The natural enemies Diaphorencyrtus aligarhensis and Tamarixia radiata may have a future together in California. By Ivan Milosavljević and Mark S. Hoddle Over the past 11 years, the Asian citrus psyllid (ACP)-Candidatus Liberibacter asiaticus (CLas) (manifested as citrus greening) complex has become a “duo from hell” for Florida’s citrus industry, causing a substantial negative economic effect. ACP-CLAS MANAGEMENT IN CALIFORNIA …
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 …
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 …
HLB Quarantine Expansions Impact California Commercial Citrus
Agriculture officials have expanded the areas quarantined for citrus greening disease (known as huanglongbing or HLB) in California. The quarantined area in the Corona area of Riverside County was expanded by 37 square miles. The San Juan Capistrano quarantined area of Orange County was expanded by 18 square miles. The actions were taken by the U.S. Department of Agriculture Animal …
Planning Pest Management for Florida Citrus in 2026
By Lauren Diepenbrock Pest management is a year-round challenge in Florida citrus. But with knowledge of insect, mite and snail seasonal biology in relation to tree phenology, plans can be developed to protect fruit and maintain productive citrus trees. Populations of some highly problematic pests (Asian citrus psyllid and citrus leafminer) generally increase with flush/new growth development, so targeting peak …
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 …
CITRUS NURSERY SOURCE: NVDMC’s Research Initiatives for 2025–26
By Peter Chaires Last month’s Citrus Nursery Source article promised additional details on New Varieties Development & Management Corp.’s (NVDMC) 2025–26 sponsored projects. While there is only space for general summaries, it is important to highlight the areas of focus for each research team, and the emphasis on short-term benefits while continuing to build a foundation for the future. NVDMC …
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 …
All In For Citrus Podcast, October 2025
The October All In For Citrus podcast features citrus under protective screen (CUPS). Over the past decade, the practice has grown in popularity due to its ability to exclude the Asian citrus psyllid and huanglongbing (HLB) disease. Roughly 1,500 acres of citrus are grown under screen in Florida with more acreage under development. Lauren Diepenbrock, associate professor of entomology at …
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 …
Psyllids and HLB Spreading in Georgia
Populations of Asian citrus psyllids (ACP) have been found in residential and commercial citrus in Georgia’s Lowndes and Wayne counties during the past two months. ACP spread huanglongbing (HLB) disease. In several places where ACP were found, HLB-infected trees were identified nearby. University of Georgia College of Agricultural and Environmental Sciences (UGA CAES) entomologist Apurba Barman provided details about the …
Citrus Greening Quarantine Expanded in California
Federal and state agriculture officials have expanded the quarantine for citrus greening in the Perris area of Riverside County in California by 33 square miles. The U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS) in cooperation with the California Department of Food and Agriculture (CDFA) expanded the quarantine. The measure parallels the intrastate quarantine that CDFA established …
Preventing Citrus Greening Establishment in Georgia Groves
Citrus greening disease has yet to find its footing in Georgia. But that doesn’t mean it can’t or won’t eventually. Mary Sutton, University of Georgia assistant professor and citrus Extension specialist, discussed the ramifications of citrus greening during the recent Southeast Citrus Update in Lyons, Georgia. “If we get greening established here, we’ll start seeing lower and lower production on …
Honeymoon Phase for Georgia Citrus Production
Georgia citrus growers are still in the honeymoon phase of production with regards to disease, said Jonathan Oliver, University of Georgia (UGA) assistant professor and small fruits pathologist. While established groves in Florida have had to deal with disease buildup for decades, disease has yet to be problematic for South Georgia citrus production. But that could be changing. “With respect …
Managing Psyllids in Groves and Protected Structures
By Jawwad A. Qureshi The impact of the Asian citrus psyllid continues to intensify through devastation of its vectored huanglongbing (HLB) disease. Although there is no permanent solution for HLB yet, psyllid suppression reduces its impact. Chemical control is the most implemented method. Its strategic use helps reduce psyllid resistance and collateral damage to non-target organisms, including beneficial organisms needed …
Citrus Greening Quarantines Expanded in California
Federal and state agriculture officials recently expanded the areas quarantined for citrus greening disease in California. They expanded the quarantined area in the Coto de Caza area of Orange County by 11 square miles, the Rancho Santa Margarita area of Orange County by 93 square miles, the Perris area of Riverside County by 37 square miles, and the Rancho Cucamonga …




























