Posts Tagged: huanglongbing
Parasitic wasps battle Asian citrus psyllid
Western Farm Press ran a detailed update on efforts at UC Riverside to identify and release natural enemies of Asian citrus psyllid to aid in the fight against the feared citrus pest and the deadly citrus disease huanglongbing it carries in other parts of the U.S. and world.
To date more than 160,000 parasitic wasps have been released in over 400 locations spanning 350 zip codes, 64 cities and six counties in southern California, the story said. The counties are Los Angeles, Orange, San Bernardino, Riverside, San Diego and Imperial.
“What was remarkable was we had put out few parasites in relatively few areas (and) they survived just fine,” Hoddle said. “They came through their first winter here in southern California with no problem. That is always the first test: can they survive their first winter?”
Hoddle told Fitchette he is encouraged by the success of the program and by the biological success of the wasp. Since it was first released, it has developed its own breeding populations and has been discovered as far as eight miles away from initial release sites, indicating that it is quite mobile.
Hoddle cautions that the Tamarixia, and another parasitoid called Diaphorencyrtus aligarhensis (Encyrtidae), which could be released in California later this year, are not “silver bullets” in the Asian citrus psyllid/huanglongbing fight. Nevertheless, they do offer hope.
Commercial orchards will continue to spray for the ACP, but urban environments can employ biological control measures when the spray program operated by the state is too expensive to continue.
“As long as we maintain well-irrigated urban environments with plenty of citrus in them the Asian citrus psyllid is going to be here to stay,” he said.
New Asian citrus psyllid website helps farmers and homeowners connect the dots
The early morning agriculture show on KMJ 580 in Fresno opened this morning with comments about UC's new Asian citrus psyllid website from Beth Grafton-Cardwell, UC Cooperative Extension specialist in the Department of Entomology at UC Riverside.
"There are a lot of websites out there relating to Asian citrus psyllid and huanglongbing disease," Grafton-Cardwell said. "What I tried to do in this one is give it a management focus with action steps: Here's where the bug and disease are, here's what you should do if you're a grower, here's what you should do if you're a homeowner. It connects the dots."
The story notes that the website includes a cost estimator for growers and homeowners that was developed by Karen Jetter, economist with the UC Agricultural Issues Center. The estimator lists effective pesticides and calculates the costs of application.
"It's a good way to figure out how you can help control Asian citrus psyllid," Grafton-Cardwell said.
The new website is at http://ucanr.edu/sites/acp.
The new Asian citrus psyllid website can be found at http://ucanr.edu/sites/acp.
San Diego County neighborhoods to be treated for Asian citrus psyllid
Residents in the area have been notified, said Steve Lyle, spokesman for the California Department of Food and Agriculture. He said officials have used the same preventive approach in San Diego County since 2008, when the pest was first discovered locally.
Union Tribune reporter Chris Nichols added information in the article from UC's Asian citrus psyllid and huanglongbing disease website.
"The Asian citrus psyllid is a brown insect about the size of an aphid. It attacks new citrus leaf growth and causes the new leaf tips to twist or burn back. Most concerning, it can spread bacteria that cause a citrus-greening disease known as Huanglongbing or HLB, according to a description on the University of California’s Agriculture and Natural Resources website," the reporter wrote.
Two Asian citrus psyllids found in Tulare County
This week a quarantine goes into effect in some parts of Tulare County to stop the spread of Asian citrus psyllid, according to a 3-minute story on The California Report. The decision comes after officials found ACP in traps near Strathmore and Terra Bella. For an update on the pest and the disease it can carry, The California Report's Rachael Myrow spoke with Mark Hoddle, UC Cooperative Extension specialist in the Department of Entomology at UC Riverside.
Myrow asked why the effort to prevent movement of ACP has not been successful.
"It's very difficult to police the movement of all types of citrus plants in and out of infested areas," Hoddle said. "People may accidentally and unwittingly move plants that have Asian citrus psyllid on them out of infested areas in Southern California to uninfested areas. Another way these psyllids may move is they potentially have the ability to hitchhike on farm machinery or even vehicles."
Listen to the full interview here:
Some citrus orchards in Tulare County will have to comply with quarantine restrictions.
Micronutrient deficiency can look like HLB infection
Neil O’Connell, UC Cooperative Extension advisor in Tulare County, a citrus expert, recommends that field staff also be well versed on these issues since they are in the field daily during the citrus harvest.
Huanglongbing, a disease spread by Asian citrus psyllid, is the worst citrus disease in the world. The disease was detected on one tree in Southern California in March, the first such find in the state. Officials are asking for farmers and home gardeners to be on the look-out for other HLB-infected trees.
O'Connell says deficiencies of zinc, iron and manganese can resemble leaf symptoms found in trees with HLB.
"Some deficiencies have fairly similar symptoms," O'Connell said. "If you are very familiar with deficiency patterns in these elements then it is much easier to separate this out. You can recognize whether the problem is zinc, iron, manganese, or another deficiency while possibly ruling out HLB."
A distinguishing characteristic of HLB infection is a yellow area that crosses from one interveinal area to another, O'Connell explained.