expansion

California Growers and Nurseries Affected by Quarantine Expansions

Daniel CooperCalifornia Corner, HLB Management, Regulation

The California Department of Food and Agriculture (CDFA) has expanded the huanglongbing (HLB) quarantine boundary in San Diego County following the confirmation of one HLB-positive residential citrus tree in Fallbrook. CDFA is also expanding the Asian Citrus Psyllid (ACP) Bulk Citrus Regional Quarantine Zone 6 to reflect the HLB quarantine boundary expansion. A map of the expanded boundary can be …

efforts

Efforts to Control Psyllids in California

Daniel CooperCalifornia Corner, Psyllids

Grove edges, detector dogs and the California Citrus Research and Field Trials (CA-CRaFT) Program were prominent topics in a virtual presentation about California’s efforts to control HLB-spreading Asian citrus psyllids (ACP). Ivan Milosavljevic, Citrus Research Board (CRB) integrated pest management entomologist, delivered the report. His June 23 presentation was part of the 2026 CRB Webinar Series. GROVE EDGES Conventional human …

biocontrol

Stepping Up Psyllid Biocontrol in California

Daniel CooperBiologicals, California Corner, HLB Management

California Citrus Research and Field Trials (CA-CRaFT) plans in Ventura County call for expanded activities and a stronger emphasis on biological control of the HLB-spreading Asian citrus psyllid (ACP) with the parasitic wasp Tamarixia radiata. In a June 23 virtual presentation, Citrus Research Board integrated pest management entomologist Ivan Milosavljevic reported that the Ventura County program will utilize self-release T. …

scientists

Scientists Speak About Long-Term HLB Solutions

Daniel CooperEvents, HLB Management

The recent Florida Citrus Industry Annual Conference featured seminars from several scientists who are working on solutions to fight huanglongbing (HLB) disease. GENETIC RESEARCH Vivian Irish of Yale University presented her research on combating HLB through gene editing. She noted several promising gene-editing targets have been identified. Plans call for getting these lines planted to evaluate their resistance to HLB. …

HLB

How HLB Research Has Evolved

Daniel CooperHLB Management, International, Research

Huanglongbing (HLB, or citrus greening) disease has been the focus of an enormous amount of scientific research over the past two decades. A new study — “Bibliometric Mapping of Citrus Greening Disease Reflecting Trends, Shifts and Focus Areas” — takes a unique look at that research. It analyzes thousands of scientific publications to identify where scientists have concentrated their efforts …

Cyprus

Biocontrol of Psyllids Is Successful in Cyprus

Daniel CooperBiologicals, International, Pests

Classical biological control is having a very significant impact on populations of the Asian citrus psyllid (ACP) in Cyprus, according to Ángel Marhuenda, director general of common agricultural policy for the Valencian Institute of Agricultural Research (IVIA). ACP is the vector of huanglongbing (HLB) disease. Marhuenda said, however, that “the detection of residual populations of the vector indicates that continued …

natural

Boost Natural Defenses Against Psyllids in Summer

Daniel CooperBiologicals, Psyllids, Tip of the Week

By Lukasz Stelinski As summer takes hold in June, Asian citrus psyllid (ACP) populations are often high coinciding with availability of new flush. This is also a time when natural enemies can provide meaningful ACP suppression. Growers can improve biological control by making management decisions that help predators and parasitoids survive and function in the grove. MANAGE ANTS One important …

CUPS

Pest Avoidance and Monitoring in CUPS

Daniel CooperCUPS, Pests, Tip of the Week

By Jawwad A. Qureshi Citrus under protective screen (CUPS) is a novel system for large-scale citrus production in screen houses covered with a tightly woven mesh screen on all four sides and the roof. The primary goal of this shift from a traditional open orchard to a CUPS system is to protect citrus crops from huanglongbing (HLB) disease, which is …

expansion

How Trunk Injection Is Affecting Psyllid Populations

Daniel CooperEvents, HLB Management, Psyllids

Research and field trials have been fairly consistent in showing that trunk injection of oxytetracycline (OTC) will reduce the HLB-causing bacteria in citrus trees, resulting in improved yield and quality. But what happens to the Asian citrus psyllid (ACP) when it feeds on treated trees? The answer to that question is becoming clearer now from research conducted by the University …

eggs

Three Bugs That Eat Asian Citrus Psyllid Eggs

Daniel CooperBiologicals, HLB Management, Psyllids

University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers have found three commercially available insect species that devour the eggs of the HLB-spreading Asian citrus psyllid. These natural predators could become an important new line of defense against the devastating citrus disease. This is particularly true for organic growers who have limited options to control the psyllid, said …

enemies

Natural Enemies for Integrated Citrus Pest Management

Daniel CooperPests, Tip of the Week

By Jawwad A. Qureshi Natural enemies are the beneficial organisms that control insect and mite pests. Citrus trees produce most of their young shoots (flush) for the year in spring and will continue to produce more in summer and fall. Arthropod activity has already started in citrus groves. For example, overwintering Asian citrus psyllid (ACP) adults have started reproducing. Other …

mandarin

Complex Responses to IPCs in Mandarin Trees

Daniel CooperHLB Management, IPCs, Mandarins

Recent research showed that individual protective covers (IPCs) proved highly effective in reducing Asian citrus psyllid (ACP) populations and thereby preventing HLB infection in three mandarin cultivars. However, overall tree response varied. The research was published in the Journal of the American Society for Horticultural Science. The authors are Saoussen Ben-Abdallah, Susmita Gaire, Ute Albrecht, Ozgur Batuman, Jawwad Qureshi and …

positive

California Psyllids Positive for HLB-Causing Bacterium

Daniel CooperCalifornia Corner, HLB Management, Psyllids

Two adult Asian citrus psyllid (ACP) samples were confirmed positive for Candidatus Liberibacter asiaticus (CLas) in two central California coastal counties on March 10, the Citrus Pest & Disease Prevention Program (CPDPP) reported. CLas is the bacterium that causes HLB. One sample was collected during a routine commodity survey in a commercial citrus grove in the Fillmore area of Ventura …

pest

Pest Management Challenges in CUPS

Daniel CooperCUPS, Pests

By Lauren Diepenbrock Citrus under protective screen (CUPS) has provided growers with a profitable method for producing fresh fruit in Florida. Growers who have implemented this system have noted quality fruit production and reduced inputs. However, when changes are imposed to the production environment, they are also imposed to the invertebrate pest complex, which can be either beneficial or detrimental …

sweet orange scab

Sweet Orange Scab and HLB Quarantines Updated

Daniel CooperCalifornia Corner, Diseases, Regulation

Agriculture officials announced the expansion of the sweet orange scab (SOS) quarantine and establishment of a new HLB quarantine area, both in California. SWEET ORANGE SCAB On March 11, the quarantine area for SOS in the Van Nuys area of Los Angeles County was expanded by 80 square miles. The U.S. Department of Agriculture Animal and Plant Health Inspection Service …

control

Pest Control in Protected Production Systems

Daniel CooperCUPS, IPCs, Pests

In a recent virtual presentation, entomologist Jawwad Qureshi discussed monitoring and control measures for citrus pests in trees under individual protective covers (IPCs) and in citrus under protective screen (CUPS). Qureshi is an associate professor at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Southwest Florida Research and Education Center in Immokalee. MONITORING METHODS Qureshi’s noted that …

Asian citrus

What To Do About Asian Citrus Psyllids Postfreeze

Daniel Cooperfreeze, Psyllids, Tip of the Week

This winter’s hard freeze may have knocked back visible Asian citrus psyllid (ACP) activity, but research shows the pest is not reliably eliminated by the cold. In lab studies, many ACP adults and nymphs survived several hours at 21 to 23 degrees, and eggs could still hatch after several hours at temperatures as low as 8 degrees. Adults can also …

Arizona

Federal HLB Quarantine Established in Arizona

Daniel CooperPests, Regulation

Federal agriculture officials recently established an area quarantined for HLB in, paralleling the intrastate quarantine that the Arizona Department of Agriculture (AZDA) established on Feb. 7, 2025. The quarantined area of approximately 9 square miles is in the Nogales area of Santa Cruz County. The U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS) took the recent action …

psyllid

Postfreeze Psyllid Populations Reduced

Daniel Cooperfreeze, Psyllids

Southeast citrus growers hoping that the Feb. 1 freeze would wipe out the Asian citrus psyllid (ACP) population are going to be disappointed. “What we do know about freezes is a lot of time they will reduce or delay the buildup of many of the populations of pests that we worry about,” said Lauren Diepenbrock, University of Florida Institute of …

UGA

UGA Extension Monitoring for Psyllid Movement

Daniel CooperGeorgia, Psyllids

The vector of citrus greening disease remains in low numbers in Georgia. University of Georgia (UGA) researchers are hoping the Asian citrus psyllid (ACP) stays that way. Led by UGA entomologist Apurba Barman, UGA Extension is monitoring for the insect in hopes of limiting its migration throughout South Georgia. “The good thing is, so far, we’ve found ACP in only …