A meeting last week of interested parties on the Goldspotted oak borer provides a good moment to take stock of where we are in relation to this destructive pest.
The GSOB is an invasive insect brought to San Diego County around 2004 and since then has devastated the oak trees of many San Diego communities. Traveling mainly in firewood, GSOB was found in Idyllwild by the sharp eyes of Cal Fire’s Kathleen Edwards in 2012. Since then various groups and people have acted to stop the spread before it reaches outbreak proportions in the San Jacintos.
Kevin Turner and Tom Scott of University of California, Riverside, Gregg Bratcher of Cal Fire, Edwina Scott of the Mountain Communities Fire Safe Council, and many volunteers have all worked together to contain the spread. The latest number of identified oak trees infested with the insect in Idyllwild and Pine Cove is 53, an encouraging number.
It is likely that most of the trees identified do not represent recent spreading, but rather trees that have been infected from the first years of entry in the community. Put another way, we are not seeing a dramatic spike with this number, as one would see in an epidemic, but a modest upward slope, meaning it is spreading but not very fast.
What we need to contain the beetle and protect our oaks is to continue identifying and removing infected trees. A single tree can act in spring as a veritable GSOB factory, throwing as many as 8,000 insects into the surrounding area. Anyone who owns oaks or who regularly walks the neighborhoods can be a very helpful part of the early identification process. If you see a black oak that is keeping its leaves longer than others, and the leaves are crinkly and brown rather than full and yellow, please call the hotline (951-659-8328) to have people look at it.
No tree can be removed without the owner’s permission, but we hope people understand that if you do have an infested tree, the best thing to do for all the oak trees around it is to have it removed.
One team that has been regularly searching for GSOB comprises Doris Lombard, Ron Perry and Eliott Taylor. Since the team was challenged to describe precise locations, Ron found a program that allows the team to take a picture of the tree with an iPad, allowing the picture and its GPS coordinates to be sent immediately to Kevin at UCR. You can imagine what an advance this was. Also helping in this mapping effort is Dan Dever, another skilled volunteer who maintains a data base of trees at the MCFSC.
At this point we need more volunteers to search for infected trees (call 951-659-6208), and we need more calls from the community to help spot them (call the hotline). We also need people to be extremely cautious about buying firewood, and we suggest no one buy firewood from off the Hill. If you have firewood you are unsure of, make sure you burn it this winter so GSOB can’t fly in the spring.
Moving forward from this meeting, Edwina will host a meeting of the volunteers to share best practices, and she will organize another public meeting in the spring. At that time we hope we will have more guidance from researchers on using pesticides for tree protection, which at this time is promising but not conclusive.
