scholarly journals Progress Toward an Attract-and-Kill Device for Asian Citrus Psyllid (Hemiptera: Liviidae) Using Volatile Signatures of Citrus Infected With Huanglongbing as the Attractant

2020 ◽  
Vol 20 (6) ◽  
Author(s):  
Xavier Martini ◽  
Angelique Hoyte ◽  
Agenor Mafra-Neto ◽  
Alexander A Aksenov ◽  
Cristina E Davis ◽  
...  
Keyword(s):  
Slow Release ◽  
Field Trials ◽  
Citrus Greening ◽  
Asian Citrus Psyllid ◽  
Phytopathogenic Bacterium ◽  
Geranyl Acetone ◽  
Attract And Kill ◽  
Candidatus Liberibacter ◽  
Small Plot ◽  
Citrus Orchards

Abstract Asian citrus psyllid, Diaphorina citri (Kuwayama), preferentially orient toward citrus hosts infected with the phytopathogenic bacterium, Candidatus liberibacter asiaticus (CLas) the agent of citrus greening (Huanglongbing, HLB), compared to uninfected counterparts. We investigated whether this preference for the odors of infected plants could be useful for the development of an attract-and-kill (AK) device for D. citri. Twenty-nine blends of volatile organic compounds derived from the odor of citrus infected with CLas were tested in laboratory olfactometer tests, and two blends were also assessed under field conditions. A seven component blend of tricosane: geranial: methyl salicylate: geranyl acetone: linalool: phenylacetaldehyde: (E)-β-ocimene in a 0.40: 0.06: 0.08: 0.29: 0.08: 0.06: 0.03 ratio released from a proprietary slow-release matrix attracted twice more D. citri to yellow sticky traps compared with blank control traps. The attractive blend was subsequently co-formulated with spinosad insecticide into a slow-release matrix to create a prototype AK formulation against D. citri. This formulation effectively reduced the population density of D. citri up to 84% as measured with tap counts when deployed at a density of eight 2.5 g dollops per tree as compared with untreated controls in small plot field trials conducted in citrus orchards. Psyllid populations were not statistically affected at a deployment rate of four dollops per tree. Our results indicate that an AK formulation incorporating spinosad and a volatile blend signature of citrus greening into a slow-release matrix may be useful to suppress D. citri populations.

scholarly journals Tracing Penicillin Movement in Citrus Plants Using Fluorescence-Labeled Penicillin

Antibiotics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 262
Author(s):  
Nabil Killiny ◽  
Pedro Gonzalez-Blanco ◽  
Yulica Santos-Ortega ◽  
Fuad Al-Rimawi ◽  
Amit Levy ◽  
...  
Keyword(s):  
Vascular Tissue ◽  
Vascular System ◽  
Citrus Greening ◽  
Application Site ◽  
Asian Citrus Psyllid ◽  
Diaphorina Citri ◽  
Candidatus Liberibacter Asiaticus ◽  
Citrus Industry ◽  
Candidatus Liberibacter ◽  
Liberibacter Asiaticus

Huánglóngbìng (HLB), citrus greening, is one of the most destructive diseases of citrus plants worldwide. In North America, HLB is caused by the phloem-limited bacterium Candidatus Liberibacter asiaticus and is transmitted by the Asian citrus psyllid, Diaphorina citri. No cure exists at present, and the use of antibiotics for the control of HLB has gained interest due to the significant losses to the citrus industry. Because of unsatisfactory results when using foliar applications of antibiotics, concerns were raised regarding the uptake and translocation of these materials within trees. We, therefore, investigated a method that allows us to study the movement of antibiotic materials in citrus plants. Herein, we utilized a fluorescence-labeled penicillin, BOCILLIN™ FL-Penicillin (FL-penicillin), to study the uptake and translocation of penicillin in citrus plants. FL-penicillin was applied by puncture to the stem of young citrus seedlings and was traced by using fluorescence microscopy. After application, we detected FL-penicillin in the leaves and in the stem xylem and phloem tissues above and below the application site in both intact and partially bark-girdled citrus seedlings, indicating that it is easily taken up and transported through the plant vascular system. In addition, we detected FL-penicillin in the gut of D. citri, which were allowed to feed on the treated plants, suggesting translocation of this molecule into the vascular tissue. We propose that the use of fluorescent-labeled molecules could be an effective tool for understanding the uptake and translocation of antibiotics and other macromolecules in plants and insects.

scholarly journals Understanding Citrus Greening Disease and Its Possible Management Strategies in Nepal

2021 ◽  
Vol 9 (4) ◽  
pp. 227-234
Author(s):  
Sameer Pokhrel ◽  
Swikriti Pandey ◽  
Ashish Ghimire ◽  
Savyata Kandel
Keyword(s):  
Management Strategies ◽  
Citrus Greening ◽  
Insect Vector ◽  
Candidatus Liberibacter Asiaticus ◽  
Citrus Greening Disease ◽  
The World ◽  
Citrus Production ◽  
Candidatus Liberibacter ◽  
Liberibacter Asiaticus ◽  
Citrus Orchards

Huanglongbing (HLB), also known as citrus greening, is a devastating disease of citrus that has decimated several citrus orchards throughout the world. The disease is associated with three species of unculturable and phloem-limited bacteriae, Candidatus Liberibacter asiaticus, Candidatus Liberibacter africanus and Candidatus Liberibacter americanus. The most common species of bacteria found in Nepal is Candidatus Liberibacter asiaticus which is transmitted by an insect vector, Asian citrus psyllid (Diaphorina citri). This disease has been detected in several economically important citrus production areas of Nepal, which resulted in heavy yield loss. No cure for the disease has been discovered yet and it is essential to practice proper management strategies to maintain citrus health and sustain citrus production under HLB pressure. Several disease management approaches such as pathogen-free nursery establishment, use of disease tolerant rootstock cultivars, proper irrigation and nutrient supply, removal of HLB affected trees, and control of psyllid with frequent insecticide application are widely practiced throughout the world. This review article highlights the characteristics of the citrus greening disease and its insect vector and gives insights into their management techniques. Several technologically advanced options available to minimize the HLB infection might not be feasible currently in Nepal due to economic and topographic constraints. This article also aims to bring into focus the cost-effective methods that growers in Nepal can practice to mitigate the impact of HLB disease in their citrus orchards. Int. J. Appl. Sci. Biotechnol. Vol 9(4): 227-238.

scholarly journals Can the Addition of Odor and Visual Targets Enhance Attraction of the Asian Citrus Psyllid (Hemiptera: Liviidae) to Sticky Traps?

2020 ◽  
Vol 113 (5) ◽  
pp. 2563-2567 ◽  
Author(s):  
Arjun Khadka ◽  
Sandra A Allan ◽  
Daniel Cho ◽  
Emma N I Weeks
Keyword(s):  
Methyl Salicylate ◽  
Trapping Efficiency ◽  
Citrus Greening ◽  
Asian Citrus Psyllid ◽  
Citrus Industry ◽  
Sticky Traps ◽  
Yellow Traps ◽  
Candidatus Liberibacter ◽  
Visual Targets ◽  
Yellow Sticky Traps

Abstract Asian citrus psyllid, Diaphorina citri Kuwayama, negatively impacts the citrus industry as it transmits Candidatus Liberibacter spp., the causal agent of citrus greening. Monitoring D. citri population levels is critical for management of vectors and citrus greening and is usually through use of yellow sticky traps. In our study, use of odors, odor blends, and visual targets were evaluated to determine whether attraction to yellow sticky traps could be improved. Methyl salicylate consistently increased D. citri attraction to decoy yellow but not to other yellow or yellow/green traps. Addition of a visual target did not enhance attraction to sticky traps. While several chemical blends were evaluated, they did not increase psyllid attraction to decoy yellow traps. The increased attraction to traps with methyl salicylate is promising and may contribute to trapping efficiency under field conditions.

scholarly journals Temporal Rhythm Affects the Efficiency of Asian Citrus Psyllid (Diaphorina citri) to Acquire Huanglongbing Pathogen

Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1956
Author(s):  
Yan-Jun Guo ◽  
Yi-Han Li ◽  
Zheng-Qin Su ◽  
Pei-Ping Xu ◽  
Bao-Li Qiu ◽  
...  
Keyword(s):  
Guangdong Province ◽  
Management Program ◽  
Citrus Greening ◽  
Effective Control ◽  
Asian Citrus Psyllid ◽  
Diaphorina Citri ◽  
Citrus Greening Disease ◽  
Feeding Duration ◽  
Candidatus Liberibacter ◽  
Temporal Rhythm

Huanglongbing, commonly known as citrus greening, is a devastating disease of citrus worldwide. Candidatus liberibacter asiaticus is the putative cause of citrus greening disease in China and is spread through the process of plant grafting and feeding by insect vectors. Asian citrus psyllid (Diaphorina citri) is a destructive pest due to insecticide resistance development and the main cause of dissemination of Huanglongbing. The purpose of this study was to determine the level of Huanglongbing present in Guangdong province and the acquisition of the pathogen by D. citri through feeding. Six different city areas of Guangdong province were sampled. The results demonstrated that Yunfu currently has the highest infestation rate of CLas in Guangdong province, followed by Chaozhou, Jiangmen, and Foshan. In comparison, Zhongshan and Maoming have the lowest infestation rates. Results also showed that CLas acquisition was directly proportional to the insect feeding duration. The longer an insect fed on an infested plant, the more CLas it acquired. The acquisition efficiency of the pathogen was higher at night compared to during the daytime. During the time period of 15:00–07:00 D. citri acquires more pathogens than during the period of 07:00–15:00. This study provides a basic understanding of the feeding pattern of D. citri, which aids in devising a management program for effective control of direct and indirect losses caused by D. citri.

scholarly journals Dynamics of the Degradation of Acetyl-CoA Carboxylase Herbicides in Vegetables

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 405
Author(s):  
Miroslav Jursík ◽  
Kateřina Hamouzová ◽  
Jana Hajšlová
Keyword(s):  
Linear Models ◽  
Growing Season ◽  
Field Trials ◽  
Baby Food ◽  
Vegetable Production ◽  
The Czech Republic ◽  
Herbicide Residues ◽  
Harvest Intervals ◽  
Small Plot

(1) Background: Aryloxyphenoxy-propionates and cyclohexanediones are herbicides most widely used in dicot crops worldwide. The main objective of the study was to determine the dynamics of herbicide residues in carrot, lettuce, cauliflower, and onion in order to suggest a low level of residues in harvested vegetables. (2) Methods: Small plot field trials were carried out in four vegetables in the Czech Republic. The samples of vegetables were collected continuously during the growing season. Multiresidue methods for the determination of herbicide residues by LC-MS/MS were used. Non-linear models of degradation of individual herbicides in vegetables were calculated using the exponential decay formula. Action GAP pre-harvest intervals for the 25% and 50% maximum residue limit (MRL) and 10 µg kg−1 limit (baby food) were established for all tested herbicides. (3) Results: The degradation dynamics of fluazifop in carrot, onion, and cauliflower was significantly slower compared to quizalofop and haloxyfop. The highest amount (2796 µg kg−1) of fluazifop residues was detected in cauliflower 11 days after application. No residue of propaquizafop and cycloxydim was detected in any vegetable samples. (4) Conclusions: Aryloxyphenoxy-propionate herbicide (except propaquizafop) could contaminate vegetables easily, especially vegetables with a short growing season. Vegetables treated with fluazifop are not suitable for baby food. Lettuce and cauliflower treated by quizalofop are not suitable for baby food, but in onion and carrot, quizalofop could be used. Propaquizafop and cycloxydim are prospective herbicides for non-residual (baby food) vegetable production.

Insecticide sprays, natural enemy assemblages and predation on Asian citrus psyllid, Diaphorina citri (Hemiptera: Psyllidae)

2014 ◽  
Vol 104 (5) ◽  
pp. 576-585 ◽  
Author(s):  
C. Monzo ◽  
J.A. Qureshi ◽  
P.A. Stansly
Keyword(s):  
Natural Enemy ◽  
Early Spring ◽  
Citrus Greening ◽  
Asian Citrus Psyllid ◽  
Late Winter ◽  
Diaphorina Citri ◽  
Citrus Groves ◽  
Arthropod Fauna ◽  
Predator Exclusion ◽  
Insecticide Sprays

AbstractThe Asian citrus psyllid (ACP), Diaphorina citri Kuwayama is considered a key citrus pest due to its role as vector of ‘huanglongbing’ (HLB) or citrus greening, probably the most economically damaging disease of citrus. Insecticidal control of the vector is still considered a cornerstone of HLB management to prevent infection and to reduce reinoculation of infected trees. The severity of HLB has driven implementation of intensive insecticide programs against ACP with unknown side effects on beneficial arthropod fauna in citrus agroecosystems. We evaluated effects of calendar sprays directed against this pest on natural enemy assemblages and used exclusion to estimate mortality they imposed on ACP populations in citrus groves. Predator exclusion techniques were used on nascent colonies of D. citri in replicated large untreated and sprayed plots of citrus during the four major flushing periods over 2 years. Population of spiders, arboreal ants and ladybeetles were independently assessed. Monthly sprays of recommended insecticides for control of ACP, adversely affected natural enemy populations resulting in reduced predation on ACP immature stages, especially during the critical late winter/early spring flush. Consequently, projected growth rates of the ACP population were greatest where natural enemies had been adversely affected by insecticides. Whereas, this result does not obviate the need for insecticidal control of ACP, it does indicate that even a selective regimen of sprays can impose as yet undetermined costs in terms of reduced biological control of this and probably other citrus pests.

scholarly journals A Survey for ‘Candidatus Liberibacter’ Species in South Africa Confirms the Presence of Only ‘Ca. L. africanus’ in Commercial Citrus

Plant Disease ◽  
2010 ◽  
Vol 94 (2) ◽  
pp. 244-249 ◽  
Author(s):  
G. Pietersen ◽  
E. Arrebola ◽  
J. H. J. Breytenbach ◽  
L. Korsten ◽  
H. F. le Roux ◽  
...  
Keyword(s):  
South Africa ◽  
Western Cape ◽  
Chain Reaction ◽  
Citrus Production ◽  
Candidatus Liberibacter ◽  
Citrus Orchards ◽  
Polymerase Chain ◽  
Serious Disease ◽  
Production Areas ◽  
Representative Samples

Greening disease of citrus is a serious disease known in South Africa since the late 1920s. In South Africa, it is associated with infection by ‘Candidatus Liberibacter africanus’, a heat sensitive, phloem-limited, noncultured alpha-proteobacterium. Huanglongbing (HLB), a similar, but more devastating disease that was described initially from China but which now occurs in several citrus producing countries, is associated with a different Liberibacter species, ‘Ca. L. asiaticus’. A ‘Ca. L. africanus’ subspecies, ‘Ca. L. africanus subsp. capensis’, has been found only in South Africa infecting an indigenous Rutaceous species, Calodendrum capense (Cape Chestnut), in the Western Cape in 1995. The discovery of a new Liberibacter species in Brazil, ‘Ca. L. americanus’, and the spread of ‘Ca. L. asiaticus’ to a number of additional countries over the last few years prompted us to assess whether only ‘Ca. L. africanus’ is present in commercial citrus orchards in South Africa. Samples displaying greening or similar symptoms were collected from 249 citrus trees from 57 orchards distributed throughout the greening affected citrus production areas of South Africa. Multiplex polymerase chain reaction (PCR) was performed on DNA extracts to detect the known citrus Liberibacters. Amplicons were obtained from 197 samples. None of the samples yielded a 1,027-bp amplicon indicative of ‘Ca. L. americanus’ infection. The amplicons of 84 samples were sequenced, and all were identical to the cognate ‘Ca. L. africanus’ Nelspruit sequence in GenBank. No instance of ‘Ca. L. asiaticus’ or ‘Ca. L. africanus subsp. capensis’ sequence was found. Geographically representative samples that tested negative for Liberibacter also tested negative for phytoplasmas based on real-time PCR results. Based on the results of this survey, it is concluded that to date only ‘Ca. L. africanus’ is associated with citrus greening in commercial citrus in South Africa.

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