Invasive Species

Sudden oak death (SOD) is a disease syndrome that has killed millions of native oak trees (Figure 1) along the west coast of the United States, from Big Sur in California up to Southern Oregon.

Wildfires are part of California's ecosystems, and they do not have to lead to the destruction of structures and livelihoods. Each of us can contribute to improving wildfire resilience, from individual homeowners and businesses to entire communities.

The Invasive Pest Spotlight focuses on relevant or emerging invasive species in California. In this issue we are covering brooms, a group of invasive shrubs. Invasive Broom facts Brooms are upright shrubs in the legume family that typically produce small, yellow, pea-shaped flowers.

They may seem too tiny to do much damage to a mature, healthy tree, but invasive shothole borers (ISHB) are responsible for the deaths of tens of thousands of trees in Southern California. These beetles bore into trees and infect them with Fusarium dieback, a fungal disease that kills the trees.

In the lottery of troublesome termite infestations, Roger, a Rancho Santa Fe homeowner, hit the jackpot (a pseudonym is used to protect his privacy).

The Formosan subterranean termite (FST), Coptotermes formosanus, is a very destructive pest first reported in California in 1992 in La Mesa, San Diego County. FST has since been found in Canyon Lake, Riverside County, Rancho Santa Fe (San Diego County) and Highland Park (Los Angeles County).

Although all cockroaches in California are considered pests, the Turkestan cockroach is of particular concern.

There are several flatheaded boring beetles in California, however only a few are of particular concern. The goldspotted oak borer (GSOB), Agrilus auroguttatus, is a metallic wood-boring beetle that threatens our native trees.

The Spotted Lanternfly (SLF) is an invasive pest that poses a great threat to California's agriculture. It was first discovered in the U.S. in Pennsylvania in 2014, and has since taken the east coast by storm, causing damage to many plant species and proving to be difficult to control.

You've probably seen this invasive plant growing along highways or the coast in California. Highway iceplant, Carpobrotus edulis, was intentionally introduced to prevent soil erosion along highways and coasts but it has since invaded many different ecosystems and outcompetes native plant species.