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José Roberto Postali Parra - One of the best experts on this subject based on the ideXlab platform.

Bryce W Falk - One of the best experts on this subject based on the ideXlab platform.

  • Endogenous viral element-derived piRNAs are not required for production of ping-pong-dependent piRNAs from Diaphorina citri densovirus
    2020
    Co-Authors: Jared C Nigg, Yen-wen Kuo, Bryce W Falk
    Abstract:

    Partial integrations of DNA and non-retroviral RNA virus genomes, termed endogenous viral elements (EVEs), are abundant in arthropod genomes and often produce PIWI-interacting RNAs (piRNAs) speculated to target cognate viruses through the ping-pong cycle, a post-transcriptional RNA silencing mechanism. Here we describe a Diaphorina citri densovirus (DcDV)-derived EVE in the genome of Diaphorina citri. We found that this EVE gives rise to DcDV-specific primary piRNAs and is unevenly distributed among D. citri populations. Unexpectedly, we found that DcDV is targeted by ping-pong-dependent viral piRNAs (vpiRNAs) in D. citri lacking the DcDV-derived EVE, while four naturally infecting RNA viruses of D. citri are not targeted by vpiRNAs. Furthermore, a recombinant Cricket paralysis virus containing a portion of the DcDV genome corresponding to the DcDV-derived EVE was not targeted by vpiRNAs during infection in D. citri harboring the EVE. These results represent the first report of ping-pong-dependent vpiRNAs outside of mosquitoes.

  • Diaphorina citri reovirus is most closely related to fijiviruses.
    Virology, 2020
    Co-Authors: Qian Chen, Shahideh Nouri, Yuele Zhang, Anna I. Erickson, Bryce W Falk
    Abstract:

    Abstract The Asian citrus psyllid, Diaphorina citri Kuwayama, is an important insect vector of Candidatus Liberibacter asiaticus, the causal agent of Huanglongbing, which is the most destructive disease of citrus worldwide. Sequences for putative Diaphorina citri reovirus (DcRV) were identified from some worldwide populations of D. citri. Here, field surveys indicated that the virus was common in D. citri populations from Hawaii and Fuzhou of PR China. Electron microscopy showed that DcRV virions possessed a typical reovirus-like morphology. The U. S. and Chinese DcRV isolates both showed 10 segments of double-stranded RNA sharing >96% nucleotide sequence identity, and encoding 11 deduced proteins. All genome segments contained conserved 5′ and 3′ terminal nucleotide sequences and inverted repeats that are hallmarks of reovirus sequence. Phylogenetic analysis showed that DcRV may be considered a new species of the genus Fijivirus sharing a most recent common ancestor with the insect-specific fijivirus Nilaparvata lugens reovirus.

  • Diaphorina citri densovirus is a persistently infecting virus with a hybrid genome organization and unique transcription strategy
    Journal of General Virology, 2020
    Co-Authors: Jared C Nigg, Bryce W Falk
    Abstract:

    Diaphorina citri densovirus (DcDV) is an ambisense densovirus with a 5071 nt genome. Phylogenetic analysis places DcDV in an intermediate position between those in the Ambidensovirus and Iteradensovirus genera, a finding that is consistent with the observation that DcDV possesses an Iteradensoviris-like non-structural (NS) protein-gene cassette, but a capsid-protein (VP) gene cassette resembling those of other ambisense densoviruses. DcDV is maternally transmitted to 100 % of the progeny of infected female Diaphorina citri, and the progeny of infected females carry DcDV as a persistent infection without outward phenotypic effects. We were unable to infect naive individuals by oral inoculation, however low levels of transient viral replication are detected following intrathoracic injection of DcDV virions into uninfected D. citri insects. Transcript mapping indicates that DcDV produces one transcript each from the NS and VP gene cassettes and that these transcripts are polyadenylated at internal sites to produce a ~2.2 kb transcript encoding the NS proteins and a ~2.4 kb transcript encoding the VP proteins. Additionally, we found that transcriptional readthrough leads to the production of longer non-canonical transcripts from both genomic strands.

  • Complete Genome Sequence of the Largest Known Flavi-Like Virus, Diaphorina citri flavi-like virus, a Novel Virus of the Asian Citrus Psyllid, Diaphorina citri
    Genome announcements, 2016
    Co-Authors: Emilyn E. Matsumura, Jared C Nigg, Bryce W Falk, Luca Nerva, Shahideh Nouri
    Abstract:

    ABSTRACT A novel flavi-like virus tentatively named Diaphorina citri flavi-like virus (DcFLV) was identified in field populations of Diaphorina citri through small RNA and transcriptome sequencing followed by reverse transcription (RT)-PCR. We report here the complete nucleotide sequence and genome organization of DcFLV, the largest flavi-like virus identified to date.

  • Complete Genome Sequence of a Putative Densovirus of the Asian Citrus Psyllid, Diaphorina citri.
    Genome announcements, 2016
    Co-Authors: Jared C Nigg, Shahideh Nouri, Bryce W Falk
    Abstract:

    Here, we report the complete genome sequence of a putative densovirus of the Asian citrus psyllid, Diaphorina citri Diaphorina citri densovirus (DcDNV) was originally identified through metagenomics, and here, we obtained the complete nucleotide sequence using PCR-based approaches. Phylogenetic analysis places DcDNV between viruses of the Ambidensovirus and Iteradensovirus genera.

Valmir Antonio Costa - One of the best experts on this subject based on the ideXlab platform.

David G. Hall - One of the best experts on this subject based on the ideXlab platform.

  • ‘Candidatus Liberibacter asiaticus’ (CLas) acquisition rates and Ct values of Diaphorina citri isofemale lines.
    2018
    Co-Authors: El-desouky Ammar, David G. Hall, Saeed Hosseinzadeh, Michelle Heck
    Abstract:

    ‘Candidatus Liberibacter asiaticus’ (CLas) acquisition rates and Ct values of Diaphorina citri isofemale lines.

  • Effects of Temperature, Photoperiod, and Rainfall on Morphometric Variation of Diaphorina citri (Hemiptera: Liviidae)
    Environmental entomology, 2017
    Co-Authors: Thomson M. Paris, David G. Hall, Sandra A. Allan, Matthew G. Hentz, Scott D. Croxton, Niharika Ainpudi, Philip A. Stansly
    Abstract:

    Phenotypic plasticity provides a mechanism by which an organism can adapt to new or changing environments. Earlier studies have demonstrated the variability of Diaphorina citri Kuwayama (Asian citrus psyllid) population dynamics, but no analysis of morphological changes induced by seasonal or artificial laboratory-induced conditions has yet been documented. Such morphometric variation has been found to correspond in dispersal capabilities in several insect taxa. In this study, the effects of temperature and photoperiod on morphometric variation of D. citri were examined through laboratory rearing of psyllids under controlled temperatures (20 °C, 28 °C, and 30 °C) and under a short photoperiod of 10.5:13.5 (L:D) h and a long photoperiod of 16:8 (L:D) h. Diaphorina citri were field-collected monthly from three citrus groves in Fort Pierce, Gainesville, and Immokalee, FL, to evaluate potential field-associated environmental effects. Both traditional and geometric morphometric data were used to analyze the correlation between environmental and morphometric variation. A strong correlation was found between temperature and shape change, with larger and broader wings at colder temperatures in the laboratory. Short day length resulted in shorter and narrower wings as well. From the field, temperature, rainfall, and photoperiod were moderately associated with shape parameters. Adult D. citri with blue/green abdomens collected in the laboratory and field studies were larger in size and shape than those with brown/gray abdomens.

  • Host-Choice Behavior of Diaphorina citri Kuwayama (Hemiptera: Psyllidae) Under Laboratory Conditions
    Journal of Insect Behavior, 2015
    Co-Authors: Chuanqing Ruan, David G. Hall, Bo Liu, Yongping Duan, Guocheng Fan
    Abstract:

    The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is the vector of the bacterial pathogens that cause Huanglongbing (HLB), considered to be the most devastating disease of citrus worldwide. Knowledge of the ACP's host-plant finding behavior aids in our understanding of the epidemiology of HLB and in designing experiments to investigate host plant resistance to ACP. We present the results of

  • Diaphorina citri (Hemiptera: Liviidae) Abundance in Puerto Rico Declines with Elevation
    Journal of economic entomology, 2015
    Co-Authors: David A. Jenkins, David G. Hall, Ricardo Goenaga
    Abstract:

    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 strong trend in both years for decreasing psyllid abundance with increased elevation based on the number of psyllids captured on traps and the proportion of trees shown to be infested. No psyllids were collected at an elevation of >600 m. Reduced populations at higher elevations could be a consequence of differences in temperature, air pressure, oxygen levels, ultraviolet light, or other factors alone or in combination. We discuss our results as they pertain to management of D. citri and Huanglongbing.

  • Responses of Diaphorina citri (Hemiptera: Psyllidae) to Conspecific Vibrational Signals and Synthetic Mimics
    Annals of the Entomological Society of America, 2013
    Co-Authors: B. Rohde, David G. Hall, Thomson M. Paris, E. M. Heatherington, Richard W. Mankin
    Abstract:

    ABSTRACT Mate-seeking in Diaphorina citri Kuwayama, a vector of the economically damaging huanglongbing citrus disease, typically includes male—female duetting behaviors. First, the male calls by beating his wings at ≈170–250 Hz, producing vibrations that are transmitted along the host tree branches to the female. If receptive, she immediately replies, helping to direct the searching male toward her. The duetting and searching continues until the male locates the female. Males and females are similar in size and produce wingbeat vibrations with similar temporal and spectral patterns. A study of male and female responses to playbacks of recorded and synthetic mimics of different vibrational signals on citrus plants was conducted to better understand the range of signals to which D. citri respond and potentially to co-opt or disrupt their vibrational communication. In general, both sexes responded well to a variety of 0.3–0.5-s signals that included multiple harmonics of ≈200-Hz wingbeatfrequency chirps up ...

Lukasz L. Stelinski - One of the best experts on this subject based on the ideXlab platform.

  • Trail Chemicals of the Convergens Ladybird Beetle, Hippodamia convergens , Reduce Feeding and Oviposition by Diaphorina citri (Hemiptera: Psyllidae) on Citrus Plants
    Journal of Insect Behavior, 2018
    Co-Authors: Meeja Seo, Monique J. Rivera, Lukasz L. Stelinski
    Abstract:

    We investigated feeding and oviposition behavior of the Asian citrus psyllid, Diaphorina citri, when exposed to the foraging trails of the convergens ladybird beetle, Hippodamia convergens. Diaphorina citri females feeding on citrus leaves directly exposed to the ladybird adults or treated with trail extract excreted significantly less honeydew droplets than controls. The trail chemicals of the ladybird beetle also decreased oviposition by D. citri females on citrus. In a no-choice experiment, D. citri females preferred to oviposit on control flush and plants than those with ladybird trail-extract treatments. In two-choice experiments, 68.0% of D. citri released into cages exhibited strong selection preference for settling and eventual oviposition on control plants than plants treated with ladybird trail extract. Diaphorina citri eggs were found on all new leaf flush of control plants, whereas only 29.5% of flush on treatment plants were selected for oviposition. The trail chemical deposited by the convergens ladybird beetle elicits repellency of D. citri feeding and oviposition. Therefore, the trail chemicals my contain components that could be useful for behavior-based management of D. citri and HLB disease by reducing psyllid feeding and oviposition.

  • Ladybird beetle trails reduce host acceptance by Diaphorina citri Kuwayama (Hemiptera: Liviidae)
    Biological Control, 2018
    Co-Authors: Meeja Seo, Lukasz L. Stelinski, Monique J. Rivera, Xavier Martini
    Abstract:

    Abstract We investigated the behavioral responses of the Asian citrus psyllid, Diaphorina citri, to the trail of the convergent ladybird beetle, Hippodamia convergens. We tested the hypothesis that H. convergens trails reduce D. citri host acceptance using choice tests. Citrus plants previously exposed to ladybird beetle larvae and adult trails were avoided by D. citri compared to untreated controls. Female D. citri settling on H. convergens-exposed plants decreased as the density of ladybird beetle larvae or adults used to expose treatment plants was increased. Larval and adult trails were equally repellent to D. citri. In laboratory olfactometer assays that measured orientation to volatile chemical cues, D. citri females avoided citrus plants that were pre-exposed to caged H. convergens larvae for 1, 5 or 10 days as compared with non-exposed controls. Diaphorina citri did not avoid the odor of citrus plants pre-exposed to caged adult H. convergens for 1 or 5 days as compared with the control. However, more female D. citri chose untreated control arms as compared with plants exposed to H. convergens adults for 10 days. We collected larval trails deposited by H. convergens and mechanically re-applied them to citrus plants as a spray solution. D. citri significantly avoided plants treated with previously collected H. convergens trail solutions in choice tests as compared with untreated controls; treatments caused 15 days of residual behavioral activity on D. citri. Our results indicate that chemical cues mediate avoidance of ladybird beetle trails by D. citri. Implications for biological and non-insecticidal control of D. citri are discussed.

  • Patterns of habitat use by the Asian citrus psyllid, Diaphorina citri, as influenced by abiotic and biotic growing conditions
    Agricultural and Forest Entomology, 2016
    Co-Authors: Kirsten S. Pelz-stelinski, Xavier Martini, Heather Kingdom-gibbard, Lukasz L. Stelinski
    Abstract:

    The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) is an economically important pest of citrus throughout Asia and the Americas because it transmits Candidatus Liberibacter asiaticus (CLas), which is the presumed causal agent of citrus greening disease. We investigated whether biotic and abiotic characteristics can be used to predict Diaphorina citri population abundance and assessed whether agricultural intensity explained the distribution of D. citri populations during winter dormant periods (December to March). Over two consecutive winters, we examined the abundance of D. citri in groves throughout Florida in response to four different management regimes, defined as: conventional, intermittent, unmanaged and organic. During both years, the winter abundance of D. citri in groves with intermittent management was greater than in groves with other management regimes. Latitude and row orientation both had a significant effect on psyllid density during winter. Diaphorina citri abundance was higher when more than 20% of the surrounding landscape was urbanized. These findings suggest that only conventional management of groves reduced D. citri populations during winter periods. By contrast, intermittent management was associated with higher D. citri populations. These results might be of some concern in light of the economic and environmental costs of repeated insecticide applications and the dramatic decline of citrus production in the U.S.A.

  • Reversal of Insecticide Resistance in Florida Populations of Diaphorina citri (Hemiptera: Liviidae)
    Florida Entomologist, 2016
    Co-Authors: Monique R. Coy, Liu Bin, Lukasz L. Stelinski
    Abstract:

    Abstract We report the results from surveys conducted in 2013 and 2014 to monitor insecticide susceptibility in Florida field populations of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). These surveys are a component of the insecticide resistance management program for D. citri, which is the vector of ‘Candidatus’ Liberibacter asiaticus. ‘Candidatus’ Liberibacter asiaticus is the plant pathogen that causes citrus greening disease. The insecticides evaluated (carbaryl, chlorpyrifos, dimethoate, fenpropathrin, flupyradifurone, imidacloprid, and thiamethoxam) represent several modes of action and are among those that are currently used to manage D. citri in commercial groves in Florida. The 2013 and 2014 surveys revealed a decrease in the resistance ratios at the 50% response level (RR50) as compared with the 2009 survey, which was the last time this parameter was investigated. The results of the 2013 and 2014 surveys suggest a reversal to pre-2009 susceptibility levels in D. cit...

  • Effects of Cold-Acclimation, Pathogen Infection, and Varying Temperatures on Insecticide Susceptibility, Feeding, and Detoxifying Enzyme Levels in Diaphorina citri (Hemiptera: Liviidae)
    Florida Entomologist, 2015
    Co-Authors: Siddharth Tiwari, Nabil Killiny, Bin Liu, Rajinder S. Mann, Lukasz L. Stelinski
    Abstract:

    Abstract Infection of Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), with ‘Candidatus' Liberibacter asiaticus (Las), the causal pathogen of citrus greening disease or huanglongbing, increases psyllid susceptibility to insecticides. Diaphorina citri populations in citrus occur year-round in tropical and sub-tropical habitats, and thus insecticide applications for managing this plant disease vector occur over a wide temperature range (10–40 °C). During the winter season, D. citri is occasionally exposed to periods of freezing temperatures, when temperatures fall below -6.5 °C. In this investigation, we compared insecticide susceptibility of uninfected and Las-infected D. citri at various temperatures (20–37 °C). Cold-acclimated (6 ± 1 °C) D. citri adults were less susceptible to neonicotinoid insecticides as compared with non-acclimated controls, but this trend was not observed for other insecticides tested. A positive correlation between temperature and percentage mortality caused b...