By Romain Exilien and Xavier Martini Residential gardens serve as reservoirs for Asian citrus psyllids (ACP) and citrus greening disease (also known as huanglongbing or HLB) due to unmanaged citrus trees. The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) conducted a survey to assess residents’ needs regarding ACP and HLB management. The survey examined their current control …
Scouting Critical for Georgia’s Citrus Industry
Regular scouting for Asian citrus psyllids and citrus greening disease is critical for Georgia’s citrus industry to remain healthy. That advice applies to both commercial growers and homeowners, Jonathan Oliver, University of Georgia (UGA) assistant professor and small fruits pathologist, said during the recent Citrus Grower’s Summer Update meeting in Valdosta. Oliver encouraged all growers to scout for the disease …
Psyllid Control Discussed at South African Citrus Symposium
Researchers Marcelo Miranda and Haroldo Volpe with Brazil’s Fundecitrus discussed control of the HLB-spreading psyllid during a recent visit to a South African research symposium and accompanying events. During the Citrus Research Symposium in Drakensberg, Miranda discussed studies developed at Fundecitrus on the management of the HLB-spreading psyllid (Diaphorina citri). In South Africa, HLB is caused by a bacteria different …
HLB and Psyllids in Georgia Commercial Citrus
One of Georgia citrus growers’ worst fears is slowly becoming a reality. Citrus greening, also known as huanglongbing (HLB), was observed in a Georgia commercial citrus grove for the first time in 2023. This is alarming news for the industry, says Jonathan Oliver, University of Georgia (UGA) assistant professor and small fruits pathologist. “We knew HLB was here in residential …
Psyllid Nanopesticide Developed in Brazil
In Brazil, a more effective and sustainable insecticide for HLB-spreading psyllids was developed by Embrapa (Brazilian Agricultural Research Company) in partnership with the Institute of Chemistry of the State University of Campinas (Unicamp). The work resulted in a controlled-release system of the insecticide thiamethoxam molecule. Encapsulation was performed in polymeric nanoparticles, structures more than 80,000 times smaller than the thickness …
Fundecitrus Declares ‘Battle Time’ Against Psyllids
Brazil’s Fundecitrus recently declared battle in the fight against HLB-spreading psyllids. The citrus association’s recently launched “It’s battle time!” advertising campaign reinforces the need for rigor in psyllid control during the most critical period of the year. It is at this time, between the end of winter and spring, that high numbers of psyllids are captured in traps installed in …
Greening Bacterium Causes Changes in Psyllids
Recent studies, including a partnership project between Fundecitrus and the University of California, revealed that the citrus greening bacterium Candidatus Liberibacter asiaticus causes physiological changes in psyllids, posing additional challenges to management strategies. An increase in the number of eggs, more frequent dispersal flights over longer distances and greater attractiveness to the host are some of the changes observed in …
CLas-Positive Psyllid Sample in Riverside County
An adult Asian citrus psyllid (ACP) sample from a residential property in the San Jacinto Valley area of Riverside County, California, has tested positive for Candidatus Liberibacter asiaticus (CLas), the bacterium that causes huanglongbing (HLB). The positive sample was collected as part of the Multi-Pest Risk Survey on a residential property in Hemet. It was confirmed positive for CLas on …
ACP Management in High-Density Plantings
By Jawwad Qureshi The Asian citrus psyllid (ACP, Figure 1) is the vector of huanglongbing (HLB) disease associated with the phloem-limited bacterium Candidatus Liberibacter asiaticus. Infected trees start to decline and produce poor-quality fruit, which drops prematurely. Consequently, citrus production has decreased dramatically since the advent of HLB in Florida in 2005. There is no cure for the disease yet. …
‘The Psyllids Will Like Georgia Just Fine’
A California citrus leader believes Georgia will make an ideal home for the Asian citrus psyllid, which vectors the devastating huanglongbing (HLB) disease. “North of Florida, it is colder, and it’s certainly not as suitable a place as Florida is, but the psyllid is still going to be fine. The cold isn’t long enough here to knock the populations out,” …
New Tool Will Help Brazilian Growers Manage Psyllids
Fundecitrus has launched Evaluate Psyllid, a tool that will help citrus growers choose insecticides to manage the pest that spreads citrus greening disease. Evaluate Psyllid will make available the results of insecticide efficacy experiments on field psyllid populations in different regions of Brazil’s citrus belt. The insecticide efficacy data will be constantly updated as experiments are carried out. It will …
Pheromone-Based Psyllid Control Not Viable
Studies with psyllid pheromones show that the insect’s behavior is altered when it is infected by the HLB-causing bacterium Candidatus Liberibacter (CLas). This makes it difficult to produce a commercial psyllid-control product based on the insect pheromone, Brazil’s Fundecitrus has concluded. “The sexual pheromone is an attractant produced by the female of the species, which promotes behavioral changes in male …
California’s CRaFT Accepting Cycle 2 Applications
California’s Citrus Research and Field Trials (CA-CRaFT) program is now accepting Cycle 2 applications from commercial growers. This initiative aims to showcase the efficacy of additional control measures against the Asian citrus psyllid (ACP). ACP is the carrier of the Candidatus Liberibacter asiaticus bacterium causing huanglongbing (HLB) disease in citrus. For Cycle 2, applications will be accepted until program capacity …
New Discovery About Asian Citrus Psyllids
A failed field test has led to a major discovery about Asian citrus psyllids (ACP). According to new research, the bacterium that causes HLB disease can interfere with ACP’s sense of smell, rendering some kinds of insect traps useless. The work is currently available as a preprint. HLB, also known as citrus greening, is caused by the Candidatus Liberibacter asiaticus (CLas) bacterium. …
Mulch Suppresses Psyllids in Young Trees
By Jawwad A. Qureshi, Lauren Diepenbrock and Davie Kadyampakeni Protecting citrus trees from the Asian citrus psyllid (ACP) is critical to reducing the spread and severity of huanglongbing (HLB) disease. The frequent availability of viable shoots in young trees is attractive to psyllid colonization, feeding and oviposition events. UV-metalized reflective mulches reflect ultraviolet light, which is disturbing for some insects …
New Research on Neonicotinoids for Psyllids
Continuing Brazilian research into the application of neonicotinoids via drench for control of HLB-spreading psyllids shows higher efficacy than earlier results indicated. In September, Fundecitrus released preliminary results on the application of neonicotinoids via drench. At that time, tests carried out on a property in Casa Branca, São Paulo, showed that the efficiency of the molecules for this type of …
Follow Thresholds for ACP Control
One of the key components of managing HLB is keeping its vector, the Asian citrus psyllid (ACP), in check. Management recommendations for the pest have evolved over time. The history of that evolution is a subject of discussion in the November episode of the All In For Citrus podcast. Lukasz Stelinksi, an entomologist with the University of Florida Institute of …
First CLas-Positive Psyllids Found in Ventura County
A Candidatus Liberibacter asiaticus (CLas)-positive Asian citrus psyllid (ACP) sample has been collected from a residential property in California’s Ventura County. CLas is the bacterium that causes HLB. The Citrus Research Board’s Jerry Dimitman Laboratory confirmed the positive sample. This is the first confirmed CLas-positive ACP sample found in Ventura County. The positive sample, comprised of 12 adult psyllids from …
Psyllid Resistance to Organophosphates Begins in Brazil
Research has confirmed the initial phase of resistance of the HLB-spreading psyllid to the active ingredient malathion in some microregions of the citrus belt of São Paulo and Triângulo/Southwest Mineiro. Malathion is from the organophosphate chemical group. The research was conducted by Fundecitrus in partnership with Luiz de Queiroz College of Agriculture/University of São Paulo (Esalq/USP). This is the third …
Brazil Breaks Psyllid Record Again
The Brazilian citrus belt of São Paulo and Triângulo/Sudoeste Mineiro has recorded yet another record high in the average number of greening-spreading Asian citrus psyllids captured by traps. In the second half of August, there was an average growth of 147% in the average catch compared to the previous two-week period. The average jumped from 3.4 to 8.4 insects per …