would determine whether the trees are infested with the beetle. Part of that process may involve chipping bark to see if there is evidence of characteristic staining and whether larvae are present. DNA laboratory confirmation may also be required for a positive identification.

If scientists determine the suspect trees are infested with Goldspotted oak borer, Pine Cove would be added to the expanding list of “micro-zones” in which the insect has already been positively confirmed. Those zones presently include Highway 243 from Mountain Top Liquor to La Bella Montagna Italian Restaurant, the area around Town Hall, and around the American Legion Post on Marian View Drive.

Once a positive Goldspotted oak borer identification is made, homeowners can have the tree removed at no cost through one of two means — by Southern California Edison if the oak is near its power lines, or through federal grants which pay 100 percent for removal of infested oaks. Removing an infested tree is presently the surest way to prevent further Goldspotted oak borer spread.

Landowners can schedule an inspection by calling the GSOB hotline (951) 659-8328. Information that would help a landowner make a preliminary inspection and assessment can be found on www.gsob.org.

Emergency group hears Goldspotted oak borer update


After chipping bark on the downed oak, GSOB Program Director Kevin Turner, holds live larvae in his hand. Tom Scott said there were more than 500 live larvae in the tree. Photo by Marshall Smith

CAL FIRE Unit Forester Chief Gregg Bratcher delivered some good news — federal grant extensions — and some bad news — more Goldspotted oak borer infested oak trees — to the Mountain Emergency Services Committee on Thursday, March 14.

The good news is that a current CAL FIRE tree removal grant, which was originally authorized during the bark beetle crisis in the early part of the last decade, will pay 100 percent of the cost to private landowners for removal of Goldspotted oak borer infected black oaks. Hill landowners will not be required to pay 25 to 30 percent of tree removal costs, a cost sharing that was standard for the bark beetle Forest Care program.

“This will not be a cost share,” Bratcher said. “We already have a contractor set up.” The cost to remove a large oak, depending on proximity to a structure, could easily exceed $2,000, according to Bratcher, who believes landowners will welcome the news of eliminating any cost sharing.

The bad news, said Bratcher, is that two more infested trees have been discovered, raising the current known total to nine. The two recently identified infested oaks are on Marion View Drive across from the American Legion. This is the same location of a very large GSOB-infected oak that Southern California Edison crews removed on Thursday, March 14.

Edison crew member cuts a section of the tree for Tom Scott and other scientists to use for study. Photo by Marshall Smith

UCR Natural Resource Specialist Tom Scott, one of the lead GSOB scientists, estimated this oak had more than 500 live larvae. “It was heavily infested,” Scott said. Scott advised any landowner with oaks near the American Legion to start monitoring their trees carefully, inasmuch as wider oak infestation in that area is likely, given the high numbers of live larvae in the recently removed oak.

“Right now, there are three ‘micro areas’ of GSOB infestation that have been identified in Idyllwild,” Bratcher said — Highway 243 from Mountaintop Liquor to the Bella Montagna Italian Restaurant, the area around Town Hall and the Marion View Drive area. Bratcher advised that when oaks began to leaf out in the spring, further oak borer infestation may be visible — from leaf die off, abnormalities in the leaves themselves and an unusual number of woodpeckers foraging in the trees for beetle larvae.

“Aerial photographs have identified about 6,000 Hill black oaks of the size that Goldspotted oak borer could attack in the wider Idyllwild area,” Scott said. A team of trained local oak borer spotting volunteers, comprised mainly of the Mountain Communities Fire Safe Council Woodies, will begin deploying for site visits in the three identified areas. They will then contact landowners if their oaks exhibit signs of infestation.

Bratcher advised landowners, “If you have questions, call the GSOB hotline.” That number is (951) 659-8328. He said that scientists, looking at sections of the infested local trees, believe Goldspotted oak borer has probably been in Idyllwild for two or three seasons. “It was brought in by firewood,” he said. “That is a 98 percent certainty.”

Oak borer found in four more trees in Idyllwild


GSOB volunteers gather around an infected tree during Tuesday’s training. Photo by Marshall Smith

Four more Goldspotted oak borer-infested trees have been identified in Idyllwild. When authorities identified the first infested tree here in November, they expressed hope that it was an isolated incident. Authorities no longer believe the outbreak is limited.

Since tree one was on Highway 243, it appears to have been almost certainly infested from firewood transported from San Diego County and perhaps the imported firewood location was near the infested tree.

Trees two and three were identified on Jan. 19, one near Mountain Top Liquor and one at Town Hall. Last week, authorities identified four more infested trees, Three are along Highway 243 between tree one and tree two. The seventh tree, which CAL FIRE Forester Gregg Bratcher called a monster oak, 147 inches in diameter, is on private property on Marian View Drive, and was identified by an Edison employee.

At this point, although Dr. Tom Coleman, U.S. Forest Service entomologist and lead Goldspotted oak borer scientist, has begun to talk about insecticides, both topical and systemic. Those candidate insecticides have never been used in the field against California Goldspotted oak borer. If used, application costs would not be small, and results could be short-lived, long-lasting or ineffective, depending on success of application mathods. Another potential control agent, importing a Goldspotted oak borer predator from Arizona where this particular oak borer is native, waits years of scientific trial and investigation to ensure the importation would be effective and have no unintended consequences.

At present, the surest way to stop the insect’s spread is to remove and grind the tree, tarp the firewood (using window screen that won’t deteriorate with the elements), or debark the firewood and arrange to have the bark taken to the grinding station.

Removal stops spread, but removal is also expensive, depending on the size of the tree, location near a home. camp or park. And should the Idyllwild outbreak grow to the extent of the catastrophic bark beetle crisis in the early part of the last decade, the issue becomes for public and private landowners, who would bear costs of removal?

Bratcher said he is working on obtaining county grants that could assist private landowners, much like the Forest Care program has helped thin parcels. He also mentioned that Southern California Edison, much as it did during the bark beetle emergency, could remove infested trees that threaten its power lines, although that has not yet been agreed with SCE.

CAL FIRE, University of California, Riverside, and the Forest Service are conducting field exercises to train professional responders, public agencies, volunteer groups and private citizens on how to spot Goldspotted oak borer infestation in Hill oaks.

On Tuesday Feb. 5, Bratcher, UCR GSOB Program Coordinator Kevin Turner, and Dr. Tom Scott, UCR GSOB scientist conducted a field training for about 30 members of the Mountain Communities Fire Safe Council’s Woodies, the Idyllwild Garden Club, and some CAL FIRE personnel in a two-hour spotting exercise. By spring, CAL FIRE wants as many citizen-scientists on the ground in the Idyllwild area as possible to assist in GSOB tree identification. Spring is when a larger outbreak is likely to occur.

If anyone has a tree that they feel looks as if it could be infested, call the new GSOB Hot Line at the Resource Center on Franklin Drive. That number is (951) 659-8328. Bratcher stressed that all potential oak borer calls must come to the Resource Center number, so that they are logged in. “We need to have a protocol and stick to it,” he said. “Go through the mechanism, the GSOB line.”

Volunteers for citizen scientist GSOB training, to act and report as civilian spotters, should call the Mountain Communities Fire Safe Council at (659) 659-6208. CAL FIRE has smartphone apps that could be used by field personnel to identify the oak borer infestation.

Many in the Tuesday training discovered how hard it is to identify the “D” shaped GSOB exit holes in Hill black oak. Scott explained that the trees most affected in San Diego County are not black oak, and the exit holes are larger and easier to spot. In black oak, with darker bark striations, the smaller holes are harder to see.

Forest Service response to oak borer in San Diego County


Oak tree die off in San Diego County. Photo courtesy of University of California
Editor’s Note: Next week we will review firewood laws in other states as well as statewide quarantines in place in many states in the East and Midwest. Restrictive firewood laws and quarantines were enacted in response to invasive pests. In San Diego County, hard hit by the Goldspotted oak borer, no firewood laws or quarantines are in place at this time.

Some readers have discounted on our website the importance of the discovery of the Goldspotted oak borer in Idyllwild, noting that other pests or birds would take care of it and eliminate the problem. Those readers have not seen the devastation in San Diego County where more than $8 million in public and private funds have been spent or lost on oak borer mitigation activities, including dead tree removals and infested wood disposal.

Ninety thousand dead oaks, killed off since the Goldspotted oak borer was discovered in 2004 in San Diego County, is no small problem. And the reason it is a problem is that there are no natural predators for it in California. It is a non-native pest transported here in firewood from southeastern Arizona where there are natural predators that keep it in check. Were this insect to spread throughout California, mitigation costs would be enormous and property values would be greatly reduced.

Oak tree death in San Diego. Photo courtesy of University of California

In San Diego County, much of the die-off has occurred on Forest Service land. Dr. Tom Coleman, Forest Service entomologist and Goldspotted oak borer expert, has spent the years since its identification studying the beetle’s patterns and investigating ways to combat it, either through topical applications, importation of a predator or other means to stop spread. Still, at this point in time, there are no existing effective treatments or approaches to stop die off.

Anabele Cornejo, assistant public affairs officer of the USDA Forest Service, Cleveland National Forest in San Diego, said, “At the California state level, a quarantine must be initiated by request from a county agricultural commissioner to the California Department of Food and Agriculture. To date, no county commissioners have made such a request, but rather they have expressed concern about a potential quarantine’s effectiveness, cost, logistical difficulties, and potential to draw away existing resources currently combating other invasive pest that threaten agricultural commodities.”

D-shaped exit holes indicating infected tree. Photo courtesy of University of California

Cornejo said the extent of action to date in San Diego is the establishment of a committee to deal with eradication and containment issues. “In San Diego County, federal, state, county and city officials, working with the University of California, established a Goldspotted oak borer Steering Committee for a comprehensive cooperative approach to learning more about this invasive pest as well as how to confine, control and eradicate it.”

Cornejo also noted lack of funding is an impediment to erecting signs around infested Forest Service lands warning against transportation of firewood out of the infested zone. “Due to tight budgets, agencies cannot afford to rent billboard space,” she said.

Asked whether the Forest Service would continue to issue wood cutting permits in the GSOB zone of infestation, Cornejo said, “The Cleveland National Forest’s Descanso Ranger District has continued to issue wood permits to the public. Permitees are shown on a map specific areas where they can collect wood legally. The areas where trees have been down for two or more years and are not infested with GSOB. The inspection [of those areas] is done by either Dr. Tom Coleman or the Descanso District Lands Officer, Russ LaJoie.”

When asked what is being done with wood from infested trees (the oak borer can live in firewood for up to two years), Cornejo said, “Some trees are left where downed and used as habitat for area animals. Hazardous trees are downed and are allowed to sit for two years and then allowed to be used for firewood.”

GSOB confirmed in Pine Cove


UCR GSOB project coordinator Kevin Turner holds a cross section of a tree removed from the western part of Marion View Drive. He said it appeared GSOB had been in the tree for around three years. Photo by J.P. Crumrine
DNA analysis of larvae from a tree in Pine Cove confirmed the presence of Goldspotted oak borer. CAL FIRE Forester Gregg Bratcher made the announcement at the April 24 Mountain Area Safety Taskforce meeting. Confirmation of Goldspotted oak borer in the tree on Pine Needles Lane brings the total of confirmed Idyllwild area infested trees to 11, according to Bratcher. “We’re seeing new GSOB trees at the rate of about one per week and that’s in the winter,” he noted.

Kevin Turner, University of California Riverside GSOB project coordinator, said they will ask the state forestry board to add Idyllwild as an additional GSOB Zone of Infestation. Last fall, the board established parts of San Diego County as a Zone of Infestation.

Goldspotted oak borer is thought to have been in San Diego County for at least 10 years, during which time it has caused widespread oak die off. One of the stated purposes of a zone of infestation is to “recognize GSOB as a threat to California’s forest and woodland resources and exhibit leadership in the effort to combat GSOB while providing the public with important information.”

Analyses of cross sections of Goldspotted oak borer infested trees removed in Idyllwild indicate the beetle has been present here for at least three years. In displaying a cross section of a tree recently removed from the western section of Marion View Drive, Turner said ring analysis seems to confirm that same time period. It would probably take five to seven more years before the broad devastation seen in San Diego County is clearly visible here, according to Forest Service entomologist Tom Coleman.

Confirmation of GSOB in Pine Cove expands the known micro zones of Hill infestation. Previously, oak borer infested trees were identified in four areas —along Highway 243 in the center of Idyllwild, near Town Hall, on Marion View near the American Legion Post 800, and on west Marion View nearer Idyllwild Arts. Although not contiguous, these zones were closer together than the new discovery in Pine Cove, which indicates wider area infestation than previously known.

Costs to remove and funding sources
The costs of taking down infested oaks average between $1,300 and $1,700, according to Bratcher. He said that if CAL FIRE grants are used to remove an infested tree, then no firewood from the tree can remain or be retained by the landowner. “That is the current line, we’re not leaving any firewood behind,” Bratcher said.

He advised the taskforce that current CAL FIRE funding for removing Goldspotted oak borer infested trees ends Sept. 30. “We’ve applied for an extension of the grant but if it is not approved our role would be limited to education only and cost of removal would fall on the landowner.”

Southern California Edison representative Dave Simmons has said that Edison would remove infested trees that threaten Edison lines at no cost to landowners.

Coleman advised the group that the Goldspotted oak borer’s flight season begins in May and still greater area-wide infestation is likely. Coleman said he had brought traps to track beetle migration during flight season which runs through July.

Efficacy of using topical sprays against GSOB
In response to an audience question about the utility of topical sprays, Coleman said all research at this point has been lab based and not field tested to any level of certainty. He said it is a five- to 10-year project to adequately field test efficacy of insecticides on Goldspotted oak borer infested trees.

“It is not easy to save a tree with insecticides,” Coleman said. A landowner could choose to spray a high value oak with chemicals that have shown some efficacy in laboratory tests or against other woodborers in other areas. But Coleman cautioned, that in his opinion, at this point sprays are better as preventive measures to be used on healthier trees than as curative actions on significantly infested ones. He recommended anyone with questions about treatment options should consult www.gsob.org, “Pest Notes,” for the latest information currently available. Costs of herbicidal spraying treatments are the responsibility of landowners, Bratcher said.

From “Pest Notes,” dated January 2013, is the following regarding chemical controls: “Although research testing various insecticides for GSOB management is underway, results are too preliminary to provide precise guidelines for this newly arrived species. … Trees with moderate to severe injury are likely to be difficult if not impossible to save with current management tools. Severely infested trees should be removed rather than sprayed and wood from these trees properly managed to prevent GSOB spread.”

Bratcher outlined the current property inspection process, usually initiated by a landowner calling the GSOB hotline, (951) 659-8328. Once Fire Safe Council teams make a preliminary Goldspotted oak borer finding, CAL FIRE does a second inspection, and then Forest Service and UCR scientists and staff perform a third to confirm the oak borer.

Oak borer infestation zone in San Diego County


In an ongoing campaign to educate the public about the Goldspotted oak borer and the danger it presents to California’s oaks, the California Department of Forestry and Fire Protection declared and mapped a zone of infestation in San Diego County. The declaration and the borders of the zone were adopted at a September meeting of the Board Forestry and Fire Protection and were based on recommendations made by CAL FIRE Chief Ken Pimlott.

At this time, the plan is to foster greater interagency cooperation and to inform and enlist the public in containing the spread of the beetle outside the current infestation zone, according to Board Executive Office George Gentry. It is also to educate the public about the dangers of transporting firewood from the zone to destinations outside the zone. In adopting the zone, the agency considered particular risks to uninfected communities like Idyllwild with large stands of oak.

The educational message being propagated is to burn wood where it is harvested and don’t transport it, especially from San Diego County to any location outside the county. Debarked oak and oak that has been cured for two years pose little to no danger of beetle spread, but those who buy and transport firewood must try to get proof that the wood is harvested from a noninfected area, said Dr. Tom Scott, University of California Riverside natural research specialist and a lead activist in the oak borer battle.

The zone declaration is a step toward greater regulation but at this time the focus is only on education, Scott said. The oak borer infestation zone is clearly demarked and any buyer of firewood from a commercial seller has a right to ask for a bill of sale that shows where it was harvested.

Scott suggested threatened communities, such as Idyllwild, should seek county support for roadside signs that warn firewood importers, both commercial and those bringing it for personal use, that only locally harvested wood is permitted in the community. “Burn only local wood,” said Scott.

He also suggested appealing to the self-interest of vacation rental owners and property managers to advise their clients against firewood importation. “Otherwise owner property values will be affected when oak borer destroys local oak forests,” he said.

The CAL FIRE education campaign is especially critical to educate visitors to Idyllwild about the dangers in bringing firewood from San Diego County. Many San Diego County residents visit Idyllwild. Many have second homes here. Others stay in vacation rentals.

At present, there is no way to know if they are bringing firewood in from the infected zone, Scott noted. There the beetle has destroyed over 80,000 trees since it was discovered in 2002, according to the CAL FIRE news release. Scientists believe the pest emigrated from Mexico and southeastern Arizona into San Diego County, most probably in firewood.

“The insect causes mortality in healthy, mature coast live oak, canyon live oak and California black oak trees,” said Gentry.

Scott said the public is the frontline against oak borer spread. “Firewood is one of the least regulated commodities,” said Scott, noting that no one should buy firewood without asking for source documentation.

MAST tackles GSOB: Public meeting scheduled for Jan. 19


The Mountain Area Safety Taskforce devoted its primary focus during its quarterly meeting to the threat to local forests of the Goldspotted oak borer.

Third District Supervisor Jeff Stone included the oak borer in an ongoing emergency declaration originally enacted for the bark beetle in 2002. He placed the issue on the Tuesday, Dec. 18, board of supervisors’ agenda. While the bark beetle problem was confined to the Hill, Stone’s Chief of Staff Verne Lauritzen stressed that the other four supervisors must be educated on the damage the pest could do if it escapes the Third District.

The Goldspotted oak borer was first discovered last month in Idyllwild. At least one tree and some firewood that had been imported from San Diego County confirmed the presence of the destructive beetle on the Hill. While only one tree has been positively identified, officials and scientists urged the MAST group to use the winter and early spring to prepare for possible further outbreaks in warmer months.

“We’re monitoring the sites more intensely this year,” said Dr. Tom Coleman, Forest Service entomologist. Coleman, lead GSOB scientist, was the first to identify the beetle in 2008 as the cause of the oak die-off in San Diego County. He said of the recent discovery in Idyllwild, “We believe the population in Idyllwild is fairly isolated at this time. We haven’t seen anything else at eye level [GSOB infestation is most evident from tree base to 10 feet up the trunk]. And we haven’t picked anything up in traps we’ve set.” But Coleman acknowledged there are no current treatments that can prevent tree die off once infection is confirmed.

Former Hill CAL FIRE Division Chief Kevin Turner is the GSOB program coordinator at UC Cooperative Extension Service at University of California, Riverside. “One thing the San Jacinto Mountains have in MAST is a key player,” he said, while imploring the multiagency leadership to get involved and be prepared. “You’ll be the test case for rapid response. We don’t know if this one tree ends it. At this point, we’ve got to act decisively. Now that it’s here it could be in many more trees. You must begin to think how you are going to be involved. If you [MAST and area volunteers] are successful, you’ll be the model for other counties.”

San Diego County is the current locus of primary GSOB infestation. The beetles have killed 90,000 black, canyon live and coastal live oaks since 2002. More than $8 million in public and private funds has already been spent on GSOB mitigation activities, including dead tree removals, disposing of infested wood and closure of parks and campgrounds due to dead and hazardous trees.

CAL FIRE Forest Battalion Chief Gregg Bratcher, current MAST chair, said the recent discovery of the beetle in Idyllwild has lent a new urgency to the tasks and agenda of this working group. In the past, MAST has successfully focused on measures to prevent catastrophic wildfires — tree removal as part of the bark beetle emergency and thinning of the forests and creation of fuel breaks. Bratcher noted that the oak borer has the potential to run a destructive path north through California to the Pacific Northwest. “Now where do we go from here?” he asked in beginning the discussion of a coordinated multiagency approach.

The MAST group then began developing an action plan to prepare and address the situation in case GSOB has established a wider base on the Hill. Areas covered in the plan include regulatory options — which sworn officers have authority to stop transit of firewood under an existing California penal code; management of transit of firewood into federal, state and county parks; survey, detection and monitoring for oak borer insects in trees and firewood, including training of professional and volunteer groups; outbreak containment; infested tree removal, and public education including mass mailings to mountain residents.

One of the issues Turner addressed was the disposition of infested wood if Goldspotted oak borer has an established population here. As Turner said, “We can ship only so many trees to San Diego County.”

The concern is how to keep the pest isolated on the Hill before it spreads throughout the county. “Isn’t there also a risk of spreading the borer into any oak area in Riverside County if firewood is transported there?” asked Riverside County Fire Chief John Hawkins.

Although it is winter and the oak trees are not showing any symptoms, Scott and others noted that adequate tracking and investigation of beetle spread requires many trained spotters on the ground. “We’re blind right now,” Scott said. “We can’t do much from the air until the leaves are out,” He said. “That means we’ve got to get more [on the ground] information. We need cradle-to-grave documentation of firewood.”

Firewood is the principal means for oak borer to travel and infect new areas. Lauritzen stressed that the public has to be more vigilant demanding to know the source of oak firewood. And Scott raised the idea of possible state legislation.

In order to develop a core of trained GSOB spotters, MAST plans two training sessions for official personnel and key volunteer groups in January. Training will focus on identifying signs of infestation in local oaks, bark and firewood.

A public education meeting for Hill residents to learn about Goldspotted oak borer infestation signs, how to have their oaks checked, and recommendations about firewood purchases and current transportation regulations is scheduled from 2 to 4 p.m. on Saturday, Jan. 19, at Town Hall. Idyllwild residents and property owners are urged to attend.

Planners selected a weekend afternoon to give part-time homeowners, many of whom are from San Diego, an opportunity to attend. Loss of Hill oak stands, on the scale that San Diego County experienced, could severely diminish property values. Cost to remove single infested oaks can range from $750 to $10,000 depending upon proximity to residential structures, campgrounds and schools.

Gearing up to stop oak borer spread


A large crowd attends Dr. Tom Scott’s GSOB seminar. Photo by Marshall Smith

Since discovery of the invasive and dangerous Goldspotted oak borer in Idyllwild two weeks ago, scientists and professional responders from CAL FIRE and the Forest Service have been meeting to devise steps to contain the spread of the destructive beetle.

Kevin Turner, Goldspotted oak borer coordinator at the University of California, Riverside, said the next step is to work with the Forest Service to get an aerial survey of the Idyllwild area to map distribution of California black oak, the local oak Turner said is most susceptible to the beetle. “We’re hoping to identify and map black oak distribution on both public and private land in the Idyllwild area,” Turner said.

UCR’s GSOB scientist, Dr. Tom Scott. Photo by Marshall Smith
“We’ve already done a ‘windshield survey’ of the Idyllwild area, checking trees to see if any have shown the same symptoms of early leaf shriveling and die off that characterized the infected tree recently removed on Highway 243.” Those involved included Turner, Forest Service lead entomologist Dr. Tom Coleman, CAL FIRE Division Chief Kathleen Edwards and UCR’s Dr. Tom Scott. “We did not find any that were similar,” said Turner. He also noted that there will be little movement of larvae during the winter months, and that symptoms of infection would not likely be seen until the arrival of warm weather next year. “We’ve surveyed areas around the infected tree, over where the Woodies cut wood (Idyllwild HELP Center), the County Park and South Circle,” Turner said. “I’ve been up there a lot and I saw nothing obvious that matched the same symptoms.”

Turner requested that private landowners with black oaks on their property report any symptoms that might be indicative of infestation. Again, those include early browning or shrinking of leaves, canopy thinning, and “D” shaped exit holes in the oak bark. Also, if people have firewood they suspect came from infected areas of San Diego County, they should call Turner’s office for someone to come out to inspect it. The number to call is (951) 827-2973.

If property owners suspect their trees are infected, Turner said someone from his working group would come out to check. “We can go back with the property owner’s permission, peel back the bark and look for [oak borer] larvae.”

Scott and Turner met with community members, including the Garden Club and master gardeners and staff at the Nature Center on Tuesday, Nov. 20, as part of a citizen outreach. Scott presented a slide show and explanation of how the beetle infects a tree, the life cycle within the tree and how quickly tree die-off can occur.

He explained that entry is no higher than 30 feet from the ground with most around 10 feet. “The heaviest time of mortality is during times of drought,” said Scott. “Trees with thicker bark are attacked more frequently. And with infected large trees, there is a 90 to 95 percent mortality. What we’ve seen in San Diego County is 80 to 95 percent death, in outbreak mode, within six to eight years after infection.”

The news Scott delivered was sobering given what has already happened in San Diego County. Turner said he and Scott were encouraged to see a large turnout of around 35 people, since locals, here each day, can contribute very helpful information by observing local black oaks.

The Garden Club distributed flyers at the Tree Lighting Ceremony requesting that anyone who has purchased oak firewood from a supplier south of Idyllwild in the last three years, who has noticed any oak trees that are not as robust as they had been and are different in appearance from similar and nearby black oaks, and who knows of anyone importing wood to the Hill from an outside source to call Turner’s office at (951) 827-2973.

Third District Supervisor Jeff Stone has also requested that any roadside wood sellers be reported to his office at (951) 698-7326. Roadside vending is illegal in Riverside County.

Why should local property owners be worried? The cost to bring down an infected oak could run from $700 to $10,000 depending on tree size and proximity to structures. Property values and habitat would also be diminished by loss of Hill black oak. “This is an emergency,” Stone said.

Many states have firewood ordinances because of concern over invasive species damage. Those ordinances are strict and enforceable. Currently neither California nor Riverside County has any specific firewood ordinances that require source labeling and limit transportation.