- Author: Mike Hsu
Preliminary results indicate 3.5% of ACP collected showed signs of bacterium that can cause huanglongbing
An ongoing study in the commercial citrus groves of coastal Southern California is looking at whether Asian citrus psyllids – the insect vector of huanglongbing “citrus greening” disease – are carrying the bacterium that can cause HLB.
Thus far, the project has tested more than 3,000 adult ACP collected from 15 commercial citrus sites across the region, of which 138 – just over 3.5% – had some level of the bacterium present, according to researchers from UC Agriculture and Natural Resources, UC Davis, UC Riverside and the University of Arizona, Tucson.
“While the results are a cause for concern, the situation in California is much better than in Florida and Texas, where ACP carrying the bacterium make up the majority of the population and HLB is widespread in commercial citrus,” said Neil McRoberts, a UC Davis plant pathologist and UC Integrated Pest Management program affiliate advisor. “The results indicate that there is no room for complacency, but also no cause for panic.”
Since the first HLB-infected tree in California was found in 2012, nearly 4,000 infected trees have been detected and removed from residential properties in Southern California, mainly in Orange and Los Angeles counties. According to McRoberts, “to date, no HLB has been found in commercial citrus” in California.
He stressed, however, that the aforementioned ACP study – funded by the HLB Multi Agency Coordination Group and managed by USDA-APHIS – does not involve any testing of trees for HLB and focuses only on looking at the insect which spreads the bacterium.
McRoberts also emphasized that the project's detections of the bacterium cannot be considered “official” because the researchers' lab procedures differ from the official testing protocols of the California Department of Food and Agriculture.
“Follow-up sampling by CDFA staff would allow official samples to be collected for further investigation, but is entirely voluntary for the growers involved,” he said, adding that his research team is currently wrapping up the sampling phase of the project, with data analysis continuing into 2023.
While commending the “huge coordinated effort” by the California citrus industry, California Department of Food and Agriculture, UC ANR and other partners to suppress the ACP vector and slow the spread of HLB, McRoberts also urged continued vigilance.
“Our study results indicate that it is not time to declare the emergency status for ACP/HLB in California over – the situation is still evolving,” he said.
For further information about the research, contact Neil McRoberts at nmcroberts@ucdavis.edu or (530) 752-3248.
From UC IPM Pests in the Urban Landscape blog.
According to Gary Goodman, District Manager of Sacramento Yolo Mosquito and Vector control, many residents are anxious and excited to get outside and enjoy the warm weather so it's important to protect yourself from mosquito bites by wearing a good mosquito repellent.
The Centers for Disease Control and Prevention (CDC) recommend using an insect repellent that contains the active ingredients DEET, Picaridin, IR3535 or the plant-based oil of lemon eucalyptus.
Aside from personal protection against mosquito bites, it's important to ensure mosquitoes are not breeding at home. Drain stagnant water from sprinklers, irrigation, and rainstorms. Be sure to check your backyard and dump any water in flower pots, kiddie pools, tires, pet dishes, bird baths and other common household containers that can hold water.
Another ongoing concern is the invasive mosquito Aedes aegypti which has been detected in several counties throughout Southern California and the Central Valley. For county level information, see this map. Invasive mosquitoes pose a significant health threat because they can transmit dangerous viruses including Zika, dengue fever and chikungunya. Surveillance efforts have continued since the initial detection last August. To date, no cases of Zika virus have been reported in California.
For more information on mosquito identification and management, see our recently revised Pest Notes: Mosquitoes. Additional information on vector-borne diseases is available on the California Department of Public Health website.
/span>
As summer quickly approaches and we find ourselves getting outside a bit more, remember to take care to protect yourself from mosquitoes.
According to Gary Goodman, District Manager of Sacramento Yolo Mosquito and Vector control, many residents are anxious and excited to get outside and enjoy the warm weather so it's important to protect yourself from mosquito bites by wearing a good mosquito repellent.
The Centers for Disease Control and Prevention (CDC) recommend using an insect repellent that contains the active ingredients DEET, Picaridin, IR3535 or the plant-based oil of lemon eucalyptus. Aside from personal protection against mosquito bites, it's important to ensure mosquitoes are not breeding at home. Drain stagnant water from sprinklers, irrigation, and rainstorms. Be sure to check your backyard and dump any water in flower pots, kiddie pools, tires, pet dishes, bird baths and other common household containers that can hold water.
Another ongoing concern is the invasive mosquito Aedes aegypti which has been detected in several counties throughout Southern California and the Central Valley. For county level information, see this map. Invasive mosquitoes pose a significant health threat because they can transmit dangerous viruses including Zika, dengue fever and chikungunya. Surveillance efforts have continued since the initial detection last August. To date, no cases of Zika virus have been reported in California.
For more information on mosquito identification and management, see our recently revised Pest Notes: Mosquitoes. Additional information on vector-borne diseases is available on the California Department of Public Health website.
In the newly revised Pest Notes: Mosquitoes, you'll find general mosquito prevention tips as well as information on the most recent mosquitoes to become established in California: species in the Aedes genus which can transmit Zika virus and other deadly diseases.
This publication, written by UC Riverside entomologist William Walton and UC Davis entomologist Bruce Eldridge, discusses the life cycles and virus transmission cycles of Culex and Aedes mosquitoes.
You will find tips on managing water barrels and other water capture structures to keep mosquitoes from breeding in them. There are updates on chemical control, including new personal use repellent products and outdoor sprays, and a link to a frequently updated map of Aedes mosquito detections from the California Department of Public Health.
Read the full Pest Notes: Mosquitoes on the UC IPM website for more information and continue to stay safe and healthy out there!
/div>July 10, 2019
WEST NILE VIRUS
Elk Grove, Ca.—The Sacramento-Yolo Mosquito and Vector Control District confirmed today that the first mosquito sample of the season has tested positive for West Nile virus (WNV). The mosquito sample was collected near the Florin area of south Sacrament County. “As we expected, after finding the first positive bird earlier in the week, now we are finding virus in the mosquito populations, “ said Gary Goodman, District Manager. “With the very warm weather expected over the next few days, we expect WNV activity to quickly ramp up,” he added. The District encourages residents to take these findings seriously and do everything they can to protect themselves. Last year in California there were 211 confirmed human cases of the disease, including 11 fatalities.
The detection of this recent WNV activity is evidence that the disease is present and the public should take proper precautions to stay protected. “As more people enjoy outdoor activities during the warm summer evenings, it's important to remember that the best protection against mosquito bites is an effective insect repellent” said Goodman. Residents are also encouraged to report dead birds, neglected pools and other mosquito problems.
As a response to the finding of WNV, the District will increase its mosquito trapping and monitoring in the area to find sources where mosquitoes may be breeding. Targeted ground spraying may also be conducted to rapidly decrease the numbers of adult mosquitoes.
For current information about District activities, please visit www.FIGHTtheBITE.net. Residents may also subscribe to mailing lists to receive email notifications for upcoming mosquito treatments by zip code. To sign up, go to Spray Notifications on the website.
2019 West Nile virus activity update:
Sacramento County: 1 mosquito sample and 1 dead bird have tested positive for West Nile virus to date.
Yolo County: No activity has been detected to date.
Practice the District D's of Mosquito Prevention:
DRAIN standing water that may produce mosquitoes.
DAWN and DUSK are times to avoid being outdoors.
DRESS appropriately be wearing long sleeves and pants when outside.
DEFEND yourself by using an effective insect repellent. Make sure to follow label directions!
DOOR and window screens should be in good working condition.
DISTRICT personnel are also available to address any mosquito problems. Call them at 1-800-429-1022 or visit www.FIGHTtheBITE.net