- Author: Chris M. Webb
First detected in San Diego County in 2004, the Goldspotted Oak Borer (GSOB) is contributing to oak mortality in southern California. GSOB larvae feed under the bark, damaging patches or strips of the phloem and cambium, the vascular tissues of the tree. The result is limb and branch dieback leading to tree death.
Records dating back to the late 1880’s show GSOB in Mexico, Guatemala and Arizona. While GSOB may have arrived in California from natural range expansion, it is quite possible this pest was introduced from firewood brought from Mexico.
Adults are about 10 mm long and 2 mm wide. They can be identified by six golden-yellow spots on their dark green forewings. Mature larvae are about 18 mm long and 3 mm wide. They are legless and white with a long, slender appearance and two pincher-like spines at the tip of the abdomen. Pupae are found in the outer bark and resemble adults, but are commonly white in color.
Damage from GSOB results in extensive bark staining, which can appear as black patches or red blistering with sap oozing from under the bark. This is caused by tunnels (galleries) constructed by the larvae primarily along the main stem from the base of the tree up to the larger branches. Larval tunnels are dark in color and have a meandering and generally vertical orientation. The 3 mm, D-shaped adult exit holes signify previous GSOB attack. On coast live oak (Quercus agrifolia), the bark is frequently removed by woodpeckers and reveals the deep red-colored outer bark that contrasts starkly with the gray exterior bark.
The presence of the larvae and their galleries, the emergence holes, and the associated woodpecker damage all distinguish GSOB infestation from infections with the pathogen that causes sudden oak death.
What can you do to help? Stay informed. California-specific management practices for GSOB are still in development. At this time it is recommended that people use management practices for other borer insects, although these practices have not yet been tested on GSOB in southern California. If GSOB is found on your property carefully follow instructions for removing infested materials. Most importantly do not transport infested firewood, and be mindful of where your wood comes from.
More information and photos can be found at UC Riverside's Center for Invasive Species Research.
Goldspotted oak borers are very small. Adults like
the one shown above are about 10mm long.
- Author: Chris M. Webb
Arundo (Arundo donax) is an invasive plant present in our local waterways. It can grow at a rate of four inches per day, making it one of the fastest-growing land plants in the world, and can reach heights of 30 feet tall. It reproduces and spreads when sections of the stem or root break off and float downstream.
Originally introduced by European immigrants as material for making musical instruments, it was also used for roofing materials in California in the early 1800’s. Later it was used for erosion control. Using arundo for erosion control turned out to be a bad choice as it is extremely damaging to our native ecosystems.
Arundo requires a significant amount of water to grow, reducing available water for native plants, fish, wildlife and people. In addition, clumps of arundo and the soil around their roots can break off, causing streambank erosion. Furthermore, these clumps may create channel obstructions that lead to flooding.
In addition to displacing native plants and destroying native fish and wildlife habitat, arundo is highly flammable and can quickly carry fire along waterways. After a fire, arundo quickly grows back from its roots. With other nearby plants burned by fire, arundo can spread even more quickly, leaving no room for native plants to recover.
To help reduce the spread of this plant and the destruction it causes, take the following actions:
- Learn more about arundo, including how to identify it
- Report sightings to local conservation groups
- Join local eradication efforts or help to start one
- If you own land with an arundo infestation, request help and provide access for control efforts.
Arundo is highly flammable.
Arundo can grow at a rate of four inches per day.
- Author: Chris M. Webb
Ventura County UC Master Gardeners will be holding a series of free classes in July. They will all be held at the Oxnard Senior Services Center located at 350 North C Street in Oxnard.
- Learn how to create a sustainable landscape in your garden offered July 7 from 1:00 to 2:30 pm.
- Learn about California Native Plants on July 14 from 1:00 to 2:30 pm.
- Discover Low Cost- No Cost Gardening will be held July 21 from 1:00 to 2:30 pm.
- Water Saving Tips for Your Garden on July 28 from 1:00 to 2:30 pm.
If interested in attending any of the classes above, please contact Joe Kimbrough at kimbro@pacbell.net or (805)659-4250.
- Author: Chris M. Webb
The Ventura County Cooperative Extension Master Gardeners Speakers Bureau will present a talk on using native plants in your garden.
The talk will be held on Tuesday March 16, 2010 from 1:30pm to 3:00pm at the Simi Senior Center. The center is located at 3900 Avenida Simi, Simi Valley.
Please contact Vickie Howard to attend this event.
- Author: Chris M. Webb
The Xerces Society is a nonprofit organization that protects wildlife through the conservation of invertebrates and their habitat. Within the organization there is a pollinator resource center. The center is a collaboration of the Xerces Society and Neal Williams at the University of California at Davis.
The pollinator resource center provides a lot of great information for everyone. In addition to the basics, the site covers:
- Ways to increase native bee populations at conventional agriculture sites
- A toolkit for organic farmers designed to educate about farming practices to reduce risk and harm to pollinators
- Pollinator habitat management, including prescribed burns and grazing areas
- Ways to increase pollinators in the garden
- The important role parks and golf courses can play in enhancing, restoring and creating habitat for these important creatures
- Resources for teachers
Fact sheets are found in the publication section of the website. They are great sources of information, and some of the links and titles are included below.
Native Pollinators on the farm: What’s in it for the growers? An overview of the contribution native bees make to crop pollination, and their value to agriculture.
Butterfly gardening. Learn how to convert your garden into a paradise for butterflies.
Plants for native bees in California. Learn which plants best support native bees in California.