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transmission and propagation of 'candidatus liberibacter asiaticus' by grafting with individual citrus leaves.huanglongbing (hlb) is a chronic, progressive decline disease in citrus associated with a systemic infection by the bacterium 'candidatus liberibacter asiaticus'. transmission of the bacterium in the field is by the asian citrus psyllid, diaphorina citri kuwayama. experimental propagation of 'ca. l. asiaticus' is done primarily by grafting pieces of bud wood from an infected plant. to produce a small-scale model system for investigation of pathogen biology, we investigated grafting single leaves ...201626807818
efficacy of essential oil of piper aduncum against nymphs and adults of diaphorina citri.insecticide application is the main way to control diaphorina citri. however, it causes environmental contamination, has a negative impact on beneficial organisms and leads to psyllid resistance. the essential oil of piper aduncum has low toxicity towards the environment and contains dillapiol, which has proven to be effective against several crop pests. here, we studied its efficacy against nymphs and adults of d. citri under laboratory conditions. oils with three concentrations of dillapiol (6 ...201626331551
the push-pull strategy for citrus psyllid control.the asian citrus psyllid (acp), diaphorina citri kuwayama (hemiptera: psyllidae), is the only natural vector of candidatus liberibacter asiaticus that causes citrus huanglongbing (hlb), a most destructive disease of citrus. currently, no remedial therapy exists for the disease, and so effective control of acp is very important in curbing the transmission of the disease. the push-pull strategy should be thoroughly explored as an approach to acp management. this mini-review summarises the current ...201525256398
changes in variable number of tandem repeats in 'candidatus liberibacter asiaticus' through insect transmission.citrus greening (huanglongbing) is the most destructive citrus disease worldwide. the disease is associated with three species of 'candidatus liberibacter' among which 'ca. liberibacter asiaticus' has the widest distribution. 'ca. l. asiaticus' is commonly transmitted by a phloem-feeding insect vector, the asian citrus psyllid diaphorina citri. a previous study showed that isolates of 'ca. l. asiaticus' were clearly differentiated by variable number of tandem repeat (vntr) profiles at four loci ...201526402645
diaphorina citri (hemiptera: liviidae) vector competence for the citrus greening pathogen 'candidatus liberibacter asiaticus'.characterizing the vector competence of diaphorina citri kuwayama for 'candidatus liberibacter asiaticus,' the pathogen causing citrus greening, is essential for understanding the epidemiology of this disease that is threatening the u.s. citrus industry. vector competence studies have been difficult because of the biology of d. citri, the inability to culture the pathogen, and the available diagnostic methods used to detect the bacteria in plant and insect tissues. the methods employed in many s ...201526470202
bionomics of asian citrus psyllid (hemiptera: liviidae) associated with orange jasmine hedges in southeast central florida, with special reference to biological control by tamarixia radiata.the asian citrus psyllid, diaphorina citri kuwayama, is an important pest in florida because it transmits bacteria responsible for citrus huanglongbing disease. in addition to infesting citrus, orange jasmine (murraya exotica l.) is one of asian citrus psyllid's preferred host plants and is widely grown as an ornamental hedge. we report on asian citrus psyllid bionomics over three years at five urban plantings of orange jasmine and on biological control of asian citrus psyllid by a parasitoid ta ...201526470246
chemical control of the asian citrus psyllid and of huanglongbing disease in citrus.by 2014, huanglongbing (hlb), the most destructive disease of citrus, and its insect vector, the asian citrus psyllid (acp), diaphorina citri (kuwayama), became established in all major citrus-growing regions of the world, including the united states, with the exception of california. at present, application of insecticides is the most widely followed option for reducing acp populations, while application of antibiotics for suppressing hlb disease/symptoms is being practiced in some citrus-growi ...201525491482
sampling methods for detection and monitoring of the asian citrus psyllid (hemiptera: psyllidae).the asian citrus psyllid (acp), diaphorina citri kuwayama is a key pest of citrus due to its role as vector of citrus greening disease or "huanglongbing." acp monitoring is considered an indispensable tool for management of vector and disease. in the present study, datasets collected between 2009 and 2013 from 245 citrus blocks were used to evaluate precision, sensitivity for detection, and efficiency of five sampling methods. the number of samples needed to reach a 0.25 standard error-mean rati ...201526313984
comprehensive meta-analysis, co-expression, and mirna nested network analysis identifies gene candidates in citrus against huanglongbing disease.huanglongbing (hlb), the most devastating disease of citrus, is associated with infection by candidatus liberibacter asiaticus (calas) and is vectored by the asian citrus psyllid (acp). recently, the molecular basis of citrus-hlb interactions has been examined using transcriptome analyses, and these analyses have identified many probe sets and pathways modulated by calas infection among different citrus cultivars. however, lack of consistency among reported findings indicates that an integrative ...201526215595
infection of an insect vector with a bacterial plant pathogen increases its propensity for dispersal.the spread of vector-transmitted pathogens relies on complex interactions between host, vector and pathogen. in sessile plant pathosystems, the spread of a pathogen highly depends on the movement and mobility of the vector. however, questions remain as to whether and how pathogen-induced vector manipulations may affect the spread of a plant pathogen. here we report for the first time that infection with a bacterial plant pathogen increases the probability of vector dispersal, and that such movem ...201526083763
morphological, molecular and virulence characterization of three lencanicillium species infecting asian citrus psyllids in huangyan citrus groves.citrus greening or huanglongbing (hlb) is caused by the infection of candidatus liberibacter spp. in citrus plants. since asian citrus psyllid is the primary vector of this bacterial pathogen, the spread of hlb can be mitigated by suppressing asian citrus psyllid populations in citrus groves using entomopathogens. to expand the current data on entomopathogens infecting asian citrus psyllids, we isolated and characterized three different entomopathogens. strains zjlsp07, zjla08, and zjlp09 infect ...201525593036
asian citrus psyllid expression profiles suggest candidatus liberibacter asiaticus-mediated alteration of adult nutrition and metabolism, and of nymphal development and immunity.the asian citrus psyllid (acp) diaphorina citri kuwayama (hemiptera: psyllidae) is the insect vector of the fastidious bacterium candidatus liberibacter asiaticus (clas), the causal agent of citrus greening disease, or huanglongbing (hlb). the widespread invasiveness of the psyllid vector and hlb in citrus trees worldwide has underscored the need for non-traditional approaches to manage the disease. one tenable solution is through the deployment of rna interference technology to silence protein- ...201526091106
cloning and expressing a highly functional and substrate specific farnesoic acid o-methyltransferase from the asian citrus psyllid (diaphorina citri kuwayama).the asian citrus psyllid, diaphorina citri, transmits a phloem-limited bacterium, candidatus 'liberibacter' asiaticus that causes citrus greening disease. because juvenile hormone (jh) plays an important role in adult and nymphal development, we studied the final steps in jh biosynthesis in d. citri. a putative jh acid methyltransferase ortholog gene (jmtd) and its cognate cdna were identified by searching d. citri genome database. expression analysis shows expression in all life stages. in adul ...201525893162
living on the edges: spatial niche occupation of asian citrus psyllid, diaphorina citri kuwayama (hemiptera: liviidae), in citrus groves.the spatial niche occupation of the asian citrus psyllid, diaphorina citri kuwayama, 1908, was evaluated to determine its field colonization and food resource exploitation strategies in citrus groves. mature grapefruit and sweet orange groves were surveyed as part of an area-wide program in 2009-2010 to determine d. citri population densities and between-tree distribution. in both cultivars, significantly more psyllids were found on perimeter trees throughout the study period suggesting a strong ...201526193111
effect of cyantraniliprole, a novel insecticide, on the inoculation of candidatus liberibacter asiaticus associated with citrus huanglongbing by the asian citrus psyllid (hemiptera: liviidae).the asian citrus psyllid (diaphorina citri kuwayama) is the principal vector of 'candidatus liberibacter asiaticus' (clas) associated with huanglongbing (hlb), the most serious citrus disease worldwide. new control measures including pesticides are urgently needed to combat hlb, especially to protect young or newly planted citrus trees from clas-inoculation by vector psyllids. here, we tested clas-inoculation by d. citri adults (clas-exposed, reared on infected plants) by feeding them for 7 d on ...201526470150
diaphorina citri (hemiptera: liviidae) abundance in puerto rico declines with elevation.diaphorina citri kuwayama is the primary vector of huanglongbing, the most devastating disease of citrus. d. citri populations in puerto rico were monitored with yellow sticky traps on citrus trees or other psyllid host plants at different elevations, ranging from 10 to 880 m above sea level. trapping was conducted in march through may of 2013 and 2014 when psyllid populations usually are highest. population levels of d. citri, based on the trapping data, varied among the sites, and there was a ...201526470127
lethal and sublethal impacts of acaricides on tamarixia radiata (hemiptera: eulophidae), an important ectoparasitoid of diaphorina citri (hemiptera: liviidae).the use of synthetic acaricides for management of pest mites may alter the efficacy of the ectoparasitoid tamarixia radiata (waterston) in biological control of diaphorina citri kuwayama, the vector of the bacteria associated with huanglongbing (hlb) in citrus orchards. we evaluated the toxicity of 16 acaricides that are recommended for the control of citrus-pest mites to t. radiata. acrinathrin, bifenthrin, carbosulfan, and fenpropathrin caused high acute toxicity and were considered harmful (m ...201526453716
whole-genome sequence of "candidatus profftella armatura" from diaphorina citri in guangdong, china.the genome of "candidatus profftella armatura" strain ycpa from diaphorina citri in guangdong, china, was sequenced. the strain has a chromosome of 457,565 bp, 24.3% g+c content, 364 predicted open reading frames (orfs), and 38 rnas, and a plasmid, pycpa54, of 5,458 bp with 23.9% g+c content and 5 orfs.201526543117
host range testing of diaphorencyrtus aligarhensis (hymenoptera: encyrtidae) for use in classical biological control of diaphorina citri (hemiptera: liviidae) in california.host range tests for diaphorencyrtus aligarhensis (shafee, alam, & agarwal) (hymenoptera: encyrtidae), an endoparasitoid of asian citrus psyllid, diaphorina citri kuwayama (hemiptera: liviidae), sourced from punjab pakistan, were conducted in quarantine at the university of california, riverside, ca. seven nontarget psyllid species representing four psyllid families were exposed to mated d. aligarhensis females in four different treatment types: 1) short sequential no-choice treatments, 2) prolo ...201526470214
characterization of a recombinant cathepsin b-like cysteine peptidase from diaphorina citri kuwayama (hemiptera: liviidae): a putative target for control of citrus huanglongbing.huanglonbing (hlb) is one of the most destructive disease affecting citrus plants. the causal agent is associated with the phloem-limited bacterium candidatus liberibacter asiaticus (clas) and the psyllid diaphorina citri, vector of disease, that transmits the bacterium associated with hlb. the control of disease can be achieved by suppressing either the bacterium or the vector. among the control strategies for hlb disease, one of the widely used consists in controlling the enzymes of the diseas ...201526717484
effect of uv-blocking plastic films on take-off and host plant finding ability of diaphorina citri (hemiptera: liviidae).the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: liviidae), is a major pest of citrus worldwide due to its ability to transmit the bacteria associated with huanglongbing. vision, behavior, and performance of insect pests can be manipulated by using ultraviolet (uv)-blocking materials. thus, the aim of our study was to evaluate how uv-blocking plastic films may affect the take-off and host plant finding ability of d. citri. to assess the effect of a uv-deficient environment on take ...201526470126
metabolic interplay between the asian citrus psyllid and its profftella symbiont: an achilles' heel of the citrus greening insect vector.'candidatus liberibacter asiaticus' (clas), the bacterial pathogen associated with citrus greening disease, is transmitted by diaphorina citri, the asian citrus psyllid. interactions among d. citri and its microbial endosymbionts, including 'candidatus profftella armatura', are likely to impact transmission of clas. we used quantitative mass spectrometry to compare the proteomes of clas(+) and clas(-) populations of d. citri, and found that proteins involved in polyketide biosynthesis by the end ...201526580079
seasonal movement patterns and long-range dispersal of asian citrus psyllid in florida citrus.the asian citrus psyllid, diaphorina citri kuwayama, is the vector of the bacterial pathogen, candidatus liberibacter asiaticus, which is the causal agent of huanglongbing (hlb) in the united states. both short-range and long-range dispersal of d. citri adults affect the spread of hlb; however, little is known about the long-range dispersal capabilities of d. citri in the field or the seasonality of flight behavior. in the present study, an in situ protein marking technique was used to determine ...201526470097
draft genome sequence of "candidatus liberibacter asiaticus" from diaphorina citri in guangdong, china.the draft genome sequence of "candidatus liberibacter asiaticus" strain ycpsy from an asian citrus psyllid (diaphorina citri) in guangdong, china, is reported here. the ycpsy strain has a genome size of 1,233,647 bp, 36.5% g+c content, 1,171 open reading frames (orfs), and 53 rnas.201526543132
lethal and sublethal effects of insecticides used on citrus, on the ectoparasitoid tamarixia radiata.huanglongbing (hlb) is a disease associated with the bacteria "candidatus liberibacter spp." and has been devastating citrus orchards around the world. its management involves control of the insect vector, the asian citrus psyllid diaphorina citri kuwayama. however, the indiscriminate use of chemicals has caused pest outbreaks and eliminated the natural enemies of the vector, such as the parasitoid tamarixia radiata (waterston), the main agent for biological control of d. citri. this study asses ...201526132327
morphometric comparisons of diaphorina citri (hemiptera: liviidae) populations from iran, usa and pakistan.the asian citrus psyllid (acp), diaphorina citri kuwayama (hemiptera: liviidae), vector of citrus greening disease pathogen, huanglongbing (hlb), is considered the most serious pest of citrus in the world. prior molecular based studies have hypothesized a link between the d. citri in iran and the usa (florida). the purpose of this study was to collect morphometric data from d. citri populations from iran (mtcoi haplotype-1), florida (mtcoi haplotype-1), and pakistan (mtcoi haplotype-6), to deter ...201526038715
asymptomatic spread of huanglongbing and implications for disease control.huanglongbing (hlb) is a bacterial infection of citrus trees transmitted by the asian citrus psyllid diaphorina citri. mitigation of hlb has focused on spraying of insecticides to reduce the psyllid population and removal of trees when they first show symptoms of the disease. these interventions have been only marginally effective, because symptoms of hlb do not appear on leaves for months to years after initial infection. limited knowledge about disease spread during the asymptomatic phase is e ...201526034273
imidacloprid sorption kinetics, equilibria, and degradation in sandy soils of florida.imidacloprid (imd) is a neonicotinoid insecticide soil-drenched on sandy soils of southwest florida for the control of diaphorina citri kuwayama or asian citrus psyllid (acp). the acp vectors causal pathogens of a devastating citrus disease called citrus greening. understanding the behavior of imd in these soils and plants is critical to its performance against target pests. samples from immokalee fine sand (ifs) were used for sorption kinetics and equilibria experiments. imd kinetics data were ...201525938475
infection density dynamics of the citrus greening bacterium "candidatus liberibacter asiaticus" in field populations of the psyllid diaphorina citri and its relevance to the efficiency of pathogen transmission to citrus plants.huanglongbing, or citrus greening, is a devastating disease of citrus plants recently spreading worldwide, which is caused by an uncultivable bacterial pathogen, "candidatus liberibacter asiaticus," and vectored by a phloem-sucking insect, diaphorina citri. we investigated the infection density dynamics of "ca. liberibacter asiaticus" in field populations of d. citri with experiments using field-collected insects to address how "ca. liberibacter asiaticus" infection density in the vector insect ...201525819961
internal extracellular bacteria of diaphorina citri kuwayama (hemiptera: psyllidae), the asian citrus psyllid.the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), is an invasive insect pest that transmits candidatus liberibacter spp. this insect/pathogen system was first identified in north america in the early 2000's and has become the top threat to the citrus industry. limited options for management of this problem exist; therefore, innovative pest management strategies are being developed. in this study, we describe the first step toward a paratransgenic approach (also referred ...201525645736
effects of methoprene, a juvenile hormone analog, on survival of various developmental stages, adult emergence, reproduction and behavior of asian citrus psyllid, diaphorina citri kuwayama.the asian citrus citrus psyllid, diaphorina citri kuwayama, transmits a bacterium that causes huanglongbing in citrus. frequent and repeated use of neurotoxic insecticides against d. citri has resulted in the development of insecticide resistance. we evaluated the effects of the juvenile hormone analog methoprene on egg hatch, nymphal development, adult emergence, reproduction and behavior of d. citri.201525583143
diverse array of new viral sequences identified in worldwide populations of the asian citrus psyllid (diaphorina citri) using viral metagenomics.the asian citrus psyllid, diaphorina citri, is the natural vector of the causal agent of huanglongbing (hlb), or citrus greening disease. together; hlb and d. citri represent a major threat to world citrus production. as there is no cure for hlb, insect vector management is considered one strategy to help control the disease, and d. citri viruses might be useful. in this study, we used a metagenomic approach to analyze viral sequences associated with the global population of d. citri. by sequenc ...201526676774
the genetic structure of an invasive pest, the asian citrus psyllid diaphorina citri (hemiptera: liviidae).the asian citrus psyllid diaphorina citri is currently the major threat to the citrus industry as it is the vector of candidatus liberibacter, the causal agent of huanglongbing disease (hlb). d. citri is native to asia and now colonizes the americas. although it has been known in some countries for a long time, invasion routes remain undetermined. there are no efficient control methods for the hlb despite the intensive management tools currently in use. we investigated the genetic variability an ...201425545788
first record of diaphorina citri (hemiptera: psyllidae) in ecuador infesting urban citrus and orange jasmine trees.adults and nymphs of the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), were collected in the guayaquil, samborondón, and durán cantons in coastal ecuador. psyllids were found in high numbers in citrus (citrus spp., sapindales: rutaceae) and orange jasmine (murraya exotica [l.] jack, sapindales: rutaceae) trees within the guayaquil-samborondon-duran conurbation; however, none was found during scoutings in the main citrus producing areas in coastal ecuador. to the best of ...201425527601
innate and conditioned responses to chemosensory and visual cues in asian citrus psyllid, diaphorina citri (hemiptera: liviidae), vector of huanglongbing pathogens.asian citrus psyllid (diaphorina citri) transmits huanglongbing, a devastating disease that threatens citrus trees worldwide. a better understanding of the psyllid's host-plant selection process may lead to the development of more efficient means of monitoring it and predicting its movements. since behavioral adaptations, such as associative learning, may facilitate recognition of suitable host-plants, we examined whether adult d. citri could be conditioned to visual and chemosensory stimuli fro ...201426462949
phenology of asian citrus psyllid (hemiptera: liviidae) and associated parasitoids on two species of citrus, kinnow mandarin and sweet orange, in punjab pakistan.the population phenology of asian citrus psyllid, diaphorina citri kuwayama, was monitored weekly for 110 wk on two species of citrus, kinnow mandarin and sweet orange, at two different research sites in faisalabad, punjab pakistan. citrus flush growth patterns were monitored and natural enemy surveys were conducted weekly. flush patterns were similar for kinnow and sweet orange. however, flush on sweet orange was consistently more heavily infested with asian citrus psyllid than kinnow flush; de ...201425198345
citrus tristeza virus-based rnai in citrus plants induces gene silencing in diaphorina citri, a phloem-sap sucking insect vector of citrus greening disease (huanglongbing).a transient expression vector based on citrus tristeza virus (ctv) is unusually stable. because of its stability it is being considered for use in the field to control huanglongbing (hlb), which is caused by candidatus liberibacter asiaticus (clas) and vectored by asian citrus psyllid, diaphorina citri. in the absence of effective control strategies for clas, emphasis has been on control of d. citri. coincident cohabitation in phloem tissue by clas, d. citri and ctv was exploited to develop a no ...201424572372
differences in stylet sheath occurrence and the fibrous ring (sclerenchyma) between xcitroncirus plants relatively resistant or susceptible to adults of the asian citrus psyllid diaphorina citri (hemiptera: liviidae).the asian citrus psyllid (acp, diaphorina citri, hemiptera: liviidae), is the principal vector of the phloem-limited bacteria strongly associated with huanglongbing (hlb), the world's most serious disease of citrus. host plant resistance may provide an environmentally safe and sustainable method of controlling acp and/or hlb. two xcitroncirus accessions (hybrids of poncirus trifoliata and citrus spp.), that are relatively resistant (un-3881) or relatively susceptible (troyer-1459) to acp adults ...201425343712
temporal progression of 'candidatus liberibacter asiaticus' infection in citrus and acquisition efficiency by diaphorina citri.over the last decade, the plant disease huanglongbing (hlb) has emerged as a primary threat to citrus production worldwide. hlb is associated with infection by phloem-limited bacteria ('candidatus liberibacter' spp.) that are transmitted by the asian citrus psyllid, diaphorina citri. transmission efficiency varies with vector-related aspects (e.g., developmental stage and feeding periods) but there is no information on the effects of host-pathogen interactions. here, acquisition efficiency of 'c ...201424620723
changes in free amino acids and polyamine levels in satsuma leaves in response to asian citrus psyllid infestation and water stress.the effects of biotic and abiotic stresses on changes in amino acids and polyamine levels in satsuma orange (citrus unshiu; cultivar owari) leaves were investigated. asian citrus psyllids diaphorina citri (kuwayama) (acp) infestation was used to induce biotic stress while a water deficit was imposed to induce abiotic stress. potted trees were infested by placing 50 psyllids on 3 citrus leaves enclosed in nylon mesh bags for 5 d. a parallel set of plants were kept water stressed by maintaining th ...201424178691
comparison of potato and asian citrus psyllid adult and nymph transcriptomes identified vector transcripts with potential involvement in circulative, propagative liberibacter transmission.the potato psyllid (pop) bactericera cockerelli (sulc) and asian citrus psyllid (acp) diaphorina citri kuwayama are the insect vectors of the fastidious plant pathogen, candidatus liberibacter solanacearum (clso) and ca. l. asiaticus (clas), respectively. clso causes zebra chip disease of potato and vein-greening in solanaceous species, whereas, clas causes citrus greening disease. the reliance on insecticides for vector management to reduce pathogen transmission has increased interest in altern ...201425436509
the bacterial communities in plant phloem-sap-feeding insects.the resident microbiota of animals represents an important contribution to the global microbial diversity, but it is poorly known in many animals. this study investigated the bacterial diversity in plant phloem-sap-feeding whiteflies, aphids and psyllids by pyrosequencing bacterial 16s rrna gene amplicons. after correction for sequencing error, just 3-7 bacterial operational taxonomic units were recovered from each insect sample sequenced to sufficient depth for saturation of rarefaction curves. ...201424350573
botanicals, selective insecticides, and predators to control diaphorina citri (hemiptera: liviidae) in citrus orchards.the asian citrus psyllid (acp) diaphorina citri kuwayama vectors pathogens that cause huanglongbing (hlb) or citrus greening devastating and economically important disease present in most citrus growing regions. young citrus shoots are required for psyllid reproduction and development. during winter citrus trees produce little or no new growth. overwintering adults reproduce in spring on newly emerging shoots also attractive to other pests and beneficial insects. botanicals and relatively select ...201425205398
resistance of citrus and related genera to diaphorina citri kuwayama (hemiptera: liviidae).the present study was developed to evaluate the resistance of the following genotypes of citrus and related genera to this pest: 'pera,' 'natal', and 'washington navel' oranges (citrus sinensis), 'marsh seedless' grapefruit (citrus paradisi), hardy orange 'rubidoux' (poncirus trifoliata), kumquat (fortunella margarita swingle), citrumelo 'swingle' (c. paradisi x p. trifoliata), and citrange 'troyer' (p. trifoliata x c. sinensis). the experiments were performed in greenhouses with plants grafted ...201427193957
odorants for surveillance and control of the asian citrus psyllid (diaphorina citri).the asian citrus psyllid (acp), diaphorina citri, can transmit the bacterium candidatus liberibacter while feeding on citrus flush shoots. this bacterium causes huanglongbing (hlb), a major disease of citrus cultivation worldwide necessitating the development of new tools for acp surveillance and control. the olfactory system of acp is sensitive to variety of odorants released by citrus plants and offers an opportunity to develop new attractants and repellents.201425347318
odor coding in a disease-transmitting herbivorous insect, the asian citrus psyllid.olfactory systems discriminate odorants very efficiently and herbivorous insects use them to find hosts in confounding and complex odor landscapes. the asian citrus psyllid (acp), diaphorina citri, feeds on citrus flush and transmits candidatus liberibacter that causes citrus greening disease globally. here, we perform a systematic analysis of odor detection in the acp antenna using single-unit electrophysiology of rhinarial plate sensilla to a large panel of odorants from plants. we identify ne ...201424904081
mosquitocidal carbamates with low toxicity to agricultural pests: an advantageous property for insecticide resistance management.insecticide resistance in the malaria mosquito anopheles gambiae is well documented, and widespread agricultural use of pyrethroids may exacerbate development of resistance when pyrethroids are used in vector control. we have developed carbamate anticholinesterases that possess a high degree of an. gambiae:human selectivity for enzyme inhibition. the purpose of this study was to assess the spectrum of activity of these carbamates against other mosquitoes and agricultural pests.201425185896
detection of citrus huanglongbing-associated 'candidatus liberibacter asiaticus' in citrus and diaphorina citri in pakistan, seasonal variability, and implications for disease management.we report the detection of the huanglongbing (hlb)-associated bacterium 'candidatus liberibacter asiaticus' from both plants and insects in pakistan and the seasonal variability in the numbers of 'ca. l. asiaticus'-positive psyllid vector, diaphorina citri. our studies showed that 'ca. l. asiaticus' was detectable from trees in areas with maximum temperatures reaching nearly 50°c (average maximum of 42°c). however, the bacterium was present at very low levels in psyllids both in summer (june to ...201424134720
global genetic variation in the asian citrus psyllid, diaphorina citri (hemiptera: liviidae) and the endosymbiont wolbachia: links between iran and the usa detected.the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: liviidae), is one of the most serious pests of citrus in the world, because it transmits the pathogen that causes citrus greening disease. to determine genetic variation among geographic populations of d. citri, microsatellite markers, mitochondrial gene cytochrome oxidase i (mtcoi) and the wolbachia-diaphorina, wdi, gene wsp sequence data were used to characterize iranian and pakistani populations. also, a bayesian phylogenetic tec ...201424002991
insecticidal suppression of asian citrus psyllid diaphorina citri (hemiptera: liviidae) vector of huanglongbing pathogens.diaphorina citri vectors pathogens that cause 'huanglongbing' or citrus greening disease which poses a serious threat to citrus production worldwide. vector suppression is critical to reduce disease spread. efficacy is a main concern when choosing an insecticide. insecticidal treatments of 49 products or 44 active ingredients (a.i) labeled or experimental were field tested between 2005-2013 as foliar sprays (250 treatments, 39 a.i) or soil applications (47 treatments, 9 a.i) to control d. citri ...201425437858
double-stranded rna uptake through topical application, mediates silencing of five cyp4 genes and suppresses insecticide resistance in diaphorina citri.silencing of genes through rna interference (rnai) in insects has gained momentum during the past few years. rnai has been used to cause insect mortality, inhibit insect growth, increase insecticide susceptibility, and prevent the development of insecticide resistance. we investigated the efficacy of topically applied dsrna to induce rnai for five cytochrome p450 genes family 4 (cyp4) in diaphorina citri. we previously reported that these cyp4 genes are associated with the development of insecti ...201425330026
wolbachia infection density in populations of the asian citrus psyllid (hemiptera: liviidae).the symbiotic relationships between bacteria of the genus wolbachia (order rickettsiales) and their arthropod hosts are diverse and can range from mutualism to parasitism. whereas effects of wolbachia on host biology are well investigated, little is known about diversity and abundance of wolbachia in their natural hosts. the phloem-feeding asian citrus psyllid, diaphorina citri (kuwayama) (hemiptera: liviidae), is naturally infected with wolbachia (wdi). in the current study, we calculated the w ...201425259690
metalized polyethylene mulch to repel asian citrus psyllid, slow spread of huanglongbing and improve growth of new citrus plantings.greening or huanglongbing (hlb) is a debilitating disease of citrus caused by candidatus liberibactor asiaticus and transmitted by the asian citrus psyllid (acp), diaphorina citri. hlb now occurs worldwide in all major citrus growing regions except the mediterranean and australia. management relies principally on insecticidal control of the acp vector, but is insufficient, even for young trees which are most susceptible to the disease. we tested the ability of metalized polyethylene mulch to rep ...201423616306
host range testing of tamarixia radiata (hymenoptera: eulophidae) sourced from the punjab of pakistan for classical biological control of diaphorina citri (hemiptera: liviidae: euphyllurinae: diaphorinini) in california.abstract tests evaluating the host range of tamarixia radiata (waterson) (hymenoptera: eulophidae), a parasitoid of the pestiferous asian citrus psyllid, diaphorina citri kuwayama (hemiptera: liviidae), sourced from the punjab of pakistan, were conducted in quarantine at the university of california, riverside, ca. seven nontarget psyllid species (five native and two self-introduced species) representing five families were exposed to t radiata under the following three different exposure scenari ...201424665694
semiochemical and vibrational cues and signals mediating mate finding and courtship in psylloidea (hemiptera): a synthesis.mate finding and courtship involve complex interactions that require close coordination between individuals of the opposite gender. well-organized signalling systems, sometimes involving a combination of signal modalities, are required to convey species-specific and individual information to members of the opposite gender. previous studies of psyllids have focused on single-signal modalities and have largely ignored the potentially interdependent nature of different types of signals. several stu ...201426462826
population dynamics and growth rates of endosymbionts during diaphorina citri (hemiptera, liviidae) ontogeny.the infection density of symbionts is among the major parameters to understand their biological effects in host-endosymbionts interactions. diaphorina citri harbors two bacteriome-associated bacterial endosymbionts (candidatus carsonella ruddii and candidatus profftella armatura), besides the intracellular reproductive parasite wolbachia. in this study, the density dynamics of the three endosymbionts associated with the psyllid d. citri was investigated by real-time quantitative pcr (qpcr) at di ...201425037159
insecticide sprays, natural enemy assemblages and predation on asian citrus psyllid, diaphorina citri (hemiptera: psyllidae).the 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 bene ...201424830653
characterization of the asian citrus psyllid transcriptome.the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae) is a vector for the causative agents of huanglongbing, which threatens citrus production worldwide. this study reports and discusses the first d. citri transcriptomes, encompassing the three main life stages of d. citri, egg, nymph and adult. the transcriptomes were annotated using gene ontology (go) and insecticide-related genes within each life stage were identified to aid the development of future d. citri insecticides ...201424511328
the phloem-sap feeding mealybug (ferrisia virgata) carries 'candidatus liberibacter asiaticus' populations that do not cause disease in host plants.'candidatus liberibacter asiaticus' (las) is the primary causal agent of huanglongbing (hlb), the most devastating disease of citrus worldwide. there are three known insect vectors of the hlb-associated bacteria, and all are members of the hemiptera: diaphorina citri (psyllidae), trioza erytreae (triozidae), and cacopsylla (psylla) citrisuga (psyllidae). in this study, we found that another hemipteran, the striped mealybug ferrisia virgata (cockerell) (hemiptera: pseudococcidae), was able to acq ...201424465578
biology of the huanglongbing vector diaphorina citri (hemiptera: liviidae) on different host plants.although many studies have been conducted on the development and reproductive potential of diaphorina citri kuwayama, 1908 (hemiptera: liviidae) in different host species, few have evaluated these parameters on different varieties of the same host species. this study evaluated the influence of five commercial varieties of citrus (citrus spp. l.)--hamlin, natal, pêra, ponkan, and valencia-and orange jasmine [murraya exotica (l.) jack] on the development of d. citri. survival rates for the egg sta ...201424772551
nested-quantitative pcr approach with improved sensitivity for the detection of low titer levels of candidatus liberibacter asiaticus in the asian citrus psyllid, diaphorina citri kuwayama.candidatus liberibacter asiaticus (clas) is a phloem-limited bacterium transmitted by the asian citrus psyllid, diaphorina citri, and the presumptive causal agent of citrus greening disease. the current method of detection for clas within plant and insect samples is by a presence/absence qpcr assay using the clas 16s rdna gene target. although qpcr is highly sensitive, low bacterial titers or suboptimal qpcr conditions can result in false-negatives. using a nested qpcr assay, we determined the f ...201424769405
the control of invasive species on private property with neighbor-to-neighbor spillovers.invasive pests cross property boundaries. property managers may have private incentives to control invasive species despite not having sufficient incentive to fully internalize the external costs of their role in spreading the invasion. each property manager has a right to future use of his own property, but his property may abut others' properties enabling spread of an invasive species. the incentives for a foresighted property manager to control invasive species have received little attention. ...201425346573
vector control and foliar nutrition to maintain economic sustainability of bearing citrus in florida groves affected by huanglongbing.huanglongbing (hlb) or citrus greening is a bacterial disease vectored by the asian citrus psyllid (acp) causing tree decline, and yield loss. vector control and foliar nutrition are used in florida to slow the spread of hlb and mitigate debilitating effects of the disease. a four year replicated field study was initiated february 2008 in a 5.2-ha commercial block of young 'valencia' orange trees employing a factorial design to evaluate individual and compound effects of vector management and fo ...201423666807
geographic distribution of habitat, development, and population growth rates of the asian citrus psyllid, diaphorina citri, in mexico.the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), is an introduced pest in mexico and a vector of huanglongbing, a lethal citrus disease. estimations of the habitat distribution and population growth rates of d. citri are required to establish regional and areawide management strategies and can be used as a pest risk analysis tools. in this study, the habitat distribution of d. citri in mexico was computed with maxent, an inductive, machine-learning program that uses bi ...201324735280
horizontal gene acquisition of liberibacter plant pathogens from a bacteriome-confined endosymbiont of their psyllid vector.he asian citrus psyllid diaphorina citri is a notorious agricultural pest that transmits the phloem-inhabiting alphaproteobacterial 'candidatus liberibacter asiaticus' and allied plant pathogens, which cause the devastating citrus disease called huanglongbing or greening disease. d. citri harbors two distinct bacterial mutualists in the symbiotic organ called bacteriome: the betaproteobacterium 'candidatus profftella armatura' in the syncytial cytoplasm at the center of the bacteriome, and the g ...201324349319
candidate gene markers for candidatus liberibacter asiaticus for detecting citrus greening disease.citrus huanglongbing (hlb) also known as citrus greening is one of the most devastating diseases of citrus worldwide. the disease is caused by candidatus liberibacter bacterium, vectored by the psyllid diaphorina citri kuwayama and trioza erytreae del guercio. citrus plants infected by the hlb bacterium may not show visible symptoms sometimes for years following infection. the aim of this study was to develop effective gene-specific primer pairs for polymerase chain reaction based method for qui ...201323660656
development of rapid, sensitive and non-radioactive tissue-blot diagnostic method for the detection of citrus greening.citrus huanglongbing (hlb or citrus greening) is one of the most devastating diseases of citrus worldwide. the disease is caused by gram-negative, phloem-limited α-proteobacterium, 'candidatus liberibacter asiaticus', vectored by the psyllid, diaphorina citri kuwayama. citrus plants infected by the hlb bacterium may not show visible symptoms sometimes for years following infection and non-uniform distribution within the tree makes the detection of the pathogen very difficult. efficient managemen ...201323660459
behavioral, ultrastructural and chemical studies on the honeydew and waxy secretions by nymphs and adults of the asian citrus psyllid diaphorina citri (hemiptera: psyllidae).the asian citrus psyllid (acp), diaphorina citri (hemiptera: psyllidae) is the primary vector of the bacterium causing citrus huanglongbing (citrus greening), the most serious disease of citrus worldwide. psyllids and other hemipterans produce large amounts of honeydew, which has been used previously as an indicator of phloem sap composition and insect feeding or metabolism. behavioral, ultrastructural and chemical studies on acp, its honeydew and waxy secretions showed important differences bet ...201323762268
chemical and behavioral analysis of the cuticular hydrocarbons from asian citrus psyllid, diaphorina citri.huanglongbing (hlb) is the most destructive disease of citrus worldwide. the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), is the vector of the phloem-inhabiting bacterium, candidatus liberibacter asiaticus, which is presumed to cause hlb in florida citrus. laboratory and field studies were conducted to examine the behavioral responses of male and female d. citri to their cuticular extracts. in olfactometer assays, more male d. citri were attracted to one, five, or 10 f ...201323955888
competition between honeydew producers in an ant-hemipteran interaction may enhance biological control of an invasive pest.asian citrus psyllid, diaphorina citri kuwayama (hemiptera: liviidae), is an invasive citrus pest in southern california, which secretes honeydew and has the potential to spread a lethal bacterial disease, huanglongbing, of citrus. in urban citrus, argentine ant, linepithema humile (mayr) (hymenoptera: formicidae), also an invasive pest, tends honeydew-producing hemipterans. we used field data to determine whether the mutualistic relationship between l. humile and six established species of hone ...201323941659
methods for rapid and effective pcr-based detection of 'candidatus liberibacter solanacearum' from the insect vector bactericera cockerelli: streamlining the dna extraction/purification process.this study provides a protocol for rapid dna isolation from psyllid vectors (bactericera cockerelli and diaphorina citri) that can be used directly with dna-based methods for the detection of 'candidatus (ca.) liberibacter solanacearum,' the bacterial causal agent of potato zebra chip disease and eventually for 'ca. liberibacter asiaticus' the causal agent of huanglongbing disease in citrus. the fast dna extraction protocol was designed to work with conventional polymerase chain reaction (cpcr) ...201323865212
herbivory by the insect diaphorina citri induces greater change in citrus plant volatile profile than does infection by the bacterium, candidatus liberibacter asiaticus.the volatile organic compound (voc) profile in plant leaves often changes after biotic and abiotic stresses. monitoring changes in vocs in plant leaves could provide valuable information about multitrophic interactions. in the current study, we investigated the effect of asian citrus psyllid (acp) infestation, citrus greening pathogen (candidatus liberibacter asiaticus [clas]) infection, and simultaneous attack by acp and clas on the voc content of citrus leaves. leaf volatiles were extracted us ...201323857364
defensive bacteriome symbiont with a drastically reduced genome.diverse insect species harbor symbiotic bacteria, which play important roles such as provisioning nutrients and providing defense against natural enemies [1-6]. whereas nutritional symbioses are often indispensable for both partners, defensive symbioses tend to be of a facultative nature [1-12]. the asian citrus psyllid diaphorina citri is a notorious agricultural pest that transmits liberibacter spp. (alphaproteobacteria), causing the devastating citrus greening disease or huanglongbing [13, 14 ...201323850282
dynamic insecticide susceptibility changes in florida populations of diaphorina citri (hemiptera: psyllidae).five field populations of diaphorina citri kuwayama from various regions of florida were evaluated in 2011 for resistance to commonly used insecticides. three diagnostic doses (ld50, ld75, and ld95), developed in 2009 using a laboratory susceptible population, were used to measure changes in susceptibility levels of field-collected populations as compared with a susceptible laboratory population. further reductions in the susceptibility levels of d. citri to chlorpyriphos and fenpropathrin were ...201323448056
effects of cyantraniliprole, a novel anthranilic diamide insecticide, against asian citrus psyllid under laboratory and field conditions.the asian citrus psyllid, diaphorina citri (hemiptera: psyllidae), is the most destructive pest of citrus in florida. the development of insecticide resistance in several populations of d. citri has been documented. there is an urgent need to develop and integrate novel tools for the successful management of d. citri and also to prevent the development of insecticide resistance.201323371893
global gene expression changes in candidatus liberibacter asiaticus during the transmission in distinct hosts between plant and insect.huanglongbing (hlb) or citrus greening disease is a destructive disease of citrus worldwide, which is associated with candidatus liberibacter asiaticus. this phloem-limited fastidious pathogen is transmitted by the asian citrus psyllid, diaphorina citri, and appears to be an intracellular pathogen that maintains an intimate association with the psyllid or the plant throughout its life cycle. the molecular basis of the interaction of this pathogen with its hosts is not well understood. we hypothe ...201323336388
biology and management of asian citrus psyllid, vector of the huanglongbing pathogens.the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), is the most important pest of citrus worldwide because it serves as a vector of "candidatus liberibacter" species (alphaproteobacteria) that cause huanglongbing (citrus greening disease). all commercially cultivated citrus is susceptible and varieties tolerant to disease expression are not yet available. onset of disease occurs following a long latent period after inoculation, and thus the pathogen can spread widely prio ...201323317046
abdominal color of the asian citrus psyllid, diaphorina citri, is associated with susceptibility to various insecticides.color morphs of an insect species are known to vary in activities of detoxifying enzymes and associated susceptibility to insecticides. in diaphorina citri, three color morphs are known to occur. in the present study, susceptibility to four insecticides was compared among gray/brown, blue/green and orange/yellow color morphs of field-collected d. citri.201323193012
stylet morphometrics and citrus leaf vein structure in relation to feeding behavior of the asian citrus psyllid diaphorina citri, vector of citrus huanglongbing bacterium.the asian citrus psyllid (acp), diaphorina citri (hemiptera: psyllidae), is the primary vector of the phloem-limited bacterium candidatus liberibacter asiaticus (las) associated with huanglongbing (hlb, citrus greening), considered the world's most serious disease of citrus. stylet morphometrics of acp nymphs and adults were studied in relation to citrus vein structure and to their putative (histologically verified) feeding sites on valencia orange leaves. acp nymphs preferred to settle and feed ...201323555830
induced resistance against the asian citrus psyllid, diaphorina citri, by β-aminobutyric acid in citrus.β-aminobutyric acid (baba) is known to induce resistance to microbial pathogens, nematodes and insects in several host plant/pest systems. the present study was undertaken to determine whether a similar effect of baba occurred against the asian citrus psyllid, diaphorina citri kuwayama, in citrus. a 25 mm drench application of baba significantly reduced the number of eggs/plant as compared with a water control, whereas 200 and 100 mm applications of baba reduced the numbers of nymphs/plant and a ...201323590847
compatibility of isaria fumosorosea (hypocreales: cordycipitaceae) blastospores with agricultural chemicals used for management of the asian citrus psyllid, diaphorina citri (hemiptera: liviidae).biorational insecticides are being increasingly emphasized for inclusion in integrated pest management programs for invasive insects. the entomopathogenic fungus, isaria fumosorosea, can be used to help manage the asian citrus psyllid with minimal impact on beneficial arthropods, but its effectiveness may be compromised by agrochemicals used to control concurrent arthropod pests and diseases. we evaluated the compatibility of i. fumosorosea blastospores with a range of spray oils and copper-base ...201326462531
candidatus liberibacter americanus induces significant reprogramming of the transcriptome of the susceptible citrus genotype.citrus huanglongbing (hlb) disease is caused by endogenous, phloem-restricted, gram negative, uncultured bacteria named candidatus liberibacter africanus (calaf), ca. l. asiaticus (calas), and ca. l. americanus (calam), depending on the continent where the bacteria were first detected. the asian citrus psyllid vector, diaphorina citri, transmits calas and calam and both liberibacter species are present in brazil. several studies of the transcriptional response of citrus plants manifesting hlb sy ...201323586643
new excised-leaf assay method to test inoculativity of asian citrus psyllid (hemiptera: psyllidae) with candidatus liberibacter asiaticus associated with citrus huanglongbing disease.the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), is the primary vector of candidatus liberibacter asiaticus (las) associated with huanglongbing, or citrus greening, the most devastating citrus (citrus spp.) disease worldwide. here, we developed a new "excised-leaf assay" that can speed up las-inoculativity tests on asian citrus psyllid from the current 3-12 mo (when using whole citrus seedlings for inoculation) to only 2-3 wk. young adults of asian citrus psyllid that ...201323448011
formation of stylet sheaths in āere (in air) from eight species of phytophagous hemipterans from six families (suborders: auchenorrhyncha and sternorrhyncha).stylet sheath formation is a common feature among phytophagous hemipterans. these sheaths are considered essential to promote a successful feeding event. stylet sheath compositions are largely unknown and their mode of solidification remains to be elucidated. this report demonstrates the formation and solidification of in āere (in air) produced stylet sheaths by six hemipteran families: diaphorina citri (psyllidae, asian citrus psyllid), aphis nerii (aphididae, oleander/milkweed aphid), toxopter ...201323638086
silencing abnormal wing disc gene of the asian citrus psyllid, diaphorina citri disrupts adult wing development and increases nymph mortality.huanglongbing (hlb) causes considerable economic losses to citrus industries worldwide. its management depends on controlling of the asian citrus psyllid (acp), the vector of the bacterium, candidatus liberibacter asiaticus (clas), the causal agent of hlb. silencing genes by rna interference (rnai) is a promising tool to explore gene functions as well as control pests. in the current study, abnormal wing disc (awd) gene associated with wing development in insects is used to interfere with the fl ...201323734251
molecular characterization of wolbachia strains associated with the invasive asian citrus psyllid diaphorina citri in brazil.wolbachia is a symbiont intensively studied due to its ability to interfere with their host's reproduction, and it has been recently proposed as an alternative tool to control insect pests or vectors of diseases. the asian citrus psyllid diaphorina citri is an important pest of citrus since it vectors the bacterium that causes the "huanglongbing" disease in citrus. the frequency and diversity of wolbachia associated with d. citri is unknown, limiting the utilization of wolbachia as an alternativ ...201223269454
Morphological description of the mouthparts of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae).Scanning (SEM) and transmission (TEM) electron microscopy were used to elucidate the morphology of the rostrum, as well as the mandibular and maxillary stylets of the psyllid Diaphorina citri, vector of phloem-inhabiting bacteria associated with citrus huanglongbing (HLB) disease. D. citri has a cone-shaped rostrum that extends behind the pair of prothoracic coxae. The stylet bundle comprises a pair of mandibular (Md) and maxillary (Mx) stylets with a mean length of 513.3 µm; when retracted, the ...201221982382
survey of endosymbionts in the diaphorina citri metagenome and assembly of a wolbachia wdi draft genome.diaphorina citri (hemiptera: psyllidae), the asian citrus psyllid, is the insect vector of ca. liberibacter asiaticus, the causal agent of citrus greening disease. sequencing of the d. citri metagenome has been initiated to gain better understanding of the biology of this organism and the potential roles of its bacterial endosymbionts. to corroborate candidate endosymbionts previously identified by rdna amplification, raw reads from the d. citri metagenome sequence were mapped to reference genom ...201223166822
effects of soil-applied imidacloprid on asian citrus psyllid (hemiptera: psyllidae) feeding behavior.the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), is one of the most important pests of citrus (citrus spp.) because of its status as a vector of candidatus liberibacter asiaticus (las), the bacterium associated with citrus greening disease. the use of insecticides for vector control is the primary method of managing the spread of this pathogen. imidacloprid is an insecticide commonly applied to the root zone of young citrus trees to provide systemic protection from pes ...201223156142
overview of worldwide diversity of diaphorina citri kuwayama mitochondrial cytochrome oxidase 1 haplotypes: two old world lineages and a new world invasion.relationships among worldwide collections of diaphorina citri (asian citrus psyllid) were analyzed using mitochondrial cytochrome oxidase i (mtcoi) haplotypes from novel primers. sequences were produced from pcr amplicons of an 821bp portion of the mtcoi gene using d. citri specific primers, derived from an existing est library. an alignment was constructed using 612bps of this fragment and consisted of 212 individuals from 52 collections representing 15 countries. there were a total of eight po ...201222717059
effects of buprofezin and diflubenzuron on various developmental stages of asian citrus psyllid, diaphorina citri.diaphorina citri populations in florida are developing resistance to commonly used neurotoxic insecticides. alternatives to neurotoxins, such as insect growth regulators, are needed to control this season-long subtropical pest to prevent or delay development of insecticide resistance. in the present investigation, two insect growth regulators (igrs), buprofezin and diflubenzuron, were evaluated against various developmental stages of d. citri.201222653617
impacts of horticultural mineral oils and two insecticide practices on population fluctuation of diaphorina citri and spread of huanglongbing in a citrus orchard in sarawak.aspects of the incidence and spread of the citrus disease huanglongbing (hlb) in relation to the vector diaphorina citri population fluctuation were studied from january 1999 to december 2001 seasons in a 0.8 ha citrus orchard at jemukan (1° 33'n, 110° 41'e), southwest sarawak in malaysia. in relation to insecticide and horticultural mineral oils (hmos) use, levels of hlb infection rose quite rapidly over the next 3 years in the unsprayed control and less rapidly in the other treatments such as ...201222629178
biochemical basis of organophosphate and carbamate resistance in asian citrus psyllid.the asian citrus psyllid, diaphorina citri kuwayama, is a worldwide pest of citrus, which vectors the putative causal pathogen of huanglongbing. current management practices warrant continuous monitoring of field populations for insecticide resistance. baseline activities of acetylcholinesterase (ache), general esterase, and glutathione s-transferase as well as sensitivity of ache to selected organophosphate and carbamate insecticides were established for a susceptible laboratory strain (lab) an ...201222606825
induced release of a plant-defense volatile 'deceptively' attracts insect vectors to plants infected with a bacterial pathogen.transmission of plant pathogens by insect vectors is a complex biological process involving interactions between the plant, insect, and pathogen. pathogen-induced plant responses can include changes in volatile and nonvolatile secondary metabolites as well as major plant nutrients. experiments were conducted to understand how a plant pathogenic bacterium, candidatus liberibacter asiaticus (las), affects host preference behavior of its psyllid (diaphorina citri kuwayama) vector. d. citri were att ...201222457628
improved real-time pcr detection of 'candidatus liberibacter asiaticus' from citrus and psyllid hosts by targeting the intragenic tandem-repeats of its prophage genes.'candidatus liberibacter asiaticus' (clas) is a gram-negative α-proteobacterium, and the prominent species of liberibacter associated with a devastating worldwide citrus disease known as huanglongbing (hlb). this fastidious bacterium resides in phloem sieve cells of host plants and is vectored by the asian citrus psyllid (diaphorina citri). due to its uneven distribution in planta and highly variable bacterial titers, detection of hlb bacteria can be challenging. here we demonstrated a new utili ...201222245034
life table of tamarixia radiata (hymenoptera: eulophidae) on diaphorina citri (hemiptera: psyllidae) at different temperatures.tamarixia radiata (waterston, 1922) is the main parasitoid of diaphorina citri (kuwayama, 1907), and has been used in classical biological control programs in several countries. the current study investigated the biology and determined the fertility life table of t. radiata in different temperatures, to obtain information to support the establishment of a biological control program for d. citri in brazil. fifth-instar nymphs of d. citri were offered to females of t. radiata for parasitism, for 2 ...201222606801
characterization of the relative abundance of the citrus pathogen ca. liberibacter asiaticus in the microbiome of its insect vector, diaphorina citri, using high throughput 16s rrna sequencing.the relationship between the causal agent of huanglongbing (hlb), ca. liberibacter asiaticus(las), and the naturally occurring endosymbiotic community of its insect vector, the asian citrus psyllid (acp), diaphorina citri, was studied. variation was observed in the titer of las within an acp population feeding on the same material. the cause of this disparity is unknown, and has implications for las transmission and the spread of hlb. this study utilizes culture independent methods to establish ...201222529882
multimodal cues drive host-plant assessment in asian citrus psyllid (diaphorina citri).asian citrus psyllid (diaphorina citri) transmits the causal agent of huanglongbing, a devastating disease of citrus trees. in this study we measured behavioral responses of d. citri to combinations of visual, olfactory, and gustatory stimuli in test arenas. stimuli were presented to the psyllids in droplets or lines of an emulsified wax formulation in two different arena types in no-choice tests. first, when placed on a colored ring situated halfway between the center and perimeter of a petri ...201122217766
oral delivery of double-stranded rnas and sirnas induces rnai effects in the potato/tomato psyllid, bactericerca cockerelli.the potato/tomato psyllid, bactericerca cockerelli (b. cockerelli), and the asian citrus psyllid, diaphorina citri (d. citri), are very important plant pests, but they are also vectors of phloem-limited bacteria that are associated with two devastating plant diseases. b. cockerelli is the vector of candidatus liberibacter psyllaurous (solanacearum), which is associated with zebra chip disease of potatoes, and d. citri is the vector of ca. liberibacter asiaticus, which is associated with the huan ...201122110747
Characterization of five CYP4 genes from Asian citrus psyllid and their expression levels in Candidatus Liberibacter asiaticus-infected and uninfected psyllids.Previously, we reported that Candidatus Liberibacter asiaticus (Las)-infected Diaphorina citri are characterized by lower levels of cytochrome P450 monooxygenases than uninfected counterparts. In the present study, we investigated expression levels of family 4 cytochrome P450 (CYP4) genes in Las-infected and uninfected D.citri adults. Five novel CYP4 genes (CYP4C67, CYP4DA1, CYP4C68, CYP4DB1 and CYP4G70) were identified. Four of the five CYP4 genes were expressed at significantly higher levels i ...201121919983
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