Gold Spotted Oak Borer Spotted in Anaheim Hills

The Gold Spotted Oak Borer, a pest which has been doing significant damage to oak trees in southern California over the past decade, has now been detected in trees in Weir Canyon in Anaheim Hills, evidently at Santiago Oaks Regional Park.

This is very significant and highly concerning because this discovery represents the first documented incursion of the insect in this vicinity and could spell trouble for the oak tree woodland areas of this region, including those in and around Carbon Canyon.

According to the Center for Invasive Species Research at the University of California, Riverside, a leading agency dealing with the pest, the GSOB is native to southeastern Arizona (and a cousin coming from Mexico and Guatemala), where trees have developed a resistance.

In 2004, however, the pest was found in San Diego County and has been moving north, wreaking havoc on oak groves in its path.  The fact that an infestation has been located near here is an ominous sign for Carbon Canyon and nearby locales.

Treatment options have been very limited, mainly in seeking to keep firewood in the area, in which it was cut, and in exposing infected trees to sunlight or wrapping them in plastic.  These latter methods increase the temperature within the infected areas killing the adults, pupae, and larvae, but, obviously, this involves trees that are doomed to die and is more about preventing further infestations.

The cost of dealing with dead or dying oak trees can be very high for public agencies and private property owners and, until a natural predator can be identified that might be able to check the advance of the borer, the situation could prove devastating for our local oak trees.

To see more from the CISR, please click here.