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 …
California Psyllids Positive for HLB-Causing Bacterium
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 Management Challenges in CUPS
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 and HLB Quarantines Updated
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 …
Pest Control in Protected Production Systems
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 …
What To Do About Asian Citrus Psyllids Postfreeze
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 …
Federal HLB Quarantine Established in Arizona
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 …
Postfreeze Psyllid Populations Reduced
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 Extension Monitoring for Psyllid Movement
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 …
Benefits and Risks of Individual Protective Covers
University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers have long extolled the virtues of individual protective covers (IPCs). Multi-county citrus Extension agent Edwin Gutierrez-Rodriguez does the same but also warns of potential risks. Following is information from a recent UF/IFAS blog article he authored. In the ongoing battle against huanglongbing (HLB), also known as citrus greening disease, …
USDA Research Priorities Cite Citrus Greening
The U.S. Department of Agriculture (USDA) recently issued a directive about its research and development priorities. The priorities, which cite citrus greening in item 3, are: 1. INCREASING PROFITABILITY OF FARMERS AND RANCHERS While research to increase productivity has allowed American farmers and ranchers to provide the safest, most abundant and most affordable food and fiber supply, the volatility in …
Implementing Insecticide Sprays for Winter Management of Psyllids
By Jawwad A. Qureshi In winter, citrus trees enter a state of quiescence due to lower light and cooler temperatures, which slows their metabolic activity. Therefore, most citrus trees do not produce new shoots during this period. These young shoots are essential for the growth of the Asian citrus psyllid (ACP), Diaphorina citri. The ACP is a small sap-feeding insect …
First Psyllid in Imperial County Tests Positive for HLB Bacteria
An adult Asian citrus psyllid (ACP) sample collected from a rural residential property in Imperial County has tested positive for Candidatus Liberibacter asiaticus (CLas), the bacteria that causes huanglongbing (HLB). The ACP sample was collected from a citrus tree on Oct. 30 and was confirmed positive for CLas on Nov. 13. This is the first confirmed CLas-positive adult ACP found …
CRDF Considers Research Management Committee Recommendations
The Citrus Research and Development Foundation (CRDF) convened its November board of directors meeting to take up recommendations from its Research Management Committee. According to Rick Dantzler, CRDF chief operating officer, one of those recommendations was funding a proposal from Swadesh Santra, who is a professor of chemistry with the University of Central Florida. “This funding would allow Dr. Santra …
Fundecitrus Honors California Researcher
Brazilian citrus research organization Fundecitrus (Fund for Protection of Citriculture) recently honored University of California Davis (UC Davis) Distinguished Professor Walter Leal for his outstanding contribution to citriculture. Fundecitrus emphasized the importance of Leal’s work on the Asian citrus psyllid (ACP) and citrus fruit borer. Brazilian native Leal is a member of the Department of Molecular and Cellular Biology faculty …
Prolong Tree Health by Combining Covers and Brassinosteroids
As every Florida citrus grower knows, it has been difficult to grow trees and fruit profitably since huanglongbing (HLB) disease was discovered in the state in 2005. Soon after the disease was discovered, officials determined it couldn’t be eradicated largely because the Asian citrus psyllids (ACP) that spread it showed up years earlier and were in virtually all citrus-producing regions. …
SAR Sprays Protect Against Psyllids, HLB and Canker
Recent research has shown that systemic acquired resistance (SAR) sprays can protect young citrus tree flushes from Asian citrus psyllid (ACP) feeding, HLB and citrus canker. ACP is the vector that spreads HLB disease from tree to tree. Researchers with the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) and Bayer Crop Science report that SAR sprays can …
Silicon Benefits Citrus
A University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researcher recently highlighted a number of benefits from using silicon as a nutrient for citrus. Muhammad Shahid, assistant professor at the North Florida Research and Education Center, presented silicon research findings at the Citrus & Specialty Crop Expo in August. According to Shahid, silicon is categorized as a plant …
Psyllid Management Tactics Discussed
Control of HLB-spreading Asian citrus psyllids (ACP) can be enhanced with dormant winter sprays and a focus on spraying grove perimeters, according to Citrus & Specialty Crop Expo presenter Jawwad Qureshi. Qureshi is an associate professor of entomology at the University of Florida Institute of Food and Agricultural Sciences Southwest Florida Research and Education Center. DORMANT SPRAYS In making the …
Fall Insect and Mite Management
By Lauren Diepenbrock Unlike northern regions, fall in Florida is not generally a time when insect, mite and other invertebrate pest populations decline rapidly. In Florida citrus, we generally see the opposite of this trend. In the hot, dry end of summer and early fall, mite populations often soar, requiring management to prevent excessive damage to fruit. (See The Florida …




























