- Author: Chris M. Webb
Over the last 10 years, the Goldspotted Oak Borer (GSOB) has killed approximately 80,000 oak trees in San Diego County – including many large trees that were hundreds of years old.
To date GSOB has caused significant economic, ecological, cultural, and aesthetic losses in San Diego County. The costs of dead tree and infested wood alone is staggering.
GSOB (Agrilus Auroguttatus) is an invasive insect in California. Because it is a non-native pest there are not natural defense mechanisms to keep this insect in check. There is concern among experts that GSOB will continue to move north through California. Susceptible oak species are: coast live oak, California black oak, and canyon live oak.
It is highly suspected that GSOB entered California in firewood. GSOB larvae can live under the bark of dead oaks for over a year before exiting as adults. It is likely GSOB has spread so quickly in San Diego County via firewood movement. Because of this, it is extremely important to be mindful of where your firewood comes from. The movement of infested firewood could easily establish this destructive pest throughout the state.
To learn more about GSOB, or to get involved in preventing its spread, please see the gsob.org website.
And remember, to protect California’s Forest – Buy and Burn Local Firewood! Don’t move it around!
- Author: Chris M. Webb
While the Asian citrus psyllid/HLB pest-disease complex has received a lot of press lately, another deadly pest-disease combination has been found in Los Angeles County.
Tea Shot Hole Borer (Euwallacea fornicatus) is a vector for the Fusarium fungus. A native from Asia, this beetle is very small. Females are between 1.8 to 2.5mm (0.07-0.1 inch) long. Males are even smaller at 1.5mm (0.05 inch).
In addition to avocado trees, this insect is a serious pest of tea in Sri Lanka and India. In California, The Tea Shot Hole Borer was first reported on black locust (Robinia pseudoacacia), Lychee (Litchi chinensis), Box elder (Acer negundo), but there were no reports of fungal damage.
What to do:
- Look for a single exit hole with surrounding white powdery exudate.
- Scrape off the bark layer around the infected area to see the canker.
- Follow the gallery to look for the beetle (may or may not be present).
- Avoid movement of infested avocado wood out of infested area.
- Look for other hosts (Castor beans plant, Black locust, Lychee, and Acer) showing symptoms of the beetle/disease.
- Because the beetle tends to colonize both live and new dead wood, chip the dead wood within the grove and cover with a tarp for at least a week to prevent further beetle colonization.
- Sterilize tools to prevent spread of the disease with either 25% household bleach, Lysol (add symbol) cleaning solution, or 70% ethyl alcohol.
For more information please see the Fusarium dieback on California Avocado trees vectored by the Tea Shot Hole Borer Pest Alert developed by researchers at UC Riverside. The flyer is available in English and in Spanish.
- Author: Chris M. Webb
Huanglongbing (HLB) the deadly disease carried by the Asian citrus psyllid has recently been detected in Los Angeles County.
UCCE Ventura County Farm Advisor Ben Faber, stresses that people are responsible for much of the movement of ACP. On their own, this insect roughly the size of a grain of rice, can travel about a mile over their lifetime.
The health of citrus trees, and the health of our local citrus industry, largely depends on the responsible handling and movement of plant materials and fruit. This is of particular importance when traveling out of the county, state or country.
Please see the message below from the CDFA (California Department of Food and Agriculture).
CITRUS DISEASE HUANGLONGBING DETECTED IN HACIENDA HEIGHTS AREA OF LOS ANGELES COUNTY
SACRAMENTO, March 30, 2012 – The California Department of Food and Agriculture (CDFA) and the United States Department of Agriculture (USDA) today confirmed the state’s first detection of the citrus disease known as huanglongbing (HLB), or citrus greening. The disease was detected in an Asian citrus psyllid sample and plant material taken from a lemon/pummelo tree in a residential neighborhood in the Hacienda Heights area of Los Angeles County.
HLB is a bacterial disease that attacks the vascular system of plants. It does not pose a threat to humans or animals. The Asian citrus psyllid can spread the bacteria as the pest feeds on citrus trees and other plants. Once a tree is infected, there is no cure; it typically declines and dies within a few years.
“Citrus is not just a part of California’s agricultural economy; it’s a cherished part of our landscape and our shared history,” said CDFA Secretary Karen Ross. “CDFA is moving swiftly to protect the state’s citrus growers as well as our residential trees and the many prized citrus plantings in our parks and other public lands. We have been planning and preparing for this scenario with our growers and our colleagues at the federal and local levels since before the Asian citrus psyllid was first detected here in 2008.”
Officials are making arrangements to remove and dispose of the infected tree and conduct treatment of citrus trees within 800 meters of the find site. By taking these steps, a critical reservoir of disease and its vectors will be removed, which is essential. More information about the program will be provided at an informational open house scheduled for Thursday, April 5, at the Industry Hills Expo Center, The Avalon Room, 16200 Temple Avenue, City of Industry, from 5:30 to 7:00 pm.
Treatment for HLB will be conducted with the oversight of the California Environmental Protection Agency (Cal-EPA) and will be conducted safely, with advance and follow-up notices provided to residents in the treatment area.
An intensive survey of local citrus trees and psyllids is underway to determine the source and extent of the HLB infestation. Planning has begun for a quarantine of the infested area to limit the spread of the disease by restricting the movement of citrus trees, citrus plant parts, green waste, and all citrus fruit except what is commercially cleaned and packed. As part of the quarantine, citrus and closely related plants at nurseries in the area will be placed on hold.
Residents of quarantine areas are urged not to remove or share citrus fruit, trees, clippings/grafts or related plant material. Citrus fruit may be harvested and consumed on-site.
CDFA, in partnership with the USDA, local agricultural commissioners and the citrus industry, continues to pursue a strategy of controlling the spread of Asian citrus psyllids while researchers work to find a cure for the disease.
HLB is known to be present in Mexico and in parts of the southern U.S. Florida first detected the pest in 1998 and the disease in 2005, and the two have now been detected in all 30 citrus-producing counties in that state. The University of Florida estimates the disease has tallied more than 6,600 lost jobs, $1.3 billion in lost revenue to growers and $3.6 billion in lost economic activity. The pest and the disease are also present in Texas, Louisiana, Georgia and South Carolina. The states of Arizona, Mississippi and Alabama have detected the pest but not the disease.
The Asian citrus psyllid was first detected in California in 2008, and quarantines are now in place in Ventura, San Diego, Imperial, Orange, Los Angeles, Santa Barbara, San Bernardino and Riverside counties. If Californians believe they have seen evidence of HLB in local citrus trees, they are asked to please call CDFA’s toll-free pest hotline at 1-800-491-1899. For more information on the Asian citrus psyllid and HLB visit: http://www.cdfa.ca.gov/phpps/acp/
- Author: Chris M. Webb
On April 20, 2012 California State University, Channel Islands will host a symposium titled, ‘Agriculture in the Golden State: Challenges in Feeding California in the 21st Century.’
Strong and sustainable agricultural production is important to all of us, and to our future. UCCE Ventura County researchers Oleg Daugovish and Ben Faber will speak at the symposium.
From the event organizers:
"California is the nation’s top agricultural producer generating over $30 billion annually. However, the ability of growers to feed California and beyond is continually being challenged by the introductions of new insect pests, drug resistant pathogens, and environmental concerns at the urban-agricultural interface. CI sits within one of the top ten agriculturally important counties in California, which produces much of the States’ strawberries, raspberries, citrus, and avocados. Given our location, it is important that everyone learn about the issues affecting agriculture locally and statewide."
To learn more about this year's symposium, or to register please visit this page of the CSU Channel Islands website.
- Author: Chris M. Webb
A significant pest of plants, crops, and trees, the light brown apple moth Epiphyas postvittana (Tortricidae) is an invasive pest that is native to Australia.
At 8 to 10 mm (1/4 inch) long, these pests are smaller than a dime, but can do much damage.
Females typically lay eggs on the upper surface of host leaves; however, eggs are sometimes laid on fruit and young stems. The egg masses contain on average 20 to 50 eggs, but may contain up to 170.
Larva are usually present on the leaves of host plants most of the year. Just hatched larvae are 1.5 to 2mm long. They are pale yellow-green with a dark brown head. Mature larvae are 10 to 18 mm long. At this life stage they are a medium green, with a light yellow-brown head with a darker green central stripe. Sometimes two side stripes run the length of their bodies.
Pupae are 10 to 15 mm in length. They turn from green to reddish-brown as they mature. A single pupa can often be found inside a thin, silken cocoon between a webbing of two leaves pulled together.
To find out more Please visit the USDA’s light brown apple moth website. Additional information and photos can be found on this page of the California Department of Food and Agriculture (CDFA) website.To report suspected finding please follow these online instructionsor call the CDFA pest hotline at 1-800-491-1899.