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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
sexual transmission of a plant pathogenic bacterium, candidatus liberibacter asiaticus, between conspecific insect vectors during mating.candidatus liberibacter asiaticus is a fastidious, phloem-inhabiting, gram-negative bacterium transmitted by asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae). the bacterium is the presumed causal agent of huanglongbing (hlb), one of the most destructive and economically important diseases of citrus. we investigated whether las is transmitted between infected and uninfected d. citri adults during courtship. our results indicate that las was sexually transmitted from las-infe ...201122216209
temperature studies with the asian citrus psyllid, diaphorina citri: cold hardiness and temperature thresholds for oviposition.this study was conducted to obtain information on the cold hardiness of the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), in florida and to assess upper and lower temperature thresholds for oviposition. the psyllid is an important pest in citrus because it transmits the bacterial pathogens responsible for citrus greening disease, huanglongbing, considered the most serious citrus disease worldwide. d. citri was first found in florida during 1998, and the disease was disc ...201121870969
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
three homopteran pests of citrus as prey for the convergent lady beetle: suitability and preference.the convergent lady beetle, hippodamia convergens guérin-méneville (coleoptera: coccinellidae), is an important predator of soft-bodied insect pests in many regions of the united states, but generally uncommon in florida citrus. certain citrus producers in florida recently initiated releases of commercially available h. convergens from california against the asian citrus psyllid diaphorina citri kuwayama, vector of huanglongbing or citrus greening disease. however, there is little information o ...201122217767
unreliable pesticide control of the vector psyllid diaphorina citri (hemiptera: psyllidae) for the reduction of microorganism disease transmission.systemic insecticides and application methods were examined for the control of the vector psyllid of citrus greening disease, diaphorina citri, on grown king mandarin trees in an orchard in southern vietnam from may 2007 to september 2008. leaf spraying of imidacloprid, thiamethoxam, and clothianidin attained about 50 % to 70 % mortality of the psyllid for one month after the application and showed decreased efficacy thereafter. imidacloprid was more effective than the other two insecticides, bu ...201020512737
efficacy and uptake of soil-applied imidacloprid in the control of asian citrus psyllid and a citrus leafminer, two foliar-feeding citrus pests.the systemic neonicotinoid insecticide imidacloprid, admire pro, was applied to 3- and 4-yr-old nonbearing 'rio red' grapefruit, citrus x paradisi macfad., trees in 2006 and 2007, respectively, to determine its effects in the control of two major citrus pests, the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), and a citrus leafminer phyllocnistis citrella stainton (lepidoptera: gracillariidae). young flush shoots were randomly collected weekly for 13 and 11 wk in 2006 an ...201021061971
incidence of candidatus liberibacter asiaticus infection in abandoned citrus occurring in proximity to commercially managed groves.huanglongbing is one of the most devastating diseases of citrus (citrus spp.). one management tactic against huanglongbing is aggressive management of the vector, the asian citrus psyllid (diaphorina citri kuwayama), with insecticide applications. however, d. citri in abandoned groves are not controlled and therefore pose a risk of reinfestation for nearby commercial citrus. these abandoned groves could serve as a reservoir for the vector, as well as a source of the presumed causal agent for hua ...201021309215
medium for development of bee cell cultures (apis mellifera: hymenoptera: apidae).a media for the production of cell cultures from hymenopteran species such as honey bee, apis mellifera l. (hymenoptera: apidae) was developed. multiple bee cell cultures were produced when using bee larvae and pupae as starting material and modified hert-hunter 70 media. cell culture systems for bees solves an impasse that has hindered efforts to isolate and screen pathogens which may be influencing or causing colony collapse disorder of bees. multiple life stages of maturing larvae to early pu ...201020033792
[ovarian development and analysis of mating effects on ovary maturation of diaphorina citri kuwayama (hemiptera: psyllidae)].as many other insects with a restricted diet, the citrus psyllid diaphorina citri kuwayama, which vector the causing agent of the huanglongbing, the bacteria candidatus liberibacter spp., is intimately associated with symbiotic microorganisms. these mutualist symbionts play a key role on their host nutritional ecology, and are vertically transmitted to the progeny. however, despite the role symbionts play on host development and reproduction, and the growing opportunities of exploitation of the ...201020676515
effects of pymetrozine, an antifeedant of hemiptera, on asian citrus psyllid, diaphorina citri, feeding behavior, survival and transmission of candidatus liberibacter asiaticus.vector-borne plant disease management can be enhanced by deployment of antifeedants in addition to the use of broad-spectrum neurotoxic insecticides. the effects of pymetrozine on asian citrus psyllid (acp), diaphorina citri kuwayama, feeding behaviour, survival and transmission of candidatus liberibacter asiaticus (las), the presumed causal pathogen of huanglongbing, were investigated.201020960465
effect of candidatus liberibacter asiaticus infection on susceptibility of asian citrus psyllid, diaphorina citri, to selected insecticides.in the present investigation, the effect of candidatus liberibacter asiaticus (las), a bacterium considered to be responsible for causing huanglongbing (hlb) disease in citrus, on the physiology of its vector, the asian citrus psyllid (acp) diaphorina citri kuwayama, was determined. specifically, the effects of las infection on the susceptibility of acp to selected insecticides were determined. furthermore, total protein content and general esterase activity were quantified in las-infected and u ...201020960471
transmission parameters for candidatus liberibacter asiaticus by asian citrus psyllid (hemiptera: psyllidae).the purpose of this investigation was to evaluate acquisition and inoculation (together, transmission) efficiency of candidatus liberibacter asiaticus (las), the pathogen associated with citrus huanglongbing (hlb) by the asian citrus psyllid, diaphorina citri (kuwayama) (hemiptera: psyllidae). in laboratory studies, nymphs reared on las infected plants were more likely to acquire the bacterium than adults. acquisition by nymphs ranged from 60 to 100%, whereas acquisition by adults only reached 4 ...201021061950
sticky trap and stem-tap sampling protocols for the asian citrus psyllid (hemiptera: psyllidae).sampling statistics were obtained to develop a sampling protocol for estimating numbers of adult diaphorina citri kuwayama (hemiptera: psyllidae) in citrus by using two different sampling methods: yellow sticky traps and stem-tap samples. a 4.0-ha block of mature orange trees was stratified into 100.4-ha strata and sampled using each method seven times over a 7-mo period. one sticky trap was deployed per tree on each of 16 trees randomly selected in each stratum, and numbers of adults on the tra ...201020429472
effective use of neonicotinoids for protection of citrus seedlings from invasion by diaphorina citri (hemiptera: psyllidae).the application of insecticides to control diaphorina citri kuwayama (hemiptera: psyllidae) is a principal component of the current management for citrus greening disease or huanglongbing. it is recommended that growers apply systemic insecticides such as imidacloprid and thiamethoxam every 2 mo after seedling planting, but this practice renders the seedlings insecticide-free and vulnerable to psyllid infestation in the first 2 mo. we evaluated the risk of vector invasion during this period from ...201020214377
effect of pyriproxyfen, a juvenile hormone mimic, on egg hatch, nymph development, adult emergence and reproduction of the asian citrus psyllid, diaphorina citri kuwayama.the asian citrus psyllid (acp), diaphorina citri kuwayama, is a vector of bacteria presumably responsible for huanglongbing (hlb) disease in citrus. in this laboratory study, an investigation was made of the activity of pyriproxyfen, a juvenile hormone mimic, on acp eggs, nymphs and adults to evaluate its potential as a biorational insecticide for inclusion in an integrated pest management (ipm) program for acp.201019937968
the effects of host, geographic origin, and gender on the thermal requirements of diaphorina citri (hemiptera: psyllidae).diaphorina citri kuwayama (hemiptera: psyllidae) is the vector of the bacteria that causes citrus greening and is considered one of the world's most important citrus diseases. we examined how host, geographic region, and gender affect the thermal requirements of d. citri. the insects were reared in climatic chambers at constant temperatures of 18, 20, 22, 25, 28, 30, and 32 +/- 1 degrees c, 70 +/- 10% rh, and a 14 h photophase. host plants for d. citri included orange (citrus sinensis [rutaceae] ...201020388302
responses of the asian citrus psyllid to volatiles emitted by the flushing shoots of its rutaceous host plants.diaphorina citri kuwayama (hemiptera: psyllidae) carries candidatus liberibacter spp., the putative causal agents of huanglongbing. d. citri reproduces and develops only on the flushing shoots of its rutaceous host plants. here we examined whether d. citri is attracted to host plant odors and a mixture of synthetic terpenes. tests conducted in a vertically oriented y-tube olfactometer showed that both males and females preferentially entered the y-tube arm containing the odor from the young shoo ...201020388295
comparison of laboratory colonies and field populations of tamarixia radiata, an ectoparasitoid of the asian citrus psyllid, using internal transcribed spacer and cytochrome oxidase subunit i dna sequences.the genetic diversity of tamarixia radiata waterston (hymenoptera: eulophidae) laboratory colonies derived from collections in china, northern vietnam, pakistan, and a mixed colony from taiwan and southern vietnam was evaluated using the internal transcribed spacer (its) region 1, its-2, and the 5' end of the cytochrome oxidase subunit i gene. the strains share the same its sequence, consistent with the morphological hypothesis that the collections represent a single species. the coi marker was ...200920069864
roles of olfactory cues, visual cues, and mating status in orientation of diaphorina citri kuwayama (hemiptera: psyllidae) to four different host plants.diaphorina citri kuwayama (hemiptera: psyllidae) is an important worldwide pest of citrus that vectors bacteria (candidatus liberibacter spp.) responsible for huanglongbing (citrus greening disease). we examined the behavioral responses of mated and unmated d. citri of both sexes to odors from host plants in a y-tube olfactometer, with and without visual cues. the host plants tested were 'duncan' grapefruit (citrus paradisi macfayden), sour orange (citrus aurantium l.), navel orange (c. sinensis ...200919791618
influence of posttreatment temperature on the toxicity of insecticides against diaphorina citri (hemiptera: psyllidae).the psyllid diaphorina citri kuwayama (hemiptera: psyllidae) is one of the most important pests of citrus worldwide because it efficiently vectors three bacteria in the genus candidatus liberibacter that cause the devastating citrus greening disease (huanglongbing). current management practices for this insect pest rely on multiple sprays of foliar insecticides and one or two applications of soil systemic insecticides per season. effective psyllid and disease management in florida requires insec ...200919449650
establishment of asian citrus psyllid (diaphorina citri) primary cultures.the asian citrus psyllid (ascp), diaphorina citri kuwayama (hemiptera: psyllidae), is a highly competent vector of the phloem-inhabiting bacterium candidatus liberibacter asiaticus associated with the citrus disease huanglongbing (hlb). commonly referred to as citrus greening disease in the usa, hlb causes reduced fruit yields, quality, and ultimately tree death and is considered the most serious citrus disease. hlb has become a major limiting factor to the production of citrus worldwide. studie ...200919440802
antifeedant and sublethal effects of imidacloprid on asian citrus psyllid, diaphorina citri.asian citrus psyllid (acp), diaphorina citri kuwayama, transmits the causal bacteria of the devastating citrus disease huanglongbing (hlb). because of the variation in spatial and temporal uptake and systemic distribution of imidacloprid applied to citrus trees and its degradation over time in citrus trees, acp adults and nymphs are exposed to concentrations that may not cause immediate mortality but rather sublethal effects. the objective of this laboratory study was to determine the effects of ...200919431217
incidence of invasive diaphorina citri (hemiptera: psyllidae) and its introduced parasitoid tamarixia radiata (hymenoptera: eulophidae) in florida citrus.diaphorina citri kuwayama (hemiptera: psyllidae), vectors the bacterium candidatus liberibacter asiaticus, one of the causal organisms of the devastating citrus disease "huanglongbing" or citrus greening. in the united states, d. citri was first discovered in florida, in 1998. tamarixia radiata waterston (hymenoptera: eulophidae) was imported from asia and released in florida in 1999-2001 to improve biological control of d. citri before citrus greening was detected in florida in 2005. florida ci ...200919253643
an assessment of yellow sticky card traps as indicators of the abundance of adult diaphorina citri (hemiptera: psyllidae) in citrus.yellow sticky card traps were assessed as a tool for estimating absolute densities of adult diaphorina citri kuwayama (hemiptera: psyllidae) in citrus. weekly trapping was conducted in young and mature trees with traps deployed directly in trees, one trap per tree. in addition, a comparison was made between one and three traps per tree in the mature trees. solar radiation was positively correlated with numbers of adults trapped per week in both groups of trees. air temperature was positively cor ...200919253667
quantifying dispersal of diaphorina citri (hemiptera: psyllidae) by immunomarking and potential impact of unmanaged groves on commercial citrus management.diaphorina citri kuwayama (hemiptera: psyllidae) is an important pest of citrus. it is an efficient vector of three bacterial pathogens that are the presumptive causal agents of huanglongbing (hlb) or citrus greening disease. the movement patterns and dispersal capabilities of d. citri require study to better understand the spread of hlb and to improve management strategies for d. citri. a recently developed immunomarking technique that uses crude food proteins (chicken egg albumin, bovine casei ...200919689907
sulfur volatiles in guava (psidium guajava l.) leaves: possible defense mechanism.volatiles from crushed and intact guava leaves (psidium guajava l.) were collected using static headspace spme and determined using gc-pfpd, pulsed flame photometric detection, and gc-ms. leaf volatiles from four common citrus culitvars were examined similarly to determine the potential component(s) responsible for guava's protective effect against the asian citrus psyllid (diaphorina citri kuwayama), which is the insect vector of huanglongbing (hlb) or citrus greening disease. seven sulfur vola ...200818778077
rate, placement and timing of aldicarb applications to control asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), in oranges.the asian citrus psyllid (acp), diaphorina citri kuwayama (hemiptera: psyllidae), is a cosmopolitan insect pest of citrus and vectors the bacterium candidatus liberibacter asiaticus, a suspected causal organism of citrus greening or 'huanglongbing' disease. aldicarb 150 g kg(-1) gr (temik((r)) 15 g) was evaluated at three rates, two placements and three timings for acp control in orange trees.200818537108
morphological characterization of the antennal sensilla of the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), with reference to their probable functions.the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), is one of the most significant economic pests of citrus worldwide. this insect vectors three phloem-restricted bacteria in the genus candidatus liberibacter that cause huanglongbing (citrus greening), the most severe disease limiting citrus production worldwide. we examined the external morphology of the antennal sensilla of male and female d. citri using scanning electron microscopy (sem) and determined the putative fun ...200818573664
detection of 'candidatus liberibacter asiaticus' in diaphorina citri and its importance in the management of citrus huanglongbing in florida.citrus huanglongbing (hlb or citrus greening), is a highly destructive disease that has been spreading in both florida and brazil. its psyllid vector, diaphorina citri kuwayama, has spread to texas and mexico, thus threatening the future of citrus production elsewhere in mainland north america. even though sensitive diagnostic methods have been developed for detection of the causal organisms, candidatus liberibacter spp., the pathogen cannot be detected consistently in plants until symptoms deve ...200818944186
population ecology and phenology of diaphorina citri (hemiptera: psyllidae) in two florida citrus groves.studies were conducted to assess population densities and phenology of the psyllid diaphorina citri kuwayama at two citrus groves in east-central florida. one grove contained young, irrigated grapefruit trees and the other contained mature, nonirrigated orange trees. the two groves were sampled weekly for eggs, nymphs, and adults on flush shoots; for adults on mature leaves; and for adults captured on yellow sticky card traps. because infestations of immature d. citri develop strictly on young f ...200818801257
dispersion patterns and sampling plans for diaphorina citri (hemiptera: psyllidae) in citrus.the abundance and spatial dispersion of diaphorina citri kuwayama (hemiptera: psyllidae) were studied in 34 grapefruit (citrus paradisi macfad.) and six sweet orange [citrus sinensis (l.) osbeck] orchards from march to august 2006 when the pest is more abundant in southern texas. although flush shoot infestation levels did not vary with host plant species, densities of d. citri eggs, nymphs, and adults were significantly higher on sweet orange than on grapefruit. d. citri immatures also were fou ...200818767763
isolation and characterization of an isaria fumosorosea isolate infecting the asian citrus psyllid in florida.a fungal pathogen that killed adult diaphorina citri kuwayama (asian citrus psyllid) (hemiptera: psyllidae) in florida citrus groves during the fall of 2005 was identified and characterized. investigation of this pathogen is important because d. citri vectors citrus greening disease (huanglongbing), which was reported in florida in 2005. the morphological and genetic data generated herein support identification of the fungus as isaria fumosorosea wize (ifr) (=paecilomyces fumosoroseus) (hypocrea ...200818433768
morphological and molecular characterization of a hirsutella species infecting the asian citrus psyllid, diaphorina citri kuwayama (hemiptera: psyllidae), in florida.the asian citrus psyllid, diaphorina citri kuwayama, is an invasive pest that vectors citrus greening disease, which recently was detected in florida. mycosed adult d. citri were collected at four sites in central florida between september 2005 and february 2006. observation of the cadavers using scanning electron microscopy revealed that the pathogen had branched synnemata supporting monophiladic conidiogenous cells. a high-fidelity polymerase chain reaction (pcr) assay was used to amplify the ...200717382959
effects of a particle film on biology and behavior of diaphorina citri (hemiptera: psyllidae) and its infestations in citrus.studies were conducted to investigate the effects of a kaolin-based hydrophilic particle film, surround wp, on the biology and behavior of the psyllid diaphorina citri kuwayama (hemiptera: psyllidae) and to assess population densities of d. citri in citrus subjected to monthly applications of surround wp. laboratory investigations indicated a 3% (wt:vol) suspension of surround wp in water applied directly was not acutely toxic to eggs, older nymphs or adults. presence of the dried particle film ...200717598547
quantitative real-time pcr for detection and identification of candidatus liberibacter species associated with citrus huanglongbing.citrus huanglongbing (hlb, ex greening) is one of the most serious diseases of citrus. different forms of the disease are caused by different candidatus liberobacter species, candidatus liberibacter asiaticus (las), ca. l. africanus (laf) and ca. l. americanus (lam). the pathogen is transmitted by psyllid insects and by budding with contaminated plant materials. the vector psyllid diaphorina citri can transmit both las and lam. establishment of this vector into florida, reports of lam and las in ...200616414133
citrus huanglongbing in são paulo state, brazil: pcr detection of the 'candidatus' liberibacter species associated with the disease.symptoms of huanglongbing (hlb), one of the most serious diseases of citrus in asia and africa, have been noticed in march 2004 in the araraquara region of são paulo state, brazil. hlb has not been reported previously from america. the causal hlb bacteria, candidatus liberibacter africanus in africa and candidatus liberibacter asiaticus in asia, can be detected in symptomatic citrus leaves by pcr amplification of their 16s rdna with previously described primers. when this technique was applied t ...200515797817
'candidatus liberibacter americanus', associated with citrus huanglongbing (greening disease) in são paulo state, brazil.symptoms of huanglongbing (hlb) were reported in são paulo state (sps), brazil, in march 2004. in asia, hlb is caused by 'candidatus liberibacter asiaticus' and in africa by 'candidatus liberibacter africanus'. detection of the liberibacters is based on pcr amplification of their 16s rrna gene with specific primers. leaves with blotchy mottle symptoms characteristic of hlb were sampled in several farms of sps and tested for the presence of liberibacters. 'ca. l. asiaticus' was detected in a smal ...200516166678
effect of sucrose octanoate on survival of nymphal and adult diaphorina citri (homoptera: psyllidae).asian citrus psylla, diaphorina citri kuwayama (homoptera: psyllidae) was detected for the first time in the united states near delray beach, fl, on 2 june 1998 and is continuing to spread and multiply throughout southern florida. this psyllid is the vector of liberobacter asiaticum, a phloem-limited bacterium that causes citrus greening disease. this pathogen has not been found in the western hemisphere to date. furthermore, high infestation levels of d. citri can impact citrus plant health, fr ...200415279280
biology of diaphorina citri (homoptera: psyllidae) on four host plants.the biology of the citrus psyllid diaphorina citri kuwayama was studied at 25 degrees c on four commonly grown citrus and related plants [rough lemon, citrus jambhiri lush; sour orange, c aurantium l.; grapefruit, c. paradisi macfadyen; and orange jessamine, murraya paniculata (l.) jack] in the laboratory. the biological characteristics of each life stage are described. the average egg incubation periods on orange jessamine, grapefruit, rough lemon, and sour orange varied very little (4.1-4.2 d) ...200011142304
occurrence of free fatty acids in the phloem sap of different citrus varieties.candidatus liberibacter asiaticus is a phloem restricted bacterium causes citrus greening disease or huanglongbing (hlb), a major treat to commercial citrus production in florida. it is transmitted by the asian citrus psyllid, a phloem sap-feeding insect. studies conducted on the composition of citrus phloem sap revealed the presence amino acids, organic acids and sugars and of low amounts of free fatty acids. in the present study, the phloem sap of twelve citrus varieties with different degrees ...028532234
a plant pathogenic bacterium exploits the tricarboxylic acid cycle metabolic pathway of its insect vector.huanglongbing in citrus is caused by a phloem-limited, uncultivable, gram-negative α-proteobacterium, candidatus liberibacter asiaticus (clas). clas is transmitted by the phloem-sucking insect, diaphorina citri (hemiptera: liviidae), in a persistent, circulative, and propagative manner. in this study, we investigated the metabolomic and respiration rates changes in d. citri upon infection with clas using gas chromatography-mass spectrometry (gc-ms) and gas exchange analysis. the level of glycine ...028594267
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