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Sample records for psyllid boreioglycaspis melaleucae

  1. Ultrastructure of Wax-Producing Structures on the Integument of the Melaleuca Psyllid Boreioglycaspis melaleucae (Hemiptera: Psyllidae), with Honeydew Excretion Behavior in Males and Females.

    Science.gov (United States)

    Ammar, El-Desouky; Hentz, Matthew; Hall, David G; Shatters, Robert G

    2015-01-01

    The melaleuca psyllid, Boreioglycaspis melaleucae (Hemiptera: Psyllidae), was introduced to Florida as a biological control agent against Melaleuca quinquenervia, an invasive evergreen tree that has invaded large areas of Florida Everglades. Colonies of B. melaleucae nymphs are normally covered by white waxy secretions, and nymphs of various instars produce long bundles of white waxy filaments extending laterally and posteriorly from their abdomen. Scanning electron microscopy of 'naturally waxed' and 'dewaxed' nymphs (cleaned from wax) revealed two types of wax pore plates located dorsally and laterally on the integument of posterior abdominal segments starting with the 4th segment. Type-1 wax pore plates, with raised rim, peripheral groove, slits and pits, produce long ribbons and filaments of waxy secretions that are wound together forming long wax bundles, whereas type-2 wax pore plates, with slits only, produce shorter wax curls. Additionally, in both nymphs and adult females, the circumanal ring contained ornate rows of wax pores that produce wax filaments covering their honeydew excretions. Video recordings with stereomicroscopy showed that adult females produce whitish honeydew balls, powerfully propelled away from their body, probably to get these sticky excretions away from their eggs and newly hatched nymphs. Adult males, however, produce clear droplets of honeydew immediately behind them, simply by bending the posterior end of the abdomen downward. The possible role(s) of waxy secretions by nymphs and adults of B. melaleucae in reducing contamination of their colonies with honeydew, among other possibilities, are discussed.

  2. Influence of Temperature, Humidity, and Plant Terpenoid Profiles on Life History Characteristics of Boreioglycaspis melaleucae (Hemiptera: Psyllidae), a Biological Control Agent of the Invasive Tree Melaleuca quinquenervia

    Science.gov (United States)

    Although the introduced weed biological control agent Boreioglycaspis melaleucae Moore is widely established among stands of its host Melaleuca quinquenervia (Cav.) Blake (Myrtaceae) in south Florida, it’s population densities decline markedly during summer months. We investigated the hypothesis tha...

  3. Initial impacts and field validation of host range for Boreioglycaspis melaleucae Moore (Hemiptera: Psyllidae),a biological control agent of the invasive tree Melaleuca quinquenervia (Cav.) Blake (Myrtales: Myrtaceae: Leptosp

    Science.gov (United States)

    Invasion of south Florida wetlands by the Australian paperbark tree (“melaleuca”), Melaleuca quinquenervia (Cav.) S.T. Blake (melaleuca) has caused adverse economic and environmental impacts. The tree’s biological attributes along with favorable ambient biophysical conditions combine to complicate ...

  4. Modeling the long-term effects of introduced herbivores on the spread of an invasive tree

    Science.gov (United States)

    Zhang, Bo; DeAngelis, Don; Rayamajhi, Min B.; Botkin, Daniel B.

    2017-01-01

    ContextMelaleuca quinquenervia (Cav.) Blake (hereafter melaleuca) is an invasive tree from Australia that has spread over the freshwater ecosystems of southern Florida, displacing native vegetation, thus threatening native biodiversity. Suppression of melaleuca appears to be progressing through the introduction of insect species, the weevil, Oxiops vitiosa, and the psyllid, Boreioglycaspis melaleucae.ObjectiveTo improve understanding of the possible effects of herbivory on the landscape dynamics of melaleuca in native southern Florida plant communities.MethodsWe projected likely future changes in plant communities using the individual based modeling platform, JABOWA-II, by simulating successional processes occurring in two types of southern Florida habitat, cypress swamp and bay swamp, occupied by native species and melaleuca, with the impact of insect herbivores.ResultsComputer simulations show melaleuca invasion leads to decreases in density and basal area of native species, but herbivory would effectively control melaleuca to low levels, resulting in a recovery of native species. When herbivory was modeled on pure melaleuca stands, it was more effective in stands with initially larger-sized melaleuca. Although the simulated herbivory did not eliminate melaleuca, it decreased its presence dramatically in all cases, supporting the long-term effectiveness of herbivory in controlling melaleuca invasion.ConclusionsThe results provide three conclusions relevant to management: (1) The introduction of insect herbivory that has been applied to melaleuca appears sufficient to suppress melaleuca over the long term, (2) dominant native species may recover in about 50 years, and (3) regrowth of native species will further suppress melaleuca through competition.

  5. Insect Repellent Properties of Melaleuca alternifolia

    OpenAIRE

    Mohamad Adib Bin Edris; Awang Soh Yusuff Mamat; Muhammad Shahzad Aslam; Muhammad Syarhabil Ahmad

    2016-01-01

    The aim of this study is to compare the use of plant-based insect repellents that are environment friendly with the use of insect repellents based on chemical substances which can be harmful to the environment and human health. The plant studied here is "tea tree"; its scientific name is Melaleuca alternifolia. Essential oil from this plant is extracted by steam distillation method. Based on the previous research, tea tree oil has antimicrobial, antifungal, anti-inflammatory, and insect repel...

  6. Pacific capsular Myrtaceae 13. Melaleuca and Callistemon (New Caledonia)

    NARCIS (Netherlands)

    Dawson, J.W.

    1978-01-01

    Melaleuca Linn., Mant. 1 (1767) 14 (nom. cons), and Callistemon R. Br., App. Flind. Voy. 2: App. 3 (1814) 547, are centred in Australia where they are represented by about 180 and 40 species respectively, including the type species of both genera. Six of the Melaleucas extend to New Guinea and one

  7. Asian citrus psyllid RNAi pathway : RNAi evidence

    OpenAIRE

    Taning, Clauvis N. T.; Andrade, Eduardo C.; Hunter, Wayne B.; Olivier Christiaens; Guy Smagghe

    2016-01-01

    Diaphorina citri, known as the Asian citrus psyllid, is an important pest of citrus because it transmits a phloem-limited bacteria strongly implicated in huanglongbing (citrus greening disease). Emerging biotechnologies, such as RNA interference, could provide a new sustainable and environmentally friendly strategy for the management of this pest. In this study, genome and functional analysis were performed to verify whether the RNAi core genes are present in the Asian psyllid genome and if t...

  8. A comparison of plant species for rearing Asian citrus psyllid

    Science.gov (United States)

    Five plant genotypes were compared with respect to Asian citrus psyllid (ACP) reproduction potential: Bergera koenigii, Citrus aurantiifolia, C. macrophylla, C. taiwanica and Murraya paniculata. Asian citrus psyllid reproduction is dependent on young flush and thus Asian citrus psyllid production po...

  9. Risk assessment: progress of quarantine biocontrol research on Chinese Tallow, Melaleuca, and Downy Rose Myrtle

    Science.gov (United States)

    Risk assessments of two biocontrol candidates for Chinese tallow, Triadica sebifera (Euphoriales: Euphorbiaceae), and one for Melaleuca, Melaleuca quinquenervia (Myrtales: Myrtaceae), were conducted during 2009 and continuing into 2010 by USDA scientists located at the Florida Department of Agricul...

  10. The role of melaleuca control in Everglades restoration: accomplishments and future plans

    Science.gov (United States)

    The invasive tree Melaleuca quinquenervia (Cav.) S.T. Blake, melaleuca, was first introduced to Florida in 1886 for ornamental use. It was later planted for bank stabilization and as a forestry crop. Melaleuca now invades a variety of habitats, changing the hydroperiod and fire regime, reducing plan...

  11. The role of melaleuca control in Everglades restoration: accomplishments and future plans

    Science.gov (United States)

    The invasive tree Melaleuca quinquenervia (Cav.) S.T. Blake, melaleuca, was first introduced to Florida in 1886 for ornamental use. It was later planted for bank stabilization and as a forestry crop. Melaleuca now invades a variety of habitats, changing the hydroperiod and fire regime, reducing plan...

  12. Óleo de melaleuca (Melaleuca alternifolia Maiden & Betche, Cheel no controle de cercosporiose em beterraba

    Directory of Open Access Journals (Sweden)

    A.D. SOUZA

    2015-01-01

    Full Text Available RESUMO O óleo volátil da melaleuca (Melaleuca alternifolia Maiden & Betche, Cheel possui atividade antimicrobiana podendo causar efeitos sobre as plantas. Avaliou-se a inibição do óleo em Cercospora beticolaSacc., e seu efeito no aumento da produção e qualidade de raízes de beterraba. As doses foram de 0,13; 0,67; 0,80 e 1,00% do óleo, além das testemunhas composta pelo meio de cultura Batata Dextrose Ágar (BDA no experimento in vitro, e água no experimento in vivo. As plantas foram pulverizadas duas vezes por semana. O delineamento foi inteiramente casualizado, com 4 repetições, e as médias foram comparadas pelo teste Tukey a 5% de probabilidade. O índice de infecção das folhas foi determinado por escala diagramática além do peso e diâmetro das raízes. Os resultados de inibição do crescimento micelial para as doses do óleo foram 0; 56; 87; 83 e 99%, e os índices de infecção: 77,08; 35,62; 21,04; 19,37 e 20,00%, respectivamente, para a testemunha e as doses 0,13; 0,67; 0,80 e 1,00% do óleo. Somente na concentração de 0,80% o óleo proporcionou relação positiva entre o ganho de peso e o diâmetro das raízes. O óleo de Melaleuca foi eficaz no controle de C. beticola e, como consequência, houve produção de raízes de beterraba com melhor desenvolvimento.

  13. Insect Repellent Properties of Melaleuca alternifolia

    Directory of Open Access Journals (Sweden)

    Mohamad Adib Bin Edris

    2016-08-01

    Full Text Available The aim of this study is to compare the use of plant-based insect repellents that are environment friendly with the use of insect repellents based on chemical substances which can be harmful to the environment and human health. The plant studied here is "tea tree"; its scientific name is Melaleuca alternifolia. Essential oil from this plant is extracted by steam distillation method. Based on the previous research, tea tree oil has antimicrobial, antifungal, anti-inflammatory, and insect repellent properties. Some experiments were done on tea tree oil to determine its insect repellent properties and the suitable concentration that can be used to make sure its repelling effect is optimum. The purpose of this determination is to avoid its harmful effect on humans because it can be toxic if it is used at high concentration. The results showed that tea tree oil repelled Tribolium castaneum. Furthermore, the toxicity assays also gave positive result where the tea tree oil has toxic properties against Solenopsis invicta. The lethal dose (LD of tea tree oil to kill 50% of a group of S. invicta is 23.52 µL/mL. This LD50 is determined by using the arithmetic method of Karber. Broadly, the results showed that M. alternifolia has insect repellent properties and shows toxicity against certain insects.

  14. Plant resistance within the Rutaceae to Asian citrus psyllid

    Science.gov (United States)

    USDA-ARS recently initiated research on host plant resistance to the Asian citrus psyllid. The psyllid is an important invasive pest of citrus in the United States because it transmits a serious disease of citrus known as huanglongbing (citrus greening). There is no cure for this bacterial disease. ...

  15. Restriction digestion method for haplotyping the potato psyllid, Bactericera cockerelli

    Science.gov (United States)

    A restriction digestion method has been developed for haplotyping the potato psyllid, Bactericera cockerelli Sulc., an economically important pest of solanaceous crops. This method differentiates the four known potato psyllid haplotypes by utilizing restriction enzyme digestion of a portion of the ...

  16. Behavioral assay on Asian citrus psyllid attraction to orange jasmine

    Science.gov (United States)

    The Asian citrus psyllid (ACP) is an important pest because it transmits a bacterium putatively responsible for huanglongbing, a devastating citrus disease. Research on ACP chemical ecology is of interest with respect to identifying attractants and repellents for managing the psyllid. We report on a...

  17. Chemical constituents from Melaleuca alternifolia (Myrtaceae); Constituintes quimicos de Melaleuca alternifolia (Myrtaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Tatiana R.; Barbosa, Luiz C.A.; Maltha, Celia R.A. [Vicosa Univ., MG (Brazil). Dept. de Quimica]. E-mail: lcab@ufv.br; Paula, Vanderlucia F. [Universidade Estadual do Sudoeste da Bahia, Jequie, BA (Brazil). Dept. de Quimica e Exatas; Nascimento, Evandro A. [Uberlandia Univ., MG (Brazil). Inst. de Quimica

    2004-08-01

    The first chemical study of non-volatile constituents from the bark and stem of Melaleuca alternifolia (Myrtaceae) led to the isolation and identification of 3,3'-O-dimethylellagic acid (1) and five pentacyclic triterpenes: 2{alpha},3{beta},23-trihydroxyolean-12-en-28-oic acid (arjunolic acid, 2), 3{beta}-hydroxylup-20(29)-en-27,28-dioic acid (melaleucic acid, 3), betulinic acid (4), betuline (5), 3{beta}-O-acetylurs-12-en-28-oic acid (6), a mixture of fatty acids and esters, and several hydrocarbons. For 2{alpha},3{beta},23-trihydroxyolean-12-en-28-oic acid (2) and 3{beta}-O-acetylurs-12-en-28-oic acid (6) a first detailed assignment of {sup 1}H NMR is presented. (author)

  18. Constituintes químicos de Melaleuca alternifolia (Myrtaceae Chemical constituents from Melaleuca alternifolia (Myrtaceae

    Directory of Open Access Journals (Sweden)

    Tatiana R. Vieira

    2004-08-01

    Full Text Available The first chemical study of non-volatile constituents from the bark and stem of Melaleuca alternifolia (Myrtaceae led to the isolation and identification of 3,3'-O-dimethylellagic acid (1 and five pentacyclic triterpenes: 2alpha,3beta,23-trihydroxyolean-12-en-28-oic acid (arjunolic acid, 2, 3beta-hydroxylup-20(29-en-27,28-dioic acid (melaleucic acid, 3, betulinic acid (4, betuline (5, 3beta-O-acetylurs-12-en-28-oic acid (6, a mixture of fatty acids and esters, and several hydrocarbons. For 2alpha,3beta,23-trihydroxyolean-12-en-28-oic acid (2 and 3beta-O-acetylurs-12-en-28-oic acid (6 a first detailed assignment of ¹H NMR is presented.

  19. Impacts of the Psyllid Arytinnis hakani (Homoptera: Psyllidae) on Invasive French Broom in Relation to Plant Size and Psyllid Density.

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    Hogg, Brian N; Moran, Patrick J; Smith, Lincoln

    2017-06-01

    The impacts of weed biological control agents may vary with plant ontogeny. As plants grow, structural and chemical changes can alter plant resistance, which may reduce herbivory via chemical or structural defenses, and plant tolerance, which may enable plants to maintain fitness despite attack. Resistance and tolerance generally increase as plants grow. Nonetheless, prerelease tests of agent efficacy often overlook plant ontogeny. Here, we assess the performance and impacts of a candidate biocontrol agent, the psyllid Arytinnis hakani (Loginova), in relation to the age of its host plant, the invasive shrub French broom, Genista monspessulana. We also examined whether the psyllid can consistently kill plants when its densities are sufficiently high. Survival of psyllids to adulthood and the timing of adult emergence did not differ between plant sizes, indicating that performance of nymphs was not influenced by plant size. However, adult psyllid survival was reduced on small plants, suggesting that nymphs and adults responded differently to ontogenetic changes in plant quality. Psyllids affected the growth of small and large plants similarly; all measured plant growth parameters were lower in the presence of psyllids regardless of plant size. In a separate experiment, effects on plant survival depended on psyllid density, as higher realized densities of ∼9 psyllids per cm stem length were necessary to consistently kill plants. Thus, results suggest that the psyllid would be equally effective on a range of plant sizes, particularly at high densities, and show the potential of the psyllid to help control French broom in California. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

  20. Water Level Effects on Growth of Melaleuca Seedlings from Lake Okeechobee (Florida, USA) Littoral Zone.

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    LOCKHART; AUSTIN; AUMEN

    1999-05-01

    / The invasive exotic wetland tree, Melaleuca quinquenervia, is expanding rapidly throughout seasonally wet areas of southern Florida (USA), including the littoral zone of Lake Okeechobee. Natural resource managers are concerned that a lower lake level regulation schedule under consideration for Lake Okeechobee, while potentially beneficial to overall ecosystem health, might increase the rate of Melaleuca expansion. To investigate this possibility, Melaleuca saplings (harvested from the littoral zone) and 7-week-old seedlings (grown from harvested seeds) were subjected to various hydroperiod treatments in replicated mesocosms. Hydroperiod treatments were selected based on a simulation of historical water level variations. Saplings grew taller under longer hydroperiods with fluctuating water levels, including periods of submersion. Time since germination affected the response of seedlings to inundation. Submersed 7-week-old seedlings grew slower and had less biomass than submersed 12-week-old seedlings, yet mortality was low at both ages. Melaleuca's plasticity allows it to adapt to hypoxic, aquatic conditions by means of aquatic heterophylly and adventitious roots. Algae and drought also increased mortality. Based on faster growth of Melaleuca under longer hydroperiods and its adaptability to seasonal flooding, a lower lake regulation schedule may not stimulate its expansion. Therefore, water levels should not be manipulated only to control Melaleuca. Control of Melaleuca should continue using current practices such as manual removal or chemical treatment. KEY WORDS: Melaleuca; Lake Okeechobee; Littoral zone; Water level; Regulation schedule

  1. Differential response by Melaleuca quinquenervia trees to attack by the rust fungus Puccinia psidii in Florida

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    Melaleuca quinquenervia (melaleuca, paperbark tree) is an exotic invasive tree in Florida, Hawaii, and some Caribbean islands. Puccinia psidii (guava rust-fungus) is a Neotropical rust fungus, reported to attack many species in the Myrtaceae and one genus in the Heteropyxidaceae, both members of the...

  2. Asian Citrus Psyllid RNAi Pathway – RNAi evidence

    OpenAIRE

    Taning, Clauvis N. T.; Eduardo C. Andrade; Hunter, Wayne B.; Olivier Christiaens; Guy Smagghe

    2016-01-01

    Diaphorina citri, known as the Asian citrus psyllid, is an important pest of citrus because it transmits a phloem-limited bacteria strongly implicated in huanglongbing (citrus greening disease). Emerging biotechnologies, such as RNA interference, could provide a new sustainable and environmentally friendly strategy for the management of this pest. In this study, genome and functional analysis were performed to verify whether the RNAi core genes are present in the Asian psyllid genome and if t...

  3. Asian Citrus Psyllid RNAi Pathway – RNAi evidence

    OpenAIRE

    Taning, Clauvis N. T.; Andrade, Eduardo C. de; Hunter, Wayne B.; Christiaens, Olivier; Smagghe, Guy

    2016-01-01

    Diaphorina citri, known as the Asian citrus psyllid, is an important pest of citrus because it transmits a phloem-limited bacteria strongly implicated in huanglongbing (citrus greening disease). Emerging biotechnologies, such as RNA interference, could provide a new sustainable and environmentally friendly strategy for the management of this pest. In this study, genome and functional analysis were performed to verify whether the RNAi core genes are present in the Asian psyllid genome and if t...

  4. Asian Citrus Psyllid RNAi Pathway – RNAi evidence

    Science.gov (United States)

    Taning, Clauvis N. T.; Andrade, Eduardo C.; Hunter, Wayne B.; Christiaens, Olivier; Smagghe, Guy

    2016-01-01

    Diaphorina citri, known as the Asian citrus psyllid, is an important pest of citrus because it transmits a phloem-limited bacteria strongly implicated in huanglongbing (citrus greening disease). Emerging biotechnologies, such as RNA interference, could provide a new sustainable and environmentally friendly strategy for the management of this pest. In this study, genome and functional analysis were performed to verify whether the RNAi core genes are present in the Asian psyllid genome and if the RNAi machinery could be exploited to develop a management strategy for this pest. Analyses of RNAi-related genes in the Asian citrus psyllid genome showed an absence of sequences encoding R2D2, a dsRNA-binding protein that functions as a cofactor of Dicer-2 in Drosophila. Nevertheless, bioassays using an in Planta System showed that the Asian citrus psyllid was very sensitive to ingested dsRNA, demonstrating a strong RNAi response. A small dose of dsRNA administered through a citrus flush was enough to trigger the RNAi mechanism, causing significant suppression of the targeted transcript, and increased psyllid mortality. This study provides evidence of a functional RNAi machinery, which could be further exploited to develop RNAi based management strategies for the control of the Asian citrus psyllid. PMID:27901078

  5. Gender- and species-specific characteristics of bacteriomes from three psyllid species (Hemiptera: Psylloidae)

    Science.gov (United States)

    Psyllids (Hemiptera: Pyslloidea) harbor bacterial symbionts in specialized organs called bacteriomes. Bacteriomes may be subject to manipulation to control psyllid pests including Bactericera cockerelli (Sulc) (Hemiptera: Triozidae) and Cacopsylla pyricola (Forster) (Hemiptera: Psyllidae) if the bi...

  6. Chemistry and Biological Activities of Essential Oils from Melaleuca L. Species

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    Luiz Claudio Almeida Barbosa

    2013-03-01

    Full Text Available Essential oils from species Melaleuca genus, especially M. alternifolia (Maiden & Betche Cheel, have been widely used worldwide in various industries. This review is a contribution to Melaleuca knowledge and describes five important essential oil-producing species and two subspecies of Melaleuca in terms of their essential oil chemical composition, medicinal applications, and leaf morphoanatomy. Some relationships between essential oil composition of these species and important biological activities are presented. Useful parameters for the certification of the essential oils are also highlighted.

  7. Post-biological control invasion trajectory for Melaleuca quinquenervia in a seasonally inundated wetland

    Science.gov (United States)

    Although the exotic invasive tree Melaleuca quinquenervia has invaded and dominated South Florida wetlands since its introduction in 1886, its formerly unfettered seed production is now constrained by intentionally introduced herbivores, especially Oxyops vitiosa Pascoe (Coleoptera: Curculionidae). ...

  8. In vitro susceptibilities of Candida and Aspergillus species to Melaleuca alternafolia (tea tree) oil.

    Science.gov (United States)

    Vazquez, J A; Arganoza, M T; Boikov, D; Akins, R A; Vaishampayan, J K

    2000-06-01

    Candida species are an important cause of opportunistic infection in the oral cavity of immunocompromised patients, especially HIV infected patients. Melaleuca oil obtained commercially was investigated since it is known to have broad antifungal properties. The in-vitro susceptibilities of Aspergillus and susceptible and resistant Candida species were performed utilizing serial dilutions in microtiter plates with Sabouraud dextrose agar and the commercial preparation of Melaleuca. As a comparator, in vitro susceptibilities to amphotericin B and fluconazole were also determined using the broth microdilution technique. The results demonstrate that Melaleuca inhibited the Candida species. However, the growth of Aspergillus was not inhibited at the concentrations tested. Thus, preparations containing Melaleuca alternafolia may be a useful alternative for superficial candidal infections. In fact, it may be a useful alternative regimen for advanced HIV-positive patients with oropharyngeal candidiasis refractory to fluconazole. However, controlled clinical studies to evaluate its efficacy are still needed.

  9. Wavelength and polarization affect phototaxis of the Asian citrus psyllid

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    The Asian citrus psyllid, D. citri, is a primary pest for citrus production due to its status as a vector of the citrus disease, huanglongbing. We investigated phototactic behavior of D. citri to evaluate effects of light of specific wavelength or polarization using a horizontal bioassay arena. Wave...

  10. Entomopathogenic Fungi (Hypocreales) for Control of Potato Psyllid

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    Laboratory and field trials of the four isolates of entomopathogenic fungi, Isaria fumosorosea and Metarhizium anisopliae were conducted to evaluate their potential for control of the potato psyllid. In the laboratory, 2 ml aqueous suspension of 107conidia/ml in a of each isolate applied in a Potte...

  11. Potato psyllid vector of zebra chip disease in Pacific Northwest

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    Zebra chip is a destructive disease of potatoes in the Pacific Northwest and other potato production regions of North America. The pathogen associated with this disease is transmitted by the potato psyllid. A team of researchers which included a scientist at the ARS in Wapato, WA updated an extens...

  12. Aboveground biomass of an invasive tree Melaleuca (Melaleuca quinquenervia) before and after herbivory by adventive and introduced natural enemies: a temporal case-study in Florida

    Science.gov (United States)

    Invasive plants may respond to injury from natural enemies by altering the quantity and distribution of biomass among woody materials, foliage, fruits, and seeds. Melaleuca, an Australian tree that has naturalized in south Florida, USA, has been reunited with two natural enemies: a weevil introduce...

  13. Matrimony vine and potato psyllid in the Pacific Northwest: a worrisome marriage?

    Science.gov (United States)

    Managing zebra chip disease in the potato growing regions of Washington, Oregon, and Idaho is complicated by confusion about the source of the insect vector (potato psyllid) as it colonizes potato fields in these growing regions. Not knowing where the psyllid is before arriving in Washington potato...

  14. Field survey of Asian citrus psyllid (Hemiptera: Liviidae) infestations associated with six cultivars of Poncirus trifoliata

    Science.gov (United States)

    The Asian citrus psyllid is an important pest because it transmits a bacterium responsible for huanglongbing, also known as citrus greening disease. Insecticidal control of the psyllid is a key tactic used to manage the disease, but host plant resistance may hold some promise as an alternative. Resu...

  15. STIGMA RECEPTIVITY AND POLLEN VIABILITY OF Melaleuca alternifolia

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    Liliana Baskorowati

    2009-06-01

    Full Text Available Stigma  receptivity based on seed set and pollen  tubes growth  following controlled pollination of flowers  of different  ages was examined  in Melaleuca alternifolia. The stigma secretion during 10 days after anthesis and pollen viability under three different temperatures and five storage times were also observed. These series of research were undertaken because successful controlled pollination of M. alternifolia depends on the application of viable pollen to the receptive compatible  stigma. The objective of this research was therefore to determine the stigma receptivity and pollen viability of M. alternifolia. Results showed that the stigma receptivity began to develop  on day  one and finished  on day  seven after anthesis,  peak receptivity occurred from day three to day six. The stigma receptivity also coincides with the appearance of secretion in the stigma, occurring  from day three to day seven after anthesis. Therefore,  the time for pollination of M. alternifolia appeared to extend for  approximately 7 days after anthesis. Data for M. alternifolia showed that regardless of storage temperature, pollen  was still  viable  after 26 weeks  of storage;  results also demonstrated  that the lowest temperature  (-18oC was the best regime for long term storage.

  16. Concordance between life history traits, invasion history, and allozyme diversity of the Everglades invader Melaleuca quinquenervia

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    During the century following its initial introduction in 1886, the Australian tree Melaleuca quinquenervia(Myrtaceae) dispersed from a few introduction points to occupy over 200,000 ha, primarily in historic Everglades wetlands of southern Florida. Cellulose acetate gel electrophoresis (CAGE) was us...

  17. Male Psyllids Differentially Learn in the Context of Copulation

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    Dara G. Stockton

    2017-02-01

    Full Text Available In the Asian citrus psyllid, Diaphorina citri Kuwayama, stimulatory cuticular hydrocarbons act as sex pheromone attractants. Male psyllids locate aggregations of females using those olfactory cues, as well as vibrational communication on the plant surface. Although previous research has indicated that learning plays a role in modulating female reproductive behaviors in psyllids, it is unknown whether males similarly use learning to increase the likelihood of copulatory success. We used an olfactometer-based bio-assay to study the effects of experience on male response to female odor. First, we compared male attraction to female odor in virgin and previously mated males. Second, we tested the effect of several modes of experience with a novel odor, vanillin, to determine whether mating, feeding, or general environmental exposure elicited a learned response. We found that male attraction to female odor significantly increased after mating experience. In addition, we found that males learn about odor specifically in the context of mating, rather than feeding or general exposure. Electrophysiological measurements of antennal response to odorants confirmed that mating status did not affect the sensitivity of the peripheral nervous system to volatile stimuli implicating learning at the level of the central nervous system. These results suggest that male response to female odor is not an entirely innate behavior. Males may require mating experience with female conspecifics to develop attraction to those olfactory cues produced by the female and in association with the female’s habitat. This adaptive plasticity may allow males to detect females in an ever-changing environment and promote diversification and further specialization on different host genotypes.

  18. Male Psyllids Differentially Learn in the Context of Copulation

    Science.gov (United States)

    Stockton, Dara G.; Martini, Xavier; Stelinski, Lukasz L.

    2017-01-01

    In the Asian citrus psyllid, Diaphorina citri Kuwayama, stimulatory cuticular hydrocarbons act as sex pheromone attractants. Male psyllids locate aggregations of females using those olfactory cues, as well as vibrational communication on the plant surface. Although previous research has indicated that learning plays a role in modulating female reproductive behaviors in psyllids, it is unknown whether males similarly use learning to increase the likelihood of copulatory success. We used an olfactometer-based bio-assay to study the effects of experience on male response to female odor. First, we compared male attraction to female odor in virgin and previously mated males. Second, we tested the effect of several modes of experience with a novel odor, vanillin, to determine whether mating, feeding, or general environmental exposure elicited a learned response. We found that male attraction to female odor significantly increased after mating experience. In addition, we found that males learn about odor specifically in the context of mating, rather than feeding or general exposure. Electrophysiological measurements of antennal response to odorants confirmed that mating status did not affect the sensitivity of the peripheral nervous system to volatile stimuli implicating learning at the level of the central nervous system. These results suggest that male response to female odor is not an entirely innate behavior. Males may require mating experience with female conspecifics to develop attraction to those olfactory cues produced by the female and in association with the female’s habitat. This adaptive plasticity may allow males to detect females in an ever-changing environment and promote diversification and further specialization on different host genotypes. PMID:28178203

  19. Rooting of Melaleuca alternifolia cuttings with different plant regulatorsEnraizamento de estacas de Melaleuca alternifolia submetidas a diferentes reguladores vegetais

    Directory of Open Access Journals (Sweden)

    Tereza Cristina Carvalho

    2012-10-01

    Full Text Available The Melaleuca alternifolia is a Myrtaceae tree of great medicinal importance. Its essential oil is widely used both in human and in veterinary medicine, having great antiseptic power. It is a difficult plant in the process of rooting cuttings. This study aimed to evaluate the efficacy of different concentrations of NAA and IBA on the rooting of M. alternifolia. Melaleuca cuttings with 10 cm in length were submitted to treatments with two regulators, NAA and IBA, in the following concentrations: 0 (control, 1000, 2000 and 4000 mg L-1. Evaluation occurred at 97 days throughout the live and dead cuttings rooted, medium length, volume and mass of roots. The growth regulator NAA at a concentration of 4000 mg L-1 showed to be phytotoxic to the cuttings of melaleuca; the use of IBA in comparable with NAA at concentration of 4000 mg L-1 provided a higher percentage of rooting and root length increases.A Melaleuca alternifolia é uma árvore da família Myrtaceae, de grande importância medicinal. Seu óleo essencial é muito utilizado tanto na medicina humana quanto na medicina veterinária, tendo grande poder antiséptico. É uma planta de difícil enraizamento no processo de estaquia. Assim, o presente trabalho teve como objetivo avaliar a eficiência de diferentes concentrações de ANA e AIB, no enraizamento de estacas de M. alternifolia. Foram utilizadas estacas com 10 cm de comprimento, submetidas ao tratamento para enraizamento com dois reguladores vegetais ANA e AIB, nas seguintes concentrações: 0 (testemunha; 1000; 2000 e 4000 mg L-1. Aos 97 dias foram avaliados a porcentagem de estacas enraizadas, vivas e mortas, o comprimento, o volume e a massa seca de raízes. O regulador vegetal ANA na concentração de 4000 mg L-1 demonstrou ser fitotóxico para as estacas de melaleuca e o uso de AIB em relação ao ANA, na concentração de 4000 mg L-1, proporcionou maior porcentagem de estacas enraizadas e maior comprimento radicial.

  20. Annotation of the Asian citrus psyllid genome reveals a reduced innate immune system

    Science.gov (United States)

    Citrus production worldwide is currently facing significant losses due to citrus greening disease, also known as huanglongbing. The citrus greening bacteria, Candidatus Liberibacter asiaticus (CLas), is a persistent propagative pathogen transmitted by the Asian citrus psyllid, Diaphorina citri Kuway...

  1. Elucidating genetic variation in Candidatus Liberibacter asiaticus transmission between Asian citrus psyllid isofemale lines

    OpenAIRE

    Dixon, Danielle; Kruse, Annie; Ramsey, John; Hosmani, Prashant; Hall, David; Saha, Surya; Ammar, El-Desouky; Cilia, Michelle; Mueller, Lukas A

    2017-01-01

    Citrus greening disease or Huanglongbing (HLB) is an epidemic bacterial infection that has devastated citrus industries across the globe. HLB leads to a reduction in fruit quality, decrease in overall fruit production and eventual death of the citrus tree.The disease is associated with this bacterium Candidatus Liberibacter asiaticus (CLas), is transmitted by the Asian citrus psyllid (ACP).Objective 1: Improve the current psyllid genome through manual curation.Objective 2: Characterize genet...

  2. Activity of tea tree (Melaleuca alternifolia) essential oil against L3 larvae of Anisakis simplex.

    Science.gov (United States)

    Gómez-Rincón, Carlota; Langa, Elisa; Murillo, Paula; Valero, Marta Sofía; Berzosa, César; López, Víctor

    2014-01-01

    Nematicidal activity of Melaleuca alternifolia essential oil, commonly known as tea tree oil (TTO), was assayed in vitro against L3 larvae of Anisakis simplex. The results showed a mortality of 100% for concentrations between 7 and 10 μL/mL after 48 h of incubation, obtaining an LD50 value of 4.53 μL/mL after 24 hours and 4.27 μL/mL after 48 hours. Concentration-dependent inhibition of acetylcholinesterase was observed for tea tree essential oil showing inhibition values of 100% at 100 μL/mL. This fact suggests that TTO may act as an AChE inhibitor. Terpinen-4-ol was discarded as main larvicide compound as it did not show larvicidal or anticholinesterase activity. The data obtained suggest that the essential oil of Melaleuca alternifolia may have a great therapeutic potential for the treatment of human anisakiasis.

  3. Dormência e germinação de sementes de Melaleuca alternifolia Cheel Dormancy and germination of Melaleuca alternifolia Cheel. seeds

    Directory of Open Access Journals (Sweden)

    J.I Anselmini

    2010-06-01

    Full Text Available A Melaleuca alternifolia Cheel. é uma espécie aromática de expressivo interesse econômico, em função da presença de óleo essencial armazenado no tecido foliar. As sementes, entretanto, apresentam baixo poder germinativo, o que tem dificultado a obtenção de novos materiais genéticos e o avanço tecnológico para produção no Brasil. O presente trabalho teve por objetivo determinar uma metodologia adequada para avaliar o poder germinativo de sementes de melaleuca. Para tanto, foram realizados dois experimentos, um em condições de laboratório e outro em casa-de-vegetação, avaliando-se diferentes tratamentos para promover a germinação da semente. O delineamento experimental empregado foi o inteiramente casualizado, com quatro repetições, sendo nove tratamentos em laboratório e sete em casa de vegetação; a comparação de médias foi realizada pelo teste Tukey, a 5% de probabilidade. Diante dos resultados obtidos, concluiu-se que a pré-embebição das sementes por 18h, em água, é o procedimento mais adequado, dentre os testados, para avaliar o poder germinativo da semente de melaleuca, sendo que em condições de casa de vegetação, o referido tratamento pode ser usado com os substratos areia ou Plantmax.Melaleuca alternifolia Cheel. is an aromatic species of high economic interest due to the presence of essential oil in its leaf tissue. However, its seeds have low germinative potential, which has made difficult the obtaining of new genetic materials and the technological advance for production in Brazil. The present work aimed to determine a suitable methodology to evaluate the germinative potential of Narrow-leaved Paperbark seeds. Thus, two experiments were carried out, one under lab conditions and other in greenhouse, in order to evaluate different treatments to stimulate seed germination. Experimental design was completely randomized, with four replicates; nine treatments were used in the lab and other seven in

  4. Melaleuca alternifolia (Tea Tree) Oil: a Review of Antimicrobial and Other Medicinal Properties

    OpenAIRE

    Carson, C. F.; Hammer, K. A.; Riley, T V

    2006-01-01

    Complementary and alternative medicines such as tea tree (melaleuca) oil have become increasingly popular in recent decades. This essential oil has been used for almost 100 years in Australia but is now available worldwide both as neat oil and as an active component in an array of products. The primary uses of tea tree oil have historically capitalized on the antiseptic and anti-inflammatory actions of the oil. This review summarizes recent developments in our understanding of the antimicrobi...

  5. In vitro activity of Melaleuca alternifolia (tea tree) oil against dermatophytes and other filamentous fungi.

    Science.gov (United States)

    Hammer, K A; Carson, C F; Riley, T V

    2002-08-01

    The in vitro activity of Melaleuca alternifolia (tea tree) oil against dermatophytes (n = 106) and filamentous fungi (n = 78) was determined. Tea tree oil MICs for all fungi ranged from 0.004% to 0.25% and minimum fungicidal concentrations (MFCs) ranged from tea tree oil of germinated and non-germinated Aspergillus niger conidia showed germinated conidia to be more susceptible than non-germinated conidia. These data demonstrate that tea tree oil has both inhibitory and fungicidal activity.

  6. The push-pull strategy for citrus psyllid control.

    Science.gov (United States)

    Yan, Huaxue; Zeng, Jiwu; Zhong, Guangyan

    2015-07-01

    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 progress towards more effective repellent and attractant chemicals through investigating known repellent and attractive plants. Interactions between ACP and its host plants are also addressed, with emphasis on the possible involvement of the host biochemicals in attracting the insect. Potential ways to increase the effectiveness of the pull-push strategy are briefly discussed. It is expected that the pull-push strategy will be gradually developed following more extensive research.

  7. 75 FR 28233 - Availability of an Environmental Assessment for a Biological Control Agent for Asian Citrus Psyllid

    Science.gov (United States)

    2010-05-20

    ... for use as a biological control agent to reduce the severity of Asian citrus psyllid infestations. We... continental United States for use as a biological control agent to reduce the severity of Asian citrus psyllid... include chemical control and the release of an alternative biological control agent, an encyrtid...

  8. Insecticidal Activity of Entomopathogenic Fungi (Hypocreales) for Potato Psyllid, Bactericera cockerelli (Hemiptera: Triozidae): Development of Bioassay Techniques, Effect of Fungal Species and Stage of the Psyllid

    Science.gov (United States)

    The potato psyllid, Bactericera cockerelli (Šulc), is a pest of potato, tomato, and some other solanaceous vegetables and has also been incriminated in the transmission of a bacterial pathogen, Candidatus Liberibacter solanacearum, resulting in a serious disease known as “zebra chip”. Although there...

  9. First records of parasitoids attacking the Asian citrus psyllid in Ecuador

    Directory of Open Access Journals (Sweden)

    Diego E. Portalanza

    Full Text Available ABSTRACT First records of parasitoids attacking the Asian citrus psyllid in Ecuador. The objective of the current study was to investigate the presence of natural enemies of Diaphorina citri (Hemiptera: Liviidae (the Asian citrus psyllid in Ecuador. Incidence of parasitoid Diaphorencyrtus aligarhensis (Hymenoptera: Encyrtidae was assessed between November 2015 and March 2016, in Letamendi, Febres-Cordero and Tarqui, urban districts of Guayaquil. Highest incidence of parasitism occurred in those regions and seasons of the year with the highest temperatures commensurate with increase of citrus plant shoots. Similar to their host, these parasitoids appear to have established in Ecuador by accident, and were not the result of purposeful introduction. This fortuitous introduction is a potentially helpful tool in controlling the Asian citrus psyllid, and potentially Huanglongbing.

  10. Glycaspis brimblecombei (Hem.: Psyllidae, the invasive red gum lerp psyllid recorded in Italy

    Directory of Open Access Journals (Sweden)

    Garonna AP

    2011-05-01

    Full Text Available During 2010 in central and southern Italy (Campania, Basilicata and Latium, the invasive red gum lerp psyllid, Glycaspis brimblecombei Moore (Hemiptera: Psyllidae, has been recorder for the first time in Italy. The psyllid was detected on Eucalyptus camaldulensis in several sampling sites. The host plant, like other species of the genus Eucalyptus, is very common in Italy as ornamental and forest species. The native country of G. brimblecombei is Australia, from which the psyllid spread throughout the world in the last decade. In the Palaearctic Region the species was first collected from the Iberian Peninsula in 2007. In this note we report some observations on the biology and distribution of this species in the new colonized Italian areas. Generalist predators, such as wasps and pirate bugs, were observed attacking G. brimblecombei, however no parasitoid activity has been detected.

  11. Melaleuca alternifolia anthelmintic activity in gerbils experimentally infected by Haemonchus contortus.

    Science.gov (United States)

    Grando, Thirssa H; Baldissera, Matheus D; Gressler, Lucas T; de Sá, Mariângela Facco; Bortoluzzi, Bruna N; Schafer, Andressa S; Ebling, Rafael C; Raffin, Renata P; Santos, Roberto C V; Stefani, Lenita M; Vaucher, Rodrigo; Leal, Marta L R; Monteiro, Silvia G

    2016-11-01

    Gastrointestinal parasites are one of the biggest health problems faced in sheep, mainly due to their pathogenicity and resistance to drugs used to control these parasites. Thus, the following study aimed to assess the anthelmintic efficacy of Melaleuca alternifolia against Haemonchus contortus in gerbils (Meriones unguiculatus) experimentally infected. Three treatments were tested: M. alternifolia essential oil, popularly known as tea tree oil (TTO), a solid lipid nanocarrier made with essential oil of Melaleuca (nanoTTO), and terpinen-4-ol (terp-4-ol). In vivo studies were performed by determining the mean worm burden of H. contortus in gerbils TTO (0.75 mL/kg); nanoTTO (0.5 mL/kg) and terp-4-ol (0.5 mL l/kg) were able to reduce 46.36%; 48.64%, and 43.18% worm burden, respectively. H. contortus increased alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, as demonstrated by liver injury. It was found that the TTO, nanoTTO, and terp-4-ol were not toxic to liver and kidneys since hepatic and renal functions were not affected. Moreover, terp-4-ol was able to prevent increased levels of seric AST and ALT in infected animals, indicating a hepatoprotective effect. Thus, our results indicate that TTO, nanoTTO, and terp-4-ol are safe and efficient against H. contortus infection in gerbils, and possibly the terp-4-ol may be considered the compound present in the Melaleuca alternifolia responsible for parasitic action against H. contortus.

  12. Successful topical treatment of hand warts in a paediatric patient with tea tree oil (Melaleuca alternifolia).

    Science.gov (United States)

    Millar, B Cherie; Moore, John E

    2008-11-01

    Tea tree oil (TTO) (Melaleuca alternifolia) has been used recently as an effective topical application for the treatment of skin infections due to a variety of aetiological microbial agents, including mainly bacterial infections. We detail the first report in the peer-reviewed literature of the successful treatment with TTO of a paediatric patient with warts on her right middle finger. TTO was applied topically once daily to the lesions for 12 days, with a successful outcome, including complete re-epithelization of the infected areas. The case highlights the potential use of TTO in the treatment of common warts due to human papilloma virus.

  13. Activity of Tea Tree (Melaleuca alternifolia) Essential Oil against L3 Larvae of Anisakis simplex

    OpenAIRE

    Carlota Gómez-Rincón; Elisa Langa; Paula Murillo; Marta Sofía Valero; César Berzosa; Víctor López

    2014-01-01

    Nematicidal activity of Melaleuca alternifolia essential oil, commonly known as tea tree oil (TTO), was assayed in vitro against L3 larvae of Anisakis simplex. The results showed a mortality of 100% for concentrations between 7 and 10  μ L/mL after 48 h of incubation, obtaining an LD50 value of 4.53  μ L/mL after 24 hours and 4.27  μ L/mL after 48 hours. Concentration-dependent inhibition of acetylcholinesterase was observed for tea tree essential oil showing inhibition values of 100% at 100 ...

  14. Pengaruh Cara Aplikasi Minyak Suling Melaleuca bracteata dan Metil Eugenol terhadap Daya Pikat Lalat Buah Bactrocera dorsalis

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    Agus Kardinan

    1998-07-01

    Full Text Available Research has been conducted at farmer’s fruit garden in Cilebut area, Bogor during 1997–1998. The objective is to know the effect of some application techniques of oil distilled from Melaleuca bracteata leaves on trapping fruit fly. Research consisted of three activities, those were the effect of some techniques of application on trapping fruit flies (I weekly, (2 in two weeks and (3 the effects of some concentrations of methyl eugenol (ME on trapping fruit fly. All treatments were hung at the fruit trees as high as 1.5 m. Observations were done in the number and gender of fruit flies trapped weekly and two-weekly. Result revealed that melaleuca distilled oil can be applied either by dropping into water or into cotton ball. Melaleuca leaves distilled oil should be applied once in two weeks, since its effectiveness lasted for two weeks only. The minimum concentration of methyl eugenol which could fruit flies effectively was 57%. Key words: Melaleuca bracteata, Bactrocera dorsalis

  15. A review of the toxicity of Melaleuca alternifolia (tea tree) oil.

    Science.gov (United States)

    Hammer, K A; Carson, C F; Riley, T V; Nielsen, J B

    2006-05-01

    The essential oil of Melaleuca alternifolia, also known as tea tree or melaleuca oil, is widely available and has been investigated as an alternative antimicrobial, anti-inflammatory and anti-cancer agent. While these properties are increasingly well characterised, relatively limited data are available on the safety and toxicity of the oil. Anecdotal evidence from almost 80 years of use suggests that the topical use of the oil is relatively safe, and that adverse events are minor, self-limiting and occasional. Published data indicate that TTO is toxic if ingested in higher doses and can also cause skin irritation at higher concentrations. Allergic reactions to TTO occur in predisposed individuals and may be due to the various oxidation products that are formed by exposure of the oil to light and/or air. Adverse reactions may be minimised by avoiding ingestion, applying only diluted oil topically and using oil that has been stored correctly. Data from individual components suggest that TTO has the potential to be developmentally toxic if ingested at higher doses, however, TTO and its components are not genotoxic. The limited ecotoxicity data available indicate that TTO is toxic to some insect species but more studies are required.

  16. Activity of Tea Tree (Melaleuca alternifolia Essential Oil against L3 Larvae of Anisakis simplex

    Directory of Open Access Journals (Sweden)

    Carlota Gómez-Rincón

    2014-01-01

    Full Text Available Nematicidal activity of Melaleuca alternifolia essential oil, commonly known as tea tree oil (TTO, was assayed in vitro against L3 larvae of Anisakis simplex. The results showed a mortality of 100% for concentrations between 7 and 10 μL/mL after 48 h of incubation, obtaining an LD50 value of 4.53 μL/mL after 24 hours and 4.27 μL/mL after 48 hours. Concentration-dependent inhibition of acetylcholinesterase was observed for tea tree essential oil showing inhibition values of 100% at 100 μL/mL. This fact suggests that TTO may act as an AChE inhibitor. Terpinen-4-ol was discarded as main larvicide compound as it did not show larvicidal or anticholinesterase activity. The data obtained suggest that the essential oil of Melaleuca alternifolia may have a great therapeutic potential for the treatment of human anisakiasis.

  17. Factors affecting transmission rates of 'Candidatus Liberibacter asiaticus' by Asian citrus psyllid

    Science.gov (United States)

    The Asian citrus psyllid (ACP), Diaphorina citri, is an important pest because it transmits a bacterium ‘Candidatus Liberibacter asiaticus’ (CLas) responsible for a serious disease of citrus known as Asiatic huanglongbing (citrus greening disease). USDA-ARS researchers recently established a program...

  18. Gender differences and effect of photophase on Asian citrus psyllid (Diaphorina citri Kuwayama) feeding behavior

    Science.gov (United States)

    Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), thought to be primarily a phloem-feeding insect, transmits the presumptive pathogen for Huanglongbing, ‘Candidatus Liberibacter asiaticus’. Because this bacterium is restricted to the phloem and bacterial transmission is the res...

  19. First report of 'Candidatus Liberibacter solanacearum' associated with psyllid-affected carrots in Norway

    Science.gov (United States)

    Carrot (Daucus carota) plants with symptoms resembling those associated with the carrot psyllid Trioza apicalis and the bacterium “Candidatus Liberibacter solanacearum” were observed in 70-80% of commercial fields and experimental plots in southeastern Norway from late July to mid-September 2011; al...

  20. H NMR analyses of Citrus macrophylla subjected to Asian citrus psyllid (Diaphorina citri Kuwayama) feeding

    Science.gov (United States)

    The Asian citrus psyllid (ACP) is a phloem feeding insect that can host and transmit the bacterium Candidatus Liberibacter asiaticus (CLas), which is the putative causative agent of the economically important citrus disease, Huanglongbing (HLB). ACP are widespread in Florida, and are spreading in Ca...

  1. First report of 'Candidatus Liberibacter solanacearum' associated with psyllid-affected carrots in Sweden

    Science.gov (United States)

    Carrot (Daucus carota) plants with symptoms resembling those of the carrot psyllid Trioza apicalis and “Candidatus Liberibacter solanacearum” damage were observed in 70% of commercial fields in southern Sweden in August 2011; all cultivars grown were affected, at about 1 to 45% symptomatic plants pe...

  2. Effects of soil-applied imidacloprid on Asian citrus psyllid (Hemiptera: Psyllidae) feeding behavior

    Science.gov (United States)

    The Asian citrus psyllid, Diaphorina citri Kuwayama is one of the most important pests of citrus due to its status as a vector of Candidatus Liberibacter asiaticus, the bacterium associated with huanglongbing (HLB) disease. The use of insecticides for vector control is the primary method of managing...

  3. Complete Genome Sequence of a Putative Densovirus of the Asian Citrus Psyllid, Diaphorina citri.

    Science.gov (United States)

    Nigg, Jared C; Nouri, Shahideh; Falk, Bryce W

    2016-07-28

    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.

  4. Incidence of ‘Candidatus Liberibacter asiaticus’ in a Florida population of Asian citrus psyllid

    Science.gov (United States)

    A study was conducted to assess the incidence of a bacterium ‘Candidatus Liberibacter asiaticus’ in a Florida population of Asian citrus psyllid (ACP), Diaphorina citri. The bacterium is the presumed causal agent of Asiatic huanglongbing, a serious citrus disease also known as citrus greening or yel...

  5. Current statewide updates regarding the battle of the Asian Citrus Psyllid and Huanglongbing

    Science.gov (United States)

    Huanglongbing (HLB) is a serious economic disease of citrus, vectored by the Asian Citrus Psyllid (ACP). The disease and its vector have become established in the United States in the last few decades. This submission reviews recent developments for pest control industry professionals. The submissio...

  6. Bindweed Psyllid: Biology, Natural History, and Interactions with the Zebra Chip Pathogen

    Science.gov (United States)

    Bactericera maculipennis is a native psyllid that commonly occurs on field bindweed in the western United States. We have found that Pacific Northwest populations of B. maculipennis carry Liberibacter solanacearum, the pathogen associated with zebra chip disease of potato. In North America, this p...

  7. Chemical and behavioral analysis of the cuticular hydrocarbons from Asian citrus psyllid, Diaphorina citri

    Science.gov (United States)

    Huanglongbing (HLB) is the most destructive disease of citrus worldwide. 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. Laboratory and field studies were cond...

  8. Correlation of an electrical penetration graph waveform with walking by Asian citrus psyllid, Diaphorina citri Kuwayama

    Science.gov (United States)

    Electrical penetration graph (EPG) monitoring is being used to study how feeding behavior of the Asian citrus psyllid (ACP) (Diaphorina citri Kuwayama) changes in response to insecticides, in an effort to improve the efficacy of widespread insecticide treatments against the insect in Florida citrus....

  9. The influence of the essential oil of Melaleuca alternifolia on the healing of infected dental alveoli: a histological study in rats

    OpenAIRE

    Kreuger,Maria Regina Orofino; Ternes,Carlos Eduardo; Mello,Leonardo Lamim; Cruz,Alexandre Bella; Leite,Silvana Nair; Tames,David Rivero

    2007-01-01

    The plant Melaleuca alternifolia is native to Australia. The distillation of its leaves produces an essential oil, commonly known as oil of Melaleuca, or Tea tree oil, which present antimicrobial activity. This study investigates the action of this oil on the repair process of infected dental alveoli. 48 rats were used (Rattus novergicus albinus, Wistar). After tooth extraction and posterior infection of the dental alveoli with Staphylococcus aureus, the animals were separated into three grou...

  10. Monitoring for Insecticide Resistance in Asian Citrus Psyllid (Hemiptera: Psyllidae) Populations in Florida.

    Science.gov (United States)

    Kanga, Lambert H B; Eason, Julius; Haseeb, Muhammad; Qureshi, Jawwad; Stansly, Philip

    2016-04-01

    The development of insecticide resistance in Asian citrus psyllid, Diaphorina citri Kuwayama, populations is a serious threat to the citrus industry. As a contribution to a resistance management strategy, we developed a glass vial technique to monitor field populations of Asian citrus psyllid for insecticide resistance. Diagnostic concentrations needed to separate susceptible genotypes from resistant individuals were determined for cypermethrin (0.5 μg per vial), malathion (1.0 μg per vial), diazinon (1.0 μg per vial), carbaryl (1.0 μg per vial), carbofuran (0.1 μg per vial), methomyl (1.0 μg per vial), propoxur (1.0 μg per vial), endosulfan (1.0 μg per vial), imidacloprid (0.5 μg per vial), acetamiprid (5.0 μg per vial), chlorfenapyr (2.5 μg per vial), and fenpyroximate (2.5 μg per vial). In 2014, resistance to two carbamate insecticides (carbaryl and carbofuran), one organophosphate (malathion), one pyrethroid (cypermethrin), and one pyrazole (fenpyroximate) was detected in field populations of Asian citrus psyllid in Immokalee, FL. There was no resistance detected to diazinon, methomyl, propoxur, endosulfan, imidacloprid, and chlorfenapyr. The levels of insecticide resistance were variable and unstable, suggesting that resistance could be successfully managed. The results validate the use of the glass vial bioassay to monitor for resistance in Asian citrus psyllid populations and provide the basis for the development of a resistance management strategy designed to extend the efficacy of all classes of insecticides used for control of the Asian citrus psyllid.

  11. Endosymbiont hunting in the metagenome of Asian citrus psyllid (Diaphorina citri) (7th Annual SFAF Meeting, 2012)

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Surya [Cornell University

    2012-06-01

    Surya Saha on "Endosymbiont hunting in the metagenome of Asian citrus psyllid (Diaphorina citri)" at the 2012 Sequencing, Finishing, Analysis in the Future Meeting held June 5-7, 2012 in Santa Fe, New Mexico.

  12. Phenology of Asian citrus psyllid (Hemiptera: Liviidae) and associated parasitoids on two species of Citrus, kinnow mandarin and sweet orange, in Punjab Pakistan.

    Science.gov (United States)

    Khan, Shouket Zaman; Arif, Muhammad Jalal; Hoddle, Christina D; Hoddle, Mark S

    2014-10-01

    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; densities of Asian citrus psyllid eggs, nymphs, and adults were higher on sweet orange when compared with kinnow. When measured in terms of mean cumulative insect or Asian citrus psyllid days, eggs, nymphs, and adults were significantly higher on sweet orange than kinnow. Two parasitoids were recorded attacking Asian citrus psyllid nymphs, Tamarixia radiata (Waterston) and Diaphorencyrtus aligarhensis (Shafee, Alam and Agarwal). The dominant parasitoid species attacking Asian citrus psyllid nymphs on kinnow and sweet orange was T. radiata, with parasitism averaging 26%. D. aligarhensis parasitism averaged 17%. Generalist predators such as coccinellids and chrysopids were collected infrequently and were likely not important natural enemies at these study sites. Immature spiders, in particular, salticids and yellow sac spiders, were common and may be important predators of all Asian citrus psyllid life stages. Low year round Asian citrus psyllid densities on kinnow and possibly high summer temperatures, may, in part, contribute to the success of this cultivar in Punjab where Candidatus Liberibacter asiaticus, the putative causative agent of huanglongbing, a debilitating citrus disease, is widespread and vectored by Asian citrus psyllid.

  13. Titers of 'Ca. Liberibacter asiaticus' in Murraya paniculata and Murraya-reared Diaphorina citri Are Much Lower than in Citrus and Citrus-reared Psyllids

    National Research Council Canada - National Science Library

    Walter, Abigail; Duan, Y; Hall, David G

    2012-01-01

    Huanglongbing, one of the most devastating diseases of citrus, is associated with the bacterium 'Candidatus Liberibacter asiaticus' vectored by the Asian citrus psyllid, Diaphorina citri, in North America...

  14. Development of Microsatellite Loci for the Riparian Tree Species Melaleuca argentea (Myrtaceae Using 454 Sequencing

    Directory of Open Access Journals (Sweden)

    Paul G. Nevill

    2013-05-01

    Full Text Available Premise of the study: Microsatellite primers were developed for Melaleuca argentea (Myrtaceae to evaluate genetic diversity and population genetic structure of this broadly distributed northern Australian riparian tree species. Methods and Results: 454 GS-FLX shotgun sequencing was used to obtain 5860 sequences containing putative microsatellite motifs. Two multiplex PCRs were optimized to genotype 11 polymorphic microsatellite loci. These loci were screened for variation in individuals from two populations in the Pilbara region, northwestern Western Australia. Overall, observed heterozygosities ranged from 0.27 to 0.86 (mean: 0.52 and the number of alleles per locus ranged from two to 13 (average: 4.3. Conclusions: These microsatellite loci will be useful in future studies of the evolutionary history and population and spatial genetic structure in M. argentea, and inform the development of seed sourcing strategies for the species.

  15. The effect of tea tree oil (Melaleuca alternifolia) on wound healing using a dressing model.

    Science.gov (United States)

    Chin, Karen B; Cordell, Barbara

    2013-12-01

    Numerous studies have shown the promising antibacterial effects of Melaleuca alternifolia, or tea tree essential oil. The study detailed here replicates in humans a 2004 in vitro study that used a dressing model over Petri dishes to determine the antimicrobial effects of the fumes of tea tree essential oil. The current study used the same dressing model with patients who had wounds infected with Staphylococcus aureus. Ten participants volunteered for the quasi-experimental study, and four of the 10 were used as matched participants to compare wound healing times between conventional treatment alone and conventional treatment plus fumes of tea tree essential oil. The results demonstrated decreased healing time in all but one of the participants treated with tea tree oil. The differences between the matched participants were striking. The results of this small investigational study indicate that additional study is warranted.

  16. DESCRIÇÃO ANATÔMICA DO LENHO DE Melaleuca leucadendron (L. L

    Directory of Open Access Journals (Sweden)

    Linéia Roberta Zen

    2016-03-01

    Full Text Available This work aimed the anatomical description of Melaleuca leucadendron wooden. The study was conducted from an individual tree collecting three discs for confection of histological slides and macerated. Was used to mashing nitricacetic method and for histology was used simple staining with 1% safranin. The wood anatomy agrees in general aspects to the typical pattern of Myrtaceae Family: flocking diffuse porosity, solitary pores, simple perforation plates, besides paratracheal axial parenchyma linear aliforme, very numerous rays and heterocellular, pits-ray vascular parenchyma-vascular and fibrous tissue composed of prominent fibrotraqueoids, very short fibers, distinct growth rings of walls marked by the end of the fibers flattened latewood. Qualitatively and quantitatively the wood did not reveal expressive characteristic, thus can be characterized by presenting a relatively simple anatomical structure, agreeing in general lines to Myrtaceae family.

  17. Supercritical Fluid Extraction (SFE of Monoterpenes from the Leaves of Melaleuca alternifolia (Tea Tree

    Directory of Open Access Journals (Sweden)

    Deidre Tronson

    2001-01-01

    Full Text Available The technique of supercritical fluid extraction (SFE was applied to various sample matrices under a range of supercritical carbon dioxide (scCO2 densities and chamber temperatures. The purpose was to develop an effective extraction condition for the removal of eight target monoterpenes from Australian tea tree (Melaleuca alternifolia Cheel leaves. The optimum conditions for extraction were found to be 0.25 g/mL scCO2 density at a chamber temperature of 110oC. These condition were most effective when applied to whole fresh and rehydrated whole dried leaves, where it yielded maximum recovery of target analytes with minimum change in oil composition for the extractor system employed. This study demonstrates the importance of the type of sample matrix used in SFE work, and that a different extraction protocol would need to be developed for each matrix.

  18. Pharmacological and antimicrobial studies on different tea-tree oils (Melaleuca alternifolia, Leptospermum scoparium or Manuka and Kunzea ericoides or Kanuka), originating in Australia and New Zealand.

    Science.gov (United States)

    Lis-Balchin, M; Hart, S L; Deans, S G

    2000-12-01

    Three different species of Myrtaceae growing in Australia and New Zealand are known as 'Tea-tree': the Australian Tea tree (Melaleuca alternifolia), the New Zealand Manuka (Leptospermum scoparium) and Kanuka (Kunzea ericoides). All three essential oils are used by aromatherapists, although only Melaleuca has been tested for toxicity, and its antimicrobial effects studied. The pharmacology and antimicrobial activity of the three 'tea-tree' oils was determined using guinea-pig ileum, skeletal muscle (chick biventer muscle and the rat phrenic nerve diaphragm) and also rat uterus in vitro. Differences were shown between the three essential oils in their action on smooth muscle: Manuka had a spasmolytic action, while Kanuka and Melaleuca had an initial spasmogenic action. Using the diaphragm, Manuka and Melaleuca decreased the tension and caused a delayed contracture; Kanuka had no activity at the same concentration. The action on chick biventer muscle was, however, similar for all three oils, as was the action on the uterus, where they caused a decrease in the force of the spontaneous contractions. The latter action suggests caution in the use of these essential oils during childbirth, as cessation of contractions could put the baby, and mother, at risk. The comparative antimicrobial activity showed greater differences between different samples of Manuka and Kanuka than Melaleuca samples. The antifungal activity of Kanuka was inversely proportional to its strong antibacterial activity, whilst Manuka displayed a stronger antifungal effect, though not as potent as Melaleuca. The antioxidant activity of Manuka samples was more consistent than that of Kanuka, while Melaleuca showed no activity. The variability in the Manuka and Kanuka essential oils suggests caution in their usage, as does the fact that the oils have not been tested for toxicity.

  19. Treatment of acne with tea tree oil (melaleuca) products: a review of efficacy, tolerability and potential modes of action.

    Science.gov (United States)

    Hammer, K A

    2015-02-01

    Over-the-counter acne treatments containing tea tree oil from the plant Melaleuca alternifolia are widely available, and evidence indicates that they are a common choice amongst those self-treating their acne. The aims of this review were to collate and evaluate the clinical evidence on the use of tea tree oil products for treating acne, to review safety and tolerability and to discuss the underlying modes of therapeutic action.

  20. 澳洲茶油树栽培管理技术%Introduction and Artificial Planting Technique of Melaleuca alternifolia

    Institute of Scientific and Technical Information of China (English)

    陈永锦

    2010-01-01

    澳洲茶油树(Melaleuca alternifolia)是经济价值很高的油用树种,也可用于园林造景.文章通过栽培实践,总结了其形态特征与生态习性、引种、栽培,为推广营造人工林提供科学依据.

  1. Use of Electrical Penetration Graph Technology to Examine Transmission of 'Candidatus Liberibacter solanacearum' to Potato by Three Haplotypes of Potato Psyllid (Bactericera cockerelli; Hemiptera: Triozidae.

    Directory of Open Access Journals (Sweden)

    Tariq Mustafa

    Full Text Available The potato psyllid, Bactericera cockerelli (Šulc (Hemiptera: Triozidae, is a vector of the phloem-limited bacterium 'Candidatus Liberibacter solanacearum' (Lso, the putative causal agent of zebra chip disease of potato. Little is known about how potato psyllid transmits Lso to potato. We used electrical penetration graph (EPG technology to compare stylet probing behaviors and efficiency of Lso transmission of three haplotypes of potato psyllid (Central, Western, Northwestern. All haplotypes exhibited the full suite of stylet behaviors identified in previous studies with this psyllid, including intercellular penetration and secretion of the stylet pathway, xylem ingestion, and phloem activities, the latter comprising salivation and ingestion. The three haplotypes exhibited similar frequency and duration of probing behaviors, with the exception of salivation into phloem, which was of higher duration by psyllids of the Western haplotype. We manipulated how long psyllids were allowed access to potato ("inoculation access period", or IAP to examine the relationship between phloem activities and Lso transmission. Between 25 and 30% of psyllids reached and salivated into phloem at an IAP of 1 hr, increasing to almost 80% of psyllids as IAP was increased to 24 h. Probability of Lso-transmission was lower across all IAP levels than probability of phloem salivation, indicating that a percentage of infected psyllids which salivated into the phloem failed to transmit Lso. Logistic regression showed that probability of transmission increased as a function of time spent salivating into the phloem; transmission occurred as quickly as 5 min following onset of salivation. A small percentage of infected psyllids showed extremely long salivation events but nonetheless failed to transmit Lso, for unknown reasons. Information from these studies increases our understanding of Lso transmission by potato psyllid, and demonstrates the value of EPG technology in

  2. The influence of the essential oil of Melaleuca alternifolia on the healing of infected dental alveoli: a histological study in rats Influência do óleo essencial de Melaleuca alternifolia na cicatrização de alveolite dental infectada: um estudo histológico em ratos

    OpenAIRE

    Maria Regina Orofino Kreuger; Carlos Eduardo Ternes; Leonardo Lamim Mello; Alexandre Bella Cruz; Silvana Nair Leite; David Rivero Tames

    2007-01-01

    The plant Melaleuca alternifolia is native to Australia. The distillation of its leaves produces an essential oil, commonly known as oil of Melaleuca, or Tea tree oil, which present antimicrobial activity. This study investigates the action of this oil on the repair process of infected dental alveoli. 48 rats were used (Rattus novergicus albinus, Wistar). After tooth extraction and posterior infection of the dental alveoli with Staphylococcus aureus, the animals were separated into three grou...

  3. Extraction and refining of essential oil from Australian tea tree, Melaleuca alterfornia, and the antimicrobial activity in cosmetic products

    Science.gov (United States)

    Huynh, Q.; Phan, T. D.; Thieu, V. Q. Q.; Tran, S. T.; Do, S. H.

    2012-03-01

    Tea tree oil (TTO) comes from the leaves of Melaleuca alternifornia that belongs to the myrtle family (Myrtaceae). It is one of the most powerful immune system stimulants and sorts out most viral, bacterial and fungal infections in a snap, while it is great to heal wounds and acnes. In Vietnam, Melaleuca trees can grow on acid land that stretches in a large portion of lands in the Mekong Delta region. So, there are some Melaleuca plantations developed under the Vietnamese government plans of increasing plantation forests now. However, TTO contains various amounts of 1,8-cineole that causes skin irritant. So TTO purification is very necessary. In this study, the purification of TTO that meet International Standard ISO 4730 was carried out via two steps. The first step is steam distillation to obtain crude TTO (terpinen-4-ol 35% v/v) and the average productivity is among 2.37% (v/wet-wt) or 1.23% (v/dry-wt). In the second step, the cleaned TTO is collected by vacuum distillation column and extraction yield of the whole process is about 0.3% (w/w). Besides, high concentration essential oil was applied in the cosmetic products to increase its commercial value.

  4. Use of Electrical Penetration Graph Technology to Examine Transmission of ‘Candidatus Liberibacter solanacearum’ to Potato by Three Haplotypes of Potato Psyllid (Bactericera cockerelli; Hemiptera: Triozidae)

    Science.gov (United States)

    The potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae), is a vector of the phloem-limited bacterium ‘Candidatus Liberibacter solanacearum’ (Lso), the putative causal agent of zebra chip disease of potato. Little is known about how potato psyllid transmits Lso to potato. We used ele...

  5. Molecular detection of aster yellows phytoplasma and 'Candidatus Liberibacter solanacearum' in carrots affected by the psyllid Trioza apicalis (Hemiptera: triozidae) in Finland

    Science.gov (United States)

    Carrot psyllid (Trioza apicalis Förster) causes considerable damage to carrot (Daucus carota L.) in many parts of Europe. It was recently established that the new bacterium “Candidatus Liberibacter solanacearum” is associated with carrot psyllid and plants affected by this insect pest. No other path...

  6. Maintenance of primary cell cultures of immunocytes from Cacopsylla sp. psyllids: a new in vitrio tool for the study of pest insects

    Science.gov (United States)

    Psyllid species are major vectors of plant pathogens, such as phytoplasmas and Liberibacter bacteria, which threaten economic stability of fruit tee crops and vegetable production worldwide. Primary cell cultures of immunocytes have been developed from the three psyllid species, Cacopsylla melanone...

  7. Use of Melaleuca alternifolia Cheel (Myrtaceae) oil in dentistry: perspectives on its use as alternative antimicrobial to infectious diseases of oral origin

    OpenAIRE

    Oliveira, A.C.M.; Fontana, A; Negrini, T.C.; Nogueira, M.N.M. [UNESP; Bedran, T.B.L.; de Andrade, C R; Spolidorio, L.C. [UNESP; Spolidorio, D.M.P.

    2011-01-01

    O interesse por medicamentos alternativos, principalmente daqueles provenientes de extratos naturais, tem aumentado nas últimas décadas. A Melaleuca alternifolia é um arbusto pertencente ao gênero Melaleuca, popularmente conhecida como "árvore de chá", cujo principal produto é o óleo essencial (TTO - tea tree oil), de grande importância medicinal por possuir comprovada ação bactericida e antifúngica contra diversos patógenos humanos. Em virtude da atividade terapêutica em diversas especialida...

  8. Melaleuca alternifolia essential oil possesses potent anti-staphylococcal activity extended to strains resistant to antibiotics.

    Science.gov (United States)

    Ferrini, A M; Mannoni, V; Aureli, P; Salvatore, G; Piccirilli, E; Ceddia, T; Pontieri, E; Sessa, R; Oliva, B

    2006-01-01

    Melaleuca alternifolia Cheel essential oil (TTO) and its major component terpinen-4-ol were examined against a large number of clinical isolates of Staphylococcus aureus to establish their anti-staphylococcal activities. Classic and established procedures were used to study M.I.C., time-kill curves, synergism and mutational frequency. The anti-staphylococcal activity of terpinen-4-ol and TTO were superior to those of antibiotics belonging to the major families (all the tested drugs are for topical use or included in ointments, eye drops or used during surgery); terpinen 4-ol and TTO were active against strains resistant to mupirocin, fusidic acid, vancomycin, methicillin and linezolid. TTO and terpinen-4-ol were bactericidal as revealed by time-kill curves; the frequency of mutational frequency to TTO was < 2.9 x 10 9. The study demonstrates good anti-staphylococcal activity of TTO and terpinen-4-ol against a large number of S.aureus isolates and suggests the possible application of these agents for topical treatment of staphylococcal infections. This is the first extensive study on the anti-staphylococcal activity of TTO. The results suggest that this compound may have application as a topical agent for the control of superficial staphylococcal infections, including activity against organisms resistant to antibiotics which can be used, or are specific, for topical use.

  9. Comparison of hand hygiene antimicrobial efficacy: Melaleuca alternifolia essential oil versus triclosan

    Directory of Open Access Journals (Sweden)

    Juliana Rizzo Gnatta

    2013-12-01

    Full Text Available OBJECTIVE: this study aimed to evaluate the efficacy of hand hygiene performed with two different soap formulations: 0.3% Melaleuca alternifolia essential oil versus 0.5% triclosan, and to compare them with two reference hygiene procedures: the official methodology procedure (soft soap versus the draft version of the procedure (soft soap + propan-2-ol. METHOD: using the European EN 1499 method, logarithmic reduction factors were determined for the number of colony forming units of Escherichia coli K12 before and after hand hygiene of 15 volunteer subjects, and compared using the one-tailed Wilcoxon test. RESULTS: referring to the soft soap, there was no difference between the performance of soap with 0.3% M. alternifolia and soap containing 0.5% triclosan. The soft soap + propan-2-ol proved to be more effective than the other hand hygiene procedures. CONCLUSION: studies to verify the therapeutic efficacy of essential oil in hand hygiene can improve adherence to this practice.

  10. Influence of Melaleuca alternifolia oil nanoparticles on aspects of Pseudomonas aeruginosa biofilm.

    Science.gov (United States)

    Comin, Vanessa M; Lopes, Leonardo Q S; Quatrin, Priscilla M; de Souza, Márcia E; Bonez, Pauline C; Pintos, Francieli G; Raffin, Renata P; Vaucher, Rodrigo de A; Martinez, Diego S T; Santos, Roberto C V

    2016-04-01

    The Pseudomonas aeruginosa is a gram-negative bacillus and frequent cause of infection. This microorganism is resistant intrinsically to various drugs. The P. aeruginosa is associated with the biofilm formation, which causes worsen the prognosis and difficulty the treatment. The influence of Melaleuca alternifolia oil or "tree of tee" oil (TTO) and TTO nanoparticles on adhesion of P. aeruginosa in buccal epithelial cells was investigated. Also was determined the antimicrobial and antibiofilm activity against this microorganism. The TTO nanoparticles were produced by deposition of preformed polymer and the physic-chemical properties of nanoparticles were measured by electrophoresis and dynamic light scattering. The characterization of nanoparticle showed acceptable values for diameter and zeta potential. The evaluation of antimicrobial and antibiofilm activity against P. aeruginosa PAO1 was performed by microdilution indicating the minimal inhibitory concentration, and the potential antibiofilm. It was verified the action on virulence factors such the motility, besides the influence on adhesion in buccal epithelial cells. Both oil and nanoparticles showed a decrease in adhesion of microorganisms to buccal cells, decrease of biofilm and interfering on P. aeruginosa PAO1 motility. The nanostructuration of TTO, shows be a viable alternative against formed biofilm microorganisms.

  11. Influence of tea tree oil (Melaleuca alternifolia) on the cattle tick Rhipicephalus microplus.

    Science.gov (United States)

    Pazinato, Rafael; Klauck, Vanderlei; Volpato, Andreia; Tonin, Alexandre A; Santos, Roberto C; de Souza, Márcia E; Vaucher, Rodrigo A; Raffin, Renata; Gomes, Patrícia; Felippi, Candice C; Stefani, Lenita M; Da Silva, Aleksandro S

    2014-05-01

    The aim of this study was to verify the influence of tea tree oil (TTO) (Melaleuca alternifolia) tested in its pure and nanostructured (TTO nanoparticles) forms on the reproduction of female Rhipicephalus microplus. For our purpose, female ticks were collected from naturally infected animals and treated in vitro with TTO (1, 5, and 10 %) and TTO nanoparticles (0.075, 0.375, and 0.75 %). In order to validate the tests, they were performed in triplicate using positive (amitraz) and negative (untreated) controls. It was possible to observe that pure TTO (5 and 10 %) and TTO nanoparticles (0.375 and 0.75 %) showed 100 % reproductive inhibition on female ticks. Additionally, pure TTO (1 %) also showed an acaricide effect (70 %), similarly to the positive control (78.3 %). This is the first study demonstrating the activity of pure TTO and TTO nanoparticles on female ticks. Therefore, based on these results, we were able to show that both forms and all concentrations of M. alternifolia affected tick reproduction by inhibiting egg laying and hatching. We were also able to show that TTO nanoparticles potentiated the inhibitor effect of pure TTO on the reproduction of R. microplus.

  12. Bioactivity of tea tree oil from Melaleuca alternifolia against sheep lice (Bovicola ovis Schrank) in vitro.

    Science.gov (United States)

    James, P J; Callander, J T

    2012-07-06

    Tea tree oil (TTO) from the Australian native plant Melaleuca alternifolia has wide ranging bio-active properties, including insecticidal and repellent activity against arthropods. Furthermore, composition of commercially available Australian TTO is specified under an International Organization for Standardization standard (ISO 4730), reducing the potential for variable effects often noted with botanical pesticides. The effect of TTO, meeting the ISO standard for terpinen-4-ol chemotype, was tested against sheep lice (Bovicola ovis Schrank) in a series of laboratory studies. Immersion of wool for 60s in formulations containing concentrations of 1% TTO and above caused 100% mortality of adult lice and eggs. Exposure to vapours from TTO, delivered as droplets in fumigation chambers and when applied to wool also caused high mortality in both lice and eggs. The main active component of TTO in the fumigant tests was terpinen-4-ol. Treated surface assays and tests with wool where the formulation was allowed to dry before exposure of lice indicated low persistence. These studies demonstrate that TTO is highly toxic to sheep lice and active at concentrations that suggest potential for the development of TTO-based ovine lousicides.

  13. Insecticidal and repellent effects of tea tree (Melaleuca alternifolia) oil against Lucilia cuprina.

    Science.gov (United States)

    Callander, J T; James, P J

    2012-03-23

    Laboratory studies were conducted to assess the effect of tea tree oil (TTO) from Melaleuca alternifolia (terpinen-4-ol chemotype) against different stages of the Australian sheep blowfly Lucilia cuprina. When applied to wool, 3% TTO formulation repelled gravid female L. cuprina and prevented oviposition for six weeks. Formulations containing 1% TTO caused 100% mortality of L. cuprina eggs and 1st instar larvae and 2.5% TTO caused mortality of most second and third instar larvae in agar feeding assays. In experiments where third instar larvae were dipped in TTO formulations for 60s, concentrations of up to 50% TTO gave less than 50% kill. TTO at concentrations of 0.5%, 2% and 5% was strongly repellent to third instar larvae and caused them to evacuate treated areas. Inclusion of TTO in formulations with diazinon, ivermectin and boric acid reduced mortality in comparison with the larvicides used alone, at least partially because of avoidance behaviour stimulated by the TTO. Addition of TTO to wound treatments may aid in wound protection and myiasis resolution by preventing oviposition by L. cuprina adults, insecticidal action against L. cuprina eggs and larvae, stimulating larvae to leave the wound and through antimicrobial and anti-inflammatory properties that aid in wound healing.

  14. Dipping and jetting with tea tree (Melaleuca alternifolia) oil formulations control lice (Bovicola ovis) on sheep.

    Science.gov (United States)

    James, P J; Callander, J T

    2012-10-26

    The in vivo pediculicidal effectiveness of 1% and 2% formulations of tea tree (Melaleuca alternifolia) oil (TTO) against sheep chewing lice (Bovicola ovis) was tested in two pen studies. Immersion dipping of sheep shorn two weeks before treatment in both 1% and 2% formulations reduced lice to non detectable levels. No lice were found on any of the treated sheep despite careful inspection of at least 40 fleece partings per animal at 2, 6, 12 and 20 weeks after treatment. In the untreated sheep louse numbers increased from a mean (± SE) of 2.4 (± 0.7) per 10 cm fleece part at 2 weeks to 12.3 (± 4.2) per part at 20 weeks. Treatment of sheep with 6 months wool by jetting (high pressure spraying into the fleece) reduced louse numbers by 94% in comparison to controls at two weeks after treatment with both 1% and 2% TTO formulations. At 6 and 12 weeks after treatment reductions were 94% and 91% respectively with the 1% formulation and 78% and 84% respectively with the 2% formulation. TTO treatment also appeared to reduce wool damage in infested sheep. Laboratory studies indicated that tea tree oil 'stripped' from solution with a progressive reduction in concentration as well as volume as more wool was dipped, indicating that reinforcement of active ingredient would be required to maintain effectiveness when large numbers of sheep are treated. The results of these studies suggest significant potential for the development of ovine lousicides incorporating TTO.

  15. In vitro and ex vivo activity of Melaleuca alternifolia against protoscoleces of Echinococcus ortleppi.

    Science.gov (United States)

    Monteiro, Danieli Urach; Azevedo, Maria Isabel; Weiblen, Carla; DE Avila Botton, Sônia; Funk, Nadine Lysyk; DE Bona DA Silva, Cristiane; Zanette, Régis Adriel; Schwanz, Thiago Guilherme; DE LA Rue, Mário Luiz

    2017-02-01

    Cystic echinococcosis is a zoonotic disease of difficult diagnosis and treatment. The use of protoscolicidal agents in procedures is of utmost importance for treatment success. This study was aimed at analysing the in vitro and ex vivo activity of Melaleuca alternifolia oil (tea tree oil - TTO), its nanoemulsion formulation (NE-TTO) and its major component (terpinen-4-ol) against Echinococcus ortleppi protoscoleces obtained from cattle. Concentrations of 2·5, 5 and 10 mg mL-1 of TTO, 10 mg mL-1 of NE-TTO and 1, 1·5 and 2 mg mL-1 of terpinen-4-ol were evaluated in vitro against protoscoleces at 5, 10, 15 and 30 min. TTO was also injected directly into hydatid cysts (ex vivo analysis, n = 20) and the viability of protoscoleces was evaluated at 5, 15 and 30 min. The results indicated protoscolicidal effect at all tested formulations and concentrations. Terpinen-4-ol (2 mg mL-1) activity was superior when compared with the highest concentration of TTO. NE-TTO reached a gradual protoscolicidal effect. TTO at 20 mg mL-1 showed 90% protoscolicidal action in hydatid cysts at 5 min. The results showed that TTO affects the viability of E. ortleppi protoscoleces, suggesting a new protoscolicidal option to the treatment of cystic equinococcosis.

  16. Melaleuca alternifolia Concentrate Inhibits in Vitro Entry of Influenza Virus into Host Cells

    Directory of Open Access Journals (Sweden)

    Lifang Jiang

    2013-08-01

    Full Text Available Influenza virus causes high morbidity among the infected population annually and occasionally the spread of pandemics. Melaleuca alternifolia Concentrate (MAC is an essential oil derived from a native Australian tea tree. Our aim was to investigate whether MAC has any in vitro inhibitory effect on influenza virus infection and what mechanism does the MAC use to fight the virus infection. In this study, the antiviral activity of MAC was examined by its inhibition of cytopathic effects. In silico prediction was performed to evaluate the interaction between MAC and the viral haemagglutinin. We found that when the influenza virus was incubated with 0.010% MAC for one hour, no cytopathic effect on MDCK cells was found after the virus infection and no immunofluorescence signal was detected in the host cells. Electron microscopy showed that the virus treated with MAC retained its structural integrity. By computational simulations, we found that terpinen-4-ol, which is the major bioactive component of MAC, could combine with the membrane fusion site of haemagglutinin. Thus, we proved that MAC could prevent influenza virus from entering the host cells by disturbing the normal viral membrane fusion procedure.

  17. [Antimicrobial effects of tea tree oil (Melaleuca alternifolia) on oral microorganisms].

    Science.gov (United States)

    Kulik, E; Lenkeit, K; Meyer, J

    2000-01-01

    The essential oil of Melaleuca alternifolia (tea tree oil) exhibits antimicrobial activity against a wide range of Gram-positive and Gram-negative bacteria, yeasts and fungi. In this study the bacteriostatic and bacteriocidal/fungicidal activity of a tea tree oil solution, of a new tea tree oil (Tebodont) and the respective placebo-gel, of a chlorhexidindigluconate-solution and of PlakOut was tested in vitro against ten different oral microorganisms. Minimum inhibitory concentrations were in the range from 0.0293% to 1.25% for the tea tree oil solution and from 0.0082% to 1.25% for the tea tree oil gel. The values for minimum bacteriocidal/fungicidal concentrations were in the range from 0.0521% to 2.5% for the tea tree oil solution and from tea tree oil gel. The most susceptible microorganisms were Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis, whereas Streptococcus mutans and Prevotella intermedia were the least susceptible ones. Both for the chlorhexidindigluconate solution and for PlakOut the values for the minimal inhibitory concentration and for the minimal cidal concentration were between <0.0002% and 0.0125%.

  18. The mode of antimicrobial action of the essential oil of Melaleuca alternifolia (tea tree oil).

    Science.gov (United States)

    Cox, S D; Mann, C M; Markham, J L; Bell, H C; Gustafson, J E; Warmington, J R; Wyllie, S G

    2000-01-01

    The essential oil of Melaleuca alternifolia (tea tree) exhibits broad-spectrum antimicrobial activity. Its mode of action against the Gram-negative bacterium Escherichia coli AG100, the Gram-positive bacterium Staphylococcus aureus NCTC 8325, and the yeast Candida albicans has been investigated using a range of methods. We report that exposing these organisms to minimum inhibitory and minimum bactericidal/fungicidal concentrations of tea tree oil inhibited respiration and increased the permeability of bacterial cytoplasmic and yeast plasma membranes as indicated by uptake of propidium iodide. In the case of E. coli and Staph. aureus, tea tree oil also caused potassium ion leakage. Differences in the susceptibility of the test organisms to tea tree oil were also observed and these are interpreted in terms of variations in the rate of monoterpene penetration through cell wall and cell membrane structures. The ability of tea tree oil to disrupt the permeability barrier of cell membrane structures and the accompanying loss of chemiosmotic control is the most likely source of its lethal action at minimum inhibitory levels.

  19. Suppression of native Melaleuca ericifolia by the invasive Phragmites australis through allelopathic root exudates.

    Science.gov (United States)

    Uddin, Md Nazim; Robinson, Randall William; Caridi, Domenic; Al Harun, Md Abdullah Yousuf

    2014-03-01

    Invasive plants are a great threat to the conservation of natural ecosystems and biodiversity. Allelopathy as a mechanism for invasion of plants such as Phragmites australis, one of the most aggressive invaders, has the potential to suppress neighboring plant species. Allelopathic interference, through root exudates of P. australis on native Melaleuca ericifolia, was investigated to find out the underlying invasion mechanisms. Germination and growth effects of P. australis on M. ericifolia were studied in the greenhouse using potting mix both with and without activated carbon, and a combination of single and repeated cuttings of P. australis as the management tool. P. AUSTRALIS had significant negative effects on germination and growth of M. ericifolia by inhibiting germination percentage, maximum root length and plant height, biomass, stem diameter, and number of growth points with little effect on leaf physiology. Activated carbon (AC) in turn moderately counteracted these effects. The cutting of P. australis shoots significantly reduced the suppressive effects on M. ericifolia compared to the addition of AC to soil. Furthermore, significant changes in soil such as pH, electrical conductivity, osmotic potential, phenolics, and dehydrogenase activity were identified among cutting treatments with little variation between AC treatments. The results demonstrated that allelopathy through root exudates of P. australis had relatively low contribution in suppressing M. ericifolia in comparison to other competitive effects. Management tools combining repeated cutting of P. australis shoots with AC treatments may assist partly in the restoration of native ecosystems invaded by P. australis.

  20. Innate and Conditioned Responses to Chemosensory and Visual Cues in Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae), Vector of Huanglongbing Pathogens.

    Science.gov (United States)

    Patt, Joseph M; Stockton, Dara; Meikle, William G; Sétamou, Mamoudou; Mafra-Neto, Agenor; Adamczyk, John J

    2014-11-19

    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 from host and non-host-plant sources. Response was measured as the frequency of salivary sheaths, the residue of psyllid probing activity, in a line of emulsified wax on the surface of a test arena. The psyllids displayed both appetitive and aversive conditioning to two different chemosensory stimuli. They could also be conditioned to recognize a blue-colored probing substrate and their response to neutral visual cues was enhanced by chemosensory stimuli. Conditioned psyllids were sensitive to the proportion of chemosensory components present in binary mixtures. Naïve psyllids displayed strong to moderate innate biases to several of the test compounds. While innate responses are probably the psyllid's primary behavioral mechanism for selecting host-plants, conditioning may enhance its ability to select host-plants during seasonal transitions and dispersal.

  1. GC-MS method validation and levels of methyl eugenol in a diverse range of tea tree (Melaleuca alternifolia) oils.

    Science.gov (United States)

    Raymond, Carolyn A; Davies, Noel W; Larkman, Tony

    2017-03-01

    Tea tree oil distilled from Melaleuca alternifolia has widespread use in the cosmetic industry as an antimicrobial as well as for other functions in topical products. Concerns were first raised by the European Commission's Scientific Committee on Consumer Products in 2004 about the level of the potentially carcinogenic phenylpropanoid compound methyl eugenol in tea tree oil. Limits on oil content in different types of cosmetic products were set based on a reported upper level of 0.9% methyl eugenol in the oil. A previous publication indicated that these levels were based on oil from a Melaleuca species not used in the commercial production of oil. Even the highest recorded levels in Melaleuca alternifolia, the overwhelmingly most common species used, were ∼15 times less than this, meaning that more oil could be safely used in the products. The current study, including details on methodology and reproducibility, extends that work across a suite of 57 plantation-sourced oils from a range of geographical locations and production years, as well as many Australian and international commercial oils. Lower levels of methyl eugenol in oils of known provenance were confirmed, with a recorded range of 160-552 ppm and a mean of 337 ppm. Analysis of variance showed methyl eugenol levels in Australian plantation oils to be correlated to the geographical region but not to the year of production. Average methyl eugenol levels in commercial oils were significantly lower, and these samples were divided into an authentic group and a group that were suspected of being adulterated based on an independent test. Authentic commercial oils had similar levels of methyl eugenol to Australian provenance material, whilst the oils classed as suspect had significantly lower levels.

  2. Seasonal Population Dynamics of the Asian Citrus Psyllid, Diaphorina citri Kuwayama in Sarawak

    Directory of Open Access Journals (Sweden)

    Stephen L.C. Teck

    2011-01-01

    Full Text Available Problem statement: Effective control of phytophagous pests requires a thorough understanding of their seasonal population dynamics, dispersion behavior, natural enemy activity and climate. To date, although very little detail information had been published on the ecology of Diaphorina citri. The objective of this investigation was to test through field experiment the hypothesis that the major factors influencing local D. citri populations particularly their seasonal population dynamics in Sarawak are (a flushing cycles, (b climate and (c the impact of the primary parasitoids namely Tamarixia radiata and Diaphorencyrtus aligarhensis. Approach: Seasonal abundance D. citri was studied weekly from March 1998 to December 2000 in the 1-ha citrus honey mandarin (Citrus aurantium L. commercial orchard at Jemukan (1° 33'N, 110° 41'E, Kota Samarahan Division, Southwest Sarawak, in Malaysia. Results: Field studies on citrus trees showed that the D. citri population fluctuates throughout the year on citrus honey mandarin in Sarawak. Generations overlapped but adult and egg population peaks for a short period generally coincided with three annual flushing cycles, in August-September, February-March and June-July between March 1998 and December 2000. Conclusion: Psyllid population levels are positively related to the availability of new shoot flushes. Psyllid populations are adversely affected by weather conditions and parasitoids. Adult psyllid populations increased exponentially during periods of flush growth and migration and dispersal of the adults was also related to flushing cycles. Dispersal and colonization of new trees is greatest in September-October, at the onset of the rainy season.

  3. Multimodal cues drive host-plant assessment in Asian citrus psyllid (Diaphorina citri).

    Science.gov (United States)

    Patt, Joseph M; Meikle, William G; Mafra-Neto, Agenor; Sétamou, Mamoudou; Mangan, Robert; Yang, Chenghai; Malik, Nasir; Adamczyk, John J

    2011-12-01

    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 dish, D. citri spent more time on yellow versus gray rings; however, this response disappeared when either gray or yellow wax droplets were applied. When the psyllids were presented with droplets scented with terpenes, the response to both scent and color was increased. The addition of a dilute (≍0.1 M) sucrose solution to the wax droplets increased the magnitude of D. citri responses. Next, groups of D. citri were placed on plastic laboratory film covering a sucrose solution, to mimic a leaf surface. Test stimuli were presented via two 'midribs' made from lines of emulsified wax formulation. Probing levels were measured as a function of color saturation and scent composition, and concentration. The test scents were based on qualitatively major volatiles emitted by Murraya paniculata (L.) Jack, Citrus aurantifolia (Christm.) Swingle, and C. sinensis (L.) Osbeck. The highest probing response was observed on the middle concentration (20-μl scent/10 ml wax formulation) of the C. aurantifolia-scented wax lines. Results indicate that there are interactive effects between the different sensory modalities in directing host-plant assessment behavior.

  4. Melaleuca alternifolia Essential Oil against the Lesser Mealworm (Alphitobius diaperinus) and Its Possible Effect on the Soil Fauna

    OpenAIRE

    Volpato, A.; WR Lorenzetti; T Zortea; LCDD Giombelli; Baretta,D.; RCV Santos; RA Vaucher; RP Raffin; ME Souza; LM Stefani; AA Boligon; ML Athayde; AS da Silva

    2016-01-01

    ABSTRACT The aim of this study was to evaluate the in vitro bioactivity of tea tree (Melaleuca alternifolia) essential oil against larvae and adult forms of lesser mealworms (Alphitobius diaperinus) and its influence on the soil fauna. Tests were performed in triplicate using pure tea tree oil (TTO; 1, 5, 10, 25, 50, and 100%), TTO nanoparticles (1, 3, and 7.5%), or terpinen-4-ol, the main compound of the tea tree oil, at the same concentrations of TTO. Larvae and adult mortality occurred at ...

  5. Enhanced Acquisition Rates of 'Candidatus Liberibacter asiaticus' by the Asian Citrus Psyllid (Hemiptera: Liviidae) in the Presence of Vegetative Flush Growth in Citrus.

    Science.gov (United States)

    Sétamou, Mamoudou; Alabi, Olufemi J; Kunta, Madhurababu; Jifon, John L; da Graça, John V

    2016-10-01

    The Asian citrus psyllid preferentially feeds and exclusively reproduces on young, newly emerged flush shoots of citrus. Asian citrus psyllid nymphs feed and complete their life stages on these flush shoots. Recent studies conducted under greenhouse conditions have shown that the transmission rates of 'Candidatus Liberibacter asiaticus' (CLas), the putative causal agent of huanglongbing disease of citrus, are enhanced when flush shoots are present. However, it is unclear if CLas acquisition by migrant adult Asian citrus psyllids is similarly enhanced. To address this knowledge gap, cohorts of Asian citrus psyllid adults were allowed 1-wk acquisition access period (AAP) on flushing and nonflushing shoots of qPCR-tested symptomatic (CLas+) and asymptomatic (CLas-) 10-yr-old sweet orange trees under field conditions. After the AAP, they were tested for CLas by qPCR. Progeny Asian citrus psyllid adults that emerged 4 wk post-AAP were similarly retrieved and tested. Eighty percent of flushing and 30% of nonflushing CLas+ trees produced infective Asian citrus psyllid adults, indicating that flush shoots have greater potential to be inoculum sources for CLas acquisition. Concomitantly, 21.1% and 6.0% infective adults were retrieved, respectively, from flushing and nonflushing CLas+ trees, indicating that Asian citrus psyllid adults acquire CLas more efficiently from flush shoots relative to mature shoots. In addition, 12.1% of infective Asian citrus psyllid adult progeny were obtained from 70% of flushing CLas+ trees. Significantly lower mean Ct values were also obtained from infective adults retrieved from flushing relative to nonflushing trees. The results underscore the role of flush shoots in CLas acquisition and the need to protect citrus trees from Asian citrus psyllid infestations during flush cycles.

  6. Zebra chip disease incidence on potato is influenced by timing of potato psyllid infestation,but not by the host plants on which they were reared

    Institute of Scientific and Technical Information of China (English)

    Feng Gao; John Jifon; Xiangbing Yang; Tong-Xian Liu

    2009-01-01

    The Zebra chip (ZC) syndrome is an emerging disease of potato and a major threat to the potato industry.The potato psyllid,Bactericerca cockerelli (Sulc) is believed to be a vector of the ZC pathogen,which is now thought to be Candidatus Liberibacter,a bacterium.To further understand the relationship between potato psyllid infestation and ZC disease expression,healthy potato plants at different growth stages (4,6 and 10 weeks after germination) were exposed separately to potato psyllids that were separately reared on four solanaceons hosts plants (potato,tomato,eggplant or bell pepper) for more than 1 year.ZC symptoms,leaf rates and total nonstructural carbohydrate accumulation in leaves and tubers of healthy and psyllid-infested plants were monitored and recorded.Typical ZC symptoms were observed in leaves and tubers of all plants exposed to potato psyllids regardless of the host plant on which they were reared.This was also accompanied by significant reductions in net photosynthetic rate.Caged potato plants without exposure to potato psyllids (uninfested controls) did not show any ZC symptom in both foliage and in harvested tubers.Foliage damage and ZC expression were most severe in the potato plants that were exposed to potato psyllids 4 weeks after germination compared to plants infested at later growth stages.Tubers from potato psyllid-infested plants had significantly higher levels of reducing sugars (glucose) and lower levels of starch than those in healthy plants,indicating that potato psyllid infestation interfered with carbohydrate metabolism in either leaves or tubers,resulting in ZC expression.

  7. Effect of habituation to tea tree (Melaleuca alternifolia) oil on the subsequent susceptibility of Staphylococcus spp. to antimicrobials, triclosan, tea tree oil, terpinen-4-ol and carvacrol

    NARCIS (Netherlands)

    Thomsen, Natalie A.; Hammer, Katherine A.; Riley, Thomas V.; Van Belkum, Alex; Carson, Christine F.

    2013-01-01

    The aim of this study was to seek additional data on the antimicrobial susceptibility of Staphylococcus spp. after habituation to low levels of the topical antimicrobial agent tea tree (Melaleuca alternifolia) oil. Meticillin-susceptible Staphylococcus aureus (MSSA), meticillin-resistant S. aureus (

  8. Establishment, population increase, spread, and ecological host range of Lophodiplosis trifida (Diptera: Cecidomyiidae), a biological control agent of the invasive tree Melaleuca quinquenervia (Myrtales:Myrtaceae).

    Science.gov (United States)

    The Australian tree Melaleuca quinquenervia (Cav.) Blake is an invasive weed in wetland systems of Florida, USA. A biological control program targeting M. quinquenervia has culminated in the release of the gall forming midge Lophodiplosis trifida Gagné (Cecidomyiidae). Populations of the introduced ...

  9. Physiological host range of a mutualistic pair: Fergusonina turneri and its obligate nematode Fergusobia quinquenerviae, potential biological control agents of Melaleuca quinquenervia

    Science.gov (United States)

    In Australia, galls develop on Melaleuca quinquenervia (Cav.) S.T. Blake (Myrtales: Myrtaceae) as a result of the mutualistic association between the fly Fergusonina turneri Taylor (Diptera: Fergusoninidae) and its obligate nematode Fergusobia quinquenerviae Davies & Giblin-Davis (Tylenchida: Sphaer...

  10. Degradation products of citrus volatile organic compounds (VOCs) acting as phagostimulants that increase probing behavior of Asian citrus psyllid

    Science.gov (United States)

    Volatile phytochemicals play a role in orientation by phytophagous insects. We studied antennal and behavioral responses of the Asian citrus psyllid, Diaphorina citri Kuwayama, vector of the citrus greening disease pathogen. Little or no response to citrus leaf volatiles was detected by electroanten...

  11. Survey of 'Candidatus Liberibacter solanacearum' in carrot crops affected by the psyllid Trioza apicalis (Hemiptera: Triozidae) in Norway

    Science.gov (United States)

    The carrot psyllid Trioza apicalis Förster (Hemiptera: Triozidae) is a serious insect pest of carrot (Daucus carota L.) in northern Europe, where it can cause up to 100% crop loss. Although it was long believed that T. apicalis causes damage to carrot by injection of toxins into the plant, it was re...

  12. Volatile profiles of young leaves of Rutaceae spp. varying in susceptibility to the Asian citrus psyllid,(Hemiptera: Psyllidae)

    Science.gov (United States)

    Plant volatiles were identified from six species in the family Rutaceae. These species had varying degrees of susceptibility to the Asian citrus psyllid as determined by direct counts of life stages. Using a push system involving charcoal-filtered humidified air, volatiles were adsorbed on SuperQ pa...

  13. New corological and biological data of the Red Gum Lerp Psyllid, Glycaspis brimblecombei Moore, 1964 in Italy (Hemiptera, Psyllidae

    Directory of Open Access Journals (Sweden)

    Ricardo Jiménez-Peydró

    2011-03-01

    Full Text Available Glycaspis brimblecombei Moore, 1964 is a psyllid (Hemiptera: Psyllidae pest of Eucalyptus, native toAustralia and first recorded in Europe: Spain in 2008 and more recently (2010 in Italy. The present paper dealswith recent research, carried out in central Italy, with new data on the distribution and biology of this species.

  14. Localized autoinoculation and dissemination of Isaria fumosorosea for control of the Asian citrus psyllid in South Texas

    Science.gov (United States)

    The Asian citrus psyllid, Diaphorina citri Kuwayama, vectors the causal organism of citrus greening disease. Integrated strategies are needed to control D. citri in south Texas. Control approaches involving entomopathogenic fungi may be useful on ornamental and abandoned citrus and other rutaceous...

  15. Toxicity of insecticidal soaps to the Asian citrus psyllid (Diaphorina citri) and two of its natural enemies

    Science.gov (United States)

    Insecticidal soaps (hereafter “soaps”) are labeled for use by homeowners and also can be used in citrus grown for the organic market. Soaps control some insect pests and therefore might be an alternative to conventional pesticides for control of the Asian citrus psyllid, Diaphorina citri Kuwayama (...

  16. Candidatus Liberibacter asiaticus is present in orange jasmine and Asian citrus psyllid reared from jasmine at low titers

    Science.gov (United States)

    Orange jasmine, Murraya paniculata, is a common horticultural plant in Florida, and an alternate host of the Asian citrus psyllid, Diaphorina citri Kuwayama. Orange jasmine has also been reported to harbor the bacteria Candidatus Liberibacter asiaticus, the causal agent of huanglongbing disease. We ...

  17. In Vitro Activity of Melaleuca alternifolia (Tea Tree) in Its Free Oil and Nanoemulsion Formulations Against Pythium insidiosum.

    Science.gov (United States)

    de Souza Silveira Valente, Júlia; de Oliveira da Silva Fonseca, Anelise; Brasil, Carolina Litchina; Sagave, Lauren; Flores, Fernanda Cramer; de Bona da Silva, Cristiane; Sangioni, Luís Antônio; Pötter, Luciana; Santurio, Janio Morais; de Avila Botton, Sônia; Pereira, Daniela Isabel Brayer

    2016-12-01

    Pythium insidiosum is an important aquatic oomycete which can cause pythiosis in both animals and humans. This microorganism shows low susceptibility to antifungal drugs available. This study analyzed the in vitro antimicrobial activity of Melaleuca alternifolia in its free oil (FO) and nanoemulsion (NE) formulations against Brazilian P. insidiosum isolates. The antimicrobial activity evaluation was performed by the broth microdilution method according to CSLI M38-A2 document adapted to phytopharmaceuticals. Twenty-six P. insidiosum isolates were evaluated, and the minimum inhibitory concentration was determined at 100 % growth inhibition. Melaleuca alternifolia essential oil or FO was obtained commercially. The NE containing 1 % M. alternifolia essential oil was prepared by the spontaneous emulsification method. All P. insidiosum isolates evaluated showed minimum inhibitory concentrations (MIC) ranging from 531.5 to 2125 μg/mL for the FO formulation; MIC50 and MIC90 showed values between 1062.5 and 2125 μg/mL, respectively. When the NE formulation was evaluated, MIC values ranged from 132.7 to 2125 μg/mL and both MIC50 and MIC90 corresponded to 1062.5 μg/mL. FO and NE formulations of M. alternifolia showed antimicrobial activity against P. insidiosum. This study demonstrated that M. alternifolia oil can be an additional therapy in pythiosis treatment; however, further studies are needed to evaluate the applicability of the plant essential oils in the treatment of clinical pythiosis.

  18. Chemical and behavioral analysis of the cuticular hydrocarbons from Asian citrus psyllid, Diaphorina citri

    Institute of Scientific and Technical Information of China (English)

    Raiinder S.Mann; Russell L.Rouseff; Jack Smoot; Nandikeswara Rao; Wendy L.Meyer; Stephen L.Lapointe; Paul S.Robbins

    2013-01-01

    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 female cuticular extract equivalent units than blank controls.The results were confirmed in field studies in which clear or yellow traps baited with 10 female cuticular extract equivalent units attracted proportionately more males than clear traps baited with male cuticular extract or unbaited traps.Analyses of cuticular constituents of male and female D.citri revealed differences between the sexes in chemical composition of their cuticular extracts.Laboratory bioassays with synthetic chemicals identified from cuticular extracts indicated that dodecanoic acid attracted more males than clean air.Traps baited with dodecanoic acid did not increase total catch of D.cirri as compared with blank traps at the dosages tested; however,the sex ratio of psyllid catch was male biased on traps baited with the highest lure loading dosage tested (10.0 mg).

  19. Chemical and behavioral analysis of the cuticular hydrocarbons from Asian citrus psyllid, Diaphorina citri.

    Science.gov (United States)

    Mann, Rajinder S; Rouseff, Russell L; Smoot, Jack; Rao, Nandikeswara; Meyer, Wendy L; Lapointe, Stephen L; Robbins, Paul S; Cha, Dong; Linn, Charles E; Webster, Francis X; Tiwari, Siddharth; Stelinski, Lukasz L

    2013-06-01

    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 female cuticular extract equivalent units than blank controls. The results were confirmed in field studies in which clear or yellow traps baited with 10 female cuticular extract equivalent units attracted proportionately more males than clear traps baited with male cuticular extract or unbaited traps. Analyses of cuticular constituents of male and female D. citri revealed differences between the sexes in chemical composition of their cuticular extracts. Laboratory bioassays with synthetic chemicals identified from cuticular extracts indicated that dodecanoic acid attracted more males than clean air. Traps baited with dodecanoic acid did not increase total catch of D. citri as compared with blank traps at the dosages tested; however, the sex ratio of psyllid catch was male biased on traps baited with the highest lure loading dosage tested (10.0 mg). © 2012 The Authors Insect Science © 2012 Institute of Zoology, Chinese Academy of Sciences.

  20. The genetic structure of an invasive pest, the Asian citrus psyllid Diaphorina citri (Hemiptera: Liviidae.

    Directory of Open Access Journals (Sweden)

    Aline S Guidolin

    Full Text Available 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 and structure of populations of D. citri to aid in the decision making processes toward sustainable management of this species/disease. We employed different methods to quantify and compare the genetic diversity and structure of D. citri populations among 36 localities in Brazil, using an almost complete sequence of the cytochrome oxidase I (COI gene. Our analyses led to the identification of two geographically and genetically structured groups. The indices of molecular diversity pointed to a recent population expansion, and we discuss the role of multiple invasion events in this scenario. We also argue that such genetic diversity and population structure may have implications for the best management strategies to be adopted for controlling this psyllid and/or the disease it vectors in Brazil.

  1. Molecular characterization of Wolbachia strains associated with the invasive Asian citrus psyllid Diaphorina citri in Brazil.

    Science.gov (United States)

    Guidolin, A S; Cônsoli, F L

    2013-02-01

    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 alternative strategy for insect management. Thus, we aimed to determine the natural rate of infection, to characterize the Wolbachia strains associated with this psyllid by "multilocus sequencing typing" (MLST) and wsp analysis, and to verify the association of the symbiont to particular genotypes of the host. Analysis indicated Wolbachia infects 100 % of all specimens tested from all 15 sampled populations. MLST revealed the occurrence of five new sequence types (STs) of Wolbachia, while analysis based on the wsp sequences indicated only four different types of Wolbachia. ST-173 was predominant, while the remaining STs were population specific. Analysis of the host-symbiont relationship did not reveal any particular association of Wolbachia and haplotypes or a decrease in nucleotide diversity of D. citri in populations in which more than one ST was recorded. The consequences of the diversity of STs reported are still unknown, but the fact that Wolbachia infection is fixed and that there is one ST with a broad distribution highlights the use of this symbiont as an alternative strategy to control D. citri.

  2. Resistance Management for Asian Citrus Psyllid, Diaphorina citri Kuwayama, in Florida

    Directory of Open Access Journals (Sweden)

    Xue Dong Chen

    2017-09-01

    Full Text Available The Asian citrus psyllid, Diaphorina citri Kuwayma, is one of the most important pests in citrus production. The objective of this study was to evaluate D. citri resistance management with three insecticide rotations and compare them with no rotation and an untreated check. The different insecticides (modes of action tested were: dimethoate, imidacloprid, diflubenzuron, abamectin 3% + thiamethoxam 13.9%, and fenpropathrin. Eggs, nymph, and adult psyllids were counted weekly. Five insecticide applications were made in 2016. Insecticide susceptibility was determined by direct comparison with a laboratory susceptible population and field populations before and after all treatments were applied. Rankings of eggs, nymphs, and adults counted in treated plots were significantly lower than in the untreated control plots after each application. Initially, the resistance ratio (RR50 for each rotation model, as compared with laboratory susceptible strain and the field population before application, was less than 5.76 and 4.31, respectively. However, after five applications with dimethoate, the RR50 using the laboratory and pre-treatment field populations was 42.34 and 34.74, respectively. Our results indicate that effectively rotating modes of action can delay and/or prevent development of insecticide resistance in populations of D. citri.

  3. Repellency of a kaolin particle film to potato psyllid, Bactericera cockerelli (Hemiptera: Psyllidae), on tomato under laboratory and field conditions.

    Science.gov (United States)

    Peng, Linian; Trumble, John T; Munyaneza, Joseph E; Liu, Tong-Xian

    2011-07-01

    The potato psyllid, Bactericera cockerelli, is a vector of Candidatus Liberibacter solanacearum, causing several diseases in solanaceous crops. Laboratory and field no-choice and choice experiments were conducted to evaluate the repellency of kaolin particle film on adults of B. cockerelli on tomato plants that had been sprayed with kaolin particle film on the upper surface only, on the lower surface only and on both leaf surfaces. In no-choice tests in the laboratory, the numbers of adults on leaves were not different between the kaolin particle film and the water control, regardless of which leaf surface(s) were treated, but numbers of eggs were lower on the leaves treated with kaolin particle film than on those treated with water. In choice tests on plants treated with water/plants treated with kaolin particle film at ratios of 1:1, 6:3 or 8:1, fewer adults and eggs were found on the leaves treated with kaolin particle film than on leaves treated with water. Under field conditions, in caged no-choice or choice tests, fewer adults, eggs and nymphs were found on plants treated with kaolin particle film than on plants treated with water. In an uncaged test under field conditions, plants sprayed with kaolin particle film had fewer psyllids than those sprayed with water. Even though potato psyllid adults could land on plants treated with kaolin particle film when no choice was given, fewer eggs were laid. When given a choice, the psyllids avoided plants treated with kaolin particle film under laboratory and field conditions. Kaolin particle film treatment may be a useful alternative for management of potato psyllids under field conditions. Copyright © 2011 Society of Chemical Industry.

  4. Analyses of mitogenome sequences revealed that Asian citrus psyllid (Diaphorina citri) from California was related to those from Florida but different from those in Southern China

    Science.gov (United States)

    Asian citrus psyllid (ACP, Diaphorina citri Kuwayama; Hemiptera: Liviidae) transmits “Candidatus Liberibacter asiaticus” (CLas), an unculturable alpha-proteobacterium associated with citrus Huanglongbing (HLB, yellow shoot disease, also called citrus greening disease). HLB is threatening citrus prod...

  5. Differential responses to feeding by the tomato/potato psyllid between two tomato cultivars and their implications in establishment of injury levels and potential of damaged plant recovery

    Institute of Scientific and Technical Information of China (English)

    DEGUANG LIU; LINDSEY JOHNSON; JOHN T. TRUMBLE

    2006-01-01

    An invasive new biotype of the tomato/potato psyllid (Bactericera [Paratrioza] cockerelli [Sulc.]) (Homoptera: Psyllidae) recently has caused losses exceeding 50% on fresh market tomatoes in western North America. Despite these extensive losses, little is known regarding the threshold levels at which populations must be suppressed in order to prevent economic losses. A series of experiments were therefore designed using combinations of two common tomato cultivars (QualiT 21 and Yellow Pear), five pest-densities (0, 20, 30, 40 and 50 nymphs/plant), and three feeding-duration (5 days, 10 days, and lifetime) treatments to test the relative importance of pest density, feeding period, and cumulative psyllid-days to establish economic threshold levels for psyllids. The cultivars differed considerably in their response to the toxin injected by the psyllid nymphs. 'Yellow Pear' plants could recover from feeding by up to 40 nymphs for as long as 10 d, whereas 'QualiT 21' plants were irreparably damaged by densities of 20 nymphs feeding for only 5 days. On 'Yellow Pear', all plant measurements such as the number of yellow leaves and plant height were significantly better correlated with cumulative psyllid-days than with either pest density or feeding duration. On 'QualiT 21', all plant measurements other than the number of yellow leaflets and leaves were significantly better correlated with pest density than with feeding duration or cumulative psyllid-days, and pest density was a better predictor of psyllid damage. Potential reasons for the variable responses between cultivars and the implications for psyllid sampling and integrated pest management are discussed.

  6. Oral delivery of double-stranded RNAs and siRNAs induces RNAi effects in the potato/tomato psyllid, Bactericerca cockerelli.

    Directory of Open Access Journals (Sweden)

    Hada Wuriyanghan

    Full Text Available 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 Huanglongbing (citrus greening disease that currently threatens the entire Florida citrus industry. Here we used EST sequence information from D. citri to identify potential targets for RNA interference in B. cockerelli. We targeted ubiquitously expressed and gut-abundant mRNAs via injection and oral acquisition of double-stranded RNAs and siRNAs and were able to induce mortality in recipient psyllids. We also showed knockdown of target mRNAs, and that oral acquisition resulted primarily in mRNA knockdown in the psyllid gut. Concurrent with gene knockdown was the accumulation of target specific ∼ 21 nucleotide siRNAs for an abundant mRNA for BC-Actin. These results showed that RNAi can be a powerful tool for gene function studies in psyllids, and give support for continued efforts for investigating RNAi approaches as possible tools for psyllid and plant disease control.

  7. Organization of the mitochondrial genomes of whiteflies, aphids, and psyllids (Hemiptera, Sternorrhyncha)

    Science.gov (United States)

    Thao, MyLo L; Baumann, Linda; Baumann, Paul

    2004-01-01

    Background With some exceptions, mitochondria within the class Insecta have the same gene content, and generally, a similar gene order allowing the proposal of an ancestral gene order. The principal exceptions are several orders within the Hemipteroid assemblage including the order Thysanoptera, a sister group of the order Hemiptera. Within the Hemiptera, there are available a number of completely sequenced mitochondrial genomes that have a gene order similar to that of the proposed ancestor. None, however, are available from the suborder Sternorryncha that includes whiteflies, psyllids and aphids. Results We have determined the complete nucleotide sequence of the mitochondrial genomes of six species of whiteflies, one psyllid and one aphid. Two species of whiteflies, one psyllid and one aphid have mitochondrial genomes with a gene order very similar to that of the proposed insect ancestor. The remaining four species of whiteflies had variations in the gene order. In all cases, there was the excision of a DNA fragment encoding for cytochrome oxidase subunit III(COIII)-tRNAgly-NADH dehydrogenase subunit 3(ND3)-tRNAala-tRNAarg-tRNAasn from the ancestral position between genes for ATP synthase subunit 6 and NADH dehydrogenase subunit 5. Based on the position in which all or part of this fragment was inserted, the mitochondria could be subdivided into four different gene arrangement types. PCR amplification spanning from COIII to genes outside the inserted region and sequence determination of the resulting fragments, indicated that different whitefly species could be placed into one of these arrangement types. A phylogenetic analysis of 19 whitefly species based on genes for mitochondrial cytochrome b, NADH dehydrogenase subunit 1, and 16S ribosomal DNA as well as cospeciating endosymbiont 16S and 23S ribosomal DNA indicated a clustering of species that corresponded to the gene arrangement types. Conclusions In whiteflies, the region of the mitochondrial genome

  8. Organization of the mitochondrial genomes of whiteflies, aphids, and psyllids (Hemiptera, Sternorrhyncha

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    Baumann Paul

    2004-08-01

    Full Text Available Abstract Background With some exceptions, mitochondria within the class Insecta have the same gene content, and generally, a similar gene order allowing the proposal of an ancestral gene order. The principal exceptions are several orders within the Hemipteroid assemblage including the order Thysanoptera, a sister group of the order Hemiptera. Within the Hemiptera, there are available a number of completely sequenced mitochondrial genomes that have a gene order similar to that of the proposed ancestor. None, however, are available from the suborder Sternorryncha that includes whiteflies, psyllids and aphids. Results We have determined the complete nucleotide sequence of the mitochondrial genomes of six species of whiteflies, one psyllid and one aphid. Two species of whiteflies, one psyllid and one aphid have mitochondrial genomes with a gene order very similar to that of the proposed insect ancestor. The remaining four species of whiteflies had variations in the gene order. In all cases, there was the excision of a DNA fragment encoding for cytochrome oxidase subunit III(COIII-tRNAgly-NADH dehydrogenase subunit 3(ND3-tRNAala-tRNAarg-tRNAasn from the ancestral position between genes for ATP synthase subunit 6 and NADH dehydrogenase subunit 5. Based on the position in which all or part of this fragment was inserted, the mitochondria could be subdivided into four different gene arrangement types. PCR amplification spanning from COIII to genes outside the inserted region and sequence determination of the resulting fragments, indicated that different whitefly species could be placed into one of these arrangement types. A phylogenetic analysis of 19 whitefly species based on genes for mitochondrial cytochrome b, NADH dehydrogenase subunit 1, and 16S ribosomal DNA as well as cospeciating endosymbiont 16S and 23S ribosomal DNA indicated a clustering of species that corresponded to the gene arrangement types. Conclusions In whiteflies, the region of the

  9. Antennal and Abdominal Transcriptomes Reveal Chemosensory Genes in the Asian Citrus Psyllid, Diaphorina citri.

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    Zhongzhen Wu

    Full Text Available The Asian citrus psyllid, Diaphorina citri is the principal vector of the highly destructive citrus disease called Huanglongbing (HLB or citrus greening, which is a major threat to citrus cultivation worldwide. More effective pest control strategies against this pest entail the identification of potential chemosensory proteins that could be used in the development of attractants or repellents. However, the molecular basis of olfaction in the Asian citrus psyllid is not completely understood. Therefore, we performed this study to analyze the antennal and abdominal transcriptome of the Asian citrus psyllid. We identified a large number of transcripts belonging to nine chemoreception-related gene families and compared their expression in male and female adult antennae and terminal abdomen. In total, 9 odorant binding proteins (OBPs, 12 chemosensory proteins (CSPs, 46 odorant receptors (ORs, 20 gustatory receptors (GRs, 35 ionotropic receptors (IRs, 4 sensory neuron membrane proteins (SNMPs and 4 different gene families encoding odorant-degrading enzymes (ODEs: 80 cytochrome P450s (CYPs, 12 esterase (ESTs, and 5 aldehyde dehydrogenases (ADE were annotated in the D. citri antennal and abdominal transcriptomes. Our results revealed that a large proportion of chemosensory genes exhibited no distinct differences in their expression patterns in the antennae and terminal abdominal tissues. Notably, RNA sequencing (RNA-seq data and quantitative real time-PCR (qPCR analyses showed that 4 DictOBPs, 4 DictCSPs, 4 DictIRs, 1 DictSNMP, and 2 DictCYPs were upregulated in the antennae relative to that in terminal abdominal tissues. Furthermore, 2 DictOBPs (DictOBP8 and DictOBP9, 2 DictCSPs (DictOBP8 and DictOBP12, 4 DictIRs (DictIR3, DictIR6, DictIR10, and DictIR35, and 1 DictCYP (DictCYP57 were expressed at higher levels in the male antennae than in the female antennae. Our study provides the first insights into the molecular basis of chemoreception in this

  10. Effect of Essential Oils of Syzygium aromaticum and Melaleuca alternifolia on Isolates of Aspergillus sp.

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    A. Lima

    2014-03-01

    Full Text Available Essential  oils  have  antimicrobial  substances,  lower  cost  and  the  lower  resistance  of microorganism. This study aimed to evaluate the inhibition of mycelial growth of Aspergillus flavus and  A.  niger  with  essential  oils  of  Syzygium  aromaticum  and  Melaleuca  alternifolia.  For  this, aliquots  (0.5,  5,  10  and  15μL  of  essential  oils  from  S.  aromaticum  and  M.  alternifolia   were distributed on the surface of the culture medium Potato Dextrose Agar (PDA with Drigaslsky. In the control treatment were used only plates containing PDA plus chloramphenicol (1%. After 2 hours, a disc (8mm diameter of the isolated mycelium, with 10 days of age on PDA, was peaked to the center of the plates, these plates were sealed and incubated at 282°C, in the dark. The essential  oil  of  S.  aromaticum  inhibited  the  mycelial  growth  of  A.  flavus  and  A.  niger,  in  all aliquots. When using the essential oil of M. alternifolia decreased the mycelial growth of A. flavus in all aliquots, however, showed a low efficiency in control of A. niger. It was concluded that the essential  oil  S.  aromaticum  is  effective  against  A.  flavus  and  A.  niger,  which  can  be  used  in control against these microorganisms, and M. alternifolia not show satisfactory results in relation to reducing the growth of pathogens evaluated.

  11. Odor coding in a disease-transmitting herbivorous insect, the Asian citrus psyllid.

    Science.gov (United States)

    Coutinho-Abreu, Iliano V; McInally, Shane; Forster, Lisa; Luck, Robert; Ray, Anandasankar

    2014-07-01

    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 neurons that respond strongly to odorants found in the host citrus plants. Comparisons with the generalist yeast-feeding Drosophila melanogaster and specialist anthropophilic Anopheles gambiae reveal differences in odor-coding strategies for the citrus-seeking ACP. These findings provide a foundation for understanding host-odor coding in herbivorous insects.

  12. Biology and management of Asian citrus psyllid, vector of the huanglongbing pathogens.

    Science.gov (United States)

    Grafton-Cardwell, Elizabeth E; Stelinski, Lukasz L; Stansly, Philip A

    2013-01-01

    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 prior to detection. Detection of the pathogen in Brazil in 2004 and Florida in 2005 catalyzed a significant increase in research on D. citri biology. Chemical control is the primary management strategy currently employed, but recently documented decreases in susceptibility of D. citri to several insecticides illustrate the need for more sustainable tools. Herein, we discuss recent advances in the understanding of D. citri biology and behavior, pathogen transmission biology, biological control, and chemical control with respect to "Candidatus Liberibacter asiaticus." Our goal is to point toward integrated and biologically relevant management of this pathosystem.

  13. Wolbachia infection density in populations of the Asian citrus psyllid (Hemiptera: Liviidae).

    Science.gov (United States)

    Hoffmann, M; Coy, M R; Kingdom Gibbard, H N; Pelz-Stelinski, K S

    2014-10-01

    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 within-host density of Wolbachia in Florida D. citri populations using quantitative polymerase chain reaction for detection of the Wolbachia outer surface protein gene, wsp. Gene quantities were normalized to the D. citri wingless gene (Wg) to estimate Wolbachia abundance in individual D. citri. Using this method, significant geographic differences in Wolbachia densities were detected among Florida D. citri populations, with higher infection levels occurring in male versus female hosts.

  14. The yield of essential oils in Melaleuca alternifolia (Myrtaceae is regulated through transcript abundance of genes in the MEP pathway.

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    Hamish Webb

    Full Text Available Medicinal tea tree (Melaleuca alternifolia leaves contain large amounts of an essential oil, dominated by monoterpenes. Several enzymes of the chloroplastic methylerythritol phosphate (MEP pathway are hypothesised to act as bottlenecks to the production of monoterpenes. We investigated, whether transcript abundance of genes encoding for enzymes of the MEP pathway were correlated with foliar terpenes in M. alternifolia using a population of 48 individuals that ranged in their oil concentration from 39 -122 mg x g DM(-1. Our study shows that most genes in the MEP pathway are co-regulated and that the expression of multiple genes within the MEP pathway is correlated with oil yield. Using multiple regression analysis, variation in expression of MEP pathway genes explained 87% of variation in foliar monoterpene concentrations. The data also suggest that sesquiterpenes in M. alternifolia are synthesised, at least in part, from isopentenyl pyrophosphate originating from the plastid via the MEP pathway.

  15. 1998 William J. Stickel Bronze Award. Antifungal activity of Melaleuca alternifolia (tea-tree) oil against various pathogenic organisms.

    Science.gov (United States)

    Concha, J M; Moore, L S; Holloway, W J

    1998-10-01

    Tea-tree oil (oil of Melaleuca alternifolia) has recently received much attention as a natural remedy for bacterial and fungal infections of the skin and mucosa. As with most naturally occurring agents, claims of effectiveness have been only anecdotal; however, several published studies have recently demonstrated tea-tree oil's antibacterial activity. This study was conducted to determine the activity of tea-tree oil against 58 clinical isolates: Candida albicans (n = 10), Trichophyton rubrum (n = 8), Trichophyton mentagrophytes (n = 9), Trichophyton tonsurans (n = 10), Aspergillus niger (n = 9), Penicillium species (n = 9), Epidermophyton floccosum (n = 2), and Microsporum gypsum (n = 1). Tea-tree oil showed inhibitory activity against all isolates tested except one strain of E floccosum. These in vitro results suggest that tea-tree oil may be useful in the treatment of yeast and fungal mucosal and skin infections.

  16. In vito Culture of Melaleuca alternifolia%互叶白千层离体繁殖技术

    Institute of Scientific and Technical Information of China (English)

    吴幼媚; 王以红; 蔡玲; 黄金使; 梁炳增

    2001-01-01

    用1年生互叶白千层(Melaleuca alternifolia)实生苗的茎段芽作外植体,以0.1%HgCl2消毒10min,未污染率达80%以上,芽萌动快;芽在含BA 1.0 mg/L、NAA 0.5 mg/L的培养基上生长健壮,增殖率300%,有效芽100%;ABT 2.0 mg/L,IBA 0.4 mg/L的培养基有利生根,其生根率达93.3%.

  17. New excised-leaf assay method to test inoculativity of Asian citrus psyllid (Hemiptera: Psyllidae) with Candidatus Liberibacter asiaticus associated with citrus huanglongbing disease.

    Science.gov (United States)

    Ammar, El-Desouky; Walter, Abigail J; Hall, David G

    2013-02-01

    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 had been reared on Las-infected plants were caged on excised healthy sweet orange [Citrus sinensis (L.) Osbeck] leaves for a 1-2-wk inoculation access periods (IAP), and then both psyllids and leaves were tested later by quantitative polymerase chain reaction (PCR). When single adults were tested per leaf, percentages of Las-positive leaves averaged 2-6% by using HLBaspr primers and 10-20% by using the more sensitive LJ900 primers. Higher proportions of Las-positive leaves were obtained with 1) higher densities of inoculating psyllids (5-10 adults per leaf), 2) longer IAPs, and 3) incubation of leaves for 1 wk postinoculation before PCR. Logistic regression analysis indicated a positive correlation between Las titer in Asian citrus psyllid adults tested singly and the probability of detecting Las in the inoculated leaves, correlations that can be very useful in epidemiological studies. Comparison between excised leaves and whole seedlings, inoculated consecutively for 1 wk each by one or a group of psyllids, indicated no significant difference between Las detection in excised leaves or whole plants. This new excised-leaf assay method saves considerable time, materials, and greenhouse space, and it may enhance vector relation and epidemiological studies on Las and potentially other Liberibacter spp. associated with huanglongbing disease.

  18. 广东地区互叶白千层栽培技术规程%Cultivation Techniques ofMelaleuca alternifolia in Guangdong

    Institute of Scientific and Technical Information of China (English)

    韦曼华; 吴伟能; 汪迎利; 周丽华; 蔡燕灵

    2016-01-01

    互叶白千层Melaleuca alternifolia是一种生产周期短、收益快的药用和香料树种。文中总结广东地区互叶白千层的栽培技术规程,包括种苗繁育、种植方法、田间管理、采收等,为提高互叶白千层品质、保障精油质量提供标准化技术指导。%Melaleuca alternifolia was one of medicinal and perfume plants with short production cycle and quick gains. The cultivation techniques ofM. alternifolia in Guangdong were summarized including seedling propagation, plantation, field management and harvesting, which could promote the development of the standard planting and quality control ofM. alternifolia.

  19. Geographic Distribution of Habitat, Development, and Population Growth Rates of the Asian Citrus Psyllid, Diaphorina citri, in Mexico

    OpenAIRE

    López-Collado, José; Isabel López-Arroyo, J.; Robles-García, Pedro L.; Márquez-Santos, Magdalena

    2013-01-01

    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...

  20. Substratos, concentrações de ácido indolbutírico e tipos de miniestacas no enraizamento de melaleuca (Melaleuca alternifolia Cheel Substrates, indolebutyric acid levels and types of minicuttings on the rooting of tea tree (Melaleuca alternifolia Cheel

    Directory of Open Access Journals (Sweden)

    Y. Oliveira

    2012-01-01

    Full Text Available Melaleuca alternifolia tem como produto principal o óleo essencial extraído das folhas devido às propriedades antifúngicas e antibacterianas. Pouco se tem relatado sobre a propagação desta espécie, sendo a miniestaquia uma alternativa para a propagação vegetativa de clones superiores visando à implantação de campo de produção. Este trabalho teve como objetivo avaliar o efeito de diferentes substratos, concentrações de AIB, e tipo de miniestaca, no enraizamento de Melaleuca alternifolia. No primeiro experimento foram testados os substratos, areia de granulometria média, Plantmax HT®, Golden-Mix® e vermiculita. No segundo experimento foram avaliadas diferentes concentrações de AIB (0, 500, 1000 e 2000 mg L-1, em dois tipos de miniestacas (apical e mediana. As miniestacas foram confeccionadas com 5 cm de comprimento, mantidas em casa de vegetação com nebulização intermitente, e, após 45 dias do plantio, foram avaliadas as porcentagens de miniestacas enraizadas, com calos e não responsivas, o número de raízes formadas por miniestaca e o comprimento das três maiores raízes (cm. O substrato Golden-Mix® e as miniestacas coletadas da porção apical do ramo submetidas ao tratamento com 500 mg L-1 de AIB apresentaram maior porcentagem de enraizamento e melhor qualidade do sistema radicial.Melaleuca alternifolia has as major product the essential oil extracted from its leaves due to its antifungal and antibacterial properties. There are scarce reports about the propagation of this species, and minicutting is an alternative for vegetative propagation of superior clones in order to establish a production field. This study aimed to evaluate the effect of different substrates, IBA levels and types of minicuttings on the rooting of Melaleuca alternifolia. In the first experiment, the following substrates were tested: medium sand, Plantmax HT®, Golden-Mix® and vermiculite. In the second experiment, different IBA levels (0, 500

  1. Effects of Melaleuca alternifolia (Tea Tree) Essential Oil and the Major Monoterpene Component Terpinen-4-ol on the Development of Single- and Multistep Antibiotic Resistance and Antimicrobial Susceptibility

    OpenAIRE

    Hammer, Katherine A.; Carson, Christine F.; Riley, Thomas V

    2012-01-01

    This study examined the effect of subinhibitory Melaleuca alternifolia (tea tree) essential oil on the development of antibiotic resistance in Staphylococcus aureus and Escherichia coli. Frequencies of single-step antibiotic-resistant mutants were determined by inoculating bacteria cultured with or without subinhibitory tea tree oil onto agar containing 2 to 8 times the MIC of each antibiotic and with or without tea tree oil. Whereas most differences in resistance frequencies were relatively ...

  2. Comparative evaluation of co-enzyme Q10 and Melaleuca alternifolia as antioxidant gels in treatment of chronic periodontitis: A clinical study

    OpenAIRE

    Chetan Purushottam Raut; Kunal S Sethi

    2016-01-01

    Background: Conventional nonsurgical periodontal therapy has been proven to be an effective treatment for patients with chronic periodontitis. Coenzyme Q10 and tea tree oil (TTO) are known to have potential therapeutic benefits in chronic periodontitis. Aims: The aim of the study is to compare the efficacy of Coenzyme Q10 (Perio Q® ) and tea tree oil (Melaleuca alternifolia) gel as an adjunct to scaling and root planing in the treatment of chronic periodontitis. Materials and Methods: Patient...

  3. Mechanism of Action of Melaleuca alternifolia (Tea Tree) Oil on Staphylococcus aureus Determined by Time-Kill, Lysis, Leakage, and Salt Tolerance Assays and Electron Microscopy

    OpenAIRE

    Carson, Christine F.; Mee, Brian J.; Riley, Thomas V

    2002-01-01

    The essential oil of Melaleuca alternifolia (tea tree) has broad-spectrum antimicrobial activity. The mechanisms of action of tea tree oil and three of its components, 1,8-cineole, terpinen-4-ol, and α-terpineol, against Staphylococcus aureus ATCC 9144 were investigated. Treatment with these agents at their MICs and two times their MICs, particularly treatment with terpinen-4-ol and α-terpineol, reduced the viability of S. aureus. None of the agents caused lysis, as determined by measurement ...

  4. Influence of Host Plant Species and Flush Growth Stage on the Asian Citrus Psyllid, Diaphorina citri Kuwayama

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    Stephen L.C. Teck

    2011-01-01

    Full Text Available Problem statement: In order to establish the important host range of D. citri, the performance of this psyllid on different rutacous host plants was assessed. Apparent regional differences in host preferences of D. citri as noted above and the need for empirical knowledge of its host preferences in Malaysia where it is lacking. Approach: Experiments on host plant preference between citrus, jasmine orange and curry leaf were conducted over a period of 14 days in the field cage in October 1998 at the agricultural research centre, Semonggok, 15 km from Kuching, Kuching Division, Sarawak in Malaysia. Results: A comparative life cycle study of the Asian Citrus Psyllid Diaphorina citri Kuwayama on three different Rutaceous plant hosts namely citrus, jasmine orange and curry leaf plants was conducted inside the temperature controlled growth chamber maintain at 26 ± 1°C temperature, 75-80% relative humidity with artificial illumination intensity of 10,000 lux equipped with a photoperiod of 14:10 h light: dark regime to permit normal growth. Conclusion: The screenhouse studies confirmed that D. citri can colonise and breed on citrus, jasmine orange and curry leaf plant and that jasmine orange is the preferred host. It is also confirmed that females prefer to oviposit on immature flush 3-10 mm in length. In growth chamber experiments the life cycle of the psyllid was 18.5 days on jasmine orange, 19.0 days on citrus and 23.0 days on curry leaf.

  5. Living on the Edges: Spatial Niche Occupation of Asian Citrus Psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae, in Citrus Groves.

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    Mamoudou Sétamou

    Full Text Available 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 edge effect in D. citri distribution in the groves. D. citri densities and infestation levels gradually declined from the edge to the center of grove. Higher numbers of D. citri were recorded on trees located on the east and south sides of the groves than those on the west and north sides. Citrus groves located at the outer edge of the study with at least one side non-surrounded to other citrus groves harbored significantly more D. citri than groves located within the block cluster and entirely surrounded by other groves. In detailed field studies during 2012, infestation of D. citri started from border trees in the grove where possibly one generation is completed before inner trees become infested. In addition, psyllid densities decreased significantly with increasing distance from the grove edge. Using the selection index, D citri exhibited a strong niche occupation preference for border trees.

  6. Acquisition, Replication and Inoculation of Candidatus Liberibacter asiaticus following Various Acquisition Periods on Huanglongbing-Infected Citrus by Nymphs and Adults of the Asian Citrus Psyllid.

    Science.gov (United States)

    Ammar, El-Desouky; Ramos, John E; Hall, David G; Dawson, William O; Shatters, Robert G

    2016-01-01

    The Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae), is the primary vector of Candidatus Liberibacter asiaticus (Las) implicated as causative agent of citrus huanglongbing (citrus greening), currently the most serious citrus disease worldwide. Las is transmitted by D. citri in a persistent-circulative manner, but the question of replication of this bacterium in its psyllid vector has not been resolved. Thus, we studied the effects of the acquisition access period (AAP) by nymphs and adults of D. citri on Las acquisition, multiplication and inoculation/transmission. D. citri nymphs or adults (previously non-exposed to Las) were caged on Las-infected citrus plants for an AAP of 1, 7 or 14 days. These 'Las-exposed' psyllids were then transferred weekly to healthy citrus or orange jasmine plants, and sampled via quantitative polymerase chain reaction (qPCR) analysis 1-42 days post-first access to diseased plants (padp); all tested nymphs became adults 7-14 days padp. Our results indicate that following 1 or 7 day AAP as nymphs 49-59% of Las-exposed psyllids became Las-infected (qPCR-positive), whereas only 8-29% of the psyllids were infected following 1-14 day AAP as adults. Q-PCR analysis also indicated that Las titer in the Las-exposed psyllids (relative to that of the psyllid S20 ribosomal protein gene) was: 1) significantly higher, and increasing at a faster rate, following Las acquisition as nymphs compared to that following Las acquisition as adults; 2) higher as post-acquisition time of psyllids on healthy plants increased reaching a peak at 14-28 days padp for nymphs and 21-35 days padp for adults, with Las titer decreasing or fluctuating after that; 3) higher with longer AAP on infected plants, especially with acquisition as adults. Our results strongly suggest that Las multiplies in both nymphs and adults of D. citri but attains much higher levels in a shorter period of time post-acquisition when acquired by nymphs than when acquired by adults

  7. Acquisition, Replication and Inoculation of Candidatus Liberibacter asiaticus following Various Acquisition Periods on Huanglongbing-Infected Citrus by Nymphs and Adults of the Asian Citrus Psyllid.

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    El-Desouky Ammar

    Full Text Available The Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae, is the primary vector of Candidatus Liberibacter asiaticus (Las implicated as causative agent of citrus huanglongbing (citrus greening, currently the most serious citrus disease worldwide. Las is transmitted by D. citri in a persistent-circulative manner, but the question of replication of this bacterium in its psyllid vector has not been resolved. Thus, we studied the effects of the acquisition access period (AAP by nymphs and adults of D. citri on Las acquisition, multiplication and inoculation/transmission. D. citri nymphs or adults (previously non-exposed to Las were caged on Las-infected citrus plants for an AAP of 1, 7 or 14 days. These 'Las-exposed' psyllids were then transferred weekly to healthy citrus or orange jasmine plants, and sampled via quantitative polymerase chain reaction (qPCR analysis 1-42 days post-first access to diseased plants (padp; all tested nymphs became adults 7-14 days padp. Our results indicate that following 1 or 7 day AAP as nymphs 49-59% of Las-exposed psyllids became Las-infected (qPCR-positive, whereas only 8-29% of the psyllids were infected following 1-14 day AAP as adults. Q-PCR analysis also indicated that Las titer in the Las-exposed psyllids (relative to that of the psyllid S20 ribosomal protein gene was: 1 significantly higher, and increasing at a faster rate, following Las acquisition as nymphs compared to that following Las acquisition as adults; 2 higher as post-acquisition time of psyllids on healthy plants increased reaching a peak at 14-28 days padp for nymphs and 21-35 days padp for adults, with Las titer decreasing or fluctuating after that; 3 higher with longer AAP on infected plants, especially with acquisition as adults. Our results strongly suggest that Las multiplies in both nymphs and adults of D. citri but attains much higher levels in a shorter period of time post-acquisition when acquired by nymphs than when acquired by

  8. Influence of carrot psyllid (Trioza apicalis) feeding or exogenous limonene or methyl jasmonate treatment on composition of carrot (Daucus carota) leaf essential oil and headspace volatiles.

    Science.gov (United States)

    Nissinen, Anne; Ibrahim, Mohamed; Kainulainen, Pirjo; Tiilikkala, Kari; Holopainen, Jarmo K

    2005-11-02

    The effect of carrot psyllid (Trioza apicalis Förster) feeding and limonene and methyl jasmonate (MeJA) treatments on the essential oil composition and headspace volatiles of carrot (Daucus carota ssp. sativus), cvs. Parano and Splendid, leaves was studied. Carrot psyllid feeding significantly increased the concentrations of sabinene, beta-pinene, and limonene, whereas limonene treatment increased the concentration of (Z)-beta-ocimene in the leaves of both cultivars. The limonene treatment significantly increased the concentration of total phenolics in the leaves of both cultivars, and MeJA treatment increased phenolic concentration in the leaves of Parano. Exogenous limonene spray did not decrease the number of carrot psyllid eggs laid either 2 or 24 h after treatment. The results suggest that carrot psyllid feeding induces changes in the endogenous monoterpene pool in the carrot leaves. Limonene and MeJA treatments affect some induced defenses of the carrot, but the exogenous limonene spray is not an effective oviposition deterrent against carrot psyllid.

  9. Innate and Conditioned Responses to Chemosensory and Visual Cues in Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae, Vector of Huanglongbing Pathogens

    Directory of Open Access Journals (Sweden)

    Joseph M. Patt

    2014-11-01

    Full Text Available 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 from host and non-host-plant sources. Response was measured as the frequency of salivary sheaths, the residue of psyllid probing activity, in a line of emulsified wax on the surface of a test arena. The psyllids displayed both appetitive and aversive conditioning to two different chemosensory stimuli. They could also be conditioned to recognize a blue-colored probing substrate and their response to neutral visual cues was enhanced by chemosensory stimuli. Conditioned psyllids were sensitive to the proportion of chemosensory components present in binary mixtures. Naïve psyllids displayed strong to moderate innate biases to several of the test compounds. While innate responses are probably the psyllid’s primary behavioral mechanism for selecting host-plants, conditioning may enhance its ability to select host-plants during seasonal transitions and dispersal.

  10. Study on Pharmacological Action of Aqueous Extract from Melaleuca Ahemifolia%互叶白千层水提物药理作用研究*

    Institute of Scientific and Technical Information of China (English)

    李燕婧; 钟正贤; 林霄; 刘布鸣

    2013-01-01

      目的:观察互叶白千层水提物的药理作用。方法:采用巴豆油致小鼠耳廓肿胀法、微量2倍稀释法、小鼠热板法、小鼠被动皮肤过敏试验、豚鼠磷酸组胺致痒试验等试验方法观察互叶白千层水提物的药理作用,并对其进行急性毒性试验。结果:互叶白千层水提物能抑制巴豆油引起小鼠耳廓肿胀;提高小鼠热刺激疼痛的痛阈值;对金黄色葡萄球菌、表皮葡萄球菌、大肠埃希杆菌、白色念珠菌有较强抑菌作用;抑制小鼠被动皮肤通透性;增加豚鼠耐受磷酸组胺的致痒阈;互叶白千层水提物的最大给药量为225.62 g生药/kg。结论:互叶白千层水提物具有抗炎、镇痛、抗菌、抗过敏、止痒等药理作用,且毒性小。%Objective: To observe the pharmacological action of aqueous extract from Melaleuca Ahemifolia. Methods: The experiments concluded mice ear-swollen induced by croton oil, double broth dilution method, hot plate test, passive cutaneous anaphylaxis (PCA)in mouse, cavy itch test by histamine phosphate and acute toxicity test to observe the pharmacological action of aqueous extract from Melaleuca Ahemifolia. Results: Aqueous Extract from Melaleuca Ahemifolia can inhibit the mice ear-swollen induced by croton oil, enhance the threshold of pain in mice due to hot stimulation, provide obvious bacteriostatic ac-tion on staphylococcus aureus, staphylococcus epidermidis, bacillus coli and albicans Saccharomyces, reduce the PCA and im-prove cavy itch-threshold by histamine phosphate. The acute toxicity test showed that maximum tolerance of water extract of melaleuca alternifolia was 225.62 g crude drug/kg. Conclusion: Aqueous Extract from Melaleuca Ahemifolia can provide obvious anti-inflammatory, analgesic, antimicrobial, anti-allergic and antipruritic effects, with low toxicity.

  11. Emprego do óleo de Melaleuca alternifolia Cheel (Myrtaceae na odontologia: perspectivas quanto à utilização como antimicrobiano alternativo às doenças infecciosas de origem bucal Use of Melaleuca alternifolia Cheel (Myrtaceae oil in dentistry: perspectives on its use as alternative antimicrobial to infectious diseases of oral origin

    Directory of Open Access Journals (Sweden)

    A.C.M. Oliveira

    2011-01-01

    Full Text Available O interesse por medicamentos alternativos, principalmente daqueles provenientes de extratos naturais, tem aumentado nas últimas décadas. A Melaleuca alternifolia é um arbusto pertencente ao gênero Melaleuca, popularmente conhecida como "árvore de chá", cujo principal produto é o óleo essencial (TTO - tea tree oil, de grande importância medicinal por possuir comprovada ação bactericida e antifúngica contra diversos patógenos humanos. Em virtude da atividade terapêutica em diversas especialidades médicas, o TTO passou a ser empregado na área odontológica. Esta revisão de literatura foi realizada com o objetivo de discutir os ensaios já realizados com o TTO contra microrganismos relacionados à doença cárie, doença periodontal e problemas pulpares. O óleo de Melaleuca tem demonstrado boa ação antibacteriana in vitro contra microrganismos bucais, porém, pesquisas envolvendo o estudo do mecanismo de ação sobre as células microbianas ou estudos in vivo ainda são escassos e precisam ser realizados, já que esse produto pode ser útil na odontologia, seja na manutenção química da higiene ou prevenção de doenças bucais.The interest in alternative medicines, especially those from natural extracts, has increased in recent decades. Melaleuca alternifolia is a shrub belonging to the genus Melaleuca, popularly known as "tea tree", the main product of which is its essential oil (TTO - tea tree oil, of great medicinal importance for its proven bactericidal and antifungal activity against several human pathogens. By virtue of its therapeutic activity in various medical specialties, TTO is now used in dentistry. This literature review was conducted in order to discuss the tests already carried out with TTO against microorganisms related to dental caries, periodontal disease and pulpal problems. Melaleuca oil has shown good in vitro antibacterial activity against oral microorganisms; however, research involving the study of its

  12. Optimization of Extraction Conditions for Maximal Phenolic, Flavonoid and Antioxidant Activity from Melaleuca bracteata Leaves Using the Response Surface Methodology.

    Science.gov (United States)

    Hou, Wencheng; Zhang, Wei; Chen, Guode; Luo, Yanping

    2016-01-01

    Melaleuca bracteata is a yellow-leaved tree belonging to the Melaleuca genus. Species from this genus are known to be good sources of natural antioxidants, for example, the "tea tree oil" derived from M. alternifolia is used in food processing to extend the shelf life of products. In order to determine whether M. bracteata contains novel natural antioxidants, the components of M. bracteata ethanol extracts were analyzed by gas chromatography-mass spectrometry. Total phenolic and flavonoid contents were extracted and the antioxidant activities of the extracts evaluated. Single-factor experiments, central composite rotatable design (CCRD) and response surface methodology (RSM) were used to optimize the extraction conditions for total phenolic content (TPC) and total flavonoid content (TFC). Ferric reducing power (FRP) and 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH·) scavenging capacity were used as the evaluation indices of antioxidant activity. The results showed that the main components of M. bracteata ethanol extracts are methyl eugenol (86.86%) and trans-cinnamic acid methyl ester (6.41%). The single-factor experiments revealed that the ethanol concentration is the key factor determining the TPC, TFC, FRP and DPPH·scavenging capacity. RSM results indicated that the optimal condition of all four evaluation indices was achieved by extracting for 3.65 days at 53.26°C in 34.81% ethanol. Under these conditions, the TPC, TFC, FRP and DPPH·scavenging capacity reached values of 88.6 ± 1.3 mg GAE/g DW, 19.4 ± 0.2 mg RE/g DW, 2.37 ± 0.01 mM Fe2+/g DW and 86.0 ± 0.3%, respectively, which were higher than those of the positive control, methyl eugenol (FRP 0.97 ± 0.02 mM, DPPH·scavenging capacity 58.6 ± 0.7%) at comparable concentrations. Therefore, the extracts of M. bracteata leaves have higher antioxidant activity, which did not only attributed to the methyl eugenol. Further research could lead to the development of a potent new natural antioxidant.

  13. Repellent Activity of Botanical Oils against Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae).

    Science.gov (United States)

    Kuhns, Emily H; Martini, Xavier; Hoyte, Angel; Stelinski, Lukasz L

    2016-07-14

    The Asian citrus psyllid, Diaphorina citri Kuwayama, is the insect vector of the pathogen causing huanglongbing. We selected three botanical oils to evaluate behavioral activity against D. citri. In laboratory olfactometer assays, fir oil was repellent to D. citri females, while litsea and citronella oils elicited no response from D. citri females. In choice settling experiments, D. citri settled almost completely on control plants rather than on plants treated with fir oil at a 9.5 mg/day release rate. Therefore, we conducted field trials to determine if fir oil reduced D. citri densities in citrus groves. We found no repellency of D. citri from sweet orange resets that were treated with fir oil dispensers releasing 10.4 g/day/tree as compared with control plots. However, we found a two-week decrease in populations of D. citri as compared with controls when the deployment rate of these dispensers was doubled. Our results suggest that treatment of citrus with fir oil may have limited activity as a stand-alone management tool for D. citri and would require integration with other management practices.

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

    Science.gov (United States)

    Monzo, C; Qureshi, J A; Stansly, P A

    2014-10-01

    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 beneficial arthropod fauna in citrus agroecosystems. We evaluated effects of calendar sprays directed against this pest on natural enemy assemblages and used exclusion to estimate mortality they imposed on ACP populations in citrus groves. Predator exclusion techniques were used on nascent colonies of D. citri in replicated large untreated and sprayed plots of citrus during the four major flushing periods over 2 years. Population of spiders, arboreal ants and ladybeetles were independently assessed. Monthly sprays of recommended insecticides for control of ACP, adversely affected natural enemy populations resulting in reduced predation on ACP immature stages, especially during the critical late winter/early spring flush. Consequently, projected growth rates of the ACP population were greatest where natural enemies had been adversely affected by insecticides. Whereas, this result does not obviate the need for insecticidal control of ACP, it does indicate that even a selective regimen of sprays can impose as yet undetermined costs in terms of reduced biological control of this and probably other citrus pests.

  15. Odorants for surveillance and control of the Asian Citrus Psyllid (Diaphorina citri.

    Directory of Open Access Journals (Sweden)

    Iliano V Coutinho-Abreu

    Full Text Available BACKGROUND: 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. RESULTS: In this study, we performed single-unit electrophysiology to identify odorants that are strong activators, inhibitors, and prolonged activators of ACP odorant receptor neurons (ORNs. We identified a suite of odorants that activated the ORNs with high specificity and sensitivity, which may be useful in eliciting behavior such as attraction. In separate experiments, we also identified odorants that evoked prolonged ORN responses and antagonistic odorants able to suppress neuronal responses to activators, both of which can be useful in lowering attraction to hosts. In field trials, we tested the electrophysiologically identified activating odorants and identified a 3-odor blend that enhances trap catches by ∼230%. CONCLUSION: These findings provide a set of odorants that can be used to develop affordable and safe odor-based surveillance and masking strategies for this dangerous pest insect.

  16. Spatiotemporal dynamics of the Southern California Asian citrus psyllid (Diaphorina citri) invasion.

    Science.gov (United States)

    Bayles, Brett R; Thomas, Shyam M; Simmons, Gregory S; Grafton-Cardwell, Elizabeth E; Daugherty, Mathew P

    2017-01-01

    Biological invasions are governed by spatial processes that tend to be distributed in non-random ways across landscapes. Characterizing the spatial and temporal heterogeneities of the introduction, establishment, and spread of non-native insect species is a key aspect of effectively managing their geographic expansion. The Asian citrus psyllid (Diaphorina citri), a vector of the bacterium associated with huanglongbing (HLB), poses a serious threat to commercial and residential citrus trees. In 2008, D. citri first began expanding northward from Mexico into parts of Southern California. Using georeferenced D. citri occurrence data from 2008-2014, we sought to better understand the extent of the geographic expansion of this invasive vector species. Our objectives were to: 1) describe the spatial and temporal distribution of D. citri in Southern California, 2) identify the locations of statistically significant D. citri hotspots, and 3) quantify the dynamics of anisotropic spread. We found clear evidence that the spatial and temporal distribution of D. citri in Southern California is non-random. Further, we identified the existence of statistically significant hotspots of D. citri occurrence and described the anisotropic dispersion across the Southern California landscape. For example, the dominant hotspot surrounding Los Angeles showed rapid and strongly asymmetric spread to the south and east. Our study demonstrates the feasibility of quantitative invasive insect risk assessment with the application of a spatial epidemiology framework.

  17. Seasonal variation of natural mortality factors of the guava psyllid Triozoida limbata.

    Science.gov (United States)

    Semeão, A A; Martins, J C; Picanço, M C; Chediak, M; da Silva, E M; Silva, G A

    2012-12-01

    It is important to understand how components of the agroecosystem interfere with the attack of a pest species and their seasonality in order to use these components in IPM programs. This study focused on the evaluation of the seasonality of natural control factors associated with the guava psyllid Triozoida limbata (Enderlein) in Brazil. Life-table data were collected from an experimental guava orchard during four periods that roughly represented four seasons. Natural mortality was monitored daily through the immature stages, and the relative importance of each natural mortality factor and its seasonality was determined. Significant statistical differences were observed in the mortality during the four periods (P analysis (PCA) showed some trends in the relationship of natural control agents and weather conditions. For example, the occurrence of predatory wasps was positively correlated with temperature and occurrence of winds; the occurrence of syrphids and Psyllaephagus sp. were negatively correlated with temperature and winds; and the occurrence of other generalist predators were negatively correlated with the occurrence of rainfall and photoperiod. The results showed the importance of natural mortality factors for the management of T. limbata and their changes through the different seasons which should be considered when implementing IPM programs in guava orchards.

  18. Spatiotemporal dynamics of the Southern California Asian citrus psyllid (Diaphorina citri) invasion

    Science.gov (United States)

    Thomas, Shyam M.; Simmons, Gregory S.; Grafton-Cardwell, Elizabeth E.; Daugherty, Mathew P.

    2017-01-01

    Biological invasions are governed by spatial processes that tend to be distributed in non-random ways across landscapes. Characterizing the spatial and temporal heterogeneities of the introduction, establishment, and spread of non-native insect species is a key aspect of effectively managing their geographic expansion. The Asian citrus psyllid (Diaphorina citri), a vector of the bacterium associated with huanglongbing (HLB), poses a serious threat to commercial and residential citrus trees. In 2008, D. citri first began expanding northward from Mexico into parts of Southern California. Using georeferenced D. citri occurrence data from 2008–2014, we sought to better understand the extent of the geographic expansion of this invasive vector species. Our objectives were to: 1) describe the spatial and temporal distribution of D. citri in Southern California, 2) identify the locations of statistically significant D. citri hotspots, and 3) quantify the dynamics of anisotropic spread. We found clear evidence that the spatial and temporal distribution of D. citri in Southern California is non-random. Further, we identified the existence of statistically significant hotspots of D. citri occurrence and described the anisotropic dispersion across the Southern California landscape. For example, the dominant hotspot surrounding Los Angeles showed rapid and strongly asymmetric spread to the south and east. Our study demonstrates the feasibility of quantitative invasive insect risk assessment with the application of a spatial epidemiology framework. PMID:28278188

  19. Annotation of the Asian Citrus Psyllid Genome Reveals a Reduced Innate Immune System.

    Science.gov (United States)

    Arp, Alex P; Hunter, Wayne B; Pelz-Stelinski, Kirsten S

    2016-01-01

    Citrus production worldwide is currently facing significant losses due to citrus greening disease, also known as Huanglongbing. The citrus greening bacteria, Candidatus Liberibacter asiaticus (CLas), is a persistent propagative pathogen transmitted by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). Hemipterans characterized to date lack a number of insect immune genes, including those associated with the Imd pathway targeting Gram-negative bacteria. The D. citri draft genome was used to characterize the immune defense genes present in D. citri. Predicted mRNAs identified by screening the published D. citri annotated draft genome were manually searched using a custom database of immune genes from previously annotated insect genomes. Toll and JAK/STAT pathways, general defense genes Dual oxidase, Nitric oxide synthase, prophenoloxidase, and cellular immune defense genes were present in D. citri. In contrast, D. citri lacked genes for the Imd pathway, most antimicrobial peptides, 1,3-β-glucan recognition proteins (GNBPs), and complete peptidoglycan recognition proteins. These data suggest that D. citri has a reduced immune capability similar to that observed in A. pisum, P. humanus, and R. prolixus. The absence of immune system genes from the D. citri genome may facilitate CLas infections, and is possibly compensated for by their relationship with their microbial endosymbionts.

  20. Repellent Activity of Botanical Oils against Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae

    Directory of Open Access Journals (Sweden)

    Emily H. Kuhns

    2016-07-01

    Full Text Available The Asian citrus psyllid, Diaphorina citri Kuwayama, is the insect vector of the pathogen causing huanglongbing. We selected three botanical oils to evaluate behavioral activity against D. citri. In laboratory olfactometer assays, fir oil was repellent to D. citri females, while litsea and citronella oils elicited no response from D. citri females. In choice settling experiments, D. citri settled almost completely on control plants rather than on plants treated with fir oil at a 9.5 mg/day release rate. Therefore, we conducted field trials to determine if fir oil reduced D. citri densities in citrus groves. We found no repellency of D. citri from sweet orange resets that were treated with fir oil dispensers releasing 10.4 g/day/tree as compared with control plots. However, we found a two-week decrease in populations of D. citri as compared with controls when the deployment rate of these dispensers was doubled. Our results suggest that treatment of citrus with fir oil may have limited activity as a stand-alone management tool for D. citri and would require integration with other management practices.

  1. Emprego do óleo de Melaleuca alternifolia Cheel (Myrtaceae) na odontologia: perspectivas quanto à utilização como antimicrobiano alternativo às doenças infecciosas de origem bucal

    OpenAIRE

    Oliveira, A.C.M.; Fontana, A; Negrini, T.C.; Nogueira, M.N.M. [UNESP; Bedran, T.B.L.; de Andrade, C R; Spolidorio, L.C. [UNESP; Spolidorio, D.M.P.

    2011-01-01

    O interesse por medicamentos alternativos, principalmente daqueles provenientes de extratos naturais, tem aumentado nas últimas décadas. A Melaleuca alternifolia é um arbusto pertencente ao gênero Melaleuca, popularmente conhecida como "árvore de chá", cujo principal produto é o óleo essencial (TTO - tea tree oil), de grande importância medicinal por possuir comprovada ação bactericida e antifúngica contra diversos patógenos humanos. Em virtude da atividade terapêutica em diversas especialida...

  2. Effect of tea tree oil (Melaleuca alternifolia) on the longevity and immune response of rats infected by Trypanosoma evansi.

    Science.gov (United States)

    Baldissera, Matheus D; Da Silva, Aleksandro S; Oliveira, Camila B; Vaucher, Rodrigo A; Santos, Roberto C V; Duarte, Thiago; Duarte, Marta M M F; França, Raqueli T; Lopes, Sonia T A; Raffin, Renata P; Boligon, Aline A; Athayde, Margareth L; Stefani, Lenita M; Monteiro, Silvia G

    2014-06-01

    This study aimed to evaluate the effect of tea tree oil (TTO - Melaleuca alternifolia) on hepatic and renal functions, and the immune response of rats infected by Trypanosoma evansi. A pilot study has shown that rats treated with TTO orally (1 ml kg(-1)) had increased survival rate without curative effect. In order to verify if increased longevity was related to a better immune response against T. evansi when using tea tree oil, a second experiment was conducted. Thus, twenty-four rats were divided into four groups. The groups A and B were composed of uninfected animals, and the groups C and D had rats experimentally infected by T. evansi. Animals from the groups B and D were treated orally with TTO (1 ml kg(-1)) for three days. Blood samples were collected to verify humoral response analysis for immunoglobulins (IgA, IgM, IgE, and IgG) and cytokines (TNF-α, INF-γ, IL-1, IL-6, IL-4, and IL-10) at days 0, 3, 5 and 15 post-infection (PI). TTO treatment caused changes in the immunoglobulins and cytokines profile, as well as the course of T. evansi infection in rats. It was found that the TTO was not toxic, i.e., hepatic and renal functions were not affected. Therefore, it is possible to conclude that TTO influences the levels of inflammatory mediators and has trypanocidal effect, increasing life expectancy of rats infected by T. evansi.

  3. ENRAIZAMENTO DE MELALEUCA: INFLUÊNCIA DA ALTURA DE COLETA DAS ESTACAS E APLICAÇÃO DE IBA

    Directory of Open Access Journals (Sweden)

    Carlos André Stuepp

    2013-06-01

    Full Text Available Melaleuca alternifolia Cheel is an economically important medicinal plant. Its chemical constitution is well known, being rich in terpinen-4-ol, which is the main responsible for its medicinal properties. However, in this species is difficult to obtain good seedlings from seed germination, what makes the vegetative propagation benefic to its commercialization, maintaining the productive characteristics and quality of extracted oil. This study aimed to evaluate the rooting of tea tree cuttings, collected in the apical, middle and basal portions of the stock plant branches, and treated with different concentrations of indolebutyric acid (IBA. Cuttings with a length of 6 cm, with one third of the apex leaves and a bevel cutting on the base, were treated with hydroalcoholic solutions of IBA (0, 1500 and 3000 mg L-1 immersing the base for 10 seconds. In the sequence cuttings were planted in tubes containing vermiculite and placed in a greenhouse. After 91 days, the rooting percentage, number of roots, average length of roots, callus percentage, survival and mortality were evaluated. Percentage of rooting cuttings was less than 43.8%, and it was not influenced by the branch type or by tested IBA concentrations.

  4. Melaleuca alternifolia Essential Oil against the Lesser Mealworm (Alphitobius diaperinus and Its Possible Effect on the Soil Fauna

    Directory of Open Access Journals (Sweden)

    A Volpato

    2016-03-01

    Full Text Available ABSTRACT The aim of this study was to evaluate the in vitro bioactivity of tea tree (Melaleuca alternifolia essential oil against larvae and adult forms of lesser mealworms (Alphitobius diaperinus and its influence on the soil fauna. Tests were performed in triplicate using pure tea tree oil (TTO; 1, 5, 10, 25, 50, and 100%, TTO nanoparticles (1, 3, and 7.5%, or terpinen-4-ol, the main compound of the tea tree oil, at the same concentrations of TTO. Larvae and adult mortality occurred at concentrations up to 10 and 50% of TTO, respectively. No larvicidal or insecticidal effect of TTO nanoparticles was observed. Terpinen-4-ol showed insecticidal and larvicidal effect at concentrations higher than 25%. The evaluation of TTO effect on soil organisms was performed by standard ecotoxicological tests (ISO with the springtail species Folsomia candida. Only TTO was used for ecotoxicological tests in doses of 1, 5, 10, 25, 50, and 100 mg kg-1 of soil. TTO had no negative effects on F. candida survival or reproduction. Therefore, it was concluded that M. alternifolia oil may be a new alternative for control of the lesser mealworm.

  5. Essential oil of Melaleuca alternifolia for the treatment of oral candidiasis induced in an immunosuppressed mouse model.

    Science.gov (United States)

    de Campos Rasteiro, Vanessa Maria; da Costa, Anna Carolina Borges Pereira; Araújo, Cássia Fernandes; de Barros, Patrícia Pimentel; Rossoni, Rodnei Dennis; Anbinder, Ana Lia; Jorge, Antonio Olavo Cardoso; Junqueira, Juliana Campos

    2014-12-15

    The search for alternative therapies for oral candidiasis is a necessity and the use of medicinal plants seems to be one of the promising solutions. The objective of this study was to evaluate the in vitro and in vivo effects of the essential oil of Melaleuca alternifolia on Candida albicans. The minimum inhibitory concentration (MIC) and minimum biofilm eradication concentration (MBEC) of M. alternifolia were determined by the broth microdilution assay. For the in vivo study, twelve immunosuppressed mice with buccal candidiasis received topical applications of M. alternifolia with MBEC. After treatment, yeasts were recovered from the mice and quantified (CFU/mL). Mice were killed for morphologic analysis of the tongue dorsum by optical and scanning electron microscopy. Data were analyzed using Student's t test or Mann-Whitney test. The MIC of M. alternifolia was 0.195% and the MBEC was 12.5%. Treatment with M. alternifolia achieved a 5.33 log reduction in C. albicans and reduced the microscopic lesions of candidiasis. M. alternifolia oil at a 12.5% was effective to eradicate a C. albicans biofilm formed in vitro and to reduce yeasts of C. albicans in an immunosuppressed mouse model.

  6. Influence of organic matter, cations and surfactants on the antimicrobial activity of Melaleuca alternifolia (tea tree) oil in vitro.

    Science.gov (United States)

    Hammer, K A; Carson, C F; Riley, T V

    1999-03-01

    The effect of some potentially interfering substances and conditions on the antimicrobial activity of Melaleuca alternifolia (tea tree) oil was investigated. Agar and broth dilution methods were used to determine minimum inhibitory and cidal concentrations of tea tree oil in the presence and absence of each potentially interfering substance. Activity was determined against Gram-positive and -negative bacteria, and Candida albicans. Minimum inhibitory or cidal concentrations differed from controls by two or more dilutions, for one or more organisms, where Tween-20, Tween-80, skim-milk powder and bovine serum albumin were assessed. These differences were not seen when assays were performed in anaerobic conditions, or in the presence of calcium and magnesium ions. The effect of organic matter on the antimicrobial activity of tea tree oil was also investigated by an organic soil neutralization test. Organisms were exposed to lethal concentrations of tea tree oil ranging from 1-10% (v/v), in the presence of 1-30% (w/v) dry bakers' yeast. After 10 min contact time, viability was determined. At > or = 1%, organic matter compromised the activity of each concentration of tea tree oil against Staphylococcus aureus and C. albicans. At 10% or more, organic matter compromised the activity of each tea tree oil concentration against Pseudomonas aeruginosa. Organic matter affected 1 and 2% tea tree oil, but not 4 and 8%, against Escherichia coli. In conclusion, organic matter and surfactants compromise the antimicrobial activity of tea tree oil, although these effects vary between organisms.

  7. GROWTH PERFORMANCE, BIOMASS AND PHYTOEXTRACTION EFFICIENCY OF ACACIA MANGIUM AND MELALEUCA CAJUPUTI IN REMEDIATING HEAVY METAL CONTAMINATED SOIL

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    Shibli Nik Mohd

    2013-01-01

    Full Text Available Heavy metals are very toxic and soil contaminated with sewage sludge urgently need remediation in order to avoid related health hazards. Phytoremediation is a low cost and reliable technique to remediate heavy metal contamination. However phytoremediation using timber species was rarely reported and its efficiency was questionable. A field study was conducted to examine the efficiency of two timber species namely Acacia mangium and Melaleuca cajuputi in phytoextraction of Zn, Cu and Cd from contaminated soil. Two hundred of A. mangium and M. cajuputi were planted on sewage sludge disposal site and the growth was recorded for 12 months before at the end total biomass of each species was determined. Results show in 12 months, about 72 and 4 t ha-1 of aboveground biomass can be produced by A. mangium and M. cajuputi, respectively. Both species show potential for phytoremediation, however A. mangium is more efficient compared to M. cajuputi where efficiency of A. mangium to remove Zn was 24.4, 6.2 for Cu and 9.5% for Cd. As for M. cajuputi the efficiency was 1.3, 0.3 and 0.14% for Zn, Cu and Cd, respectively. It is projected that A. mangium require 5, 17 and 20 years to remove 79.82 kg ha-1 of Zn, 46.94 kg ha-1 of Cu and 2.33 kg ha-1 of Cd, respectively.

  8. Sclerenchymatous ring as a barrier to phloem feeding by Asian citrus psyllid: Evidence from electrical penetration graph and visualization of stylet pathways

    Science.gov (United States)

    Asian citrus psyllid (ACP) feeding behaviors play a significant role in the transmission of the phloem-limited Candidatus Liberibacter asiaticus (CLas) bacteria that cause citrus greening disease. Sustained phloem ingestion by ACP on CLas infected plants is very important in pathogen acquisition and...

  9. First Report of "Candidatus Liberibacter psyllaurous" (synonym "Ca. L. solanacearum") Associated with 'Tomato Vein-Greening' and 'Tomato psyllid yellows' Diseases in Commercial Greenhouses in Arizona

    Science.gov (United States)

    During 2006-2007, tomato plants in two independent, commercial greenhouses in Arizona were infested with potato psyllid Paratrioza cockerelli. Over 60% and ~20% of plants in GH-1 and GH-2, respectively, exhibited leaf curling, stunting, and shortened internodes, and GH-1 plants also showed vein-gree...

  10. Comparison of Potato and Asian Citrus Psyllid Adult and Nymph Transcriptomes Identified Vector Transcripts with Potential Involvement in Circulative, Propagative Liberibacter Transmission

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    Tonja W. Fisher

    2014-11-01

    Full Text Available 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 alternative approaches, including RNA interference to abate expression of genes essential for psyllid-mediated Ca. Liberibacter transmission. To identify genes with significantly altered expression at different life stages and conditions of CLso/CLas infection, cDNA libraries were constructed for CLso-infected and -uninfected PoP adults and nymphal instars. Illumina sequencing produced 199,081,451 reads that were assembled into 82,224 unique transcripts. PoP and the analogous transcripts from ACP adult and nymphs reported elsewhere were annotated, organized into functional gene groups using the Gene Ontology classification system, and analyzed for differential in silico expression. Expression profiles revealed vector life stage differences and differential gene expression associated with Liberibacter infection of the psyllid host, including invasion, immune system modulation, nutrition, and development.

  11. New geographic records for the Nearctic psyllid Bactericera maculipennis (Crawford) with biological notes and descriptions of the egg and fifth-instar nymph (Hemiptera: Psylloidea: Triozidae)

    Science.gov (United States)

    The Nearctic psyllid Bactericera maculipennis (Crawford) is one of only four known species of Psylloidea worldwide whose primary hosts are species of Convolvulaceae. Taxonomic syntheses of the Nearctic Psylloidea list B. maculipennis only from California and Utah. Our surveys of field bindweed, Co...

  12. Correlation of electronic monitoring and stylet pathways elucidate the role of sclerenchymatous ring as a barrier to phloem feeding on citrus leaves by Asian citrus psyllid

    Science.gov (United States)

    Asian citrus psyllid (ACP, Diaphorina. citri) feeding behaviors play a significant role in the transmission of the phloem-limited Candidatus Liberibacter asiaticus (CLas) bacterium that causes the economically devastating citrus greening disease. Recent studies have shown a fibrous ring of thick-wal...

  13. Titers of 'Ca. Liberibacter asiaticus' in Murraya paniculata and Murraya-reared Diaphorina citri are much lower than in citrus and citrus-reared psyllids

    Science.gov (United States)

    Huanglongbing, one of the most devastating diseases of citrus, is associated with the bacterium Candidatus Liberibacter asiaticus vectored by the Asian citrus psyllid, Diaphorina citri, in North America. Murraya paniculata is a common ornamental plant that is an alternate host of Ca. L. asiaticus an...

  14. Bionomics of Asian citrus psyllid (Hemiptera: Liviidae) associated with orange jasmine hedges in southest central Florida, with special reference to biological control by Tamarixia radiata

    Science.gov (United States)

    The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is an important pest in Florida because it vectors bacteria responsible for citrus huanglongbing disease. In addition to infesting citrus, orange jasmine (Murraya paniculata) is one of ACP’s favorite host plants and is widely grown as an orn...

  15. Bionomics of Asian citrus psyllid associated with orange jasmine hedges in Florida, with special reference to biological control by Tamarixia radiata

    Science.gov (United States)

    The Asian citrus psyllid (ACP) is an important invasive citrus pest because it vectors a bacterium responsible for a devastating disease of citrus known as huanglongbing. Orange jasmine (Murraya paniculata) is a favored alternate ACP host plant and is widely grown as an ornamental plant in urban ar...

  16. Retracted stylets in nymphs of the Asian citrus psyllid are held externally against the clypeus by a special paired organ not found in the adults

    Science.gov (United States)

    Differences in ultrastructure of the mouthparts in nymphs and adults of the Asian citrus psyllid Diaphorina citri (Hemiptera, Psyllidae), vector of the bacterium associated with citrus huanglongbing disease, were studied using scanning electron microscopy. The number of sensilla on the labial tip in...

  17. Cloning and expressing a highly functional and substrate specific farnesoic acid o-methyltransferase from the Asian citrus psyllid (Diaphorina citri Kuwayama)

    Science.gov (United States)

    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 juvenile hormone biosynthesis...

  18. Chemical control of the Asian citrus psyllid and of huanglongbing disease in citrus.

    Science.gov (United States)

    Boina, Dhana Raj; Bloomquist, Jeffrey R

    2015-06-01

    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-growing regions. Application of insecticides during the dormant winter season, along with cultivation of HLB-free seedlings and early detection and removal of symptomatic and asymptomatic trees, has been very effective in managing ACP. Area-wide management of ACP by application of insecticides at low volume in large areas of citrus cultivation has been shown to be effective in managing HLB and reducing management costs. As insecticide resistance is a major problem in sustainable management of ACP, rotation/alternation of insecticides with different chemistries and modes of action needs to be followed. Besides control of the insect vector, use of antibiotics has temporarily suppressed the symptoms of HLB in diseased trees. Recent efforts to discover and screen existing as well as new compounds for their antibiotic and antimicrobial activities have identified some promising molecules for HLB control. There is an urgent need to find a sustainable solution to the HLB menace through chemical control of ACP populations and within HLB-infected trees through the judicious use of labeled insecticides (existing and novel chemistries) and antibiotics in area-wide management programs with due consideration to the insecticide resistance problem. © 2014 Society of Chemical Industry.

  19. Sampling Methods for Detection and Monitoring of the Asian Citrus Psyllid (Hemiptera: Psyllidae).

    Science.gov (United States)

    Monzo, C; Arevalo, H A; Jones, M M; Vanaclocha, P; Croxton, S D; Qureshi, J A; Stansly, P A

    2015-06-01

    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 ratio was estimated using Taylor's power law and used to compare precision among sampling methods. Comparison of detection sensitivity and time expenditure (cost) between stem-tap and other sampling methodologies conducted consecutively at the same location were also assessed. Stem-tap sampling was the most efficient sampling method when ACP densities were moderate to high and served as the basis for comparison with all other methods. Protocols that grouped trees near randomly selected locations across the block were more efficient than sampling trees at random across the block. Sweep net sampling was similar to stem-taps in number of captures per sampled unit, but less precise at any ACP density. Yellow sticky traps were 14 times more sensitive than stem-taps but much more time consuming and thus less efficient except at very low population densities. Visual sampling was efficient for detecting and monitoring ACP at low densities. Suction sampling was time consuming and taxing but the most sensitive of all methods for detection of sparse populations. This information can be used to optimize ACP monitoring efforts.

  20. Germinação de sementes de Melaleuca quinquenervia em condições de estresse hídrico e salino Germination of Melaleuca quinquenervia seeds under water and salt stress conditions

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    C.C. Martins

    2011-03-01

    Full Text Available O comportamento invasivo de Melaleuca quinquenervia em áreas úmidas deve-se à sua estratégia de regeneração agressiva, que está alicerçada na produção de sementes em massa. O conhecimento da fisiologia da germinação de sementes de plantas daninhas pode contribuir significativamente para o desenvolvimento de estratégias de manejo. O objetivo deste trabalho foi avaliar os possíveis efeitos dos estresses hídrico e salino na germinação de sementes de M. quinquenervia. A semeadura foi realizada com quatro repetições de 0,05 g de sementes em papel umedecido com soluções nos potenciais osmóticos de 0,0; -0,2; -0,4; e -0,8 MPa, induzidos com polietilenoglicol (PEG 6000 e NaCl. O teste de germinação foi conduzido a 25 ºC na presença de luz. Avaliou-se a primeira contagem do teste aos sete dias após a semeadura e, semanalmente, a germinação (plântulas normais até os 28 dias. Foi calculado o índice de velocidade de germinação. A análise dos resultados permitiu a conclusão de que o estresse hídrico acarreta maior redução na velocidade de germinação e na germinação acumulada de sementes de M. quinquenervia do que o estresse salino e, independentemente da substância utilizada para indução do estresse, o limite para germinação está entre -0,4 e -0,8MPa.The invasive behavior of Melaleuca quinquenervia in wetlands seems attributable to its inherently aggressive regeneration strategies associated to massive seed production. The knowledge of the germination physiology of weed seeds can contribute significantly to the development of strategies for their management. This work aimed to evaluate the possible effects of water and salt stress on the germination of M. quinquenervia seeds. Four replications with 0.05 g of seeds were sown in paper moistened with solutions with the potential of 0.0; -0.2; -0.4 and -0.8 MPa, induced with polyethylene glycol (PEG 6000 and NaCl. Germination test was carried out at 25 ºC in the

  1. Análise econômica do cultivo e extração do óleo essencial de Melaleuca alternifolia Cheel Economic analysis of the cultivation and extraction of the essential oil of Melaleuca alternifolia Cheel

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    Ciro de Castro

    2005-04-01

    Full Text Available Este trabalho estudou a viabilidade econômica do cultivo e extração do óleo essencial de um plantio de Melaleuca alternifolia Cheel. Foi realizado um levantamento dos rendimentos e custos da cultura das atividades de produção de mudas, implantação, manutenção, colheita, transporte e extração do óleo essencial, bem como as receitas. A análise econômica foi realizada utilizando-se os seguintes indicadores econômicos: Valor Presente Líquido, Razão Benefício/Custo, Taxa Interna de Retorno, Valor Anual Equivalente e Custo Médio de Produção. Posteriormente foi feita uma análise de sensibilidade, utilizando-se a técnica de simulação de Monte Carlo, por meio do software @Risk. Uma vez reunidos e analisados os dados, fixaram-se parâmetros mínimos, médios e máximos para as distribuições de probabilidade triangular dos custos de implantação, manutenção, colheita, destilação e da receita, oriundos do projeto de produção do óleo essencial, permitindo uma melhor avaliação dos indicadores econômicos perante a análise de riscos. Como resultado, obteve-se um rendimento de 81,82 L de óleo essencial por ha por ano, conseqüentemente um lucro anual de R$497,18 por hectare, enquanto a análise de sensibilidade apresentou uma baixa probabilidade de a atividade tornar-se inviável economicamente.This paper describes the study of the economic viability of cultivation and essential oil extraction of Melaleuca alternifolia Cheel. An assessment was made of profits and costs for activities of seedling production, implantation, maintenance, harvesting, transport and essential oil extraction, as well as revenues. The economic analysis was accomplished using the following economic indicators: Net Present Value, Benefit/Cost Ratio, Internal Return Rate, Equivalent Annual Value and Average Cost of Production. Then a sensibility analysis was performed using the simulation technique of Monte Carlo _ software @Risk. Once data were

  2. Silencing abnormal wing disc gene of the Asian citrus psyllid, Diaphorina citri disrupts adult wing development and increases nymph mortality.

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    Ibrahim El-Shesheny

    Full Text Available 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 flight of psyllids. Our study showed that transcription of awd is development-dependent and the highest level was found in the last instar (5(th of the nymphal stage. Micro-application (topical application of dsRNA to 5(th instar of nymphs caused significant nymphal mortality and adult wing-malformation. These adverse effects in ACP were positively correlated with the amounts of dsRNA used. A qRT-PCR analysis confirmed the dsRNA-mediated transcriptional down-regulation of the awd gene. Significant down-regulation was required to induce a wing-malformed phenotype. No effect was found when dsRNA-gfp was used, indicating the specific effect of dsRNA-awd. Our findings suggest a role for awd in ACP wing development and metamorphosis. awd could serve as a potential target for insect management either via direct application of dsRNA or by producing transgenic plants expressing dsRNA-awd. These strategies will help to mitigate HLB by controlling ACP.

  3. Digital Gene Expression Analysis of Ponkan Mandarin (Citrus reticulata Blanco) in Response to Asia Citrus Psyllid-Vectored Huanglongbing Infection.

    Science.gov (United States)

    Zhong, Yun; Cheng, Chunzhen; Jiang, Bo; Jiang, Nonghui; Zhang, Yongyan; Hu, Minlun; Zhong, Guangyan

    2016-07-02

    Citrus Huanglongbing (HLB), the most destructive citrus disease, can be transmitted by psyllids and diseased budwoods. Although the final symptoms of the two main HLB transmission ways were similar and hard to distinguish, the host responses might be different. In this study, the global gene changes in leaves of ponkan (Citrus reticulata) mandarin trees following psyllid-transmission of HLB were analyzed at the early symptomatic stage (13 weeks post inoculation, wpi) and late symptomatic stage (26 wpi) using digital gene expression (DGE) profiling. At 13 wpi, 2452 genes were downregulated while only 604 genes were upregulated in HLB infected ponkan leaves but no pathway enrichment was identified. Gene function analysis showed impairment in defense at the early stage of infection. At late stage of 26 wpi, however, differentially expressed genes (DEGs) involved in carbohydrate metabolism, plant defense, hormone signaling, secondary metabolism, transcription regulation were overwhelmingly upregulated, indicating that the defense reactions were eventually activated. The results indicated that HLB bacterial infection significantly influenced ponkan gene expression, and a delayed response of the host to the fast growing bacteria might be responsible for its failure in fighting against the bacteria.

  4. Digital Gene Expression Analysis of Ponkan Mandarin (Citrus reticulata Blanco in Response to Asia Citrus Psyllid-Vectored Huanglongbing Infection

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    Yun Zhong

    2016-07-01

    Full Text Available Citrus Huanglongbing (HLB, the most destructive citrus disease, can be transmitted by psyllids and diseased budwoods. Although the final symptoms of the two main HLB transmission ways were similar and hard to distinguish, the host responses might be different. In this study, the global gene changes in leaves of ponkan (Citrus reticulata mandarin trees following psyllid-transmission of HLB were analyzed at the early symptomatic stage (13 weeks post inoculation, wpi and late symptomatic stage (26 wpi using digital gene expression (DGE profiling. At 13 wpi, 2452 genes were downregulated while only 604 genes were upregulated in HLB infected ponkan leaves but no pathway enrichment was identified. Gene function analysis showed impairment in defense at the early stage of infection. At late stage of 26 wpi, however, differentially expressed genes (DEGs involved in carbohydrate metabolism, plant defense, hormone signaling, secondary metabolism, transcription regulation were overwhelmingly upregulated, indicating that the defense reactions were eventually activated. The results indicated that HLB bacterial infection significantly influenced ponkan gene expression, and a delayed response of the host to the fast growing bacteria might be responsible for its failure in fighting against the bacteria.

  5. Study on the Quality Standard of Essential Oil of 1,8-cineole Rich Melaleuca alterni f olia%1,8-桉叶素型互叶白千层精油的质量标准研究

    Institute of Scientific and Technical Information of China (English)

    杨辉; 刘布鸣; 韦刚; 林霄; 柴玲; 莫建光; 白懋嘉

    2011-01-01

    The essential oil of 1, 8-cineole rich Melaleuca alternifolia was extracted from Melaleuca alternifolia leaves by steam distillation. The TLC method was adopted to analyze and identify the oil and GC-FID was used to determine the relative content of main components in the oil. Comparing with the standard of tea tree oil, we gave the quality standard proposal of the oil of 1,8-cineole rich Melaleuca alternifolia , which provided references for the development and research of the oil of 1,8-cineole rich Melaleuca alternifolia .%用水蒸气蒸馏法提取1,8-桉叶素型互叶白干层精油,通过薄层色谱法对其进行定性鉴别,并采用气相色谱测定不同产地精油中的主要成分.结合茶树油标准,提出1.8-桉叶素型互叶白干层精油的质量标准的建议,为1,8-桉叶素型互叶白千层精油的开发、研究提供参考依据.

  6. Transmission Rates of ‘Ca. Liberibacter asiaticus’ by Asian Citrus Psyllid Are Enhanced by the Presence and Developmental Stage of Citrus Flush.

    Science.gov (United States)

    Hall, David G; Albrecht, Ute; Bowman, Kim D

    2016-04-01

    Asian citrus psyllid (Diaphorina citri Kuwayama) transmits a bacterium ‘Candidatus Liberibacter asiaticus’ (CLas) putatively responsible for a devastating citrus disease known as Asiatic huanglongbing (HLB) (citrus greening disease). The psyllid and disease have invaded many citrus-growing regions including the United States, where the disease is seriously jeopardizing the Florida citrus industry. We recently concluded research that showed CLas transmission rates are increased when citrus flush is present. Flush is any new leaf growth ranging in development from first emergence up until the leaves are fully expanded yet still tender. In an experiment with seedlings of a rootstock cultivar ‘US-942’, a 1-wk infestation of 20 Asian citrus psyllids from an infected colony resulted in 53–60% of seedlings becoming infected when flush was present compared with only 7% when no flush was present. In a second experiment with ‘US-942’, 77–97% of seedlings became infected when flush was present compared with 40% when no flush was present. A similar experiment with ‘Valencia’ sweet orange resulted in 23, 80, and 3% seedlings becoming infected when young, older, or no flush was present, respectively. Young plants are therefore more likely to contract HLB if flush is present, with older flush promoting higher infection rates under the conditions of this study. Based on this finding, healthy citrus should be protected from Asian citrus psyllid infestations throughout a flush. To evaluate germplasm for CLas resistance, inoculations using infected Asian citrus psyllid would best be achieved if flush is present.

  7. 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.

    Science.gov (United States)

    Coy, M R; Hoffmann, M; Kingdom Gibbard, H N; Kuhns, E H; Pelz-Stelinski, K S; Stelinski, L L

    2014-07-01

    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 false-negative rate of the 16S presence/absence qPCR assay was greater than 50%. Studies to determine the performance parameters of the qPCR assays for CLas 16S and Wingless (Wg), the D. citri endogenous gene, using plasmid and psyllid DNA, revealed suboptimal and variable performance of the 16S assay in psyllid samples. Average efficiencies and sensitivity limits of the plasmid assays were 99.0% and 2.7 copies of template for Wg, respectively, and 98.5% and 2.2-22.1 copies for 16S, respectively. Variability in efficiency was significantly greater in psyllid samples for both gene targets compared to the corresponding plasmid assays, and efficiencies as low as 76% were obtained for 16S. A secondary structure analysis revealed the formation of two stem-loop structures that block the forward and probe binding sites in the 16S template, which could hinder amplification. In summary, our results suggest that suboptimal qPCR efficiency is not uncommon for the 16S presence/absence qPCR assay, which combined with lowCLas titers in some samples, could contribute significantly to the under-reporting of CLas infection in psyllid and plant samples.

  8. Asian Citrus Psyllid Expression Profiles Suggest Candidatus Liberibacter Asiaticus-Mediated Alteration of Adult Nutrition and Metabolism, and of Nymphal Development and Immunity.

    Science.gov (United States)

    Vyas, Meenal; Fisher, Tonja W; He, Ruifeng; Nelson, William; Yin, Guohua; Cicero, Joseph M; Willer, Mark; Kim, Ryan; Kramer, Robin; May, Greg A; Crow, John A; Soderlund, Carol A; Gang, David R; Brown, Judith K

    2015-01-01

    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-protein interactions essential for ACP-mediated CLas invasion and transmission. To identify psyllid interactor-bacterial effector combinations associated with psyllid-CLas interactions, cDNA libraries were constructed from CLas-infected and CLas-free ACP adults and nymphs, and analyzed for differential expression. Library assemblies comprised 24,039,255 reads and yielded 45,976 consensus contigs. They were annotated (UniProt), classified using Gene Ontology, and subjected to in silico expression analyses using the Transcriptome Computational Workbench (TCW) (http://www.sohomoptera.org/ACPPoP/). Functional-biological pathway interpretations were carried out using the Kyoto Encyclopedia of Genes and Genomes databases. Differentially expressed contigs in adults and/or nymphs represented genes and/or metabolic/pathogenesis pathways involved in adhesion, biofilm formation, development-related, immunity, nutrition, stress, and virulence. Notably, contigs involved in gene silencing and transposon-related responses were documented in a psyllid for the first time. This is the first comparative transcriptomic analysis of ACP adults and nymphs infected and uninfected with CLas. The results provide key initial insights into host-parasite interactions involving CLas effectors that contribute to invasion-virulence, and to host nutritional exploitation and immune-related responses that appear to be essential for successful ACP-mediated circulative, propagative CLas transmission.

  9. Molecular and physiological properties associated with zebra complex disease in potatoes and its relation with Candidatus Liberibacter contents in psyllid vectors.

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    Veria Y Alvarado

    Full Text Available Zebra complex (ZC disease on potatoes is associated with Candidatus Liberibacter solanacearum (CLs, an α-proteobacterium that resides in the plant phloem and is transmitted by the potato psyllid Bactericera cockerelli (Šulc. The name ZC originates from the brown striping in fried chips of infected tubers, but the whole plants also exhibit a variety of morphological features and symptoms for which the physiological or molecular basis are not understood. We determined that compared to healthy plants, stems of ZC-plants accumulate starch and more than three-fold total protein, including gene expression regulatory factors (e.g. cyclophilin and tuber storage proteins (e.g., patatins, indicating that ZC-affected stems are reprogrammed to exhibit tuber-like physiological properties. Furthermore, the total phenolic content in ZC potato stems was elevated two-fold, and amounts of polyphenol oxidase enzyme were also high, both serving to explain the ZC-hallmark rapid brown discoloration of air-exposed damaged tissue. Newly developed quantitative and/or conventional PCR demonstrated that the percentage of psyllids in laboratory colonies containing detectable levels of CLs and its titer could fluctuate over time with effects on colony prolificacy, but presumed reproduction-associated primary endosymbiont levels remained stable. Potato plants exposed in the laboratory to psyllid populations with relatively low-CLs content survived while exposure of plants to high-CLs psyllids rapidly culminated in a lethal collapse. In conclusion, we identified plant physiological biomarkers associated with the presence of ZC and/or CLs in the vegetative potato plant tissue and determined that the titer of CLs in the psyllid population directly affects the rate of disease development in plants.

  10. Effect of Cyantraniliprole, a Novel Insecticide, on the Inoculation of Candidatus Liberibacter Asiaticus Associated with Citrus Huanglongbing by the Asian Citrus Psyllid (Hemiptera: Liviidae).

    Science.gov (United States)

    Ammar, El-Desouky; Hall, David G; Alvarez, Juan M

    2015-04-01

    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 excised healthy citrus leaves with dry residues of cyantraniliprole (Exirel), a novel insecticide, in comparison with fenpropathrin (Danitol 2.4EC), an insecticide commonly used against D. citri. Fewer adults settled (putatively feeding or probing) on leaves treated with cyantraniliprole than those treated with fenpropathrin or water controls. Also, psyllid adults died at a slower rate on leaves treated with cyantraniliprole than those treated with fenpropathrin, although the final cumulative mortality did not differ between the two treatments. In quantitative real-time polymerase chain reaction tests, 59.0-65.3% of the CLas-exposed psyllid adults were proven to be CLas-positive. Inoculation rates of CLas (using 10 adults per leaf) into untreated healthy citrus leaves (47.5-85%) were significantly higher than rates into leaves treated with cyantraniliprole or fenpropathrin (2.5-12.5%). Reduced inoculation rates to leaves treated with cyantraniliprole probably occurred as a result of reduced feeding or probing by D. citri. The excised leaf assay method, which took only a few weeks compared with up to a year or longer using whole plants, can be an effective tool for testing the effect of new pesticides or other treatments in reducing CLas inoculation or transmission by psyllid vectors. Published by Oxford University Press on behalf of Entomological Society of America 2015. This work is written by a US Government employees and is in the public domain in the US.

  11. Asian Citrus Psyllid Expression Profiles Suggest Candidatus Liberibacter Asiaticus-Mediated Alteration of Adult Nutrition and Metabolism, and of Nymphal Development and Immunity.

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    Meenal Vyas

    Full Text Available 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-protein interactions essential for ACP-mediated CLas invasion and transmission. To identify psyllid interactor-bacterial effector combinations associated with psyllid-CLas interactions, cDNA libraries were constructed from CLas-infected and CLas-free ACP adults and nymphs, and analyzed for differential expression. Library assemblies comprised 24,039,255 reads and yielded 45,976 consensus contigs. They were annotated (UniProt, classified using Gene Ontology, and subjected to in silico expression analyses using the Transcriptome Computational Workbench (TCW (http://www.sohomoptera.org/ACPPoP/. Functional-biological pathway interpretations were carried out using the Kyoto Encyclopedia of Genes and Genomes databases. Differentially expressed contigs in adults and/or nymphs represented genes and/or metabolic/pathogenesis pathways involved in adhesion, biofilm formation, development-related, immunity, nutrition, stress, and virulence. Notably, contigs involved in gene silencing and transposon-related responses were documented in a psyllid for the first time. This is the first comparative transcriptomic analysis of ACP adults and nymphs infected and uninfected with CLas. The results provide key initial insights into host-parasite interactions involving CLas effectors that contribute to invasion-virulence, and to host nutritional exploitation and immune-related responses that appear to be essential for successful ACP-mediated circulative, propagative CLas

  12. Influence of field attack by carrot psyllid (Trioza apicalis Förster) on sensory quality, antioxidant capacity and content of terpenes, falcarindiol and 6-methoxymellein of carrots (Daucus carota L.).

    Science.gov (United States)

    Seljåsen, Randi; Vogt, Gjermund; Olsen, Elisabeth; Lea, Per; Høgetveit, Lars Arne; Tajet, Torgeir; Meadow, Richard; Bengtsson, Gunnar B

    2013-03-20

    The effect of different degrees of attack by carrot psyllid (Trioza apicalis) on quality parameters of carrots was studied in field experiments for two years. Treatments were different degrees of physical insect protection by floating row cover. An increasing attack level of psyllids showed an enhancement effect on the antioxidant capacity (ORAC), content of falcarindiol, 6-methoxymellein, and terpenes, and scores for bitter taste, chemical flavor, terpene flavor, and toughness. Carrot psyllid attack decreased the yield, total sugar, fructose, glucose, and sensory attributes sweet taste, color hue, color strength, crispiness, and juiciness. Carrot plants at 8-10 weeks of age tolerated attack by psyllids at low levels (2% leaves with curling or discoloration).

  13. In vitro effects of Melaleuca alternifolia essential oil on growth and production of volatile sulphur compounds by oral bacteria

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    GRAZIANO, Talita Signoreti; CALIL, Caroline Morini; SARTORATTO, Adilson; FRANCO, Gilson César Nobre; GROPPO, Francisco Carlos; COGO-MÜLLER, Karina

    2016-01-01

    ABSTRACT Objective Halitosis can be caused by microorganisms that produce volatile sulphur compounds (VSCs), which colonize the surface of the tongue and subgingival sites. Studies have reported that the use of natural products can reduce the bacterial load and, consequently, the development of halitosis. The aim of this study was to evaluate the antimicrobial activity of the essential oil of Melaleuca alternifolia on the growth and volatile sulphur compound (VSC) production of oral bacteria compared with chlorhexidine. Material and Methods The effects of these substances were evaluated by the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) in planktonic cultures of Porphyromonas gingivalis and Porphyromonas endodontalis. In addition, gas chromatography analyses were performed to measure the concentration of VSCs from bacterial cultures and to characterize M. alternifolia oil components. Results The MIC and MBC values were as follows: M. alternifolia - P. gingivalis (MIC and MBC=0.007%), P. endodontalis (MIC and MBC=0.007%=0.5%); chlorhexidine - P. gingivalis and P. endodontalis (MIC and MBC=1.5 mg/mL). M. alternifolia significantly reduced the growth and production of hydrogen sulfide (H2S) by P. gingivalis (p<0.05, ANOVA-Dunnet) and the H2S and methyl mercaptan (CH3SH) levels of P. endodontalis (p<0.05, ANOVA-Dunnet). Chlorhexidine reduced the growth of both microorganisms without altering the production of VSC in P. endodontalis. For P. gingivalis, the production of H2S and CH3SH decreased (p<0.05, ANOVA-Dunnet). Conclusion M. alternifolia can reduce bacterial growth and VSCs production and could be used as an alternative to chlorhexidine. PMID:28076463

  14. In vitro activity of Melaleuca alternifolia (tea tree) oil on filamentous fungi and toxicity to human cells.

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    Homeyer, Diane C; Sanchez, Carlos J; Mende, Katrin; Beckius, Miriam L; Murray, Clinton K; Wenke, Joseph C; Akers, Kevin S

    2015-04-01

    Invasive fungal wound infections (IFIs) are increasingly reported in trauma patients and cause considerable morbidity and mortality despite standard of care treatment in trauma centers by experienced medical personnel. Topical agents such as oil of melaleuca, also known as tea tree oil (TTO), have been proposed for adjunctive treatment of IFIs. We evaluated the activity of TTO against filamentous fungi associated with IFIs by testing 13 clinical isolates representing nine species via time-kill assay with seven concentrations of TTO (100%, 75%, 50%, 25%, 10%, 5%, and 1%). To ascertain the safety of topical application to wounds, cell viability assays were performed in vitro using human fibroblasts, keratinocytes, osteoblasts, and umbilical vein endothelial cells with 10 concentrations of TTO (75%, 50%, 25%, 10%, 5%, and 10-fold serial dilutions from 1 to 0.0001%) at five time points (5, 15, 30, 60, and 180 min). Compatibility of TTO with explanted porcine tissues was also assessed with eight concentrations of TTO (100%, 75%, 50%, 25%, 10%, 5%, 1%, and 0.1%) at the time points used for cellular assays and at 24 h. The time-kill studies showed that fungicidal activity was variable between isolates. The effect of TTO on cell viability was primarily concentration dependent with significant cytotoxicity at concentrations of ≥ 10% and ≥ 50% for cells lines and whole tissue, respectively. Our findings demonstrate that TTO possesses antifungal activity against filamentous fungi associated with IFIs; furthermore that negligible effects on whole tissues, in contrast to individual cells, were observed following exposure to TTO. Collectively, these findings indicate a potential use of TTO as topical treatment of IFIs. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. In vitro effects of Melaleuca alternifolia essential oil on growth and production of volatile sulphur compounds by oral bacteria

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    Talita Signoreti GRAZIANO

    Full Text Available ABSTRACT Objective Halitosis can be caused by microorganisms that produce volatile sulphur compounds (VSCs, which colonize the surface of the tongue and subgingival sites. Studies have reported that the use of natural products can reduce the bacterial load and, consequently, the development of halitosis. The aim of this study was to evaluate the antimicrobial activity of the essential oil of Melaleuca alternifolia on the growth and volatile sulphur compound (VSC production of oral bacteria compared with chlorhexidine. Material and Methods The effects of these substances were evaluated by the Minimum Inhibitory Concentration (MIC and Minimum Bactericidal Concentration (MBC in planktonic cultures of Porphyromonas gingivalis and Porphyromonas endodontalis. In addition, gas chromatography analyses were performed to measure the concentration of VSCs from bacterial cultures and to characterize M. alternifolia oil components. Results The MIC and MBC values were as follows: M. alternifolia - P. gingivalis (MIC and MBC=0.007%, P. endodontalis (MIC and MBC=0.007%=0.5%; chlorhexidine - P. gingivalis and P. endodontalis (MIC and MBC=1.5 mg/mL. M. alternifolia significantly reduced the growth and production of hydrogen sulfide (H2S by P. gingivalis (p<0.05, ANOVA-Dunnet and the H2S and methyl mercaptan (CH3SH levels of P. endodontalis (p<0.05, ANOVA-Dunnet. Chlorhexidine reduced the growth of both microorganisms without altering the production of VSC in P. endodontalis. For P. gingivalis, the production of H2S and CH3SH decreased (p<0.05, ANOVA-Dunnet. Conclusion M. alternifolia can reduce bacterial growth and VSCs production and could be used as an alternative to chlorhexidine.

  16. Acaricidal activity of Melaleuca alternifolia (tea tree) oil: in vitro sensitivity of sarcoptes scabiei var hominis to terpinen-4-ol.

    Science.gov (United States)

    Walton, Shelley F; McKinnon, Melita; Pizzutto, Susan; Dougall, Annette; Williams, Edwina; Currie, Bart J

    2004-05-01

    To compare the acaricidal activity of Melaleuca alternifolia (tea tree) oil (TTO) and some of its individual active components on the itch mite Sarcoptes scabiei var hominis. In vitro acaricide sensitivity assessment. The Menzies School of Health Research laboratory, located near the Infectious Diseases Ward of the Royal Darwin Hospital, Australia, where patients are admitted and treated for crusted scabies. Scabies mites (S scabiei var hominis) were collected from a 20-year-old Aboriginal woman admitted to the Royal Darwin Hospital with crusted scabies. Interventions Within 3 hours of collection, scabies mites were placed in continuous direct contact with the TTO products and control acaricides and were observed at regular intervals. Percentage of mites dead at regular observation intervals between 5 minutes and 24 hours during continuous exposure to the TTO products and acaricides. The 5% TTO and active component terpinen-4-ol were highly effective in reducing mite survival times. Statistically significant differences in mite survival curves were observed for 5% TTO, 2.1% terpinen-4-ol, 5% permethrin, and ivermectin (100 microg/g of Emulsifying Ointment British Pharmacopoeia 88). In vivo effectiveness was also observed. Documentation of resistance against antiectoparasitic compounds is increasing. Reported S scabiei treatment failures with lindane, crotamiton, and benzyl benzoate, as well as likely emerging resistance to 5% permethrin and oral ivermectin, are of concern and advocate for the identification and development of novel acaricidal drugs. Tea tree oil is a membrane-active biocide extracted from the tree M alternifolia. It is a principal antimicrobial in a wide range of pharmaceuticals sold in Australia, with the main active component being oxygenated terpenoids. The results suggest that TTO has a potential role as a new topical acaricide and confirm terpinen-4-ol as the primary active component.

  17. Atividade de nanoformulações de Melaleuca alternifolia e terpinen-4-ol em isolados de Rhodococcus equi

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    L. Sagave

    2015-02-01

    Full Text Available Rhodococcus equi é o agente etiológico da rodococose equina, importante doença respiratória de potros. Especialmente na última década, a emergência de cepas resistentes aos antimicrobianos empregados no tratamento da rodococose tem sido relatada. Nesse sentido, há a necessidade de estudos envolvendo terapias alternativas e novas tecnologias, incluindo o uso de plantas medicinais e nanotecnologia. Neste trabalho utilizou-se Melaleuca alternifolia nas seguintes formulações: óleo livre, nanocápsula, nanoemulsão e a combinação de óleo livre com nanocápsula e com nanoemulsão, além do seu composto majoritário, terpinen-4-ol, a fim de verificar a atividade antimicrobiana frente a isolados de R. equi de diferentes origens. Utilizou-se o método de microdiluição em caldo na determinação das concentrações inibitória mínima (CIM e bactericida mínima (CBM das diferentes formulações frente aos isolados (n=24. Verificou-se baixo potencial para atividade antibacteriana de M. alternifolia na formulação de óleo livre. Todavia, essa atividade foi potencializada quando se incorporou o óleo essencial às nanoformulações. O composto terpinen-4-ol demonstrou potencial atividade antibacteriana quando incorporado ao óleo essencial e quando utilizado isoladamente. Verificou-se que tanto M. alternifolia quanto terpinen-4-ol testados possuem atividade antimicrobiana contra isolados de R. equi, sugerindo seu emprego em estudos avaliando seu potencial para o tratamento da rodococose.

  18. Activity of Melaleuca alternifolia (tea tree) oil on Influenza virus A/PR/8: study on the mechanism of action.

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    Garozzo, A; Timpanaro, R; Stivala, A; Bisignano, G; Castro, A

    2011-01-01

    Our previous study demonstrated that Melaleuca alternifolia (tea tree) oil (TTO) had an interesting antiviral activity against Influenza A in MDCK cells. In fact, when we tested TTO and some of its components, we found that TTO had an inhibitory effect on influenza virus replication at doses below the cytotoxic dose; terpinen-4-ol, terpinolene, and alfa-terpineol were the main active components. The aim of this study was to investigate the mechanism of action of TTO and its active components against Influenza A/PR/8 virus subtype H1N1 in MDCK cells. None of the test compounds showed virucidal activity nor any protective action for the MDCK cells. Thus, the effect of TTO and its active components on different steps of the replicative cycle of influenza virus was studied by adding the test compounds at various times after infection. These experiments revealed that viral replication was significantly inhibited if TTO was added within 2h of infection, indicating an interference with an early step of the viral replicative cycle of influenza virus. The influence of the compound on the virus adsorption step, studied by the infective center assay, indicated that TTO did not interfere with cellular attachment of the virus. TTO did not inhibit influenza virus neuraminidase activity, as shown by the experiment measuring the amount of 4-methylumbelliferone, cleaved by the influenza virus neuraminidase from the fluorogenic substrate 2'-O-(4-methylumbelliferyl)-N-acetylneuraminic acid. The effect of TTO on acidification of cellular lysosomes was studied by vital staining with acridine orange using bafilomycin A1 as positive control. The treatment of cells with 0.01% (v/v) of TTO at 37°C for 4h before staining inhibited the acridine orange accumulation in acid cytoplasmic vesicles, indicating that TTO could inhibit viral uncoating by an interference with acidification of intralysosomal compartment.

  19. The influence of the essential oil of Melaleuca alternifolia on the healing of infected dental alveoli: a histological study in rats Influência do óleo essencial de Melaleuca alternifolia na cicatrização de alveolite dental infectada: um estudo histológico em ratos

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    Maria Regina Orofino Kreuger

    2007-09-01

    Full Text Available The plant Melaleuca alternifolia is native to Australia. The distillation of its leaves produces an essential oil, commonly known as oil of Melaleuca, or Tea tree oil, which present antimicrobial activity. This study investigates the action of this oil on the repair process of infected dental alveoli. 48 rats were used (Rattus novergicus albinus, Wistar. After tooth extraction and posterior infection of the dental alveoli with Staphylococcus aureus, the animals were separated into three groups: Group I: curettage and irrigation with physiologic saline solution; Group II: curettage and irrigation with physiologic saline solution and topical application of rifamycin diethylamide B 25 mg; and Group III: curettage and irrigation with physiologic saline solution and topical application of oil of Melaleuca 20%. The animals were sacrificed 24 hours, 7, 14 and 21 days after the treatment with powder and the repair process of the dental alveoli was analyzed using an optical microscope. The results were submitted to qualitative and quantitative analysis and it was concluded that tea tree oil at 20% caused a delay in the repair process of infected dental alveoli in rats, as demonstrated by the presence of more necrosis area and less osteogenesis.A planta Melaleuca alternifolia é nativa da Austrália e a destilação de suas folhas produz um óleo essencial conhecido por óleo de Melaleuca, ou Tea tree oil, usado como antimicrobiano. Nesse estudo, foi verificado a atividade deste óleo no processo de reparo de alvéolos dentais infectados. 48 ratos foram utilizados (Rattus novergicus albinus, Wistar e após a extração do dente e posterior infecção do alvéolo com Staphylococcus aureus, os animais foram separados em três grupos: Grupo I: curetagem e irrigação do alvéolo com soro fisiológico; Grupo II: curetagem e irrigação com soro fisiológico e tratamento com Rifocina 25 mg; e Grupo III: curetagem e irrigação com soro fisiológico e aplica

  20. Antifungal activity of the essential oil of Melaleuca alternifolia (tea tree oil) against pathogenic fungi in vitro.

    Science.gov (United States)

    Nenoff, P; Haustein, U F; Brandt, W

    1996-01-01

    The in vitro antifungal activity of tea oil, the essential oil of Melaleuca alternifolia, has been evaluated against 26 strains of various dermatophyte species, 54 yeasts, among them 32 strains of Candida albicans and other Candida sp. as well as 22 different Malassezia furfur strains. Minimum inhibitory concentrations (MIC) of tea tree oil were measured by agar dilution technique. Tea tree oil was found to be able to inhibit growth of all clinical fungal isolates. For the investigated dermatophytes MIC values from 1,112.5 to 4,450.0 micrograms/ml with a geometric mean of 1,431.5 micrograms/ml were demonstrated. Both C. albicans strains and the other strains belonging to the genus Candida and Trichosporon appeared to be slightly less susceptible to tea tree oil in vitro. However, their MIC values, which varied from 2,225.0 to 4,450.0 micrograms/ml (geometric mean 4,080 micrograms/ml), indicated moderate susceptibility to the essential oil of M. alternifolia. The lipophilic yeast M. furfur seemed to be most susceptible to tea tree oil. MIC values between 556.2 and 4,450.0 micrograms/ml (geometric mean 1,261.5 micrograms/ml) were found against the tested M. furfur strains. However, when calculated as percentage tea tree oil of the agar, the above-mentioned concentrations correspond to 0.5-0.44% tea tree oil content. These values are far below the usual relatively high therapeutic concentrations of the agent; approximately 5-10% solution or even the concentrated essential oil are used for external treatment. In comparison with tea tree oil, in vitro susceptibility against miconazole, an established topical antifungal, was tested. As expected, very low MIC values for miconazole were found for dermatophytes (geometric mean 0.2 microgram/ml), yeasts (geometric mean 1.0 microgram/ml), and M. furfur (geometric mean 2.34 micrograms/ml). It is suggested that the in vivo effect of tea tree oil ointment in the therapy of fungal infections of the skin and mucous membranes as

  1. The Analysis of Management and Timber Trade System of Gelam (Melaleuca cajuputi From Peat Swamp Forest in South Kalimantan

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    Yudi Firmanul Ariffin

    2015-05-01

    Full Text Available Until now the raw material of wood especially Gelam (Melaleuca cajuputi available for supporting the construction of housing and other infrastructures is increasingly large in Indonesia. On the Island of Borneo that partly consists of swamps needs Gelam very large and continuous, particularly for residential development. However, areas of peat swamp forest habitat of this plant from year to year are degradation and shrinkage. This situation is a very big influence on the population of Gelam, while the management and timber trade systems are not well regulated. This study aims to analyze the management and timber trade systems of Gelam particularly in South Kalimantan to provide input to the policy holder in the preservation of Gelam. The method was used a field survey and interviews with traders and policy holders related regulations. The results showed in South Kalimantan the potency of Gelam is only 2,9-7,1 m3/ha and decreasing yearly. Normally Gelam with a diameter <4 cm have been cut down, as well as > 30 cm. These dimensions should not be cut because of <4 cm too young and > 30 cm can be used as seed sources. Gelam derived from peat swamp forest, which mostly comes from the Batola District and some came from Kapuas District of Central Kalimantan. Distributions of Gelam were starting gatherers logging in the forest then sold to small gatherers, next to the large gatherers and distributed to all districts/cities in South Kalimantan, wood processing industries, and some of them were sent to Java. The silviculture system of Gelam was using selective cutting. Classification of wood sizes traded by the diameter divided into 3-4cm, 5-6cm, 7-8cm, 9-10cm, 11-12cm, 13-14cm, 15-19cm and > 20cm to 4m long. Its use consists of a small diameter (3-10cm for foundry building and firewood, while the large diameter (10-20cm for the construction of houses in swampy areas, and waste as well as the stems are bent and deformed used for firewood. Until now Gelam

  2. Complete Genome Sequence of Diaphorina citri-associated C virus, a Novel Putative RNA Virus of the Asian Citrus Psyllid, Diaphorina citri.

    Science.gov (United States)

    Nouri, Shahideh; Salem, Nidà; Falk, Bryce W

    2016-07-21

    We present here the complete nucleotide sequence and genome organization of a novel putative RNA virus identified in field populations of the Asian citrus psyllid, Diaphorina citri, through sequencing of the transcriptome followed by reverse transcription-PCR (RT-PCR). We tentatively named this virus Diaphorina citri-associated C virus (DcACV). DcACV is an unclassified positive-sense RNA virus.

  3. Behavioral, ultrastructural and chemical studies on the honeydew and waxy secretions by nymphs and adults of the Asian citrus psyllid Diaphorina citri (Hemiptera: Psyllidae.

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    El-Desouky Ammar

    Full Text Available 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 between nymphs, males and females, and suggested some mechanisms by which the psyllids, especially nymphs and adult females, can minimize their contamination with honeydew excretions. The anal opening in ACP, near the posterior end of the abdomen, is on the ventral side in nymphs and on the dorsal side in adult males and females. Video recordings showed that adult males produce clear sticky droplets of honeydew gently deposited behind their body on the leaf surface, whereas adult females produce whitish honeydew pellets powerfully propelled away from the female body, probably to get their excretions away from eggs and newly hatched nymphs. ACP nymphs produce long ribbons or tubes of honeydew that frequently stay attached to the exuviae after molting, or drop when feeding on the lower side of citrus leaves. Furthermore, honeydew excretions of both nymphs and adult females are covered with a thin layer of whitish waxy material ultrastructurally composed of a convoluted network of long fine filaments or ribbons. This material is extruded from intricate arrays of wax pores in the circumanal ring (around the anus that is found in nymphs and females but not in males of ACP or other psyllid species. Infrared microscopy and mass spectroscopy revealed that, in addition to various sugars, honeydew excretions of ACP nymphs and females are covered with a thin layer of wax similar in profile to ester waxes.

  4. In vitro repellent effect of tea tree (Melaleuca alternifolia) and andiroba (Carapa guianensis) oils on Haemotobia irritans and Chrysomya megacephala flies.

    Science.gov (United States)

    Klauck, V; Pazinato, R; Radavelli, W M; Volpato, A; Stefani, L M; Santos, R C V; Vaucher, R A; Boligon, A A; Athayde, M L; Da Silva, A S

    2015-03-01

    This study aimed to evaluate the repellent effect of tea tree (Melaleuca alternifolia) and andiroba (Carapa guianensis) essential oils on two species of flies (Haemotobia irritans and Chrysomya megacephala). For the in vitro studies, free-living adult flies were captured and reared in the laboratory. To verify the repellency effect, an apparatus was constructed where H. irritans and C. megacephala were exposed to andiroba and tea tree oils (5.0%), as well as to a known repellent (citronella, 5.0%) to validate the test. The study demonstrated that all three oils used showed in vitro repellent effect against both species of flies. It is possible to conclude that the essential oils (tea tree and andiroba) have repellent effect on these species of flies used in this study.

  5. In vitro anti-microbial activity of the Cuban medicinal plants Simarouba glauca DC, Melaleuca leucadendron L and Artemisia absinthium L

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    Aymé Fernández-Calienes Valdés

    2008-09-01

    Full Text Available In the present study, an extensive in vitro antimicrobial profiling was performed for three medicinal plants grown in Cuba, namely Simarouba glauca, Melaleuca leucadendron and Artemisia absinthium. Ethanol extracts were tested for their antiprotozoal potential against Trypanosoma b. brucei, Trypanosoma cruzi, Leishmania infantum and Plasmodium falciparum. Antifungal activities were evaluated against Microsporum canis and Candida albicans whereas Escherichia coli and Staphylococcus aureus were used as test organisms for antibacterial activity. Cytotoxicity was assessed against human MRC-5 cells. Only M. leucadendron extract showed selective activity against microorganisms tested. Although S. glauca exhibited strong activity against all protozoa, it must be considered non-specific. The value of integrated evaluation of extracts with particular reference to selectivity is discussed.

  6. Compatibility of Isaria fumosorosea (Hypocreales: Cordycipitaceae Blastospores with Agricultural Chemicals Used for Management of the Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae

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    Pasco B. Avery

    2013-11-01

    Full Text Available 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-based fungicides registered for use in citrus groves. Results of laboratory and greenhouse tests showed a range of responses of the fungus to the different materials, including compatibility and incompatibility. Overall, I. fumosorosea growth in vitro was reduced least by petroleum-based materials and most by botanical oils and borax, and some of the copper-based fungicides, suggesting that tank mixing of I. fumosorosea with these latter products should be avoided. However, equivalent negative effects of test materials on fungal pathogenicity were not always observed in tests with adult psyllids. We hypothesize that some oils enhanced adherence of blastospores to the insect cuticle, overcoming negative impacts on germination. Our data show that care should be taken in selecting appropriate agrochemicals for tank-mixing with commercial formulations of entomopathogenic fungi for management of citrus pests. The prospects of using I. fumosorosea for managing the invasive Asian citrus psyllid and other citrus pests are discussed.

  7. In vitro activity of essential oils of free and nanostructured Melaleuca alternifolia and of terpinen-4-ol on eggs and larvae of Haemonchus contortus.

    Science.gov (United States)

    Grando, T H; de Sá, M F; Baldissera, M D; Oliveira, C B; de Souza, M E; Raffin, R P; Santos, R C V; Domingues, R; Minho, A P; Leal, M L R; Monteiro, S G

    2016-05-01

    Haemonchus contortus is one of the major gastrointestinal nematodes responsible for significant economic and production losses of sheep. Diseases caused by this species lack effective anthelmintic products, and the search for new compounds to replace synthetic anthelmintics has been extensive. The present investigation assesses the in vitro activity of the essential oil of melaleuca (Melaleuca alternifolia), both free (TTO) and nanostructured (nanoTTO), and terpinen-4-ol (terp-4-ol) on eggs and larvae of H. contortus. Tests of egg hatching (EHT) and inhibition of larval migration (LMIT) were used to assess the in vitro efficacy of TTO, nanoTTO and terp-4-ol. Using EHT, at a concentration of 3.5 mg/ml, 100% inhibition occurred using TTO and terp-4-ol, with LC50 values of 0.43 and 0.63 mg/ml, and LC90 values of 1.75 mg/ml and 3.12 mg/ml, respectively. NanoTTO had lower activity, with 82.6% inhibition at the same concentration. Using LMIT, TTO and nanoTTO had a similar activity with 88.0% and 84.8% inhibition, respectively, at a concentration of 56 mg/ml. Terp-4-ol had a greater effect on larvae, with 85.7% inhibition at a concentration of 56 mg/ml and 82.4% at 3.5 mg/ml, demonstrating high activity at the lowest concentration tested. Therefore, the results indicate that all substances tested showed ovicidal and larvicidal activity against H. contortus. TTO, terp-4-ol and, mainly, nanoTTO may be targeted in in vivo studies, besides being a promising line of research into the control and treatment of veterinary important helminths.

  8. A randomised, assessor blind, parallel group comparative efficacy trial of three products for the treatment of head lice in children - melaleuca oil and lavender oil, pyrethrins and piperonyl butoxide, and a "suffocation" product

    OpenAIRE

    Barker Stephen C; Altman Phillip M

    2010-01-01

    Abstract Background There are many different types of pediculicides available OTC in Australia. In this study we compare the efficacy and safety of three topical pediculicides: a pediculicide containing melaleuca oil (tea tree oil) and lavender oil (TTO/LO); a head lice "suffocation" product; and a product containing pyrethrins and piperonyl butoxide (P/PB). Method This study was a randomised, assessor-blind, comparative, parallel study of 123 subjects with live head lice. The head lice produ...

  9. 互叶白千层花、果与叶挥发油成分的对比分析%Comparative Analysis on Chemical Components in Volatile Oils from Flowers,Fruits and Leaf of Melaleuca alternjfolja

    Institute of Scientific and Technical Information of China (English)

    柴玲; 刘布鸣; 林霄; 何开家; 白懋嘉

    2014-01-01

    以水蒸气蒸馏法提取互叶白千层花、果、叶三个不同部位的挥发油,采用气相色谱法、气相色谱-质谱联用法分别鉴定了花、果和叶中挥发油的化学成分,并比较互叶白千层不同部位挥发油的主要化学成分及含量差异。分析结果可为互叶白千层花、果研究提供试验依据。%The volatile oils were obtained by extracting flowers,fruits and leaf of Melaleuca alternifolia respectively with steam distillation.GC and GC-MS methods were applied to identify the components in these volatile oils from different parts of Melaleuca alternifolia ,and the differences and relative contents of the main chemical components were compared.The results provide experimental data for the study of flowers and fruits from Melaleuca alternifolia .

  10. Metalized polyethylene mulch to repel Asian citrus psyllid, slow spread of huanglongbing and improve growth of new citrus plantings.

    Science.gov (United States)

    Croxton, Scott D; Stansly, Philip A

    2014-02-01

    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 repel adult ACP as well as effects on incidence of HLB and early tree growth. Metalized mulch significantly reduced ACP populations and HLB incidence compared to whiteface mulch or bare ground. In addition, metalized mulch, together with the associated drip irrigation and fertigation system, increased soil moisture, reduced weed pressure, and increased tree growth rate. Metalized mulch slows spread of ACP and therefore HLB pressure on young citrus trees. Metalized mulch can thereby augment current control measures for young trees based primarily on systemic insecticides. Additional costs could be compensated for by increased tree growth rate which would shorten time to crop profitability. These advantages make a compelling case for large-scale trials using metalized mulch in young citrus plantings threatened by HLB. © 2013 Society of Chemical Industry.

  11. Insecticide resistance of adults and nymphs of Asian citrus psyllid populations from Apatzingán Valley, Mexico.

    Science.gov (United States)

    Pardo, Saúl; Martínez, Ana M; Figueroa, José I; Chavarrieta, Juan M; Viñuela, Elisa; Rebollar-Alviter, Ángel; Miranda, Mario A; Valle, Javier; Pineda, Samuel

    2017-07-18

    Control of the Asian citrus psyllid Diaphorina citri Kuwayama, the most important pest of citrus worldwide, is based on the use of insecticides, though unsatisfactory results have recently been reported. In this study, insecticide resistance of D. citri to three insecticides (bifenthrin, malathion, and chlorpyrifos) was examined. Three populations (designated Dci-CParácuaro, Dci-El Junco, and Dci-Antúnez) of both adults and fourth-instar D. citri individuals were collected in 2014 at two different times and on one occasion, respectively, from three locations (Crucero de Parácuaro, El Junco, and Antúnez). These locations represent the major commercial Mexican lemon production areas in the Apatzingán Valley in the state of Michoacán, Mexico. The three populations of D. citri adults and fourth-instar nymphs at the different collection times showed low levels of resistance (≤7-fold) to bifenthrin, but were very resistant to malathion (≤345- and ≤432-fold for adults and fourth instars, respectively) and chlorpyrifos (≤2435- and ≤1424-fold for adults and fourth instars, respectively). Resistance levels to the tested insecticides were highly variable but homogeneous among seasons and localities. Resistance management programmes that include crop sanitation, use of biological and cultural control practices, and rotation of insecticide classes should be established, particularly in areas where D. citri has developed resistance to malathion and chlorpyrifos. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. Geographic distribution of habitat, development, and population growth rates of the Asian citrus psyllid, Diaphorina citri, in Mexico.

    Science.gov (United States)

    López-Collado, José; Isabel López-Arroyo, J; Robles-García, Pedro L; Márquez-Santos, Magdalena

    2013-01-01

    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 bioclimatic layers and point location data. Geographic distributions of development and population growth rates were determined by fitting a temperature-dependent, nonlinear model and projecting the rates over the target area, using the annual mean temperature as the predictor variable. The results showed that the most suitable regions for habitat of D. citri comprise the Gulf of Mexico states, Yucatán Peninsula, and areas scattered throughout the Pacific coastal states. Less suitable areas occurred in northern and central states. The most important predictor variables were related to temperature. Development and growth rates had a distribution wider than habitat, reaching some of the northern states of México. Habitat, development, and population growth rates were correlated to each other and with the citrus producing area. These relationships indicated that citrus producing states are within the most suitable regions for the occurrence, development, and population growth of D. citri, therefore increasing the risk of huanglongbing dispersion.

  13. Oral delivery of double-stranded RNAs induces mortality in nymphs and adults of the Asian citrus psyllid, Diaphorina citri

    Science.gov (United States)

    Galdeano, Diogo Manzano; Breton, Michèle Claire; Lopes, João Roberto Spotti; Falk, Bryce W.

    2017-01-01

    The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is one of the most important citrus pests. ACP is the vector of the phloem-limited bacteria Candidatus Liberibacter americanus and Candidatus Liberibacter asiaticus, the causal agents of the devastating citrus disease huanglongbing (HLB). The management of HLB is based on the use of healthy young plants, eradication of infected plants and chemical control of the vector. RNA interference (RNAi) has proven to be a promising tool to control pests and explore gene functions. Recently, studies have reported that target mRNA knockdown in many insects can be induced through feeding with double-stranded RNA (dsRNA). In the current study, we targeted the cathepsin D, chitin synthase and inhibitor of apoptosis genes of adult and nymph ACP by feeding artificial diets mixed with dsRNAs and Murraya paniculata leaves placed in dsRNAs solutions, respectively. Adult ACP mortality was positively correlated with the amount of dsRNA used. Both nymphs and adult ACP fed dsRNAs exhibited significantly increased mortality over time compared with that of the controls. Moreover, qRT-PCR analysis confirmed the dsRNA-mediated RNAi effects on target mRNAs. These results showed that RNAi can be a powerful tool for gene function studies in ACP and perhaps for HLB control. PMID:28282380

  14. Metabolic Interplay between the Asian Citrus Psyllid and Its Profftella Symbiont: An Achilles' Heel of the Citrus Greening Insect Vector.

    Directory of Open Access Journals (Sweden)

    John S Ramsey

    Full Text Available '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 endosymbiont Profftella were up-regulated in CLas(+ insects. Mass spectrometry analysis of the Profftella polyketide diaphorin in D. citri metabolite extracts revealed the presence of a novel diaphorin-related polyketide and the ratio of these two polyketides was changed in CLas(+ insects. Insect proteins differentially expressed between CLas(+ and CLas(- D. citri included defense and immunity proteins, proteins involved in energy storage and utilization, and proteins involved in endocytosis, cellular adhesion, and cytoskeletal remodeling which are associated with microbial invasion of host cells. Insight into the metabolic interdependence between the insect vector, its endosymbionts, and the citrus greening pathogen reveals novel opportunities for control of this disease, which is currently having a devastating impact on citrus production worldwide.

  15. Horizontal gene acquisition of Liberibacter plant pathogens from a bacteriome-confined endosymbiont of their psyllid vector.

    Directory of Open Access Journals (Sweden)

    Atsushi Nakabachi

    Full Text Available 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 gammaproteobacterium 'Candidatus Carsonella ruddii' in uninucleate bacteriocytes. Here we report that a putative amino acid transporter LysE of Profftella forms a highly supported clade with proteins of L. asiaticus, L. americanus, and L. solanacearum. L. crescens, the most basal Liberibacter lineage currently known, lacked the corresponding gene. The Profftella-Liberibacter subclade of LysE formed a clade with proteins from betaproteobacteria of the order Burkholderiales, to which Profftella belongs. This phylogenetic pattern favors the hypothesis that the Liberibacter lineage acquired the gene from the Profftella lineage via horizontal gene transfer (HGT after L. crescens diverged from other Liberibacter lineages. K A/K S analyses further supported the hypothesis that the genes encoded in the Liberibacter genomes are functional. These findings highlight the possible evolutionary importance of HGT between plant pathogens and their insect vector's symbionts that are confined in the symbiotic organ and seemingly sequestered from external microbial populations.

  16. Sclerenchymatous ring as a barrier to phloem feeding by Asian citrus psyllid: Evidence from electrical penetration graph and visualization of stylet pathways.

    Science.gov (United States)

    George, Justin; Ammar, El-Desouky; Hall, David G; Lapointe, Stephen L

    2017-01-01

    Asian citrus psyllid (Diaphorina citri) feeding behaviors play a significant role in the transmission of the phloem-limited Candidatus Liberibacter asiaticus (CLas) bacterium that causes the economically devastating citrus greening disease. Sustained phloem ingestion by D. citri on CLas infected plants is required for pathogen acquisition and transmission. Recent studies have shown a fibrous ring of thick-walled sclerenchyma around the phloem in mature, fully expanded citrus leaves that is more prominent on the abaxial compared with the adaxial side. The composition and thickness of this fibrous ring may have an important role in selection of feeding sites by D. citri based on leaf age and leaf surface, which in turn can affect pathogen acquisition and transmission. We measured feeding behavior using electrical penetration graph (EPG) recordings of individual D. citri adults placed on abaxial or adaxial surfaces of young or mature Valencia orange leaves to study the role of the sclerenchymatous ring in modifying D. citri feeding behavior. Feeding sites on the same leaf tissues were then sectioned and examined by epifluorescence microscopy. The duration of phloem ingestion (E2 waveform) by psyllids was significantly reduced on mature compared with young leaves, and on abaxial compared with adaxial leaf surfaces. The longest duration of phloem ingestion was observed from psyllids placed on the adaxial side of young leaves that had the least developed sclerenchyma. Bouts of phloem salivation (E1 waveform), however, were significantly longer on mature leaves compared with young leaves. D. citri adults made consecutive phloem feeding attempts (bouts) on the abaxial side of mature leaves and those bouts resulted in unsuccessful or shorter periods of phloem ingestion. Adults also made more frequent and longer bouts of xylem ingestion on mature leaves compared with adult psyllids placed on young leaves. Epifluorescence microscopy showed that the fibrous ring in young

  17. In-vitro activity of essential oils, in particular Melaleuca alternifolia (tea tree) oil and tea tree oil products, against Candida spp.

    Science.gov (United States)

    Hammer, K A; Carson, C F; Riley, T V

    1998-11-01

    The in-vitro activity of a range of essential oils, including tea tree oil, against the yeast candida was examined. Of the 24 essential oils tested by the agar dilution method against Candida albicans ATCC 10231, three did not inhibit C. albicans at the highest concentration tested, which was 2.0% (v/v) oil. Sandalwood oil had the lowest MIC, inhibiting C. albicans at 0.06%. Melaleuca alternifolia (tea tree) oil was investigated for activity against 81 C. albicans isolates and 33 non-albicans Candida isolates. By the broth microdilution method, the minimum concentration of oil inhibiting 90% of isolates for both C. albicans and non-albicans Candida species was 0.25% (v/v). The minimum concentration of oil killing 90% of isolates was 0.25% for C. albicans and 0.5% for non-albicans Candida species. Fifty-seven Candida isolates were tested for sensitivity to tea tree oil by the agar dilution method; the minimum concentration of oil inhibiting 90% of isolates was 0.5%. Tests on three intra-vaginal tea tree oil products showed these products to have MICs and minimum fungicidal concentrations comparable to those of non-formulated tea tree oil, indicating that the tea tree oil contained in these products has retained its anticandidal activity. These data indicate that some essential oils are active against Candida spp., suggesting that they may be useful in the topical treatment of superficial candida infections.

  18. Antimicrobial synergism and cytotoxic properties of Citrus limon L., Piper nigrum L. and Melaleuca alternifolia (Maiden and Betche) Cheel essential oils.

    Science.gov (United States)

    Nikolić, Miloš M; Jovanović, Katarina K; Marković, Tatjana Lj; Marković, Dejan Lj; Gligorijević, Nevenka N; Radulović, Siniša S; Kostić, Marina; Glamočlija, Jasmina M; Soković, Marina D

    2017-08-17

    The chemical composition, antimicrobial and synergistic effect, and cytotoxic activity of Citrus limon (lemon), Piper nigrum (green pepper) and Melaleuca alternifoila (tea tree) essential oils (EOs) were investigated. Chemical analyses of essential oils were tested by GC-FID and GC-MS spectroscopy. The antimicrobial activity assay was conducted using microdilution method against several oral bacteria and Candida spp. originating from the humans with oral disorders. The synergistic antimicrobial activity was evaluated using checkerboard method. The cytotoxicity evaluation of EOs was assessed using MTT test. Limonene (37.5%) and β-pinene (17.9%) were the major compounds in C. limon oil, β-pinene (34.4%), δ-3-carene (19.7%), limonene (18.7%) and α-pinene (10.4%) in P. nigrum oil and terpinen-4-ol (38.6%) and γ-terpinene (21.7%) in M. alternifolia oil. The broad-spectrum antimicrobial activity was achieved by tested three EOs, with C. limon oil being the strongest against bacteria and M. alternifolia oil strongest against fungi. The EOs demonstrated synergism; their combined application revealed an increase in antimicrobial activity. All tested essential oils showed lower cytotoxic activity in comparison with the positive control, and the obtained results confirmed a dose-dependent activity. The results of this study encourage use of tested EOs in development of a novel agent intended for prevention or therapy of corresponding oral disorders. © 2017 Royal Pharmaceutical Society.

  19. Nematodes from galls on Myrtaceae. X. Fergusobia from galls on narrow-leaved Melaleuca spp. in Australia, with descriptions of three new species .

    Science.gov (United States)

    Davies, Kerrie A; Giblin-Davis, Robin M; Ye, Weimin; Taylor, Gary S; Makinson, Jeff; Purcell, Matthew

    2014-12-01

    Three new species of Fergusobia, respectively collected from shoot bud galls on narrow-leaved Melaleuca spp. in Australia, are described. Fergusobia armillarisae n. sp. Davies is characterised by the combination of an arcuate to open C-shaped parthenogenetic female with an extensile uterus and a short, conoid tail, an arcuate infective female with a broadly rounded tail tip, and an arcuate male with an angular spicule and bursa arising at 50-80% of body length. Fergusobia decorae n. sp. Davies has an arcuate parthenogenetic female with a non-extensile uterus and a broadly conoid tail, an arcuate infective female with most curvature behind the vulva and a short tail with a broadly rounded tip, and an arcuate male with an arcuate spicule and bursa arising at 40-50% of body length. Fergusobia linariifoliae n. sp. Davies is characterised by the combination of an arcuate parthenogenetic female with an extensile uterus and a short, conoid tail with a bluntly rounded tip, a barely arcuate infective female with a broadly rounded tail tip, and an arcuate male with an angular spicule and bursa arising at 40-50% of body length. Earlier molecular analyses inferred from DNA sequencing of 28S rDNA D2/D3 domains and a portion of mitochondrial DNA cytochrome oxidase subunit I (mtCOI) are further discussed. 

  20. Nematodes from galls on Myrtaceae. IX. Fergusobia rosettae n. sp. on Melaleuca quinquenervia and F. tolgaensis n. sp. on Syzygium luehmannii, from Queensland.

    Science.gov (United States)

    Davies, Kerrie A; Ye, Weimin; Giblin-Davis, Robin M; Taylor, Gary S; Purcell, Matthew; Thomas, Kelley

    2014-12-01

    Two new species of Fergusobia, collected from 'rosette' shoot bud galls on Melaleuca quinquenervia, and from leaf, stem, leaf and flower bud galls on Syzygium luehmannii, both from the Cairns region of Queensland, Australia, are described. Fergusobia rosettae Davies n. sp. is characterised by the combination of a small, arcuate parthenogenetic female having a short conoid tail with a bluntly rounded tip, an arcuate, relatively slender, infective female with an almost hemispherical tail tip, and arcuate males with arcuate to angular (not heavily sclerotised) spicules and leptoderan bursa arising at 40-50% of body length from tail tip. Fergusobia tolgaensis Davies n. sp. is characterised by the combination of a small open C-shaped parthenogenetic female with a broadly conoid tail, an arcuate infective female with a broadly rounded tail tip, and arcuate males with angular (not heavily sclerotised) spicules and short to mid-length leptoderan bursa. These two species of nematodes are associated with fly larvae that have dorsal shields comprising bars of raised cuticular ridges and spicules, similar to that of fly larvae from the M. leucadendra species group. The shield morphologies of these fly larvae and their possible genetic relationships are discussed. Possible evolutionary relationships of the Fergusobia nematodes from these galls are discussed, considering their morphology, DNA sequences, and the relationships of the associated Fergusonina flies and host plants.

  1. Trypanocidal action of tea tree oil (Melaleuca alternifolia) against Trypanosoma evansi in vitro and in vivo used mice as experimental model.

    Science.gov (United States)

    Baldissera, Matheus D; Da Silva, Aleksandro S; Oliveira, Camila B; Santos, Roberto C V; Vaucher, Rodrigo A; Raffin, Renata P; Gomes, Patrícia; Dambros, Maria G C; Miletti, Luiz C; Boligon, Aline A; Athayde, Margareth L; Monteiro, Silvia G

    2014-06-01

    This study aimed to evaluate the Trypanosoma evansi susceptibility to tea tree oil (TTO - Melaleuca alternifolia) and tea tree oil nanocapsules (TTO nanocapsules) in vitro and in vivo tests. In vitro, we observed a mortality curve of trypomastigotes proportional to dose, i.e., the TTO and TTO nanocapsules have trypanocidal effect. Treatment with TTO in vivo was assessed in experiments (I and II). For Experiment I, T. evansi infected mice were treated with TTO and/or combinations of essential oil with chemotherapy (diminazene aceturate - D.A.). Treatment with TTO at a dose of 1mLkg(-1) was able to extend animal longevity, but had no curative efficacy. However, when TTO was combined with D.A. a disease curative efficacy of 100% for disease was observed, a much better result than the D.A. treatment (33.3%). In Experiment II, T. evansi infected mice were treated with TTO nanocapsules with doses of 0.3, 0.6 and 0.9mLkg(-1). Animals treated with 0.9mLkg(-1) showed higher longevity however without curative effect. Active compounds present in natural products, such as M. alternifolia, may potentiate the treatment of trypanosomosis when associated with other trypanocidal drugs.

  2. Antibacterial efficacy of Melaleuca alternifolia (Tea tree oil, Curcuma longa (Turmeric, 2% chlorhexidine, and 5% sodium hypochlorite against Enterococcus faecalis: An in vitro study

    Directory of Open Access Journals (Sweden)

    Dakshita Joy Sinha

    2015-01-01

    Full Text Available Aim: To evaluate and compare the antibacterial efficacy of Melaleuca alternifolia (tea tree oil, Curcumalonga (turmeric, 2% chlorhexidine (CHX, and 5% sodium hypochlorite (NaOCl against Enterococcus faecalis. Materials and Methods: Agar plates were prepared using tryptone soya agar. Cultures of E. faecalis were grown in tryptone soya broth. Agar well diffusion method was performed and the plates were incubated at 37΀C for 24 h. The zones of inhibition were recorded. The readings were subjected to statistical analysis using analysis of variance (ANOVA and Tukey′s post hoc test. P-value was considered significant at P < 0.05. Results: Maximum antibacterial efficacy was exhibited by 2% CHX, followed by 5% NaOCl and C. longa with no statistically significant difference between them. It was followed by M. alternifolia (Tea tree oil. Ethanol and saline showed the least antibacterial action. Conclusion: According to the results of this study, C. longa and M. alternifolia can be used as an alternative root canal irrigant, although long-term in vivo studies are warranted.

  3. Repellent effects of Melaleuca alternifolia (tea tree) oil against cattle tick larvae (Rhipicephalus australis) when formulated as emulsions and in β-cyclodextrin inclusion complexes.

    Science.gov (United States)

    Yim, Wei Tsun; Bhandari, Bhesh; Jackson, Louise; James, Peter

    2016-07-30

    Rhipicephalus australis (formerly Boophilus microplus) is a one host tick responsible for major economic loss in tropical and subtropical cattle production enterprises. Control is largely dependent on the application of acaricides but resistance has developed to most currently registered chemical groups. Repellent compounds that prevent initial attachment of tick larvae offer a potential alternative to control with chemical toxicants. The repellent effects of Melaleuca alternifolia oil (TTO) emulsions and two β-cyclodextrin complex formulations, a slow release form (SR) and a modified faster release form (FR), were examined in a series of laboratory studies. Emulsions containing 4% and 5% TTO applied to cattle hair in laboratory studies completely repelled ascending tick larvae for 24h whereas 2% and 3% formulations provided 80% protection. At 48h, 5% TTO provided 78% repellency but lower concentrations repelled less than 60% of larvae. In a study conducted over 15 days, 3% TTO emulsion applied to cattle hair provided close to 100% repellency for 2 days, but then protection fell to 23% by day 15. The FR formulation gave significantly greater repellency than the emulsion and the SR formulation from day 3 until the end of the study (P<0.05), providing almost complete repellency at day 3 (99.5%), then decreasing over the period of the study to 49% repellency at day 15. Proof of concept is established for the use of appropriately designed controlled-release formulations to extend the period of repellency provided by TTO against R. australis larvae.

  4. Mechanism of action of Melaleuca alternifolia (tea tree) oil on Staphylococcus aureus determined by time-kill, lysis, leakage, and salt tolerance assays and electron microscopy.

    Science.gov (United States)

    Carson, Christine F; Mee, Brian J; Riley, Thomas V

    2002-06-01

    The essential oil of Melaleuca alternifolia (tea tree) has broad-spectrum antimicrobial activity. The mechanisms of action of tea tree oil and three of its components, 1,8-cineole, terpinen-4-ol, and alpha-terpineol, against Staphylococcus aureus ATCC 9144 were investigated. Treatment with these agents at their MICs and two times their MICs, particularly treatment with terpinen-4-ol and alpha-terpineol, reduced the viability of S. aureus. None of the agents caused lysis, as determined by measurement of the optical density at 620 nm, although cells became disproportionately sensitive to subsequent autolysis. Loss of 260-nm-absorbing material occurred after treatment with concentrations equivalent to the MIC, particularly after treatment with 1,8-cineole and alpha-terpineol. S. aureus organisms treated with tea tree oil or its components at the MIC or two times the MIC showed a significant loss of tolerance to NaCl. When the agents were tested at one-half the MIC, only 1,8-cineole significantly reduced the tolerance of S. aureus to NaCl. Electron microscopy of terpinen-4-ol-treated cells showed the formation of mesosomes and the loss of cytoplasmic contents. The predisposition to lysis, the loss of 260-nm-absorbing material, the loss of tolerance to NaCl, and the altered morphology seen by electron microscopy all suggest that tea tree oil and its components compromise the cytoplasmic membrane.

  5. The essential oil of Melaleuca alternifolia (tea tree oil) and its main component, terpinen-4-ol protect mice from experimental oral candidiasis.

    Science.gov (United States)

    Ninomiya, Kentaro; Maruyama, Naho; Inoue, Shigeharu; Ishibashi, Hiroko; Takizawa, Toshio; Oshima, Haruyuki; Abe, Shigeru

    2012-01-01

    The therapeutic efficacy of tea tree oil (TTO), Melaleuca alternifolia, and its main component, terpinen-4-ol, were evaluated in a murine oral candidiasis model. Prednisolone -pretreated mice were orally infected with a fluconazole-susceptible (TIMM 2640) or a resistant (TIMM 3163) strain of Candida albicans to induce oral candidiasis. TTO or terpinen-4-ol was administrated with a cotton swab 3 h and 24 h after candida infection. These treatments clearly showed a decrease in the symptom score of tongues and in the viable candida cell number in the oral cavity at 2 d after azole-susceptible C. albicans infection, although the degree of the efficacy was less than that of fluconazole. Even against oral candidiasis caused by azole-resistant C. albicans, TTO and terpinen-4-ol were similarly effective, while fluconazole appeared ineffective. These results suggest that TTO and terpinen-4-ol may have the potential of therapeutic ability for mucosal candidiasis which may also be applicable to C. albicans oral candidiasis induced by the azole-resistant strain.

  6. Evaluation of systemic neonicotinoid insecticides for the management of the Asian citrus psyllid Diaphorina citri on containerized citrus.

    Science.gov (United States)

    Byrne, Frank J; Daugherty, Matthew P; Grafton-Cardwell, Elizabeth E; Bethke, James A; Morse, Joseph G

    2017-03-01

    Studies were conducted to evaluate uptake and retention of three systemic neonicotinoid insecticides, dinotefuran, imidacloprid and thiamethoxam, in potted citrus nursery plants treated at standard label rates. Infestation of these plants placed at a field site with moderate levels of Asian citrus psyllid (ACP) was monitored for 14 weeks following treatments, and insecticide residues in leaf tissue were quantified using enzyme-linked immunosorbent assay (ELISA). Bioassays were conducted using leaves harvested on various dates post-treatment to compare the efficacies of residues against adult ACP. Residues of the three neonicotinoids were detected in leaf tissues within 1 week after treatment. Peak concentrations established at 1 week for imidacloprid and dinotefuran and at 2 weeks for thiamethoxam. Imidacloprid and thiamethoxam outperformed the control and dinotefuran treatments at protecting trees from infestations by ACP eggs and nymphs. For a given insecticide concentration in leaf tissue, thiamethoxam induced the highest mortality of the three insecticides, and dinotefuran was the least toxic. If the time needed to achieve effective thresholds of a systemic neonicotinoid is known, treatments at production facilities could be scheduled that would minimize unnecessary post-treatment holding periods and ensure maximum retention of effective concentrations after the plants have shipped to retail outlets. The rapid uptake of the insecticides and retention at effective concentrations in containerized citrus suggest that the current 30 day post-treatment shipping restriction from production facilities to retail outlets outside of quarantine could be shortened to 14 days. Thiamethoxam should be added to the list of approved nursery treatments. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  7. RNA Interference towards the Potato Psyllid, Bactericera cockerelli, Is Induced in Plants Infected with Recombinant Tobacco mosaic virus (TMV.

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    Hada Wuriyanghan

    Full Text Available The potato/tomato psyllid, Bactericera cockerelli (B. cockerelli, is an important plant pest and the vector of the phloem-limited bacterium Candidatus Liberibacter psyllaurous (solanacearum, which is associated with the zebra chip disease of potatoes. Previously, we reported induction of RNA interference effects in B. cockerelli via in vitro-prepared dsRNA/siRNAs after intrathoracic injection, and after feeding of artificial diets containing these effector RNAs. In order to deliver RNAi effectors via plant hosts and to rapidly identify effective target sequences in plant-feeding B. cockerelli, here we developed a plant virus vector-based in planta system for evaluating candidate sequences. We show that recombinant Tobacco mosaic virus (TMV containing B. cockerelli sequences can efficiently infect and generate small interfering RNAs in tomato (Solanum lycopersicum, tomatillo (Physalis philadelphica and tobacco (Nicotiana tabacum plants, and more importantly delivery of interfering sequences via TMV induces RNAi effects, as measured by actin and V-ATPase mRNA reductions, in B. cockerelli feeding on these plants. RNAi effects were primarily detected in the B. cockerelli guts. In contrast to our results with TMV, recombinant Potato virus X (PVX and Tobacco rattle virus (TRV did not give robust infections in all plants and did not induce detectable RNAi effects in B. cockerelli. The greatest RNA interference effects were observed when B. cockerelli nymphs were allowed to feed on leaf discs collected from inoculated or lower expanded leaves from corresponding TMV-infected plants. Tomatillo plants infected with recombinant TMV containing B. cockerelli actin or V-ATPase sequences also showed phenotypic effects resulting in decreased B. cockerelli progeny production as compared to plants infected by recombinant TMV containing GFP. These results showed that RNAi effects can be achieved in plants against the phloem feeder, B. cockerelli, and the TMV

  8. Economic injury levels for Asian citrus psyllid control in process oranges from mature trees with high incidence of huanglongbing.

    Science.gov (United States)

    Monzo, Cesar; Stansly, Philip A

    2017-01-01

    The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is the key pest of citrus wherever it occurs due to its role as vector of huanglongbing (HLB) also known as citrus greening disease. Insecticidal vector control is considered to be the primary strategy for HLB management and is typically intense owing to the severity of this disease. While this approach slows spread and also decreases severity of HLB once the disease is established, economic viability of increasingly frequent sprays is uncertain. Lacking until now were studies evaluating the optimum frequency of insecticide applications to mature trees during the growing season under conditions of high HLB incidence. We related different degrees of insecticide control with ACP abundance and ultimately, with HLB-associated yield losses in two four-year replicated experiments conducted in commercial groves of mature orange trees under high HLB incidence. Decisions on insecticide applications directed at ACP were made by project managers and confined to designated plots according to experimental design. All operational costs as well as production benefits were taken into account for economic analysis. The relationship between management costs, ACP abundance and HLB-associated economic losses based on current prices for process oranges was used to determine the optimum frequency and timing for insecticide applications during the growing season. Trees under the most intensive insecticidal control harbored fewest ACP resulting in greatest yields. The relationship between vector densities and yield loss was significant but differed between the two test orchards, possibly due to varying initial HLB infection levels, ACP populations or cultivar response. Based on these relationships, treatment thresholds during the growing season were obtained as a function of application costs, juice market prices and ACP densities. A conservative threshold for mature trees with high incidence of HLB would help maintain economic

  9. RNA Interference towards the Potato Psyllid, Bactericera cockerelli, Is Induced in Plants Infected with Recombinant Tobacco mosaic virus (TMV).

    Science.gov (United States)

    Wuriyanghan, Hada; Falk, Bryce W

    2013-01-01

    The potato/tomato psyllid, Bactericera cockerelli (B. cockerelli), is an important plant pest and the vector of the phloem-limited bacterium Candidatus Liberibacter psyllaurous (solanacearum), which is associated with the zebra chip disease of potatoes. Previously, we reported induction of RNA interference effects in B. cockerelli via in vitro-prepared dsRNA/siRNAs after intrathoracic injection, and after feeding of artificial diets containing these effector RNAs. In order to deliver RNAi effectors via plant hosts and to rapidly identify effective target sequences in plant-feeding B. cockerelli, here we developed a plant virus vector-based in planta system for evaluating candidate sequences. We show that recombinant Tobacco mosaic virus (TMV) containing B. cockerelli sequences can efficiently infect and generate small interfering RNAs in tomato (Solanum lycopersicum), tomatillo (Physalis philadelphica) and tobacco (Nicotiana tabacum) plants, and more importantly delivery of interfering sequences via TMV induces RNAi effects, as measured by actin and V-ATPase mRNA reductions, in B. cockerelli feeding on these plants. RNAi effects were primarily detected in the B. cockerelli guts. In contrast to our results with TMV, recombinant Potato virus X (PVX) and Tobacco rattle virus (TRV) did not give robust infections in all plants and did not induce detectable RNAi effects in B. cockerelli. The greatest RNA interference effects were observed when B. cockerelli nymphs were allowed to feed on leaf discs collected from inoculated or lower expanded leaves from corresponding TMV-infected plants. Tomatillo plants infected with recombinant TMV containing B. cockerelli actin or V-ATPase sequences also showed phenotypic effects resulting in decreased B. cockerelli progeny production as compared to plants infected by recombinant TMV containing GFP. These results showed that RNAi effects can be achieved in plants against the phloem feeder, B. cockerelli, and the TMV-plant system will

  10. Screening of LED light source of the adapter solar trap lamp for trapping the citrus psyllid%适配太阳能诱虫器诱杀柑橘木虱LED光源的筛选

    Institute of Scientific and Technical Information of China (English)

    林雄杰; 范国成; 胡菡青; 阮传清; 蔡子坚; Xia Yulu; 杜云贵; 刘波

    2013-01-01

    The citrus psyllid is the vector of Huanglongbing.In order to control citrus psyllid and prevent disease,screening of LED light source adapter solar trap lamp for citrus psyllid by using reaction vessel of insect behavior was carried out in the laboratory.The results showed that the phototaxis of 1 800 1x and 4 310 lx blue and green light sources (wavelength 460 nm and 531 nm) were best on the illumination duration of 17 h.It was also found that the phototaxis of citrus psyllid adults was positively correlated with light intensity and light duration under the same wavelength condition.It might provide an effective theoretical basis for the LED light source for forecasting and trapping citrus psyllid in the field in the future.%柑橘木虱(Dia phorina citri)是柑橘黄龙病的传播媒介.为达到治虫防病的目的,在室内利用昆虫行为反应器开展适配太阳能诱虫器的LED光源筛选,结果表明:柑橘木虱成虫对光照强度分别为1 800 lx和4 310 lx的蓝光和绿光(波长分别为460 nm和531 nm)在光照时长为17 h时的趋光性最佳,相同波长条件下,其趋光性与光照强度和光照时长成正相关.该研究结果为进一步探索适宜田间柑橘木虱测报和高效诱杀的LED光源提供理论依据.

  11. An ex vivo, assessor blind, randomised, parallel group, comparative efficacy trial of the ovicidal activity of three pediculicides after a single application - melaleuca oil and lavender oil, eucalyptus oil and lemon tea tree oil, and a "suffocation" pediculicide

    Directory of Open Access Journals (Sweden)

    Altman Phillip M

    2011-08-01

    Full Text Available Abstract Background There are two components to the clinical efficacy of pediculicides: (i efficacy against the crawling-stages (lousicidal efficacy; and (ii efficacy against the eggs (ovicidal efficacy. Lousicidal efficacy and ovicidal efficacy are confounded in clinical trials. Here we report on a trial that was specially designed to rank the clinical ovicidal efficacy of pediculicides. Eggs were collected, pre-treatment and post-treatment, from subjects with different types of hair, different coloured hair and hair of different length. Method Subjects with at least 20 live eggs of Pediculus capitis (head lice were randomised to one of three treatment-groups: a melaleuca oil (commonly called tea tree oil and lavender oil pediculicide (TTO/LO; a eucalyptus oil and lemon tea tree oil pediculicide (EO/LTTO; or a "suffocation" pediculicide. Pre-treatment: 10 to 22 live eggs were taken from the head by cutting the single hair with the live egg attached, before the treatment (total of 1,062 eggs. Treatment: The subjects then received a single treatment of one of the three pediculicides, according to the manufacturers' instructions. Post-treatment: 10 to 41 treated live eggs were taken from the head by cutting the single hair with the egg attached (total of 1,183 eggs. Eggs were incubated for 14 days. The proportion of eggs that had hatched after 14 days in the pre-treatment group was compared with the proportion of eggs that hatched in the post-treatment group. The primary outcome measure was % ovicidal efficacy for each of the three pediculicides. Results 722 subjects were examined for the presence of eggs of head lice. 92 of these subjects were recruited and randomly assigned to: the "suffocation" pediculicide (n = 31; the melaleuca oil and lavender oil pediculicide (n = 31; and the eucalyptus oil and lemon tea tree oil pediculicide (n = 30 subjects. The group treated with eucalyptus oil and lemon tea tree oil had an ovicidal efficacy of 3.3% (SD

  12. Effect of habituation to tea tree (Melaleuca alternifolia) oil on the subsequent susceptibility of Staphylococcus spp. to antimicrobials, triclosan, tea tree oil, terpinen-4-ol and carvacrol.

    Science.gov (United States)

    Thomsen, Natalie A; Hammer, Katherine A; Riley, Thomas V; Van Belkum, Alex; Carson, Christine F

    2013-04-01

    The aim of this study was to seek additional data on the antimicrobial susceptibility of Staphylococcus spp. after habituation to low levels of the topical antimicrobial agent tea tree (Melaleuca alternifolia) oil. Meticillin-susceptible Staphylococcus aureus (MSSA), meticillin-resistant S. aureus (MRSA) and coagulase-negative staphylococci (CoNS) were habituated to 0.075% tea tree oil for 3 days. Subsequently, the susceptibility of five isolates each of MSSA, MRSA and CoNS to fusidic acid, mupirocin, chloramphenicol, linezolid and vancomycin was determined by Etest, and susceptibility to tea tree oil, terpinen-4-ol, carvacrol and triclosan was determined by agar dilution. Following habituation to 0.075% tea tree oil, antimicrobial MICs differed between control and habituated isolates on 33 occasions (out of a possible 150), with MICs being higher in habituated isolates on 22 occasions. Using clinical breakpoint criteria, one MSSA isolate changed susceptibility category from vancomycin-susceptible (MIC=2 μg/mL) to intermediate susceptibility (MIC=3 μg/mL) after habituation in one of two replicates. For the non-antibiotic antimicrobial agents, MICs of habituated and control isolates differed on 12 occasions (out of a possible 120); 10 occasions in MRSA and 2 occasions in MSSA. MICs were higher for habituated isolates on five occasions. However, all the differences were one serial dilution only and were not regarded as significant. Habituation to sublethal concentrations of tea tree oil led to minor changes in MICs of antimicrobial agents, only one of which may have been clinically relevant. There is no evidence to suggest that tea tree oil induces resistance to antimicrobial agents.

  13. Comparison of microdilution and disc diffusion methods in assessing the in vitro activity of fluconazole and Melaleuca alternifolia (tea tree) oil against vaginal Candida isolates.

    Science.gov (United States)

    Ergin, A; Arikan, S

    2002-10-01

    The in vitro activity of fluconazole and Melaleuca alternifolia (tea tree) oil was evaluated against 99 vaginal Candida strains by the broth microdilution and disc diffusion methods. The microdilution method was performed in accordance with NCCLS-M27A guidelines. An investigational method was used for the disc diffusion test. Fluconazole and tea tree oil minimum inhibitory concentrations (MICs) obtained at 48 h tended to increase 1- to 2-fold or remain the same compared to 24 h readings for most of the isolates tested. C. krusei and C. norvegensis had significantly higher MICs and smaller inhibition zones for fluconazole compared to other species. Tea tree oil MICs were found to be similar, in general, for all Candida spp. tested. The geometric mean MIC of tea tree oil for all isolates was 2.2% (range, 0.25-4%) at 24 h and 3.0% (range, 1-8%) at 48 h. Tea tree oil mean inhibition zone diameter was 24 mm (range, 14-42 mm) at 24 h and 15.8 mm (range, 10-35 mm) at 48 h. In vitro activity of tea tree oil against fluconazole-resistant Candida strains was of particular interest. The isolates had similar tea tree oil MICs and inhibition zone diameters regardless of their fluconazole susceptibility profile. Tea tree oil MIC ranges (inhibition zone diameter ranges) were 2-4% (12-21 mm) and 2% (35 mm) at 48 h for C. krusei and C. norvegensis, respectively. These results suggest that tea tree oil MICs of the fluconazole-resistant isolates are comparable to those of fluconazole-susceptible isolates. This in vitro finding is promising for potential use of topical tea tree oil formulations in the treatment of candidiasis due to fluconazole-resistant strains.

  14. Effects of Melaleuca alternifolia (tea tree) essential oil and the major monoterpene component terpinen-4-ol on the development of single- and multistep antibiotic resistance and antimicrobial susceptibility.

    Science.gov (United States)

    Hammer, Katherine A; Carson, Christine F; Riley, Thomas V

    2012-02-01

    This study examined the effect of subinhibitory Melaleuca alternifolia (tea tree) essential oil on the development of antibiotic resistance in Staphylococcus aureus and Escherichia coli. Frequencies of single-step antibiotic-resistant mutants were determined by inoculating bacteria cultured with or without subinhibitory tea tree oil onto agar containing 2 to 8 times the MIC of each antibiotic and with or without tea tree oil. Whereas most differences in resistance frequencies were relatively minor, the combination of kanamycin and tea tree oil yielded approximately 10-fold fewer resistant E. coli mutants than kanamycin alone. The development of multistep antibiotic resistance in the presence of tea tree oil or terpinen-4-ol was examined by culturing S. aureus and E. coli isolates daily with antibiotic alone, antibiotic with tea tree oil, and antibiotic with terpinen-4-ol for 6 days. Median MICs for each antibiotic alone increased 4- to 16-fold by day 6. Subinhibitory tea tree oil or terpinen-4-ol did not greatly alter results, with day 6 median MICs being either the same as or one concentration different from those for antibiotic alone. For tea tree oil and terpinen-4-ol alone, day 6 median MICs had increased 4-fold for S. aureus (n = 18) and 2-fold for E. coli (n = 18) from baseline values. Lastly, few significant changes in antimicrobial susceptibility were seen for S. aureus and S. epidermidis isolates that had been serially subcultured 14 to 22 times with subinhibitory terpinen-4-ol. Overall, these data indicate that tea tree oil and terpinen-4-ol have little impact on the development of antimicrobial resistance and susceptibility.

  15. In vivo activity of terpinen-4-ol, the main bioactive component of Melaleuca alternifolia Cheel (tea tree oil against azole-susceptible and -resistant human pathogenic Candida species

    Directory of Open Access Journals (Sweden)

    Cassone Antonio

    2006-11-01

    Full Text Available Abstract Background Recent investigations on the antifungal properties of essential oil of Melaleuca alternifolia Cheel (Tea Tree Oil, TTO have been performed with reference to the treatment of vaginal candidiasis. However, there is a lack of in vivo data supporting in vitro results, especially regarding the antifungal properties of TTO constituents. Thus, the aim of our study was to investigate the in vitro and the in vivo anti-Candida activity of two critical bioactive constituents of TTO, terpinen-4-ol and 1,8-cineole. Methods Oophorectomized, pseudoestrus rats under estrogen treatment were used for experimental vaginal infection with azole (fluconazole, itraconazole -susceptible or -resistant strains of C. albicans. All these strains were preliminarily tested for in vitro susceptibility to TTO, terpinen-4-ol and 1,8-cineole for their antifungal properties, using a modification of the CLSI (formerly NCCLS reference M27-A2 broth micro-dilution method. Results In vitro minimal inhibitory concentrations (MIC90 values were 0.06% (volume/volume for terpinen-4-ol and 4% (volume/volume for 1,8-cineole, regardless of susceptibility or resistance of the strains to fluconazole and itraconazole. Fungicidal concentrations of terpinen-4-ol were equivalent to the candidastatic activity. In the rat vaginal infection model, terpinen-4-ol was as active as TTO in accelerating clearance from the vagina of all Candida strains examined. Conclusion Our data suggest that terpinen-4-ol is a likely mediator of the in vitro and in vivo activity of TTO. This is the first in vivo demonstration that terpinen-4-ol could control C. albicans vaginal infections. The purified compound holds promise for the treatment of vaginal candidiasis, and particularly the azole-resistant forms.

  16. In vivo bactericidal effect of Melaleuca alternifolia essential oil against Aeromonas hydrophila: Silver catfish (Rhamdia quelen) as an experimental model.

    Science.gov (United States)

    F Souza, Carine; Baldissera, Matheus D; A Vaucher, Rodrigo; Lopes, Leonardo Q S; Vizzotto, Bruno S; Raffin, Renata P; Santos, Roberto C V; L da Veiga, Marcelo; U M da Rocha, Maria Izabel; Stefani, Lenita M; Baldisserotto, Bernardo

    2016-09-01

    Aeromonas hydrophila is one of the main causative agent of high mortality and significative economic losses in aquaculture and has become increasingly resistant to conventional antibiotics. One feasible alternative to control and treat it is the use of essential oils. This study aimed to evaluate A. hydrophila susceptibility to tea tree oil (TTO-Melaleuca alternifolia) in vivo, and the effect of this treatment. In vivo tests were performed using silver catfish (Rhamdia quelen) as the experimental model. Silver catfish were treated with TTO at 25 and 50 μL/L for seven days before infection. After seven days, the fish were inoculated with A. hydrophila via intramuscularly. Treatment with TTO at 50 μL/L was able to extend longevity of infected fish, and showed 88% of therapeutic success, even though it did not show curative efficacy. TTO treatment was not toxic under these tested concentrations, since biomarkers of hepatic and renal functions were not affected, and the concentration of 50 μL/L was able to prevent increased levels of aspartate aminotransferase. There was no significative differences regarding hematological parameters (p < 0.05). Treatment with TTO 50 μL/L was able to reduce histopathological alterations usually caused by this type of bacteria in the gills, but it was unable to reduce hepatic histopathological alterations. Our results showed, for the first time, that TTO has high activity against A. hydrophila and proved to be a natural alternative to prevent and control this pathogen.

  17. Comparative evaluation of co-enzyme Q10 and Melaleuca alternifolia as antioxidant gels in treatment of chronic periodontitis: A clinical study

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    Chetan Purushottam Raut

    2016-01-01

    Full Text Available Background: Conventional nonsurgical periodontal therapy has been proven to be an effective treatment for patients with chronic periodontitis. Coenzyme Q10 and tea tree oil (TTO are known to have potential therapeutic benefits in chronic periodontitis. Aims: The aim of the study is to compare the efficacy of Coenzyme Q10 (Perio Q® and tea tree oil (Melaleuca alternifolia gel as an adjunct to scaling and root planing in the treatment of chronic periodontitis. Materials and Methods: Patients were divided equally into three groups: Group I (Control group: those receiving placebo gel + SRP, Group II (Test group I: those receiving Perio Q TM gel + SRP, and Group III (Test group II: those receiving tea tree oil gel + SRP. A total of 15 patients with 45 sites were enrolled in the study. Clinical parameters evaluated were plaque index (PI, gingival bleeding index (GI, probing pocket depth (PPD, and clinical attachment level (CAL. Statistical Analysis Used: Paired t-test was applied using SPSS software. Results: Mean PPD reduction for Group I, Group II, and Group III was 0.50 ± 0.2, 2.95 ± 0.20, and 2.09 ± 0.15, respectively. Mean CAL reduction for Group I, Group II, and Group III was 0.45 ± 0.22, 2.33 ± 0.04, and 2.28 ± 0.09, respectively. Changes in mean PI scores for Group I, Group II, and Group III were 0.67 ± 017, 1.00 ± 0.11, and 1.08 ± 0.05 and GBI scores were 0.92 ± 0.29, 1.08 ± 0.13, and 0.88 ± 0.28, respectively. Conclusions: Coenzyme Q10 and tea tree oil gel proved to be effective in the treatment of chronic periodontitis.

  18. 互叶白千层挥发油气相指纹图谱的化学模式识别研究%Pattern Recognition of the Fingerprint of Essential Oil of Melaleuca alternifolia by GC

    Institute of Scientific and Technical Information of China (English)

    林霄; 刘布鸣; 柴玲; 白懋嘉

    2012-01-01

    28 Batches of essential oil of Melaleuca alterni folia were studied, and a GC method was adopted to establish the chromatographic fingerprint. Nine peaks were confirmed as characteristic, three classification methods, including computer assisted similarity evaluation, hierarchical cluster analysis and discriminant analysis, were used in this study. These 3 methods are reliable, mutually reinforcing, and provides scientific basis for quality assessment of oil of Melaleuca alterni folia%以28批互叶白千层精油为研究对象,利用气相色谱法建立互叶白千层挥发油的指纹图谱,对其主要色谱峰进行归属,抽取并确定了9个色谱峰为共有特征峰,同时运用计算机辅助相似性评价、聚类分析及判别分析对其进行模式识别研究.三种方法得到的分类结果一致,相辅相成,可为评价互叶白千层挥发油以及对植物的质量评价和分类提供科学依据.

  19. 互叶白千层精油GC—MS挥发性成分及抗茵活性研究%Analysis of Essential Oil of Melaleuca Alternifolia and Its Antimicrobial Effectiveness

    Institute of Scientific and Technical Information of China (English)

    赵鑫; 鲍其泠; 张磊; 王洪梅; 胡国胜

    2012-01-01

    通过使用GC—MS联用技术对互叶白千层精油进行分析,从中鉴定了30种化学成分,占总含量的95.78%。主要成分松油烯醇-4,达到了45.81%;其次为1-松油烯,α-松油醇,α-松油烯,对伞花烃,α-蒎烯,1,8-桉叶油素,β-水芹烯。抗菌活性研究发现,互叶白干层精油对大肠杆菌、金黄色葡萄球菌以及白色念珠菌等具有一定的抗菌能力。%The components of essential oil of Melaleuca altemifolia were analyzed by GC - MS, and thirty copmponents in the oil were identified, which accounted for 95.78% of the total contents. Its main content was terpineol -4, which accounted for about 45.81% of the total contents. The other main contents were .γ- terpinene, α- terpineol, α- terpinene, P - cymene, α- pinene, 1,8 - cineole, β - phellandrene. The resulict of antimicrobial effectiveness suggested that the essential oil of melaleuca altemifolia was bactericidal against E. coli, S. aureus and C. albans.

  20. Combining 'omics and microscopy to visualize interactions between the Asian citrus psyllid vector and the Huanglongbing pathogen Candidatus Liberibacter asiaticus in the insect gut.

    Science.gov (United States)

    Kruse, Angela; Fattah-Hosseini, Somayeh; Saha, Surya; Johnson, Richard; Warwick, EricaRose; Sturgeon, Kasie; Mueller, Lukas; MacCoss, Michael J; Shatters, Robert G; Cilia Heck, Michelle

    2017-01-01

    Huanglongbing, or citrus greening disease, is an economically devastating bacterial disease of citrus. It is associated with infection by the gram-negative bacterium Candidatus Liberibacter asiaticus (CLas). CLas is transmitted by Diaphorina citri, the Asian citrus psyllid (ACP). For insect transmission to occur, CLas must be ingested during feeding on infected phloem sap and cross the gut barrier to gain entry into the insect vector. To investigate the effects of CLas exposure at the gut-pathogen interface, we performed RNAseq and mass spectrometry-based proteomics to analyze the transcriptome and proteome, respectively, of ACP gut tissue. CLas exposure resulted in changes in pathways involving the TCA cycle, iron metabolism, insecticide resistance and the insect's immune system. We identified 83 long non-coding RNAs that are responsive to CLas, two of which appear to be specific to the ACP. Proteomics analysis also enabled us to determine that Wolbachia, a symbiont of the ACP, undergoes proteome regulation when CLas is present. Fluorescent in situ hybridization (FISH) confirmed that Wolbachia and CLas inhabit the same ACP gut cells, but do not co-localize within those cells. Wolbachia cells are prevalent throughout the gut epithelial cell cytoplasm, and Wolbachia titer is more variable in the guts of CLas exposed insects. CLas is detected on the luminal membrane, in puncta within the gut epithelial cell cytoplasm, along actin filaments in the gut visceral muscles, and rarely, in association with gut cell nuclei. Our study provides a snapshot of how the psyllid gut copes with CLas exposure and provides information on pathways and proteins for targeted disruption of CLas-vector interactions at the gut interface.

  1. Insecticidal Activity of Melaleuca alternifolia Essential Oil and RNA-Seq Analysis of Sitophilus zeamais Transcriptome in Response to Oil Fumigation

    Science.gov (United States)

    Liao, Min; Xiao, Jin-Jing; Zhou, Li-Jun; Liu, Yang; Wu, Xiang-Wei; Hua, Ri-Mao; Wang, Gui-Rong; Cao, Hai-Qun

    2016-01-01

    Background The cereal weevil, Sitophilus zeamais is one of the most destructive pests of stored cereals worldwide. Frequent use of fumigants for managing stored-product insects has led to the development of resistance in insects. Essential oils from aromatic plants including the tea oil plant, Melaleuca alternifolia may provide environmentally friendly alternatives to currently used pest control agents. However, little is known about molecular events involved in stored-product insects in response to plant essential oil fumigation. Results M. alternifolia essential oil was shown to possess the fumigant toxicity against S. zeamais. The constituent, terpinen-4-ol was the most effective compound for fumigant toxicity. M. alternifolia essential oil significantly inhibited the activity of three enzymes in S. zeamais, including two detoxifying enzymes, glutathione S-transferase (GST), and carboxylesterase (CarE), as well as a nerve conduction enzyme, acetylcholinesterase (AChE). Comparative transcriptome analysis of S. zeamais through RNA-Seq identified a total of 3,562 differentially expressed genes (DEGs), of which 2,836 and 726 were up-regulated and down-regulated in response to M. alternifolia essential oil fumigation, respectively. Based on gene ontology (GO) analysis, the majority of DEGs were involved in insecticide detoxification and mitochondrial function. Furthermore, an abundance of DEGs mapped into the metabolism pathway in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database were associated with respiration and metabolism of xenobiotics, including cytochrome P450s, CarEs, GSTs, and ATP-binding cassette transporters (ABC transporters). Some DEGs mapped into the proteasome and phagosome pathway were found to be significantly enriched. These results led us to propose a model of insecticide action that M. alternifolia essential oil likely directly affects the hydrogen carrier to block the electron flow and interfere energy synthesis in

  2. Induction of Callus and Regeneration in Melaleuca alternifolia%互叶白千层愈伤组织诱导及植株再生

    Institute of Scientific and Technical Information of China (English)

    王小敏; 莫昭展; 吴敏

    2014-01-01

    本文报导了互叶白千层从无菌种子苗叶片诱导愈伤组织到植株再生的研究结果.实验表明:以继代代数不同的无菌苗叶片为诱导材料,在MS基本培养基中添加TDZ0.4mg/L+2,4-D0.4mg/L的第五代继代苗诱导效果较好,愈伤组织诱导率达100%.在互叶白千层愈伤组织分化阶段,在MS基本培养基中,激素组合筛选中以添加6-BA2.0mg/L+IAA2.5mg/L的分化效果较好,分化率高达94.53%.在分化苗伸长生根阶段,以MS+6-BA2.0mg/L+NAA0.8mg/L +AC 0.1%的效果较为显著,苗平均高度9.4cm,苗最壮,根粗且壮.%In this study, the callus induction of aseptic seedlings and the plantlet regeneration of Melaleuca alternifolia were reported. The results showed that the optimization callus induction media was MS medium add TDZ0.4 mg/L+2,4-D0.4mg/L used the fifth generation aseptic seedling and the induction rate achieved 100%. In the stage of callus differentiation, the best differential medium was MS medium supplied with 6-BA2.0mg/L+IAA2.5mg/L and differentiation rate of callus reached 94.53%. The best medium for regenerated plantlets rooting was MS + 6-BA2.0mg/L+NAA0.8mg/L +AC 0.1% and the average of seedling height reached 9.4cm. The seedlings and roots were strongest than those in the other medium.

  3. 互叶白千层(Melaleuca alternifolia)浮床对生活污水净化效果研究初报%PRELIMINARY SDUDY ON PURIFYING EFFECT OF MELALEUCA ALTERNIFLOLIA GROWN IN FLOATING-BED SYSTEMS TO DOMESTIC WASTEWATER

    Institute of Scientific and Technical Information of China (English)

    李彬; 靖元孝; 王忠正; 杨丹菁

    2010-01-01

    互叶白千层(Melaleuca alternifolia)为速生常绿木本植物,它产生的茶树油广泛应用于医药保健工业.该文研究了互叶白千层浮床系统对生活污水的净化能力,并与风车草浮床系统进行了比较.研究结果表明:在8-12月,互叶白千层浮床系统对污水净化能力较强,TN、TP、BOD5、CODCr、NH4-N和NO3-N平均去除率分别为71.39%、83.32%、84.96%、69.91%、72.53%和76.23%,分别为风车草浮床系统的87.55%、95.03%、97.48%、98.24%、88.73%和89.37%;在温度较低的1月,互叶白千层浮床系统对污水净化能力明显下降,TN、TP、BOD5、CODCr、NH4-N和NO3-N去除率分别为29.83%、61.33%、70.53%、49.89%、39.03%和53.84%,分别为风车草浮床系统的38.67%、68.24%、86.77%、77.70%、64.20%和65.87%.

  4. Two-Spotted Ladybeetle Adalia bipunctata L. (Coleoptera: Coccinellidae): A Commercially Available Predator to Control Asian Citrus Psyllid Diaphorina citri (Hemiptera: Liviidae)

    Science.gov (United States)

    Afzal, Muhammad; Stansly, Philip A.

    2016-01-01

    The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) is an economically important pest of citrus because it serves as a vector of the causal pathogens of huanglongbing (HLB) also known as citrus greening disease. The increased use of insecticides for control of D. citri negatively impacts several natural enemies including some effective ladybeetle species which are not available commercially. The two-spotted ladybeetle, Adalia bipunctata (Coleoptera: Coccinellidae) is found in some crop and forest ecosystems of Asia, Europe and North America and available commercially. It is known to attack aphids and mealybugs but there are no published records of feeding on psyllids. We evaluated suitability and preference of A. bipunctata for nymphs of D. citri compared to corn leaf aphid Rhopalosiphum maidis (Hemiptera: Aphididae) a global pest of cereal crops and prey for many predaceous insects. We also compared development and reproduction of A. bipunctata on these two species with frozen eggs of the Mediterranean flour moth Ephestia kuehniella (Lepidoptera: Pyralidae) at 25°C. Initially, more D. citri than R. maidis nymphs were consumed in the no-choice tests although final consumption by larva and adult of A. bipunctata did not differ in the choice and no-choice tests. Larval development was prolonged by one day on D. citri compared to R. maidis nymphs but did not differ between either of these diets and E. kuehniella. Larval survival to adult averaged 93–100% and was not impacted by diet. Adult life span did not differ between diets although those on D. citri and R. maidis nymphs weighed less and produced fewer but more fertile eggs than on E. kuehniella eggs. Significant reduction of D. citri nymphs averaging 54% was observed in colonies caged with adult A. bipunctata on field planted citrus. R° (net reproductive rate) was least for beetles fed R. maidis, but otherwise there were no significant differences in demographic parameters. Successful

  5. Two-Spotted Ladybeetle Adalia bipunctata L. (Coleoptera: Coccinellidae): A Commercially Available Predator to Control Asian Citrus Psyllid Diaphorina citri (Hemiptera: Liviidae).

    Science.gov (United States)

    Khan, Azhar A; Qureshi, Jawwad A; Afzal, Muhammad; Stansly, Philip A

    2016-01-01

    The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) is an economically important pest of citrus because it serves as a vector of the causal pathogens of huanglongbing (HLB) also known as citrus greening disease. The increased use of insecticides for control of D. citri negatively impacts several natural enemies including some effective ladybeetle species which are not available commercially. The two-spotted ladybeetle, Adalia bipunctata (Coleoptera: Coccinellidae) is found in some crop and forest ecosystems of Asia, Europe and North America and available commercially. It is known to attack aphids and mealybugs but there are no published records of feeding on psyllids. We evaluated suitability and preference of A. bipunctata for nymphs of D. citri compared to corn leaf aphid Rhopalosiphum maidis (Hemiptera: Aphididae) a global pest of cereal crops and prey for many predaceous insects. We also compared development and reproduction of A. bipunctata on these two species with frozen eggs of the Mediterranean flour moth Ephestia kuehniella (Lepidoptera: Pyralidae) at 25°C. Initially, more D. citri than R. maidis nymphs were consumed in the no-choice tests although final consumption by larva and adult of A. bipunctata did not differ in the choice and no-choice tests. Larval development was prolonged by one day on D. citri compared to R. maidis nymphs but did not differ between either of these diets and E. kuehniella. Larval survival to adult averaged 93-100% and was not impacted by diet. Adult life span did not differ between diets although those on D. citri and R. maidis nymphs weighed less and produced fewer but more fertile eggs than on E. kuehniella eggs. Significant reduction of D. citri nymphs averaging 54% was observed in colonies caged with adult A. bipunctata on field planted citrus. R° (net reproductive rate) was least for beetles fed R. maidis, but otherwise there were no significant differences in demographic parameters. Successful

  6. Deep Characterization of the Microbiomes of Calophya spp. (Hemiptera: Calophyidae Gall-Inducing Psyllids Reveals the Absence of Plant Pathogenic Bacteria and Three Dominant Endosymbionts.

    Directory of Open Access Journals (Sweden)

    Will A Overholt

    Full Text Available Bacteria associated with sap-feeding insect herbivores include not only symbionts that may increase their hosts' fitness but also harmful plant pathogens. Calophya spp. gall-inducing psyllids (Hemiptera: Calophyidae are being investigated for their potential as biological control agents of the noxious weed, Brazilian peppertree (Schinus terebinthifolia, in Florida. Although there are no examples of plant pathogen transmission by members of the family Calophyidae, several insects in the superfamily Psylloidea are known to transmit pathogenic bacteria in the genera Candidatus Liberibacter and Candidatus Phytoplasma. To determine whether Calophya spp. harbor potentially harmful plant pathogenic bacteria, we sequenced small subunit (SSU ribosomal RNA (rRNA gene amplicons generated from individuals from four Calophya spp. populations: All microbial SSU gene sequences fell into the bacterial domain, with 98-99% belonging to the Proteobacteria. The Calophya microbiomes contained a relatively simple community, with 49-79 operational taxonomic units (OTUs; 97% detected, and only 5-8 OTUs with greater than 1% abundance. Candidatus Carsonella showed the highest relative abundance, with OTUs from this candidate genus representing between 51-65% of all recovered sequences. The next most abundant clade observed was an unclassified Enterobacteriacae group closely related to bacteria from the genera Buchnera and Blochmannia that ranged from 20-31% in relative abundance. Wolbachia populations were the third most abundant group and represented 7-27% of the diversity in microbial OTUs. No SSU rRNA gene sequences from putative pathogenic bacteria from the genera Ca. Liberibacter or Ca. Phytoplasma were detected in the microbiomes of the four Calophya populations. The probability that infected psyllids were present in our colonies, but were not sampled, was extremley low (1.39 x 10(-10. As far as we are aware, our study is the first to characterize the microbiome of

  7. 互叶白千层幼苗光合日进程%Diurnal Change of Photosynthesis in Melaleuca alternifolia Seedlings

    Institute of Scientific and Technical Information of China (English)

    莫昭展; 梁海清

    2009-01-01

    [目的] 为改进互叶白千层栽培技术,提高其产量和质量提供理论依据.[方法] 随机选取5株互叶白千层扦插苗上的健康功能叶片作为测定对象,用TPS-1便携式光合测定系统同步测定其净光合速率等指标.[结果] 10:00左右,互叶白千层的净光合速率出现第1个峰值44.00 μmol/(m2 ·s),初步确定其光饱和点为1 900.00 μmol/(m2 ·s)左右.14:00,光合有效辐射达最高值2 000.00 μmol/(m2 ·s).16:00左右,互叶白千层的净光合速率出现第2个峰值4.05 μmol/(m2 ·s).16:00,空气CO2浓度降至最低值.11:00,叶片气孔导度达峰值800.00 mmol/(m2 ·s).12:00,蒸腾速率达峰值.8:00,水分利用率最高.[结论] 互叶白千层的光合日变化呈双峰型,其净光合速率日变化与空气CO2浓度呈显著负相关,与光合有效辐射呈极显著正相关,与胞间CO2浓度呈显著负相关.%[Objective] The research aimed to provide theoretical basis for improving the cultivation technology of Melaleuca alternifolia and enhancing its yield and quality. [Method] The healthy functional leaves on the 5 cutting seedlings of M. Alternifolia were randomly selected as measuring objects and their indexes such as net photosynthetic rate were measured synchronously by TPS-1 portable photosynthesis measurement system. [Result] At about 10:00, the net photosynthetic rate of M. Alternifolia showed its first peak value of 44.00 μmol/(m2 ·s), its light saturation point was ascertained to be about 1 900.00 μmol/(m2 ·s) preliminarily. At 14:00, the photosynthetically active radiation reached its maximum of 2 000.00 μmol/(m2 ·s). At about 16:00, the net photosynthetic rate of M. Alternifolia showed its second peak value of 4.05 μmol/(m2 ·s). At 16:00, the carbon dioxide concn. In air decreased to its lowest value. At 11:00, the leaf stomatal conductance reached its peak value of 800.00 mmol/(m2 ·s). At 12:00, the transpiration rate reached its peak value. At 8:00, the water

  8. Rare diploid females coexist with rare males: a novel finding in triploid parthenogenetic populations in the psyllid Cacopsylla myrtilli (W. Wagner, 1947) (Hemiptera, Psylloidea) in northern Europe.

    Science.gov (United States)

    Nokkala, C; Kuznetsova, V G; Nokkala, S

    2015-10-01

    Using a cytological approach, diploid females were found coexisting with rare males in triploid apomictic parthenogenetic populations of the psyllid Cacopsylla myrtilli (W. Wagner, 1947) in Norway, Sweden, Finland and northwest Russia. Diploid females were easily distinguished from triploid apomictic females by the presence of 13 chiasmate bivalents instead of 39 univalent chromosomes at metaphase I. Abundance equaled that of males, but the proportion of males and diploid females was significantly greater in high altitude compared with low altitude populations. Males mated with females but showed no mating preference for diploid females. Lack of genuine bisexual reproduction owing to either asynaptic meiosis in males, or rarity of males with normal meiosis, suggests that diploids are produced in every generation by parthenogenetic females as reversals from triploidy, with their production being enhanced by environmental factor(s) associated with high altitude. This is further supported by the observation that within a population the COI haplotype found in rare males was the same as that in parthenogenetic triploid females. Thus, in northern Europe parthenogenesis in C. myrtilli is obligate, geographic parthenogenesis. Bisexual populations of C. myrtilli should be looked for in Central and Southern Europe. From the evolutionary point of view, the presence of males and diploid females with normal meiosis in parthenogenetic populations could be significant as they exhibit the potential to re-evolve either a new sexual species of parthenogenetic ancestry or a new parthenogenetic species by contagious parthenogenesis.

  9. Global genetic variation in the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae) and the endosymbiont Wolbachia: links between Iran and the USA detected.

    Science.gov (United States)

    Lashkari, Mohammadreza; Manzari, Shahab; Sahragard, Ahad; Malagnini, Valeria; Boykin, Laura M; Hosseini, Reza

    2014-07-01

    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 technique was utilized to elucidate the relationships among the sequences data in this study and all mtCOI and wsp sequence data available in GenBank and the Wolbachia database. Microsatellite markers revealed significant genetic differentiation among Iranian populations, as well as between Iranian and Pakistani populations (FST  = 0.0428, p Mexico, Florida and Texas (USA) are similar. Wolbachia, wDi, wsp sequences were similar among Iranian populations, but different between Iranian and Pakistani populations. The South West Asia (SWA) group is the most likely source of the introduced Iranian populations of D. citri. This assertion is also supported by the sequence similarity of the Wolbachia, wDi, strains from the Florida, USA and Iranian D. citri. These results should be considered when looking for biological controls in either country. © 2013 Society of Chemical Industry.

  10. Age at reproductive maturity and effect of age and time of day on sex attraction in the potato psyllid Bactericera cockerelli

    Institute of Scientific and Technical Information of China (English)

    Christelle Guédot; David R.Horton; Peter J.Landolt

    2012-01-01

    The potato psyllid,Bactericera (=Paratrioza) cockerelli ((S)ulc) (Hemiptera:Triozidae),is a major pest of potato.Studies were conducted to determine the age at which both males and females reach reproductive maturity and the effect of age and time of day on sex attraction.Adult B.cockerelli reach reproductive maturity within 48 h post-eclosion,with females being mature on the day of eclosion and males at 1 day post-eclosion.Oviposition generally began 2 days after mating but was delayed when females mated within 2 days post-eclosion.In laboratory olfactometer assays,the age of females used as odor sources and the age of males assayed to these odors did not affect sex attraction,with both younger (1-4-day-old) and older (8-10-day-old) males being attracted to females,regardless of female age (1-4-day-old or 8-10-day-old).Males assayed to live females at different times during the photophase (between 8:00 and 20:00 hours) were attracted to females between 11:00 and 17:00 hours,showing a temporal periodicity in sex attraction with B.cockerelli at least during the photophase.

  11. Advances in Biological Control of Citrus Psyllid Diaphorina citri, a Vector Insect of Citrus Huanglongbing Disease%黄龙病媒介昆虫柑橘木虱生物防治新进展

    Institute of Scientific and Technical Information of China (English)

    代晓彦; 任素丽; 周雅婷; 任顺祥; 邱宝利

    2014-01-01

    The citrus psyllid, Diaphorina citri Kuwayama, is the primary vector of citrus Huanglongbing disease, Candidatus Liberibacter asiaticus, which has the huge potential threats to the development of citrus industry in China. Based on the comprehensive understanding of D. citri control technologies, we reviewed the latest advances in biological control of D. citri and forecasted its future prospects. The main biological control resources of citrus psyllid currently are natural enemy insects and entomopathogenic fungi, among which predatory ladybeetles, lacewings, spiders and hover flies are the dominant species of predator, while Tamarixia radiata and Diaphorencyrtus aligarhensis are the two dominant parasitoids in China. Several representative entomopathogenic fungi include Lecanicillium lecanii, Isaria fumosorosea, Beauveria bassiana and Hirsutella citriformis have been reported with high virulence to citrus psyllid. This current review is expected to provide technical support and theoretical reference for efficient and sustainable control of citrus psyllid in the future.%柑橘木虱Diaphorina citri Kuwayama是柑橘黄龙病的重要媒介昆虫,对我国柑橘产业的健康发展潜在着巨大的威胁。本文在综合国内柑橘木虱防控技术的基础上,对近年来柑橘木虱生物防治的最新研究进展进行了综述,并且对其生物防治的发展前景给予了展望。目前应用于柑橘木虱生物防治的天敌资源主要是天敌昆虫及昆虫病原真菌,其中捕食性天敌主要包括瓢虫、食蚜蝇、草蛉和蜘蛛,寄生性天敌昆虫主要包括啮小蜂和跳小峰;昆虫病原真菌主要包括蜡蚧轮枝菌、拟青霉、白僵菌、桔形被毛孢等。期望通过对柑橘木虱生物防治工作的综述,为我国今后柑橘木虱的科学、高效防控及其可持续治理提供参考,不断推动我国柑橘产业的健康发展。

  12. Technology research of composite manufacturing MDF with Melaleuca alternifolia and Eucalyptus grandis×E.urophylla wood chips%白千层与尾巨桉木片混合压制MDF工艺研究

    Institute of Scientific and Technical Information of China (English)

    曹馨蕾; 李凯夫; 陈文军

    2014-01-01

    采用正交试验设计方法,用不同工艺参数压制白千层-尾巨桉中密度纤维板(MDF),并对其力学性能进行测试。结果显示:木片的蒸煮压力对白千层-尾巨桉MDF静曲强度和吸水厚度膨胀率影响较大,而白千层木片与尾巨桉木片的混合比例则对内结合强度影响较大;对4.4 mm厚MDF试验成品的各项性能进行极差分析,得出在白千层与尾巨桉混合比例为1∶1、蒸煮时间为13 min、蒸煮压力0.95 MPa的条件下MDF的质量为最好,符合GB/T 11718-2009中对普通型中密度纤维板的性能要求。%The orthogonal test was used to explore the physical property of MDF with different process parameters. The results show that the steaming pressure had great impact in the static bending intensity and thickness swelling of the tested chips;the mixing ratio of Melaleuca alternifolia chips and Eucalyptus grandis×E.urophylla chips had great effect to the internal bond strength. By analyzing the 4.4 mm MDF products with range analysis method,the conclusions were as follows:with the conditions of the mixing ratio 1︰1 of Melaleuca alternifolia and Eucalyptus grandis×E.urophylla, steaming time 13 mins, and the steaming pressure 0.95 MPa, the products quality MDF of is the best. In this way, the quality of MDF not only would reach the standard of GB/T11718-2009, but also has the best performance..

  13. Toxicological and biochemical characterizations of AChE in phosalone-susceptible and resistant populations of the common pistachio psyllid, Agonoscena pistaciae.

    Science.gov (United States)

    Alizadeh, Ali; Talebi-Jahromi, Khalil; Hosseininaveh, Vahid; Ghadamyari, Mohammad

    2014-02-05

    The toxicological and biochemical characteristics of acetylcholinesterases (AChE) in nine populations of the common pistachio psyllid, Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Psyllidae), were investigated in Kerman Province, Iran. Nine A. pistaciae populations were collected from pistachio orchards, Pistacia vera L. (Sapindales: Anacardiaceae), located in Rafsanjan, Anar, Bam, Kerman, Shahrbabak, Herat, Sirjan, Pariz, and Paghaleh regions of Kerman province. The previous bioassay results showed these populations were susceptible or resistant to phosalone, and the Rafsanjan population was most resistant, with a resistance ratio of 11.3. The specific activity of AChE in the Rafsanjan population was significantly higher than in the susceptible population (Bam). The affinity (K(M)) and hydrolyzing efficiency (Vmax) of AChE on acetylthiocholine iodide, butyrylthiocholine iodide, and propionylthiocholine odide as artificial substrates were clearly lower in the Bam population than that in the Rafsanjan population. These results indicated that the AChE of the Rafsanjan population had lower affinity to these substrates than that of the susceptible population. The higher Vmax value in the Rafsanjan population compared to the susceptible population suggests a possible over expression of AChE in the Rafsanjan population. The in vitro inhibitory effect of several organophosphates and carbamates on AChE of the Rafsanjan and Bam populations was determined. Based on I50, the results showed that the ratios of AChE insensitivity of the resistant to susceptible populations were 23 and 21.7-fold to monocrotophos and phosphamidon, respectively. Whereas, the insensitivity ratios for Rafsanjan population were 0.86, 0.8, 0.78, 0.46, and 0.43 for carbaryl, eserine, propoxur, m-tolyl methyl carbamate, and carbofuran, respectively, suggesting negatively correlated sensitivity to organophosphate-insensitive AChE. Therefore, AChE from the Rafsanjan population showed negatively

  14. Stylet morphometrics and citrus leaf vein structure in relation to feeding behavior of the Asian citrus psyllid Diaphorina citri, vector of citrus huanglongbing bacterium.

    Science.gov (United States)

    Ammar, El-Desouky; Hall, David G; Shatters, Robert G

    2013-01-01

    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 on the lower (abaxial) side of young leaves either on secondary veins or on the sides of the midrib, whereas adults preferred to settle and feed on the upper (adaxial) or lower secondary veins of young or old leaves. Early instar nymphs can reach and probe the phloem probably because the distance to the phloem is considerably shorter in younger than in mature leaves, and is shorter from the sides of the midrib compared to that from the center. Additionally, the thick-walled 'fibrous ring' (sclerenchyma) around the phloem, which may act as a barrier to ACP stylet penetration into the phloem, is more prominent in older than in younger leaves and in the center than on the sides of the midrib. The majority (80-90%) of the salivary sheath termini produced by ACP nymphs and adults that reached a vascular bundle were associated with the phloem, whereas only 10-20% were associated with xylem vessels. Ultrastructural studies on ACP stylets and LAS-infected leaves suggested that the width of the maxillary food canal in first instar nymphs is wide enough for LAS bacteria to traverse during food ingestion (and LAS acquisition). However, the width of the maxillary salivary canal in these nymphs may not be wide enough to accommodate LAS bacteria during salivation (and LAS inoculation) into host plants. This may explain the inability of early instar nymphs to transmit LAS/HLB in earlier reports.

  15. Stylet morphometrics and citrus leaf vein structure in relation to feeding behavior of the Asian citrus psyllid Diaphorina citri, vector of citrus huanglongbing bacterium.

    Directory of Open Access Journals (Sweden)

    El-Desouky Ammar

    Full Text Available 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 on the lower (abaxial side of young leaves either on secondary veins or on the sides of the midrib, whereas adults preferred to settle and feed on the upper (adaxial or lower secondary veins of young or old leaves. Early instar nymphs can reach and probe the phloem probably because the distance to the phloem is considerably shorter in younger than in mature leaves, and is shorter from the sides of the midrib compared to that from the center. Additionally, the thick-walled 'fibrous ring' (sclerenchyma around the phloem, which may act as a barrier to ACP stylet penetration into the phloem, is more prominent in older than in younger leaves and in the center than on the sides of the midrib. The majority (80-90% of the salivary sheath termini produced by ACP nymphs and adults that reached a vascular bundle were associated with the phloem, whereas only 10-20% were associated with xylem vessels. Ultrastructural studies on ACP stylets and LAS-infected leaves suggested that the width of the maxillary food canal in first instar nymphs is wide enough for LAS bacteria to traverse during food ingestion (and LAS acquisition. However, the width of the maxillary salivary canal in these nymphs may not be wide enough to accommodate LAS bacteria during salivation (and LAS inoculation into host plants. This may explain the inability of early instar nymphs to transmit LAS/HLB in earlier reports.

  16. Risk assessment of various insecticides used for management of Asian citrus psyllid, Diaphorina citri in Florida citrus, against honey bee, Apis mellifera.

    Science.gov (United States)

    Chen, Xue Dong; Gill, Torrence A; Pelz-Stelinski, Kirsten S; Stelinski, Lukasz L

    2017-01-23

    The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is a major pest of citrus trees worldwide. A wide variety of insecticides are used to manage D. citri populations within citrus groves in Florida. However, in areas shared by citrus growers and beekeepers the use of insecticides may increase the risks of Apis mellifera  L. (Hymenoptera: Apidae) loss and contaminated honey. The objective of this research was to determine the environmental toxicity of insecticides, spanning five different modes of action used to control D. citri, to A. mellifera. The insecticides investigated were imidacloprid, fenpropathrin, dimethoate, spinetoram and diflubenzuron. In laboratory experiments, LD50 values were determined and ranged from 0.10 to 0.53 ng/μl for imidacloprid, fenpropathrin, dimethoate and spinetoram. LD50 values for diflubenzuron were >1000 ng/μl. Also, a hazard quotient was determined and ranged from 1130.43 to 10893.27 for imidacloprid, fenpropathrin, dimethoate, and spinetoram. This quotient was mellifera 3 and 7 days after application. Spinetoram and imidacloprid were moderately toxic to A. mellifera at the recommended rates for D. citri. Diflubenzuron was not toxic to A. mellifera in the field as compared with untreated control plots. Phenoloxidase (PO) activity of A. mellifera was higher than in untreated controls when A. mellifera were exposed to 14 days old residues. The results indicate that diflubenzuron may be safe to apply in citrus when A. mellifera are foraging, while most insecticides used for management of D. citri in citrus are likely hazardous under various exposure scenarios.

  17. A Preliminary Trial Report on Introduction of Tea Tree(Melaleuca altemifolia L.)from Australia%四个澳大利亚互叶白千层新品系的引种试栽试验初报

    Institute of Scientific and Technical Information of China (English)

    张孝洪; 白懋嘉

    2011-01-01

    引种栽培试验初步显示,从澳大利亚引进的287-04-02、42-04两个互叶白千层新品系在广东境内北回归线附近种植后第一年均表现出较好的适应性和丰产性,所提原油中的主要功能指标组分松油烯4-醇含量超过目前国际商业化产品的工业和化妆品级别质量标准.%The results of the experiments on introduction and cultivation of tea tree showed better adaptability and oil yields during the first year trial with two strains of tea tree (Melaleuca altemifolia L. ) introduced from Australia to China. The trials were conducted in the vicinity of tropic of cancer in Guangdong province. The content of terpinene-4-ol, as the major functional ingredient extracted from the crude oil, exceeded the international standards both commercially and cosmetically.

  18. PREPARAÇÃO DE NOVOS FILMES POLIMÉRICOS CONTENDO NANOEMULSÕES DO ÓLEO DE MELALEUCA, COPAÍBA E LIMÃO PARA APLICAÇÃO COMO BIOMATERIAL

    Directory of Open Access Journals (Sweden)

    Viviane G. A. Pires

    Full Text Available The sodium alginate is a linear polymer used in industry and in medicine for many applications such as dressings for wounds, due to low toxicity and maintains a proper moist environment. The essential oils are materials that have antimicrobial activity and are active materials, which may be incorporated in polymeric films. This study has as objective the produce alginate films incorporated with nanoemulsions of melaleuca, copaiba and lemon oil and investigate water vapor permeability (WVP analysis of the films, particle size and ζ-potential of nanoemulsions. Particle size analyzes showed formation of large and small particles nanoemulsion depending on the agitation speed used during production of nanoemulsions. Results of the WVP analyzes showed that the film with alginate 3 % w/v and nanoemulsions with little particle prepared with agitation speed of 15000 rpm showed better WVP. Produced films show good quality for a future application as dressings because it has good WVP. This is very interesting because the skin needs to breathe.

  19. 引种互叶白千层茶树油的化学成分及抑菌活性%Chemical Components and Antimicrobial Activity of Tea Tree Oil from Introduced Melaleuca alternifolia

    Institute of Scientific and Technical Information of China (English)

    钟振声; 樊丽妃; 黄继兵

    2011-01-01

    采用气相色谱-质谱联用仪(GC/MS)对从澳大利亚引种的广西玉林市互叶白千层茶树油进行化学成分分析;测试了该种茶树油的理化常数,并将结果与ISO国际标准进行了比较;以大肠杆菌和金黄色葡萄球菌为供试菌种,对该种茶树油的抑菌活性进行了研究,并用混合药剂法测得了该种茶树油对供试菌种的最小抑菌浓度;最后考察了培养基pH值、食盐和蔗糖对该种茶树油抑菌活性的影响.发现:非特征成分桉叶素的相对含量高达72.49%,而特征成分4-松油醇只有0.78%;该种茶树油的大多数理化常数均不在ISO国际标准规定的范围之内;该种茶树油对供试菌种的最小抑菌浓度均为4.00mL/L,显示其有很强的抑菌活性;在pH=5~10范围内,该种茶树油对供试菌种都有较强的抑制作用;一定用量的食盐及蔗糖与该种茶树油之间存在明显的协同抑菌作用.这些结果表明,该互叶白千层茶树极有可能发生了变种,但其抑菌活性得到了保持.%In this paper, first, the chemical components of the tea tree oil extracted from Melaleuca alternifolia introduced from Australia and planted in Yulin, Guangxi, China, were analyzed by means of GC/MS. Next, the physical and chemical parameters of the tea tree oil were measured and were compared with the data set by ISO international standard. Then, by using Escherichia coli and Staphylococcus aureus as the indicator bacteria, the antimicrobial activity of the tea tree oil was investigated, and the corresponding minimum inhibitory concentrations (MIC) were investigated by means of mixed medicament method. Finally, the effects of pH value, salt dosage and sucrose dosage on the antimicrobial activity were analyzed. The results show that ( 1 ) in the tea tree oil, the dosage of non-characteristic composition, namely 1,8-cineole, is up to 72. 49%, while that of the characteristic composition, namely terpinen-4-ol, is only 0. 78%; (2) most

  20. A randomised, assessor blind, parallel group comparative efficacy trial of three products for the treatment of head lice in children - melaleuca oil and lavender oil, pyrethrins and piperonyl butoxide, and a "suffocation" product

    Directory of Open Access Journals (Sweden)

    Barker Stephen C

    2010-08-01

    Full Text Available Abstract Background There are many different types of pediculicides available OTC in Australia. In this study we compare the efficacy and safety of three topical pediculicides: a pediculicide containing melaleuca oil (tea tree oil and lavender oil (TTO/LO; a head lice "suffocation" product; and a product containing pyrethrins and piperonyl butoxide (P/PB. Method This study was a randomised, assessor-blind, comparative, parallel study of 123 subjects with live head lice. The head lice products were applied according to the manufacturer's instructions (the TTO/LO product and the "suffocation" product were applied three times at weekly intervals according to manufacturers instructions (on Day 0, Day 7 and Day 14 and the P/PB product was applied twice according to manufacturers instructions (on Day 0 and Day 7. The presence or absence of live lice one day following the last treatment was determined. Results The percentage of subjects who were louse-free one day after the last treatment with the product containing tea tree oil and lavender oil (41/42; 97.6% and the head lice "suffocation" product (40/41, 97.6% was significantly higher compared to the percentage of subjects who were louse-free one day after the last treatment with the product containing pyrethrins and piperonyl butoxide (10/40, 25.0%; adj. p Conclusion The high efficacy of the TTO/LO product and the head lice "suffocation" product offers an alternative to the pyrethrins-based product. Trial Registration The study was entered into the Australian/New Zealand Clinical Trial Registry, ACTRN12610000179033.

  1. Uncontrolled, open-label, pilot study of tea tree (Melaleuca alternifolia) oil solution in the decolonisation of methicillin-resistant Staphylococcus aureus positive wounds and its influence on wound healing.

    Science.gov (United States)

    Edmondson, Margaret; Newall, Nelly; Carville, Keryln; Smith, Joanna; Riley, Thomas V; Carson, Christine F

    2011-08-01

    Many complementary and alternative products are used to treat wounds. The essential oil of Melaleuca alternifolia, tea tree oil, has proven antimicrobial and anti-inflammatory properties, may be useful in methicillin-resistant Staphylococcus aureus (MRSA) decolonisation regimens and is reputed to have 'wound-healing' properties, but more data are required to support these indications. The primary aim of this uncontrolled case series was to assess whether a tea tree oil solution used in a wound cleansing procedure could decolonise MRSA from acute and chronic wounds of mixed aetiology. The secondary aim was to determine if the tea tree oil solution influenced wound healing outcomes. Nineteen participants with wounds suspected of being colonised with MRSA were enrolled in a pilot study. Seven were subsequently shown not to have MRSA and were withdrawn from the study. As many as 11 of the remaining 12 participants were treated with a water-miscible tea tree oil (3·3%) solution applied as part of the wound cleansing regimen at each dressing change. Dressing changes were three times per week or daily as deemed necessary by the study nurse following assessment. One participant withdrew from the study before treatment. No participants were MRSA negative after treatment. After treatment had been implemented, 8 of the 11 treated wounds had begun to heal and reduced in size as measured by computer planimetry. Although this formulation and mode of delivery did not achieve the primary aim of the study, tea tree oil did not appear to inhibit healing and the majority of wounds reduced in size after treatment.

  2. Detection and identification of 1-methylethyl and methyl radicals generated by irradiating tea tree (Melaleuca alternifolia) oil with visible light (436 nm) in the presence of flavin mononucleotide and ferrous ion.

    Science.gov (United States)

    Mori, H-M; Iwahashi, H

    2013-08-01

    Here, we determined the electron spin resonance (ESR) spectra of standard reaction mixtures (I) containing 25 μM flavin mononucleotide (FMN), 0.018% tea tree (Melaleuca alternifolia) oil, 1.9 M acetonitrile, 20 mM phosphate buffer (pH 7.4), 0.1 M α-(4-pyridyl-1-oxide)-N-tert-butylnitrone (4-POBN), and 1.0 mM FeSO₄(NH₄)₂SO₄ irradiated with 436 nm visible light (7.8 J/cm²). Prominent ESR signals (αN = 1.58 mT and αHβ = 0.26 mT) were detected, suggesting that free radicals form in the standard reaction. In order to know whether singlet oxygen (¹O₂) is involved in the radical formation or not, ESR measurement was performed for the standard D₂O reaction mixture (I) which contained 25 μM FMN, 0.0036% tea tree oil, 1.9 M acetonitrile-d3, 20 mM phosphate buffer (pH 7.4), 0.1 M 4-POBN and 1.0 mM FeSO₄ in D₂O. The ESR peak height of the standard D₂O reaction increased to 169 ± 24% of the control. Thus, ¹O₂ seems to be involved in the formation of the radicals because D₂O increases the lifetime of singlet oxygen. High-performance liquid chromatography-ESR-mass spectrometry analyses detected 1-methylethyl and methyl radicals in the standard reaction. The radicals appear to form through the reaction of ferrous ion with α-terpinene endoperoxide (ascaridole), which generated from the reaction of α-terpinene with ¹O₂. The 1-methylethyl and methyl radicals may exert a pro-oxidant effect under these conditions.

  3. 柑橘木虱两地理种群的内共生菌群落组成及传菌能力%The endosymbiotic microbiota of two geographical populations of the Asian citrus psyllid,Diaphorina citri,in China and its ability of pathogen transmission

    Institute of Scientific and Technical Information of China (English)

    马晓芳; 张学潮; 徐海君

    2012-01-01

    柑橘黄龙病(Huanglongbing,HLB)是经柑橘木虱Diaphorina citri传播的最主要柑橘病害之一,危害严重时能对柑橘产业造成毁灭性的破坏.为了鉴定福建和海南2个地理种群柑橘木虱的内共生菌群落组成,本研究对16SrRNA部分保守序列进行PCR扩增,并利用特异性引物对不同内共生菌进行了感染率检测;另外,还通过人工接虫的方法,探索柑橘木虱成虫在带黄龙病菌蕉柑Citrus reticulata cv.Tankan 上的获菌能力,以及带菌柑橘木虱成虫对黄岩蜜橘C.reticulata cv.Subcompress的传菌能力.研究发现,这2个地理种群的柑橘木虱含有相同的内共生菌组成,包括α-Proteobacteria,Wolbachia spp.,γ-Proteobacteria,mycetocyte symbionts,β-Proteobacteria,Oxalobacter 和β-Proteobacteria,Herbaspirillum,而且这2个地理种群柑橘木虱的4种内共生菌的携带率均在95%以上.柑橘木虱成虫在带菌蕉柑上饲菌28 d后,带菌率可达到82%,而带菌柑橘木虱成虫在黄岩蜜橘上传菌75 d后,可导致橘树整体带菌.本研究为柑橘木虱的进一步研究和防虫治病途径提供了一些理论依据.%Huanglongbing (HLB) is one of the most severe citrus diseases, which is usually transmitted by the Asian citrus psyllid ( Diaphorina citri), and causes great economic loss. To understand the endosyrnbiotic microbiota of the citrus psyllid from Hainan and Fujian provinces in China, the partial conserved region of 16S rRNA was amplified by PCR, and subsequently the infection rate of each endosymbiont from two geographical populations of the citrus psyllid was detected by PCR using specific primer pairs in this stduy. Moreover, we detected the acquisition efficiency of the pathogen by adult citrus psyllid reared on Citrus reticulata cv. Tank an infected with Candidatus Liberibacter as iatic us (CLas) , and the transmission efficiency to Citrus reticulata cv, Subcompress via CLas-positive psyllids. The results demonstrated that the two

  4. 淹水解除后互叶白千层幼苗光合特性的恢复%Recovery of Photosynthetic Characteristics of Melaleuca alternifolia Seedlings after Submersion

    Institute of Scientific and Technical Information of China (English)

    靖元孝; 刘瑞仙; 肖林; 李国梁; 杨丹菁

    2011-01-01

    Periodic flooding of trees in tropical floodplains and reservoirs where water levels fluctuate is a common phenomenon. The alternating terrestrial and aquatic periods with advancing and receding floods poses a variety of constraints to the plants growing in this habitat. If flooding is recurrent before the plants recover from previous flooding, injuries will accumulate and serious damage may occur. Therefore, when assessing plant resistance to flooding, it is important to consider the ability of plants to recover from transient waterlogging. The success of tree planting on floodplain and reservoir depends not only on the tree's tolerance to submersion, but also on their subsequent recovery. Previous studies on physiological and growth responses of tree species to flooding have mostly focused on the responses to continuous flooding, but little is known about the responses to subsequent recovery after the removal of the flooding stress. Recovery effects of gas exchange, chlorophyll fluorescence and membrane permeability of Melaleuca alternifolia seedlings, a tall shrub species used in floodplain and reservoir forest restoration in southern China, were studied after submersion. Throughout a 30-day submersion and another 70-day recovery period, the survival rates of M. alternifolia seedlings were 100%. After 30-day submersion, pronounced decrease of chlorophyll content, net photosynthetic rate (Pn), stomatal conductance(Gs), transpiration rate(Tr), the maximum quantum efficiency of the photosystem II (Fv/Fm), photochemical quenching coefficient (qP), and increase of non-photochemical quenching (NPQ), membrane permeability in the period after submersion, gradual increase of chlorophyll content, Pn, Gs, Tr, Fv/Fm, qP, and decrease of NPQ, membrane permeability in the recovered seedlings were found, and the above parameters in the recovered seedlings reached the levels similar to the control after 60-day recovery. Our study demonstrated that M. alternifolia seedlings is

  5. 枸杞木虱啮小蜂寄生行为及生物学特性的研究%Behavior and bionomics of the ectoparasitoid Tetrastichus sp. Of the wolf berry psyllid(Paratrioza sinica)

    Institute of Scientific and Technical Information of China (English)

    段立清; 冯淑军; 李海平; 邹晓林

    2002-01-01

    枸杞木虱啮小蜂Tetrastichus sp.是枸杞木虱Paratrioza sinica Yang & Li若虫的外寄生蜂,自然寄生率可达86.5%.在温度为20~25℃的室内条件下,完成1个世代需14~20 d.成虫寿命与取食有关,取食15%的蜂蜜水,雌性成虫寿命为12~17 d,雄性成虫为4~6 d.成蜂最喜欢在3龄和4龄若虫上产卵.自然种群消长与寄主虫口密度相关.每年7月到8月下旬该蜂寄生率高, 9月份下降,10月份几乎不见.Behavior and bionomics of the ectoparasitoid Tetrastichus sp. of the wolf berry psyllid(Paratrioza sinica).

  6. 引种互叶白千层茶树油有效抑菌成分辨析%Studies on the Antibacterial Composition Diversity of Introduced Melaleuca Alternifolia Oil

    Institute of Scientific and Technical Information of China (English)

    钟振声; 袁裕泉; 樊丽妃

    2012-01-01

    采用广西、江西和广东三地从澳大利亚引种互叶白千层茶树所提炼出来的茶树油做研究对象,先用精密分馏分离为若干组分,然后用气质联用仪(GC/MS)定量分析,确定每一组分的主要化学成分.同时用大肠杆菌和金黄色葡萄球菌作供试菌,分别检测茶树油各段馏分对两种菌的抑菌活性,对比研究各馏分化学成分与抑菌效果之间的关系.结果发现:三种茶树油的化学成分存在巨大差异,特征成分4-松油醇的质量分数从0.78% ~43.59%不等,而1,8-桉叶素的质量分数则从2.14% ~ 72.49%.三种茶树油的化学成分虽然显著不同,但是对大肠杆菌和金黄色葡萄球菌都有较强的抑菌活性,而且三种茶树油的有效抑菌物质都是1,8-桉叶素.而主要成分4-松油醇、γ-松油烯、α-松油烯和伞花烯等物质的含量与抑菌作用没有显著关联.%Three melaleuca alternifolia tea tree oil from Guangxi, Jiangxi and Guangdong province, they are introduced from Australia, were separately into different components by fractional distillation , then make sure the main chemical composition by GC/MS. By means of antibiotic experiment with colibacillus and staphylococcus aureus, through contrast research the antimicrobial activity of the different fraction. Results indicated that the chemical components of the three kinds of tea tree oil were in great diversity. The characteristic composition terpinen-4--ol accounted from0. 78% -43. 59% , while the noncharacteris-tic composition 1, 8-cineole accounted from 2. 14% -72. 49%. The three kinds of tea tree oil were in great diversity, but they all have strong antimicrobial activity to the Staphylococcus aureus and the colibacillus, the active constituent of the three kinds of tea tree oil were 1, 8-cineole. While the main component content, such as terpinen-4-ol, γ-Terpinen, α-Terpinen, p - Cymene. et, have no significant correlation with antibiotic activity.

  7. Melaleuca alternifolia nanoparticles against Candida species biofilms.

    Science.gov (United States)

    Souza, M E; Lopes, L Q S; Bonez, P C; Gündel, A; Martinez, D S T; Sagrillo, M R; Giongo, J L; Vaucher, R A; Raffin, R P; Boligon, A A; Santos, R C V

    2017-03-01

    Candida infection is an important cause of morbidity and mortality on immunosuppressed patients. This growing trend has been associated with resistance to the antimicrobial therapy and the ability of microorganism to form biofilms. TTO oil is used as antimicrobial which shows antibiofilm activity against Candida species. However, it presents problems due to its poor solubility and high volatility. The present study aimed to evaluate in vitro antibiofilm activity of TTO nanoparticles against many Candida species. It was performed the characterization of the oil and nanoparticles. The levels of exopolysaccharides, proteins, and the biomass of biofilms were measured. The chromatographic profile demonstrated that the TTO oil is in accordance with ISO 4730 with major constituents of 41.9% Terpinen-4-ol, 20.1% of γ-Terpinene, 9,8% of α-Terpinene, and 6,0% of 1,8-Cineole. The TTO nanoparticles showed pH of 6.3, mean diameter of 158.2 ± 2 nm, polydispersion index of 0.213 ± 0.017, and zeta potential of -8.69 ± 0.80 mV. The addition of TTO and its nanoparticles represented a significant reduction of biofilm formed by all Candida species, as well as a reduction of proteins and exopolysaccharides levels. It was possible to visualize the reduction of biofilm in presence of TTO nanoparticles by Calcofluor White method. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Biologia do psilídeo-de-concha Glycaspis brimblecombei Moore (Hemiptera, Psyllidae em Eucalyptus spp. Red gum lerp psyllid Glycaspis brimblecombei Moore (Hemiptera, Psylidae biology in Eucalyptus spp.

    Directory of Open Access Journals (Sweden)

    Daniela Cristina Firmino-Winckler

    2009-01-01

    Full Text Available Biologia do psilídeo-de-concha Glycaspis brimblecombei Moore (Hemiptera, Psyllidae em Eucalyptus spp.. Glycaspis brimblecombei Moore também conhecido por psilídeo-de-concha, se caracteriza por ser uma espécie específica ao gênero Eucalyptus L'Her. Este trabalho teve por objetivo determinar o ciclo biológico de G. brimblecombei em Eucalyptus spp. O trabalho foi conduzido em câmara climatizada (BOD, sob a temperatura de 26 °C e fotofase de 12 horas. As espécies de Eucalyptus utilizadas para o experimento foram: Eucalyptus camaldulensis, E. tereticornis, E. urophylla, E. grandis, Corymbia citriodora e um híbrido de E. grandis x E. urophylla ('urograndis'. Inicialmente foram utilizados 100 repetições (ninfas tratamento (espécies de Eucalyptus. As avaliações foram diárias. Os parâmetros biológicos avaliados foram a duração e viabilidade do estágio ninfal, longevidade dos adultos, número de posturas/fêmea, duração do período embrionário, número e viabilidade ovos, longevidade dos adultos e duração do ciclo total. Os resultados obtidos demonstraram que salvo C. citriodora que apresentou ser letal ao desenvolvimento ninfal de G. brimblecombei as demais espécies de Eucalyptus testadas oferecem condições ao desenvolvimento biológico deste psilídeo, sendo que neste trabalho E. camaldulensis mostrou-se a mais adequada.Glycaspis brimblecombei Moore, also known as red gum lerp psyllid, is characterized to be specific to the genus Eucalyptus. This work aimed to evaluate G. brimblecombei biological cycle in Eucalyptus spp. The work was accomplished in acclimatized chamber (BOD, with temperature of 26 °C and photophase of 12 hours. Eucalyptus species used in this study were: Eucalyptus camaldulensis, E. tereticornis, E. urophylla, E. grandis, Corymbia citriodora and E grandis x E. urophylla hybrid ('urograndis'. Initially 100 replications (nymphs per treatment (Eucalyptus species were prepared. The evaluations were daily and

  9. Approche expérimentale de l’utilisation de glyphosate dans le contrôle de Melaleuca quinquenervia (Myrtaceae, une espèce envahissante dans la réserve communautaire de la forêt d’Analalava-Foulpointe (Madagascar

    Directory of Open Access Journals (Sweden)

    Cyprien Miandrimanana

    2014-06-01

    Full Text Available Melaleuca quinquenervia, one of the most aggressive invasive species in Madagascar, gains more and more ground and colonizes wetland environments around the New Protected Area of the Analalava forest in Foulpointe. Concerns over its invasion increase and even if eradication seems already impossible, we must now find an effective solution to control its expansion towards the protected area. Only chemical control may be considered for this species, given its resilience to cutting and fire. This study aims at identifying the best protocol for the use of glyphosate in controlling the invasion of M. quinquenervia in the Analalava forest in Foulpointe. Five solutions of different concentrations of glyphosate, S1 (0 g/l, S2 (90 g/l, S3 (180 g/l, S4 (270 g/l, and S5 (360 g/l were tested on 200 individuals, or 40 individuals for each solution. Glyphosate solutions were applied on the cut surface of the trunk of an individual using either a brush or a sprayer. The controls were done for four months by observing the status on treated individuals and the impacts of the treatment on non - target plants. Most individuals treated are dead, showing an 85 % rate mortality. Some non - target plants were affected (19 % of the surveyed ones, regardless of the concentration of active ingredient glyphosate and of the equipment used. From these experiments, the best protocol for the glyphosate use is a concentration of 90 g/l of the active ingredient applied to the cut surface of the trunk treaty using a brush.

  10. Simultanous Determination of Quercetin and Kaempferol in Melaleuca alternifolia (Maiden et Betehe) Chee 1 by HPLC%高效液相色谱法同时测定互叶白千层中的槲皮素和山奈酚

    Institute of Scientific and Technical Information of China (English)

    林霄; 董晓敏; 陈明生; 黄艳; 刘布鸣

    2012-01-01

    用高效液相色谱法同时测定广西5地互叶白千层中槲皮素和山奈酚含量.样品用盐酸-甲醇(体积比5∶100)混合溶液水浴加热回流提取,C18柱色谱分离,以甲醇-乙腈-0.4%磷酸(体积比21∶21∶58)水溶液为流动相,检测波长370 nm,柱温为室温,流速1 mL/min.测定了不同产地互叶白千层中的槲皮素和山奈酚质量分数,其中邕宁南晓的槲皮素和山奈酚的质量分数最高,分别为5.151和2.530 mg/g,邕宁的槲皮素和山奈酚的质量分数为最低,分别为2.386和1.658 mg/g.%A high-performance liquid chromatography( HPLC) method was developed for simultaneous determination of quercetin and kaempferol in Melaleuca alternifolia ( Maiden et Betehe) Chee 1. The sample was extractd by HCl-MeOH solution(volume ratio 5:100) in water bath, then separated by a C18 column with CH3OH-C2H3N-0. 4% phosphoric acid solution (volume ratio 21 :21 :58) as the mobile phase solution under 370 nm wavelength. The HPLC experiment was performed at room temperature with flow rate 1.0 mL/min. Quercetin and kaempferol contents in M. alternifolia from different area were determined. The result showed that quercetin and kaempferol content in Nanxiao town of Yongning was the highest and that in Yongning was the lowest.

  11. Trailers transporting oranges to processing plants move Asian citrus psyllids

    Science.gov (United States)

    Huanglongbing (citrus greening) is one of the most serious of citrus diseases. Movement of the disease occurs as a result of natural vector-borne infection and by movement of plant material. We demonstrate here that Diaphorina citri Kuwayama (vector of citrus greening pathogens) can be transported i...

  12. Wolbachia-infection differs among potato psyllid haplotypes

    Science.gov (United States)

    Wolbachia is a bacterial endosymbiont of insects that can manipulate insect reproduction. In many insects, Wolbachia-free females cannot produce viable offspring when mated by infected males. The manipulation of insect reproduction by Wolbachia has important implications for insect evolution and pop...

  13. MIXTURE OF CHARCOAL KAYU GALAM (Melaleuca leucadendron LINN AND SHELL CANDLENUT (Aleurites moluceana WILD

    Directory of Open Access Journals (Sweden)

    LUSYIANI LUSYIANI

    2016-09-01

    Full Text Available ABSTRACT.  The purpose of this study was to determine the effect of mixture composition Galam wood with walnut shells to the quality of the resulting charcoal briquettes. The results and analysis of variance showed that the treatment given very real effect on the moisture content, ash content, the levels of substances fly, carbon residue, and the calorific value and significantly affect the density. The addition of hazelnut shell causes an increase in moisture content, ash content, and levels of substances that reduce the amount of carbon fly and the rest of the calorific value generated. The addition of hazelnut shells up to 50% (treatment A3 results in a briquette charcoal briquettes are still compliant imports (Japanese standard. Based on the results of the test, the charcoal briquettes produced have physical and chemical properties as follows: the average water content of 7.949%, the average ash content of 2.855%, the average levels of substance flew 29.510%, the average carbon remaining 67.652%, average the average density of 0.779 gram/cm3, and the average calorific value of 6202.6594 cal / gram. Keywords: moisture content, ash content, carbon residue, ABSTRAK.  Tujuan penelitian ini adalah untuk mengetahui pengaruh komposisi campuran kayu galam dengan tempurung kemiri terhadap kualitas briket arang yang dihasilkan. Hasil penelitian dan analisis sidik ragam menunjukkan bahwa perlakuan yang diberikan berpengaruh sangat nyata terhadap kadar air, kadar abu, kadar zat terbang, karbon sisa, dan nilai kalor serta berpengaruh nyata terhadap kerapatan. Penambahan tempurung kemiri menyebabkan kenaikan kadar air, kadar abu, dan kadar zat terbang sehingga mengurangi jumlah karbon sisa dan nilai kalor yang dihasilkan. Penambahan tempurung kemiri sampai 50% (perlakuan A3 menghasilkan briket arang yang masih memenuhi standar briket impor (standar Jepang. Berdasarkan hasil pengujian, briket arang yang dihasilkan mempunyai sifat fisik dan kimia sebagai berikut : rata-rata kadar air 7,949%, rata-rata kadarabu 2,855%, rata-rata kadar zat terbang 29,510%, rata-rata karbon sisa 67,652%, rata-rata kerapatan 0,779 gram/cm3, dan rata-rata nilai kalor 6202,6594 cal/gram. Kata Kunci : kadar air, kadar abu, karbon sisa

  14. Collaborative efforts for managing Melaleuca in the Ciénega de Zapata, Cuba

    Science.gov (United States)

    The Ciénega de Zapata Biosphere Reserve is the largest protected area not only in Cuba but also throughout the Caribbean. This swamp ecosystem is characterized by a high biodiversity that comprises several endemic birds, reptiles and invertebrates and is visited by 65 species of birds during their a...

  15. Ingestion of tea tree oil (Melaleuca oil) by a 4-year-old boy.

    Science.gov (United States)

    Morris, Marilyn C; Donoghue, Aaron; Markowitz, Jennifer A; Osterhoudt, Kevin C

    2003-06-01

    A 4-year-old boy ingested a small quantity of tea tree oil. Within 30 minutes, he became ataxic and shortly thereafter progressed to unresponsiveness; he was endotracheally intubated by paramedics. His neurologic status improved gradually over 10 hours, and he remains well on follow-up. Tea tree oil is an increasingly popular topical antiseptic that is available in a wide variety of products, often without warning labels. Healthcare providers should be aware of the common uses of tea tree oil, as well as its potential toxicity.

  16. Evaluation of in vitro leishmanicidal activity of tea tree oil (Melaleuca alternifolia)

    OpenAIRE

    Moradali Fouladvand; Soliman khorami; Behrooz Naeimi

    2016-01-01

    Background: Leishmania is a trypanosomatid protozoan which is transmitted by the female Phlebotomus sand fly. Leishmaniasis is prevalent in four continents and is considered to be endemic in 88 countries, 72 of which are developing countries. It is estimated that it’s global prevalence and incidence is 12 millions and 500 thousands respectively. The recommended drugs used for the treatment of this disease are mainly ineffective, toxic and exhibit many side effects. Based on some studies...

  17. Evaluation of in vitro leishmanicidal activity of tea tree oil (Melaleuca alternifolia

    Directory of Open Access Journals (Sweden)

    Moradali Fouladvand

    2016-01-01

    Full Text Available Background: Leishmania is a trypanosomatid protozoan which is transmitted by the female Phlebotomus sand fly. Leishmaniasis is prevalent in four continents and is considered to be endemic in 88 countries, 72 of which are developing countries. It is estimated that it’s global prevalence and incidence is 12 millions and 500 thousands respectively. The recommended drugs used for the treatment of this disease are mainly ineffective, toxic and exhibit many side effects. Based on some studies,tea tree oil that is a yellow color liquid with spicy odor exhibit antibacterial and antifungal activity, so, we evaluated it’s anti-leishmanial effect. Materials and Methods: Tea tree oil was purchased from Dr Jahangiri pharmaceutical company and it’s various concentrations (mg/ml800, mg/ml400, mg/ml200, mg/ml100 were prepared in 1ml volume of TSB solvent in 15ml test tubes, then 9 ml of RPMI-1640 medium and 1×106 promastigotes was added to each tube, as a final volume of 10 ml. These tubes were incubated at 23o c for 72 hours and number of parasites in the first 6 hours once every hour and after that every 24 hours were counted by hemocytometer. Results: Lethal dose of tea tree oil for 50% of promastigotes ( IC50 is 337 mg/ml, while the 800 mg/ml of this extract can killed 95% of the parasites after 24 hours of incubation, and it’s lower concentrations of this extract showed dose-dependent leishmanicidal activity. Glucantime as positive control drug at concentration of 300 mg/ml killed all the promastigotes, while the number of promastigotes in negative control tubes was increase during the incubation period. Conclusion: Anti-Leishmanial activity of tea tree oil with IC50 of 337 mg/ml and 95% lethality of 800 mg/ml is promising and further study for analyse the active ingredients of this oil and evaluation of it’s anti-leishmanial effect, particularly in laboratory animal is recommended.

  18. Antifungal activity of tea tree oil from Melaleuca alternifolia against Trichophyton equinum: an in vivo assay.

    Science.gov (United States)

    Pisseri, F; Bertoli, A; Nardoni, S; Pinto, L; Pistelli, L; Guidi, G; Mancianti, F

    2009-11-01

    Dermatophytes are a group of keratinophilic and keratinolytic molds, some of which are responsible for ringworm. Among them Trichophyton equinum, which mostly infects equids, can cause extensive outbreaks in stud farms. The conventional treatment of equine trichophytosis is topic, based upon medicated shampoos to reduce the spread of infection among the animals. Nevertheless the popularity of phytotherapy is at an all-time peak, and the interest for natural alternatives or complements to conventional drug therapy is challenging both in human and veterinary field. Among herbal remedia Tea Tree Oil (TTO) shows a wide range of antimicrobial activities. A randomized open clinical trial was carried out on 60 thoroughbred breeding horses affected by equine ringworm. The animals were randomly divided into 2 groups of 30 subjects. Diagnostic criteria were the presence of clinical signs and positive T. equinum culture. Specificity control using TTO mixture in 5 not dermatophyte affected animals was achieved also. The antimycotic activity against T. equinum of a mixture containing 25% TTO in sweet almond oil, was evaluated in vivo treating 30 subjects, the others were administered enilconazole 2% solution. The animals of both groups were topically treated twice a day for 15 days with a 25% mixture of TTO diluted in sweet almond oil and every 3 days, four times with enilconazole rinses, respectively. The clinical and mycological outcome were evaluated at day 30 from the start of the treatments. Data analysis was performed by chi square test. All the treated animals showed complete clinical and aetiological healing. Part of control subjects also, showed an improvement and none of them exacerbate the lesions. This therapeutic protocol appears to be effective and versatile, being applicable immediately after physical examination, prior to have the laboratory response. It could be an alternative for practitioners interested in herbal medicines, contributing to fulfill the gap existing between in vitro and clinical studies.

  19. Effect of tea tree (Melaleuca alternifolia) oil as a natural antimicrobial agent in lipophilic formulations.

    Science.gov (United States)

    Mantil, Elisabeth; Daly, Grace; Avis, Tyler J

    2015-01-01

    There has been increased interest surrounding the use of tea tree oil (TTO) as a natural antimicrobial. In this study, the antimicrobial activity of TTO and its components were investigated in vitro and in a predominantly lipid-based personal care formulation. In vitro, TTO showed minimal inhibitory concentrations of 0.2% (for Saccharomyces cerevisiae and Pythium sulcatum), 0.4% (for Escherichia coli, Bacillus subtilis, and Rhizopus stolonifer), and 0.8% (for Botrytis cinerea). TTO at 0.08%-0.8% was often as efficient as parabens. Comparison of the antimicrobial activities of TTO components showed that terpinen-4-ol and γ-terpinene were generally most effective in inhibiting microbial growth. TTO activity in a personal care product was evaluated through air and water exposure, artificial inoculation, and shelf life studies. While TTO did not increase shelf life of unopened products, it decreased microbial load in products exposed to water and air. Results from this study support that antimicrobial activity of TTO can be attributed to varying levels of its components and that low levels of TTO were effective in reducing microbial growth during the use of the product. This study showed that TTO can act as a suitable preservative system within an oil-based formulation.

  20. Effects of tea tree (Melaleuca alternifolia) oil on Staphylococcus aureus in biofilms and stationary growth phase.

    Science.gov (United States)

    Kwieciński, Jakub; Eick, Sigrun; Wójcik, Kinga

    2009-04-01

    Tea tree oil (TTO) is known for its antimicrobial activity. In this study, we determined whether TTO is effective against Staphylococcus aureus in biofilms and how TTO activity is affected by the S. aureus growth phase. All clinical strains tested were killed by TTO both as planktonic cells and as biofilms. The minimum biofilm eradication concentration was usually two times higher than the minimum bactericidal concentration, yet it was never higher than 1% v/v. The fastest killing of biofilm occurred during the first 15min of contact with TTO and was not influenced by increasing TTO concentration above 1% v/v. Planktonic stationary phase cells exhibited decreased susceptibility to TTO compared with exponential phase cells. The killing rate for stationary phase cells was also less affected by increasing TTO concentration than that for exponential phase cells. These data show that TTO efficiently kills S. aureus in the stationary growth phase and within biofilms and is therefore a promising tool for S. aureus eradication.

  1. Gelam (Melaleuca spp. Honey-Based Hydrogel as Burn Wound Dressing

    Directory of Open Access Journals (Sweden)

    Rozaini Mohd Zohdi

    2012-01-01

    Full Text Available A novel cross-linked honey hydrogel dressing was developed by incorporating Malaysian honey into hydrogel dressing formulation, cross-linked and sterilized using electron beam irradiation (25 kGy. In this study, the physical properties of the prepared honey hydrogel and its wound healing efficacy on deep partial thickness burn wounds in rats were assessed. Skin samples were taken at 7, 14, 21, and 28 days after burn for histopathological and molecular evaluations. Application of honey hydrogel dressings significantly enhanced (P<0.05 wound closure and accelerated the rate of re-epithelialization as compared to control hydrogel and OpSite film dressing. A significant decrease in inflammatory response was observed in honey hydrogel treated wounds as early as 7 days after burn (P<0.05. Semiquantitative analysis using RT-PCR revealed that treatment with honey hydrogel significantly (P<0.05 suppressed the expression of proinflammatory cytokines (IL-1α, IL-1β, and IL-6. The present study substantiates the potential efficacy of honey hydrogel dressings in accelerating burn wound healing.

  2. Compare the influence of several methods dehydrate of cajuput (Melaleuca cajuputi) honey from Bac Lieu - Vietnam

    Science.gov (United States)

    Nam, Nguyen Xuan; Phuc, Nguyen Chi; Oanh, Huynh Ngoc; Hien, Phan Phuoc

    2017-09-01

    The aim of this research was exhaustive to valuate the effects of 5 methods used to dehydrate of cajuput honey from Bac Lieu - Vietnam include thermal, microwave, ultrasonic wave, silicagel, vacuum processing on water content of honey. Beside that, comparing the effects on honey quality with the industrial-scale processing. The main honey quality paramenters (reducing sugar (RS), hydroxymethylfurfural (HMF), diastase number (DN), water and colour) of cajuput honey were analyzed. RS content were analyzed by DNS method, HMF under AOAC 980.23, diastase activity based on AOAC 958.09, water content according to AOAC 969.38B and colour parameters (L*, a*, b*) were established in the CIE system. The physico-chemical characteristics of fresh honey was as follows: water content 23.18%, RS 717.42 mg/g, HMF 4.24 mg/kg, DN 4.85 mg/kg, colour parameters L*a*b* 39.51-10.51-31.81. The results of the analysis showed that excepts ultrasonic wave processing (22.93%), the other methods allowed to dehydrate of cajuput honey (thermal - 18.73%, microwave - 16.87%, silicagel - 17.86%, vacuum - 17.35% and industrial-scale processing - 16.85%).

  3. Repellency of selected biorational insecticides to potato psyllid, Bactericera cockerelli (Hemiptera: Psyllidae)

    Science.gov (United States)

    Bactericera cockerelli has recently become a major concern because of its direct feeding and vectoring of bacterial diseases in many solanaceous crops. The repellency of four biorational insecticides, MOI-201 (a Chinese medicine plant extract), Requiem (a plant extract of Chenopodium ambrosioides), ...

  4. 75 FR 34322 - Citrus Greening and Asian Citrus Psyllid; Quarantine and Interstate Movement Regulations

    Science.gov (United States)

    2010-06-17

    ...) leaves that are intended for culinary use are usually both dried and shredded prior to shipment. After.../report_pest_disease/report_pest_disease.shtml ). After a change is made to the list of quarantined...

  5. 77 FR 59709 - Citrus Greening and Asian Citrus Psyllid; Quarantine and Interstate Movement Regulations

    Science.gov (United States)

    2012-10-01

    ...: Effective October 31, 2012. FOR FURTHER INFORMATION CONTACT: Ms. Lynn Evans-Goldner, National Program... Huanglongbing disease of citrus by the international taxonomic community. We are amending the definition to... issued under Sec. 204, Title II, Public Law 106-113, 113 Stat. 1501A-293; sections 301.75-15 and...

  6. Economic injury level of the psyllid, Agonoscena pistaciae, on Pistachio, Pistacia vera cv. Ohadi.

    Science.gov (United States)

    Reza Hassani, Mohammad; Nouri-Ganbalani, Gadir; Izadi, Hamzeh; Shojai, Mahmoud; Basirat, Mehdi

    2009-01-01

    The pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Psyllidae) is a major pest of pistachio trees, Pistacia vera L. (Sapindalis: Anacardiaceae) throughout pistachio-producing regions in Iran. Different density levels of A. pistaciae nymphs were maintained on pistachio trees by different insecticide dosages to evaluate the relationship between nymph density and yield loss (weight of 1000 nuts). Psylla nymph densities were monitored weekly by counting nymphs on pistachio terminal leaflets. There was a significant reduction in weight of 1000 nuts as seasonal averages of nymphs increased. Regression analysis was used to determine the relationship between nymph density and weight of 1000 nuts. The economic injury levels varied as a function of market values, management costs, insecticide efficiency and yield loss rate and ranged from 7.7 to 30.7 nymphal days per terminal leaflet, based on weight of 1000 nuts.

  7. Field ID guide to citrus relative hosts of Asian citrus psyllid & Huanglongbing

    Science.gov (United States)

    The Rutaceae family of plants includes not only species within the genus Citrus, but also several other genera and species that may not be easily recognized as having any relationship to citrus at all. However, many of these citrus relatives are used for ornamental, culinary, or religious purposes. ...

  8. Insecticidal suppression of Asian citrus psyllid Diaphorina citri (Hemiptera: Liviidae) vector of huanglongbing pathogens.

    Science.gov (United States)

    Qureshi, Jawwad A; Kostyk, Barry C; Stansly, Philip A

    2014-01-01

    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 in citrus. A combined effect of nymphal and adult suppression in response to sprays of 23 insecticides representing 9 modes of action (MoA) groups and 3 unknown MoA provided more than 90% reduction of adult D. citri over 24-68 days. Observable effects on nymphs were generally of shorter duration due to rapid maturation of flush. However, reduction of 76-100% nymphs or adults over 99-296 days was seen on young trees receiving drenches of the neonicotinoids imidacloprid, thiamethoxam or clothianidin (MoA 4A) and a novel anthranilic diamide, cyantraniliprole (MoA 28). Effective products identified for foliar sprays to control D. citri provide sufficient MoA groups for rotation to delay evolution of insecticide resistance by D. citri and other pests. However, cyantraniliprole is now the only available alternative for rotation with neonicotinoids in soil application to young trees. Sprays of up to eight of the most effective insecticides could be rotated over a year without repetition of any MoA and little or no recourse to neonicotinoids or cyantraniliprole, so important for protection of young trees. Other considerations effecting decisions of what and when to spray include prevalence of huanglongbing, pest pressure, pre-harvest intervals, overall budget, equipment availability, and conservation of beneficial arthropods. Examples of spray programs utilizing broad-spectrum and relatively selective insecticides are provided to improve vector management and may vary depending on individual or regional assessment of all factors.

  9. 76 FR 23449 - Citrus Canker, Citrus Greening, and Asian Citrus Psyllid; Interstate Movement of Regulated...

    Science.gov (United States)

    2011-04-27

    ... analysis, especially any scientific studies that may be pertinent. Protocol Document Based on the... either case, the statement is prominently and legibly displayed. The nursery stock is moved in a... Huanglongbing. Plant Management Network International, Orlando, Florida. Copies available from the individuals...

  10. Anoeconeossa bundoorensis sp. n., a new psyllid (Hemiptera: Psylloidea) from Eucalyptus camaldulensis (Myrtaceae) from Southeast Australia.

    Science.gov (United States)

    Taylor, Gary S; Farnier, Kevin; Burckhardt, Daniel; Steinbauer, Martin J

    2013-01-30

    Anoeconeossa bundoorensis sp. n. is described from Eucalyptus camaldulensis (Myrtaceae) from southern Victoria in Southeast Australia. It is placed in the A. communis Taylor species-group as the paramere lacks combs of black rods. It differs from other members of the species-group, A. communis and A. bullata Taylor as it lacks an anterobasal expansion on the paramere and from A. unicornuta Taylor as the inner horn-shaped process of the paramere is reduced to a short spine and the apical expansion is more elongate, with a corresponding greater length of equidistant setae. Taxonomically relevant morphological details are illustrated and the species is diagnosed from other eucalypt inhabiting congeners. In-formation on the biology is presented.

  11. Use of psyllid genomes RNA interference for novel pest control strategies

    Science.gov (United States)

    Genomics has changed the strategies used to manage insects and diseases. The ability to effect a change in proteins, and transcripts, through RNA-interference, RNAi, has produced a rush towards the development of the most state-of-the-art pest suppression strategies available. To rapidly advance the...

  12. 78 FR 63369 - Citrus Canker, Citrus Greening, and Asian Citrus Psyllid; Interstate Movement of Regulated...

    Science.gov (United States)

    2013-10-24

    ... infected plants, which render the fruit unmarketable, and cause infected fruit to drop from the trees... of the fruit, and can kill trees. Once infected, there is no cure for a tree with citrus greening. In... disease that is caused by a complex of Xanthomonas spp. bacteria and that affects plants and plant...

  13. Bacteria of the genus Erwinia found in the spermatheca of the laurel psyllid Trioza alacris.

    Science.gov (United States)

    Marchini, Daniela; Ciolfi, Silvia; Gottardo, Marco; Marri, Laura

    2014-12-01

    Psylloidea are economically important insects causing serious damage to plants by direct feeding and/or vectoring bacterial pathogens. Results reported here indicate the presence of extracellular bacteria in the spermatheca of egg-laying Trioza alacris females. One phylotype, sharing 99 % identity with the non-phytopathogenic bacterium Erwinia tasmaniensis, was identified regardless of methods applied or insect sampling year and location. This is the first study, achieved by ultrastructural, cultural, and 16S rRNA gene-based analysis, of an insect spermatheca microbiota.

  14. Insecticidal suppression of Asian citrus psyllid Diaphorina citri (Hemiptera: Liviidae vector of huanglongbing pathogens.

    Directory of Open Access Journals (Sweden)

    Jawwad A Qureshi

    Full Text Available 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 in citrus. A combined effect of nymphal and adult suppression in response to sprays of 23 insecticides representing 9 modes of action (MoA groups and 3 unknown MoA provided more than 90% reduction of adult D. citri over 24-68 days. Observable effects on nymphs were generally of shorter duration due to rapid maturation of flush. However, reduction of 76-100% nymphs or adults over 99-296 days was seen on young trees receiving drenches of the neonicotinoids imidacloprid, thiamethoxam or clothianidin (MoA 4A and a novel anthranilic diamide, cyantraniliprole (MoA 28. Effective products identified for foliar sprays to control D. citri provide sufficient MoA groups for rotation to delay evolution of insecticide resistance by D. citri and other pests. However, cyantraniliprole is now the only available alternative for rotation with neonicotinoids in soil application to young trees. Sprays of up to eight of the most effective insecticides could be rotated over a year without repetition of any MoA and little or no recourse to neonicotinoids or cyantraniliprole, so important for protection of young trees. Other considerations effecting decisions of what and when to spray include prevalence of huanglongbing, pest pressure, pre-harvest intervals, overall budget, equipment availability, and conservation of beneficial arthropods. Examples of spray programs utilizing broad-spectrum and relatively selective insecticides are provided to improve vector management and may vary depending on individual or regional assessment of all factors.

  15. Insights into Putative Health Implications of Gelam (Melaleuca cajuputi Honey: Evidence from In-Vivo and In-Vitro Studies

    Directory of Open Access Journals (Sweden)

    Boon Keng Chan

    2016-02-01

    Full Text Available Honey has been used as a therapeutic agent since ancient times for health maintenance and the treatment of various ailments. In modern days, researchers reappraised the therapeutic values of honey, such as anti-oxidative, anti-inflammatory, antimicrobial, anti-diabetic, anti-tumor, and wound healing properties. These findings supported its applications in the modern healthcare system as complementary medicine. Gelam honey (GH is a monofloral Malaysian honey which has been proven to have considerable health benefits. This paper presents a state of the art review on the therapeutic values of GH. A descriptive elucidation is performed to elaborate a wide spectrum of biological activities of GH using evidence from a considerable body of literature. The compositional and physiochemical characteristics of GH have contributed substantially to its putative biological properties. A brief explanation will be presented on GH attributes to familiarize readers with this novel natural health product.

  16. Synergism and postantibiotic effect of tobramycin and Melaleuca alternifolia (tea tree) oil against Staphylococcus aureus and Escherichia coli.

    Science.gov (United States)

    D'Arrigo, Manuela; Ginestra, Giovanna; Mandalari, Giuseppina; Furneri, P M; Bisignano, G

    2010-04-01

    The application of antimicrobial combinations may address the rising resistance to established classes of both systemic and topical agents and their clinical relevance is related to the presence of a significant postantibiotic effect (PAE). We investigated the effectiveness in vitro of the association between tobramycin and tea tree oil (TTO) against Gram-positive and Gram-negative bacteria. The minimal inhibitory concentrations, the bacterial killing and the PAE of tobramycin and TTO were determined both singly and in combination against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 29213. A synergistic interaction was observed against both strains tested: the mean PAEs were 1.3 and 1.7h for tobramycin against E. coli and S. aureus respectively, 10.8h for tobramycin and TTO (0.05%) against E. coli, 10.4h and 17.4h against S. aureus for tobramycin and TTO (0.25 and 0.50%, respectively). Longer PASMEs were observed with S. aureus after TTO/tobramycin exposure. In vitro interactions can improve the antimicrobial effectiveness of the antibiotic and may contribute for the development of novel topical agents for the treatment of skin lesions including conjunctiva and respiratory infections by inhalation.

  17. Adaptation to NaCl Reduces the Susceptibility of Enterococcus faecalis to Melaleuca alternifolia (Tea Tree) Oil.

    Science.gov (United States)

    Lim, Ee Lin; Hammer, Katherine Ann

    2015-10-01

    This study investigated the hypothesis that the salt adaptation response of Enterococcus faecalis alters susceptibility to tea tree oil (TTO). Six E. faecalis isolates were adapted to 6.5 % NaCl, and then exposed to TTO in phosphate-buffered saline (PBS). One isolate was also exposed to TTO in Brain Heart Infusion Broth (BHIB). The viability of salt-adapted and non-adapted control cells was determined at 0, 45 and 90 min and compared. MICs for several antibiotics and TTO were also determined by E test and broth microdilution, respectively. Results showed that susceptibility to TTO in PBS was significantly reduced after salt adaptation for five isolates (83 %) (P < 0.05). Mean differences between salt-adapted and non-adapted cell counts were 2.51 log at 45 min and 2.13 log at 90 min. However, when E. faecalis ATCC 19433 was exposed to TTO in BHIB, no significant differences were seen. In conclusion, salt adaptation resulted in reduced susceptibility to TTO in PBS for the majority of isolates, indicating that cross protection had occurred. This effect was absent in BHIB, suggesting that the uptake of compatible solutes from the growth medium protected non-adapted cells from TTO. Whether this has implications for the clinical effectiveness of TTO remains to be determined.

  18. The influence of tea tree oil (Melaleuca alternifolia) on fluconazole activity against fluconazole-resistant Candida albicans strains.

    Science.gov (United States)

    Mertas, Anna; Garbusińska, Aleksandra; Szliszka, Ewelina; Jureczko, Andrzej; Kowalska, Magdalena; Król, Wojciech

    2015-01-01

    The aim of this study was to evaluate the activity of fluconazole against 32 clinical strains of fluconazole-resistant Candida albicans, and C. albicans ATCC 10231 reference strain, after their exposure to sublethal concentrations of tea tree oil (TTO) or its main bioactive component terpinen-4-ol. For all tested fluconazole-resistant C. albicans strains TTO and terpinen-4-ol minimal inhibitory concentrations (MICs) were low, ranging from 0.06% to 0.5%. The 24-hour exposure of fluconazole-resistant C. albicans strains to fluconazole with sublethal dose of TTO enhanced fluconazole activity against these strains. Overall, 62.5% of isolates were classified as susceptible, 25.0% exhibited intermediate susceptibility, and 12.5% were resistant. For all of the tested clinical strains the fluconazole MIC decreased from an average of 244.0 μg/mL to an average of 38.46 μg/mL, and the fluconazole minimal fungicidal concentrations (MFC) decreased from an average of 254.67 μg/mL to an average of 66.62 μg/mL. Terpinen-4-ol was found to be more active than TTO, and strongly enhanced fluconazole activity against fluconazole-resistant C. albicans strains. The results of this study demonstrate that combining natural substances such as TTO and conventional drug such as fluconazole, may help treat difficult yeast infections.

  19. Frequencies of resistance to Melaleuca alternifolia (tea tree) oil and rifampicin in Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecalis.

    Science.gov (United States)

    Hammer, Katherine A; Carson, Christine F; Riley, Thomas V

    2008-08-01

    This study was conducted to determine the frequencies at which single-step mutants resistant to tea tree oil and rifampicin occurred amongst the Gram-positive organisms Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecalis. For tea tree oil, resistance frequencies were very low at tea tree oil were undetectable at two times the minimum inhibitory concentration (MIC) for S. aureus RN4220 and derivative mutator strains or at 3 x MIC for the remaining S. aureus strains, including a clinical meticillin-resistant S. aureus isolate. Similarly, no mutants were recovered at 2x MIC for S. epidermidis or at 1x MIC for E. faecalis. Resistance frequencies determined in vitro for rifampicin (8 x MIC) ranged from 10(-7) to 10(-8) for all isolates, with the exception of the S. aureus mutator strains, which had slightly higher frequencies. These data suggest that Gram-positive organisms such as Staphylococcus and Enterococcus spp. have very low frequencies of resistance to tea tree oil.

  20. The Influence of Tea Tree Oil (Melaleuca alternifolia on Fluconazole Activity against Fluconazole-Resistant Candida albicans Strains

    Directory of Open Access Journals (Sweden)

    Anna Mertas

    2015-01-01

    Full Text Available The aim of this study was to evaluate the activity of fluconazole against 32 clinical strains of fluconazole-resistant Candida albicans, and C. albicans ATCC 10231 reference strain, after their exposure to sublethal concentrations of tea tree oil (TTO or its main bioactive component terpinen-4-ol. For all tested fluconazole-resistant C. albicans strains TTO and terpinen-4-ol minimal inhibitory concentrations (MICs were low, ranging from 0.06% to 0.5%. The 24-hour exposure of fluconazole-resistant C. albicans strains to fluconazole with sublethal dose of TTO enhanced fluconazole activity against these strains. Overall, 62.5% of isolates were classified as susceptible, 25.0% exhibited intermediate susceptibility, and 12.5% were resistant. For all of the tested clinical strains the fluconazole MIC decreased from an average of 244.0 μg/mL to an average of 38.46 μg/mL, and the fluconazole minimal fungicidal concentrations (MFC decreased from an average of 254.67 μg/mL to an average of 66.62 μg/mL. Terpinen-4-ol was found to be more active than TTO, and strongly enhanced fluconazole activity against fluconazole-resistant C. albicans strains. The results of this study demonstrate that combining natural substances such as TTO and conventional drug such as fluconazole, may help treat difficult yeast infections.

  1. Susceptibility to Melaleuca alternifolia (tea tree) oil of yeasts isolated from the mouths of patients with advanced cancer.

    Science.gov (United States)

    Bagg, Jeremy; Jackson, Margaret S; Petrina Sweeney, M; Ramage, Gordon; Davies, Andrew N

    2006-05-01

    Yeasts that are resistant to azole antifungal drugs are increasingly isolated from the mouths of cancer patients suffering from oral fungal infections. Tea tree oil is an agent possessing antimicrobial properties that may prove useful in the prevention and management of infections caused by these organisms. In this study, 301 yeasts isolated from the mouths of 199 patients suffering from advanced cancer were examined by an in vitro agar dilution assay for susceptibility to tea tree oil. All of the isolates tested were susceptible, including 41 that were known to be resistant to both fluconazole and itraconazole. Clinical studies of tea tree oil as an agent for the prevention and treatment of oral fungal infections in immunocompromised patients merit consideration.

  2. In vitro activity of Melaleuca alternifolia (tea tree) oil against bacterial and Candida spp. isolates from clinical specimens.

    Science.gov (United States)

    Banes-Marshall, L; Cawley, P; Phillips, C A

    2001-01-01

    This study investigates the in vitro activity of tea tree oil (TTO) against a range of wild strains of microorganisms isolated from clinical specimens of leg ulcers and pressure sores. The antimicrobial effectiveness of TTO is determined in terms of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) or minimum fungicidal concentration (MFC). The isolates include methicillin-resistant Staphylococcus aureus (MRSA), S. aureus, faecal streptococci, beta-haemolytic streptococci, coagulase-negative staphylococci, Pseudomonas spp. and coliform bacilli. Eleven Candida spp. isolates from skin and vaginal swabs also are tested. Using an agar dilution assay, the MICs of TTO in 88 out of 90 isolates was 0.5-1.0% (v/v), whilst with P. aeruginosa it was >2% (v/v). A broth microdilution method was used to determine MIC and minimum cidal concentration (MCC) of 80 isolates. In 64 isolates, TTO produced an inhibitory and cidal effect at 3% and 4% (v/v), respectively. S. aureus and Candida spp. were the most susceptible to TTO, with MICs and MBCs of 0.5% and 1%, respectively. P. aeruginosa and the faecal streptococci isolates, with MICs and MBCs of >8%, were resistant to TTO.

  3. An evaluation of the impact of Melaleuca quinquenervia invasion and managment on plant community structure after fire.

    Science.gov (United States)

    The successful management of invasive species can be particularly difficult in natural areas that depend on disturbances such as fire to maintain community structure and function. In these systems, fire-adapted invasive species may disproportionally benefit from post-fire resource availability, inc...

  4. PROPAGATION OF MELALEUCA ALTERNIFOLIA IN INDUSTRIAL MODE%互叶白千层工厂化育苗技术

    Institute of Scientific and Technical Information of China (English)

    周丽华; 张华通; 龚峥; 曾雷; 周志坚; 谭碧霞

    2001-01-01

    以互叶白千层萌芽条茎段为外植体材料,运用组织培养快速繁殖和组培苗嫩梢扦插技术方法,进行工厂化育苗,结果表明,该技术降低了苗木生产成本,并能在短期内荻得大量组培苗,年产苗木可达112万株.

  5. The Insecticidal Activity of Tea Tree Oil (Melaleuca Alternifolia Against the Common Pest in Mummies (Dermestes Maculatus

    Directory of Open Access Journals (Sweden)

    Gomaa ABDEL-MAKSOUD

    2013-09-01

    Full Text Available Egyptian mummies show different signs of deterioration caused by insects, such as missing parts, gaps and accumulated dust. Dermestes maculatus is one of the serious pests that cause damage to Egyptian mummies. To assess the insecticidal activity of tea tree oil against the larvae of the museum insect pest Dermestes maculatus (isolated from Egyptian mummies we tested it under different concentration and treatment times by the bioassay methods. Our results showed that tea tree oil diluted in ethanol was highly toxic to Dermestes maculatus larvae. Insecticidal activity depended on both concentration and exposure time. By increasing the concentration level and the exposure time we obtained a higher mortality rate.

  6. Modelling the long term effects of an introduced herbivore on spread of an invasive tree

    Science.gov (United States)

    Melaleuca quinquenervia (Cav.) Blake (hereafter melaleuca) is an invasive tree from Australia that has spread over the freshwater ecosystems of southern Florida, displacing native vegetation such as slash pine (Pinus elliottii), pond cypress (Taxodium ascendens), and loblolly bay (Gordonia lasianthu...

  7. Asian citrus psyllids and shade: Survival of Diaphorina citri on Murraya exotica foliage exposed to different levels of light

    Science.gov (United States)

    Using shade cloths of different densities, potted individuals of Murraya exotica (Rutaceae) were exposed to levels of photosynthetic radiation (PAR) varying from 48 µmol photons per meter2 per second to 1562 µmol photons per meter2 per second (average of three readings taken at noon during condition...

  8. Responses of the Asian citrus psyllid to volatiles emitted by the flushing shoots of its rutaceous host plants.

    Science.gov (United States)

    Patt, J M; Sétamou, M

    2010-04-01

    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 shoots of Murraya paniculata (L.) Jack and Citrus limon L. Burm. f. cultivar Eureka. Only males exhibited a preference for the odor of C. sinensis L., whereas the odor of C. x paradisi MacFadyen cultivar Rio Red was not attractive to both sexes. The volatiles emitted by young shoots of grapefruit cultivar Rio Red, Meyer lemon (Citrus x limon L. Burm.f.), and M. paniculata were analyzed by gas chromatograph-mass spectrometry. The samples were comprised of monoterpenes, monoterpene esters, and sesquiterpenes. The number of compounds present varied from 2 to 17, whereas the total amount of sample collected over 6 h ranged from 5.6 to 119.8 ng. The quantitatively dominant constituents were (E)-beta-ocimene, linalool, linalyl acetate, and beta-caryophyllene. The attractiveness of a mixture of synthetic terpenes, modeled on the volatiles collected from M. paniculata, was evaluated in screened cages in a no-choice test. At three observation intervals, significantly more individuals were trapped on white targets scented with the mixture than on unscented targets. These results indicate the feasibility of developing D. citri attractants patterned on actual host plant volatiles.

  9. A Comparative Evaluation of the Physical and Chemical Characteristics of Composted Tea Tree (Melaleuca alternifolia L. with Pine Bark Growing Media in Tobacco (Nicotiana tabucum L. Seedling Production

    Directory of Open Access Journals (Sweden)

    Johnson Masaka

    2016-01-01

    Full Text Available The search for suitable organic growing media substitutes for pine bark based media combinations has been prompted by concerns over high costs and lack of availability to smallholder farmers coupled with increasing demand for soilless media in Zimbabwe. A trial was conducted for 12 weeks to investigate the suitability of tea tree compost-based substrates for tobacco seedling production as a substitute of the traditional pine bark growing media. The use of composted tea tree growing media in float trays significantly (p<0.05 increases the bulk density of the media by 23–59% when compared with pine bark media. The cation exchange capacity of the native pine bark growing media was 14 to 95% lower than that for the composted tea tree media. The use of the composted tea as media for tobacco seedling nursery reduced seed germination by 10–37%, seedling stem height by 4–34%, and seedling stem girth by 6–175%. While the nutrient holding and supplying potential of the growing media in seedling production is important for normal seedling growth, its effect on seedling growth vigor is less important than that exerted by the presence of suitable physical conditions in the media.

  10. Atividade antimicrobiana e antibiofilme de antissépticos bucais e óleo de melaleuca sobre Candida spp. com aplicabilidade em tubos traqueais

    OpenAIRE

    Danielle Bezerra Cabral

    2014-01-01

    O uso de antissépticos complementa a higienização bucal reduzindo a microbiota e, consequentemente minimizando a colonização, a formação de biofilme e, assim promovendo a saúde bucal. Diante das opções de antissépticos bucais e produtos naturais, faz-se necessária a análise microbiológica da eficácia desses produtos e suas implicações no controle do biofilme. Neste sentido, têm-se como objetivos: determinar a diluição inibitória máxima (DIMax) de antissépticos bucais (Listerine®, Colgat...

  11. Analysis of Chemical Components in the Aromatic Water of Essential Oil from Melaleuca alternifolia%茶树油芳香水的化学成分分析

    Institute of Scientific and Technical Information of China (English)

    叶开富; 刘布鸣; 苏小川

    2008-01-01

    采用色谱-质谱-计算机(GC-MS-DS)联用方法分析水蒸汽蒸馏法提取茶树挥发油的茶树油芳香水中溶于(或微溶于)水的芳香化学组分,并与茶树油的化学成分进行对比.结果从茶树油芳香水中分离出40多个组分,确认了其中22种成分,占色谱总馏出峰面积的90%以上.茶树油芳香水和茶树油样品的色谱基本相同,化学成分既有共同也有不同,但主要化学成分基本一致.水蒸汽蒸馏法提取茶树挥发油的茶树油芳香水可以采用复馏工艺回收溶于水的轻组分以提高得油率,也可以开发成天然的医药保健、灭菌消毒、美容护肤、洗涤等新产品.

  12. Technology of Cuttage Seeding-Raising of Melaleuca alternifolia%互叶白千层扦插育苗技术研究

    Institute of Scientific and Technical Information of China (English)

    郭逸成

    2007-01-01

    通过双因子试验设计研究不同生根促进剂及不同浓度处理对互叶白千层插穗扦插生根的影响;研究了不同插穗下切口型对扦插生根的影响.结果表明,互叶白千层嫩枝以ABT-1号700 mg·kg-1处理插穗生根率高,生根数多且生根长;不同插穗下切口型以双削面生根率最高,达96.5%.

  13. Preliminary Study on Technology of Cuttage Seeding-Raising of Melaleuca alternifolia%互叶白千层扦插育苗技术初探

    Institute of Scientific and Technical Information of China (English)

    高楠

    2010-01-01

    以互叶白千层当年生的嫩枝为试验材料,采用L9(34)正交试验方案,研究不同生根促进剂、不同浓度以及不同基质对互叶白千层扦插生根的影响,筛选各因素水平的最佳组合.试验结果表明:生根促进剂的种类及其浓度对扦插生根影响显著;ABT/NAA混合促进剂,浓度为1 000 mg·kg-1,基质采用珍珠岩和泥土1: 2组合,是互叶白千层扦插最佳的因素水平组合.其生根率可达78%,生根数可达4.02条,最长生根长度为3.48 cm.

  14. Review of Volatile Oil from Melaleuca Alternifolia%互叶白千层植物精油的研究进展

    Institute of Scientific and Technical Information of China (English)

    吕永; 何庭玉; 陈珊

    2005-01-01

    互叶白千层植物精油(茶树油)是近年来发展较快的植物精油之一,本文概括了茶树油的提取分析、抗菌活性等方面的研究在国内外的研究进展,讨论了用真空间歇精馏和分子蒸馏方法精制茶树油,为茶树油的相关研究提供参考.

  15. 白千层油及其在医药上的应用%Melaleuca alternifolia oil and its medical application

    Institute of Scientific and Technical Information of China (English)

    肖凯军; 银玉容; 郭祀远; 李琳; 蔡妙颜

    2001-01-01

    目的:阐明白千层油在医药上的应用价值.方法:从白千层油的提取分离方法、主要化学成分、特性和应用等方面全面概述其研究现状.结果:白千层油是从白千层树中提取的一种生物活性物质,在医学上具有多种重要性质.结论:白千层油在医药上具有重要的研究价值和广阔的应用前景.

  16. ISSN 1816-0573 CAFOBIOS

    African Journals Online (AJOL)

    TEG

    Phenology and fruit production of Piliostigma reticulatum (DC), Hochst., an agroforestry forage species in the Sahel. ... [3]; Citrus psyllid, Trioza erytreae Del Guercio. 1918 [7]; ..... Tuthill, L.D. 1943: The Psyllids of America north of Mexico ...

  17. Unusual Behaviour — Unusual Morphology: Mutualistic Relationships between Ants (Hymenoptera: Formicidae) and Diaphorina enderleini (Hemiptera: Psylloidea), Associated with Vernonia amygdalina (Asteraceae)

    National Research Council Canada - National Science Library

    Désirée Chantal Aléné; Champlain Djiéto-Lordon; Daniel Burckhardt

    2011-01-01

    .... The lack of wax deprives them of the protection common in various free-living psyllids. Consequently the psyllid is involved in an unusual mutualistic interaction with the ants Pheidole megacephala and Crematogaster striatula...

  18. 76 FR 4859 - Availability of an Environmental Assessment and Finding of No Significant Impact for a Biological...

    Science.gov (United States)

    2011-01-27

    ... Significant Impact for a Biological Control Agent for Asian Citrus Psyllid AGENCY: Animal and Plant Health... continental United States for use as a biological control agent to reduce the severity of Asian citrus psyllid... use as a biological control agent to reduce the severity of Asian citrus psyllid (ACP)...

  19. [First record of Zoophthora radicans (Entomophthorales: Entomophthoraceae) on adults of the Paraguay tea psyllid, Gyropsylla spegazziniana Lizer & Trelles (Hemiptera: Psyllidae), in Brazil].

    Science.gov (United States)

    Alves, Luis F A; Leite, Luis G; Oliveira, Daian G P de

    2009-01-01

    We report the first occurrence of Zoophthora radicans infecting adults of Gyropsylla spegazziniana Lizer & Trelles in a commercial Paraguay tea plantation (Ilex paraguariensis), in Cascavel, PR, Brazil. The fungus prevalence was high (90% of mortality), considered a natural epizooty.

  20. Use of micro-CT to elucidate details of the anatomy and feeding of the Asian citrus psyllid Diaphorina citri Kuwayama, 1908 (Insecta: Hemiptera, Liviidae)

    Science.gov (United States)

    Huanglongbing (HLB), also known as citrus greening disease, is caused by plant-infecting bacteria. The most prominent pathogen within the Americas: United States of America, Mexico, and Brazil, is Candidatus Liberibacter asiaticus, which affects plants of the Family: Rutaceae, in particularly citrus...

  1. 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.

    Science.gov (United States)

    Matsumura, Emilyn E; Nerva, Luca; Nigg, Jared C; Falk, Bryce W; Nouri, Shahideh

    2016-09-08

    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.

  2. 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

    Science.gov (United States)

    Matsumura, Emilyn E.; Nerva, Luca; Nigg, Jared C.; Falk, Bryce W.

    2016-01-01

    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. PMID:27609921

  3. A draft whole genome sequence of “Candidatus Liberibacter asiaticus” strain TX2351 from Asian citrus psyllids in Texas, USA

    Science.gov (United States)

    The draft genome sequence of “Candidatus Liberibacter asiaticus” strain TX2351 collected from ACP in South Texas has been determined. The TX2351 genome is 1,252,043 bp in size with a 36.5% G+C content, encoding 1,184 predicted open reading frames and 51 RNA genes....

  4. Diversity of the citrus HLB bacterium, ‘Candidatus Liberibacter asiaticus’, in psyllids (Diaphorina citri) collected from Murraya paniculata and citrus spp. in Thailand

    Science.gov (United States)

    ‘Candidatus Liberibacter asiaticus’ (Las) is a phloem inhabiting bacterium that causes huanglongbing disease (HLB), also known as citrus greening associated with three species of a-Proteobacteria in the genus ‘Candidatus Liberibacter sp’. Prophage is an important genetic element of bacterial genomes...

  5. Study on Transdermal Diffusion Action of Tea Tree (Melaleuca alternifolia) Oil Liposomes Gel%茶树油脂质体凝胶剂的体外透皮扩散研究

    Institute of Scientific and Technical Information of China (English)

    吴亚妮; 徐云龙; 王伟; 姚雷

    2007-01-01

    本文采用Franz扩散池、离体鼠皮对茶树油(TTO)凝胶剂与TTO脂质体凝胶剂进行体外透皮扩散研究,分别考察不同时间点的体外透皮量、皮肤层滞留量,并对两种制剂的体外透皮规律进行拟合,得出规律方程.研究结果表明,TTO脂质体凝胶剂的体外透皮扩散的皮肤滞留量显着增加,是TTO凝胶的2.54倍,说明以脂质体为载体可对茶树油的经皮吸收起到很好的缓释作用,能有效提高其在局部炎症皮层组织中的药物浓度及停留时间,有望成为茶树油应用的新剂型.

  6. Inhibition effect on LPS-induced TNF-α release by homegrown and Australian Melaleuca alternifolia (Tea Tree) oil%不同来源茶树油抑制LPS诱导TNF-α释放的体外实验

    Institute of Scientific and Technical Information of China (English)

    王懿; 王振维

    2007-01-01

    目的 比较国产和进口茶树油(tea tree oil,TTO)对脂多糖(lipopolysaccharide, LPS)诱导炎症的抑制作用.方法 四唑盐(MTT)比色实验筛选无细胞毒性作用的TTO溶液浓度;各浓度TTO水溶液按量效和时效关系预处理细胞后,测定LPS激活RAW264.7细胞分泌肿瘤坏死因子-α(tumor necrotic factor-alpha, TNF-α)的浓度,以观察国产和进口TTO水溶液对LPS诱导炎症的抑制效果.结果 浓度低于0.001%的国产和进口TTO溶液对细胞无毒性作用;0.000 125%~0.001%进口TTO和0.000 25%~0.001%国产TTO各浓度组均能非常显著地抑制LPS诱导细胞释放TNF-α;0.000 25%进口和国产TTO分别在3 h和6 h内对细胞有显著的保护作用.结论 国产和进口TTO对LPS诱导的炎症均有显著抑制效果.

  7. Tea Tree (Melaleuca alternifolia) Oil induced Phenotypic and Functional Maturation of Murine Bone Marrow-derived Dendritic Cells%茶树油调控树突状细胞的表型和功能

    Institute of Scientific and Technical Information of China (English)

    唐永富; 李积华; 陈家翠; 林丽静; 韩志萍; 曹玉坡

    2012-01-01

    The effect of tea tree oil on the phenotypic and functional maturation of dendritic cell was investigated in vitro. Dendritic cells treated with tea tree oil (0.005 μL/mL), were enlarged, suspended, and displayed typical stellate and aggregates like cells treated with LPS (positive controls). The levels of surface marker expression were monitored throughout the culture by flow cytometry using CD1 1c-PEcy7, I-Ab-FITC, CD86-FITC, and H-2Db-PE. Dendritic cells treated with tea bee oil expressed higher level of H-2Db (48.20%), costimulatory molecule I-Ab (6.60%) and CD86 (41.00%) with the cells gated by CD11c, being of 1.28,3.40 and 1.28-fold higher for H-2Db, I-Ab and CD86, respectiely compared with untreated cells. It was also found that tea tree oil could enhance the dendritic cell to induce proliferation of T lymphocyte. And it was reduced the endocytic activity of dendritic cell by tea tree oil. These results showed that tea tree oil had significant immunoenhancing activity by inducing the phenotypic and functional maturation of dendritic cells.%本文主要探讨了茶树油对树突状细胞表型和功能的影响.采用茶树油(0.005μL/mL)干预未成熟的树突状细胞48h后,流式细胞仪检测细胞表型,MTT法检测刺激淋巴细胞增殖能力.结果发现经茶树油干预后,以CD11c设门,树突状细胞高表达H-2Db(48.20%),I-Ab(6.60%)和CD86 (41.00%),和空白对照组比较分别达到1.28倍,3.40倍和1.28倍的增长.混合淋巴培养实验发现茶树油能够增强DC刺激淋巴细胞增殖的能力,降低树突状细胞的吞噬功能.初步表明茶树油可以促进树突状细胞的表型和功能成熟.

  8. 茶树油抗菌活性的实验研究%An Experimental Study of the Antimicrobial Activity of the Essential Oil of Tea Tree(Melaleuca Alternifolia)

    Institute of Scientific and Technical Information of China (English)

    王懿; 王振维

    2004-01-01

    目的:观察茶树油对白色念珠菌、耐药金黄色葡萄球菌、枯草芽胞杆菌及芽胞、大肠埃希菌、铜绿假单胞菌和痢疾志贺菌的抗菌活性.方法:将试验中的微生物分别与不同浓度茶树油混合后进行两次培养,观察培养结果.用纸片琼脂扩散法观察不同浓度茶树油纸片对各种微生物产生的抑菌圈.结果:茶树油浓度≥10 mL·L-1时对铜绿假单胞菌有很好的抗菌活性,浓度≥5 mL·L-1时对白色念珠菌和其他各种细菌都显示出很好的抗菌活性,浓度为2.5 mL·L-1时对痢疾志贺菌仍有明显的抗菌活性,浓度为1.25 mL·L-1时对枯草芽胞杆菌及芽胞仍有明显的抗菌活性.各浓度茶树油纸片只对枯草芽胞杆菌产生抑菌圈.结论:茶树油对试验中的真菌、细菌及芽胞有明显的杀菌作用和持久的抑菌作用.

  9. 互叶白千层高精油优良单株的选择与等级划分%Selection and grade definition of high-essential-oil superior individuals of Melaleuca altennifolia

    Institute of Scientific and Technical Information of China (English)

    吴丽君; 陈碧华; 翁秋媛; 邱安彬; 李乾振; 吴开金

    2011-01-01

    There were 41 superior individuals selected out primarily through observation by eyes. Based on international criteria of tea-oil, there were 14 superior individuals screened out, with biomass of branches and leaves, content of tea-aee oil, content of terpinen4-ol and 1,8-cineloe as the indexes. By method of polygonal decision, 14 superior individuals were defined into 3 grades, 5 individuals were grade Ⅰ , 3 individuals were grade Ⅱ, 6 individuals were grade Ⅲ. The biomass of branches and leaves of 8 superior individuals were 230.86 - 147.32 g per individual, which were 2.87 - 1.83 times of the average values, eontent of tea-oil reached 1.51% -1.15%, which was 1.70-1.29 times of the average values, and the gain by selection was very significant.%在通过目测初选出的41株优良单株中,以茶树油国际标准(ISO4730-1996)为基准,以枝叶生物量、含油率、4-松油烯醇和1,8-桉叶油素含量为评价指标,运用独立标准选择法,复选出14个高精油优良单株.用多目标决策法将优良单株分为3个等级(1级5株、2级3株、3级6株).8株精选的优良单株,其生物量为230.86-147.32 g ·株-1,为群体平均值的2.87-1.83倍;其含油率达1.51%-1.15%,为群体平均值的1.70-1.29倍,选择增益明显.

  10. 机械伤对轮叶白千层叶片提炼油浓度和成分的影响%Effects of mechanical wounding on concentration and composition of essential oil from Melaleuca alternifolia leaves

    Institute of Scientific and Technical Information of China (English)

    D.Zabaras; 丁丽; 程盛华

    2005-01-01

    机械损伤对轮叶白千层叶提炼油的影响是在其伤后24 h和48 h进行野外试验测得的.因机械损伤而造成的油腺断裂导致了成熟和未成熟叶片中油浓度在前24 h内均下降,但成熟叶片却能在伤后48 h使其油浓度恢复到伤前水平.机械损伤后成熟和未成熟叶片油组分的变化均已测定.伤后每天不同的油组分表明成熟叶片对机械伤的响应,结果还表明了机械伤影响未成熟叶片的化学成熟度.试验发现两种叶片的伤后响应并不受伤前叶片中表达响应的特定化合物的含量以及整株树上叶子油组分的制约.

  11. Study on Cutting Technology of Melaleuca alternifolia plantlet Shoot via Tissue Culture%互叶白千层组培苗嫩梢扦插育苗技术研究

    Institute of Scientific and Technical Information of China (English)

    蔡乙东; 曾巧如; 林晓萍; 何旭君; 张华通

    2006-01-01

    文章以经筛选的互叶白千层组培苗8~13 cm的嫩梢作为插穗,研究了基质、季节、木质化程度、材料来源和生根促进剂浓度等对穗条生根率的影响.结果表明:采用组培苗半木质化嫩梢作插穗,用含1 000 mg/kg IBA的生根粉处理插穗基部,于春季(4月初)扦插于珍珠岩:黄心土:泥炭土(1:1:1)的基质上,插穗生根快,平均生根率达92.3%,操作简单,繁殖速度快.

  12. Tale of the Huanglongbing Disease Pyramid in the Context of the Citrus Microbiome.

    Science.gov (United States)

    Wang, Nian; Stelinski, Lukasz L; Pelz-Stelinski, Kirsten S; Graham, James H; Zhang, Yunzeng

    2017-04-01

    The Huanglongbing (HLB) disease pyramid is composed of Liberibacters, psyllid vectors, citrus hosts, and the environment. The epidemiological outcomes for Liberibacter-associated plant diseases are collectively determined by the inherent relationships among plant-Liberibacters-psyllids, and how various environmental factors affect plant-Liberibacter-psyllid interactions. Citrus-Liberibacter-psyllid interactions occur in a complex microbiome system. In this review, we focus on the progress in understanding the HLB disease pyramid, and how the microbiome affects the HLB disease pyramid including the interaction between HLB and the citrus microbiome; the interaction between Liberibacters and psyllids; the interaction between Liberibacters and gut microbiota in psyllids; and the effect of HLB on selected above- and belowground citrus pathogens. Their implications for HLB management are also discussed.

  13. Solanum habrochaites, a potential source of resistance against Bactericera cockerelli (Hemiptera: Triozidae) and "Candidatus Liberibacter solanacearum".

    Science.gov (United States)

    Levy, Julien; Tamborindeguy, Cecilia

    2014-06-01

    The potato psyllid, Bactericera cockerelli Sulc, also known as tomato psyllid, is a serious pest of solanaceous plants. Its host selection criteria are poorly understood. In this study, we tested whether the Solanum habrochaites (PI127826), a wild solanaceous plant known for its property to repel whiteflies, was repellent to potato psyllids. Using a combination of nonchoice assays and choice assays on different psyllid stages, we demonstrated that S. habrochaites is both repelling and toxic to potato psyllids compared with Solanum lycopersicum. However, those properties were not sufficient to avoid. transmission of the plant bacterial pathogen "Candidatus Liberibacter solanacearum" vectored by potato psyllids, the causative agent of potato zebra chip disease. However, a lower bacterial transmission rate to S. habrochaites was observed compared with S. lycopersicum.

  14. Micro computed tomography (CT) scanned anatomical gateway to insect pest bioinformatics

    Science.gov (United States)

    An international collaboration to establish an interactive Digital Video Library for a Systems Biology Approach to study the Asian citrus Psyllid and psyllid genomics/proteomics interactions is demonstrated. Advances in micro-CT, digital computed tomography (CT) scan uses X-rays to make detailed pic...

  15. Daily and seasonal patterns in abdomen color in Diaphoria citri (Hemiptera: Psyllidae)

    Science.gov (United States)

    Diaphorina citri Kuwayama, a psyllid vector of huanglongbing (citrus greening disease), exhibits three more or less distinct abdomen colors in the adult psyllid: gray/brown, blue/green, and orange/yellow. We explored the daily (in individuals in the laboratory) and seasonal (in a field population) p...

  16. Ecology of the Asian citrus pysllid

    Science.gov (United States)

    Host selection by psyllids in general appears to involve taste rather than olfaction. Adults are often less discriminating than nymphs. A priori, there is good reason to doubt that Asian citrus psyllid (ACP) uses a long-distance sex pheromone or that ACP orients to host plant volatiles over large (m...

  17. PROCENTAJE DE PSILIDOS PORTADORES DE Canidatus Liberibacter asiaticus Y SU RELACION CON LA INCIDENCIA DE HLB EN CINCO HUERTAS COMERCIALES DE LIMON MEXICANO {Citrus aurantifolia (Christm) Swingle} EN EL ESTADO DE COLIMA MEXICO

    Science.gov (United States)

    Asian citrus psyllids (Diaphorina citri) were individually analyzed by qPCR to detect Candidatus Liberibacter asiaticus (CLas). The psyllids were collected in Mexican lime (Citrus aurantifolia) trees in five commercial orchards in Tecomán and Manzanillo, Colima with severe symptoms of classical mott...

  18. Association of ‘Candidatus Liberibacter asiaticus’, the causal agent of citrus huanglongbing in Murraya paniculata and Diaphorina citri in Thailand

    Science.gov (United States)

    Orange jasmine, Murraya paniculata, is a preferred alternative host for the Asian citrus psyllid, the primary vector of citrus Huanglongbing (HLB) disease caused by ‘Candidatus Liberibacter asiaticus’ (Las). M. paniculata plant samples and psyllids on the Murraya plants from ten diverse geographical...

  19. The relevance of Murraya paniculata and related species as potential hosts and inoculum reservoirs of Candidatus Liberibacter asiaticus, causal agent of Huanglongbing (HLB)

    Science.gov (United States)

    Huanglongbing (HLB), considered the most serious insect-vectored bacterial disease of citrus, is transmitted in nature by the Asian citrus psyllid Diaphorina citri and the African citrus psyllid Trioza erytreae. Diaphorina citri was discovered in southern Florida in 1998 and the HLB disease in 2005...

  20. Murraya paniculata (orange jasmine), a host and possible inoculum reservoir for Candidatus Liberibacter asiaticus, causal agent of Huanglongbing

    Science.gov (United States)

    Huanglongbing (HLB), considered the most serious vectored-pathogen of citrus, is transmitted in nature by the Asian citrus psyllid Diaphorina citri and the African citrus psyllid Trioza erytreae. In 1999, D. citri was discovered in southern Florida and has become established in FL and TX. Huanglon...

  1. Sequencing and annotation of the Wolbachia endosymbiont of Diaphorina citri by the CG-HLB genome resources group reveals candidate sources of interaction with the insect host

    Science.gov (United States)

    Diaphorina citri (Hemiptera: Psyllidae), the Asian citrus psyllid, is the vector of Ca. Liberibacter asiaticus, the causal agent of huanglongbing. The D. citri metagenome has been completed to gain a better understanding of the biology of this organism and the potential roles of other psyllid bacter...

  2. An abundant biological control agent does not provide a significant predator subsidy

    Science.gov (United States)

    Classical weed biological control agents, regardless of their effectiveness, may provide subsidies to predators and parasites. The chemically defended weevil Oxyops vitiosa Pascoe is a successful agent that was introduced to control the invasive tree Melaleuca quinquenervia. Two consecutive small ...

  3. Transcriptome analyses of Bactericera cockerelli adults in response to "Candidatus Liberibacter solanacearum" infection.

    Science.gov (United States)

    Nachappa, Punya; Levy, Julien; Tamborindeguy, Cecilia

    2012-10-01

    The potato/tomato psyllid, Bactericera cockerelli (Šulc) is an economically important crop pest that not only causes damage through its feeding but also transmits the bacterium, "Candidatus Liberibacter solanacearum" (CLs), which causes zebra chip disease in potato. There is some information about the phenotypic effects of phytopathogenic bacteria on their insect vectors; however, there are no published reports of the molecular mechanisms underlying phytopathogenic bacteria-insect vector interaction. In order to investigate the effects of CLs infection on B. cockerelli, transcriptomic analyses of CLs-infected and uninfected adult psyllids that were reared on potato were performed. De novo assembly of cDNA sequences generated 136,518 and 109,983 contigs for infected and uninfected insect libraries with an average contig length of 514 bp. BlastX analysis against the NCBI-nr database revealed that 33.33 % had significant matches. Gene ontology data illustrated that the majority of the expressed psyllid genes are involved in metabolic process, biological regulation, binding and catalytic activity. The psyllid transcriptome had an abundance of genes such as vitellogenin, heat shock protein, ejaculatory bulb-specific protein, ferritin, and cytochrome oxidase. Notably absent in the psyllid transcriptome were innate immunity genes induced in response to Gram-negative bacteria (IMD pathway). Several functionally diverse contigs related to symbiotic bacteria including the primary endosymbiont Carsonella ruddii, Wolbachia, and CLs in the psyllid transcriptome were identified. A total of 247 contigs showed differential expression in response to CLs infection including immune and stress-related genes and vitellogenins. Expression analyses of selected psyllid genes were performed on psyllids that were exclusively reared on potato (host of the insects used for RNAseq) and psyllids exclusively reared on tomato (alternative host of psyllids). These genes showed similar expression

  4. Asymptomatic spread of huanglongbing and implications for disease control.

    Science.gov (United States)

    Lee, Jo Ann; Halbert, Susan E; Dawson, William O; Robertson, Cecile J; Keesling, James E; Singer, Burton H

    2015-06-16

    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 exemplified by the heretofore unknown length of time from initial infection of newly developing cluster of young leaves, called flush, by adult psyllids until the flush become infectious. We present experimental evidence showing that young flush become infectious within 15 d after receiving an inoculum of Candidatus Liberibacter asiaticus (bacteria). Using this critical fact, we specify a microsimulation model of asymptomatic disease spread and intensity in a grove of citrus trees. We apply a range of psyllid introduction scenarios to show that entire groves can become infected with up to 12,000 psyllids per tree in less than 1 y, before most of the trees show any symptoms. We also show that intervention strategies that reduce the psyllid population by 75% during the flushing periods can delay infection of a full grove, and thereby reduce the amount of insecticide used throughout a year. This result implies that psyllid surveillance and control, using a variety of recently available technologies, should be used from the initial detection of invasion and throughout the asymptomatic period.

  5. Preparing sternorrhynchous insects (Insecta: Hemiptera: Sternorrhyncha) for microscope examination: Hoyer’s mounting medium

    Science.gov (United States)

    Proper identification of aphids, scale insects, psyllids, and whitefles (Hemiptera: Sternorrhyncha) require preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare sternorrhynchous specimens on microscope slides for examination and identi...

  6. Improved annotation of the insect vector of citrus greening disease: Biocuration by a diverse genomics community

    Science.gov (United States)

    The Asian citrus psyllid (Diaphorina citri Kuwayama) is the insect vector of the bacterium Candidatus Liberibacter asiaticus (CLas), the pathogen associated with citrus Huanglongbing (HLB, citrus greening). HLB threatens citrus production worldwide. Suppression or reduction of the insect vector usin...

  7. First records of Acizzia jamatonica (Kuwayama) and Glycaspis brimblecombei Moore, (Hemiptera: Psyllidae, Aphalaridae) in Montenegro

    OpenAIRE

    Malumphy, Chris; Perović, Tatjana; Hrnčić, Snježana; RADONJIĆ, SANJA; RAIČEVIĆ, MILORAD

    2013-01-01

    Albizia psyllid, Acizzia jamatonica (Kuwayama), and red gum lerp psyllid, Glycaspis brimblecombei Moore, were found in Montenegro for the first time during 2009 and 2012 respectively. Acizzia jamatonica is native to East Asia, and has spread rapidly in Europe since it was first reported from Italy in 2002. It was first collected from Albizzia julibrissin in Podgorica, September 2009, and subsequently from Albizzia sp. and A. julibrissin in Herceg Novi, October 2010, and June and October 2012,...

  8. Effect of silicon application to Eucalyptus camaldulensis on the population of Glycaspis brimblecombei (Hemiptera: Aphalaridae)

    OpenAIRE

    Dalva Luiz de Queiroz; Joelma Melissa Malherbe Camargo; Renato Antonio Dedecek; Edilson Batista de Oliveira; Keti Maria Rocha Zanol; Raul Cesar Nogueira Melido; Daniel Burckhardt

    2016-01-01

    The use of silicon in forestry has increased recently as it is directly related to improved resistance to insect pests. The red gum lerp psyllid, Glycaspis brimblecombei, occurs in all eucalypt producing regions in Brazil. Two field experiments were conducted to study the effect of silicon applied to Eucalyptus camaldulensis on the psyllid population. In the first experiment, the applications were made via soil (calcium silicate) and leaves (potassium silicate) in a nine months old E. camaldu...

  9. Gut Content Analysis of a Phloem-Feeding Insect, Bactericera cockerelli (Hemiptera: Triozidae).

    Science.gov (United States)

    Cooper, W Rodney; Horton, David R; Unruh, Thomas R; Garczynski, Stephen F

    2016-08-01

    Potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae), is a key pest of potato (Solanum tuberosum L., Solanales: Solanaceae) and a vector of "Candidatus Liberibacter solanacearum," the pathogen associated with zebra chip disease. In addition to its presence on cultivated crops, the psyllid regularly occurs on numerous uncultivated annual and perennial species within the Solanaceae. A better understanding of landscape-level ecology of B. cockerelli would substantially improve our ability to predict which potato fields are most likely to be colonized by infected psyllids. We developed three PCR-based methods of gut content analysis to identify what plant species B. cockerelli had previously fed upon. These methods included-1) sequencing PCR amplicons of regions of plant-derived internal transcribed spacer (ITS) or the chloroplast trnL gene from psyllids, 2) high-resolution melting analysis of ITS or trnL real-time PCR products, and 3) restriction enzyme digestion of trnL PCR product. Each method was used to test whether we could identify psyllids that had been reared continuously on potato versus psyllids reared continuously on the perennial nightshade, Solanum dulcamara. All three methods of gut content analysis correctly identified psyllids from potato and psyllids from S. dulcamara Our study is the first to demonstrate that plant DNA can be detected in a phloem-feeding insect. Gut content analysis, in combination with other landscape ecology approaches, could help elucidate patterns in landscape-level movements and host plant associations of B. cockerelli. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the United States.

  10. Tea Tree (Melaleuca alternifolia) Oil and Its Main Components Cytotoxicity towards Murine Bone Marrow-derived Dendritic Cells%茶树油及其主要组分对树突状细胞体外生长的影响

    Institute of Scientific and Technical Information of China (English)

    唐永富; 李积华; 陈家翠; 曹玉坡; 魏晓奕; 静玮

    2012-01-01

    The effects of TTO and Terpin-4-ol cytotoxicity towards murine bone marrow-derived dendritic cells were analyzed by the tetrazolium salt reduction (MTT) assay in vitro. The results showed that TTO and Terpin-4-ol exhibited strong cytotoxicity properties towards DC, cell viability decreased in a concentration-dependent manner (0.002-1 μl/ml). TTO treated DC exhibited significantly decrease at the concentration (0.063-1 μl/ml, P〈0.05), while Terpin-4-ol at the concentration (0.016-1μl/ml, P〈0.05) much stronger than TTO. The inhibition rate at the concentration of 1μl/ml is 25.60_+ 5.58% for TTO (P〈0.01), 97.20± 1.33% for Terpin-4-ol (P〈0.01), respectively. The safe concentration for the cell test (P〉0.05) is 0.031μl/ml (11.75±7.66%, P〉0.05) for TTO and 0.008μl/ml (4.83±5.28%, P〉 0.05) for Terpin-4-ol, respectively. Terpin-4-ol maybe the most cytotoxicity component of TTO, the results of the present study can be referred to for the appropriate starting dose in cell test and animal toxicity studies.%研究了茶树油及其组分干预树突状细胞后.采用MTT法检测药物对树突状细胞活力的抑制.并通过倒置显微镜观察细胞形态学变化.以探讨茶树油及其主要组分对小鼠骨髓来源树突状细胞体外生长的影响。结果表明:茶树油、Terpin-4-ol、1.8-Cineole和Terpinolene在实验浓度范围内(0.0021.000μL/mL)对树突状细胞活力均有不同程度的抑制.抑制率与药物浓度呈剂量依赖关系,其中,茶树油对树突状细胞活力抑制率为25.60%(1.000μL/mL).而同等浓度下的Terpinene-4-ol抑制率为97.20%(P〈0.01),表明Terpinene-4-ol对树突状细胞有较强的细胞毒性:结果还表明,在进行茶树油对树突状细胞活性评价研究时,应控制安全实验浓度在0.310μL/mL以下.

  11. 万家辉柔枝互叶白千层生长量及其挥发油含量动态研究%A Dynamic Study on Tree Growth and Contents of Volatile Oil of Melaleuca alternifolia Limber Twig Variation

    Institute of Scientific and Technical Information of China (English)

    柴玲; 刘布鸣; 何开家; 林霄; 白懋嘉; 陈明生

    2015-01-01

    通过跟踪测定万家辉柔枝互叶白干层定植后1年生长周期内植物生长量、挥发油得油率以及主成分含量等指标,研究其生长发育规律及主要功能成分的含量变化情况,为万家辉柔枝互叶白干层的优质高产种植以及茶树油生产提供科学依据.

  12. Effects of flooding depth on gas exchange, chlorophyll fluorescence and growth of Melaleuca alternifolia seedlings%淹水深度对互叶白干层幼苗气体交换、叶绿素荧光和生长的影响

    Institute of Scientific and Technical Information of China (English)

    刘瑞仙; 靖元孝; 肖林; 李国梁; 杨丹菁; 聂坤廷

    2010-01-01

    实验设置对照、浅淹(水位高出土壤表面5cm)和深淹(水位高出土壤表面20cm)3种处理,研究了淹水深度对互叶白千层幼苗的气体交换、叶绿素荧光和生长状况的影响.研究结果表明,随着淹水深度的增加,互叶白千层受到的胁迫程度有所增强.经过270d的淹水处理,浅淹组和深淹组的株高和生物奄有所下降,分别为对照的90.86%、64.58%和74.52%、36.46%.浅淹组植株叶绿素含量、净光合速率、气孔传导率和蒸腾速率略有下降,分别为对照的95.39%、94.26%、90.02%和88.94%.深淹组植株在淹水后180d内上述参数显著下降,分别为对照的79.44%、73.54%、61.79%和71.46%,随后逐渐接近对照组.浅淹组PSⅡ的最大光化学量子效率(Fv/Fm)比较稳定,与对照组基本相同.深淹组在淹水后150d内Fv/Fm稍有下降,随后恢复到对照水平.浅淹组植株光化学淬灭系数(gP)稍有下降,非光化学淬灭(NPQ)略有上升,分别为对照的96.63%和105.66%.深淹组植株在淹水后120d内gP显著下降,ⅣPQ明显上升、分别为对照的94.51%和126.66%,随后逐渐接近对照组.另外,淹水过程中,互叶白千层形成不定根和产生发达的通气组织,淹水植株的根孔隙度显著高于对照.

  13. RESEARCH ON THE RELATIONSHIP AMONG DISTILLATION,MAIN CHEMICAL CONSTITUENTS AND YIELD OF THE ESSENTIAL OIL OF MELALEUCA ALTERNIFOLIA%蒸馏时间与互叶白千层精油主要化学成分及出油率关系的研究

    Institute of Scientific and Technical Information of China (English)

    张燕君; 陈利芳

    2002-01-01

    蒸馏的持续时间是影响互叶白千层精油质量及出油率的重要因素之一.对不同蒸馏时间段所收集的互叶白千层精油的化学成分及出油量进行了分析研究.结果表明,随着蒸馏时间段的延长,互叶白千层芳香油的主要化学成分的含量及其出油量均下降,在0~120 min内,出油率已超过98%,120~150 min阶段其出油率不到2%.而高沸点的环烯烃及其醇类却随着蒸馏时间的增加而增加.因而可以通过控制蒸馏时间,提高互叶白千层精油的质量,同时可以降低能耗.

  14. Using NextRAD sequencing to infer movement of herbivores among host plants.

    Science.gov (United States)

    Fu, Zhen; Epstein, Brendan; Kelley, Joanna L; Zheng, Qi; Bergland, Alan O; Castillo Carrillo, Carmen I; Jensen, Andrew S; Dahan, Jennifer; Karasev, Alexander V; Snyder, William E

    2017-01-01

    Herbivores often move among spatially interspersed host plants, tracking high-quality resources through space and time. This dispersal is of particular interest for vectors of plant pathogens. Existing molecular tools to track such movement have yielded important insights, but often provide insufficient genetic resolution to infer spread at finer spatiotemporal scales. Here, we explore the use of Nextera-tagmented reductively-amplified DNA (NextRAD) sequencing to infer movement of a highly-mobile winged insect, the potato psyllid (Bactericera cockerelli), among host plants. The psyllid vectors the pathogen that causes zebra chip disease in potato (Solanum tuberosum), but understanding and managing the spread of this pathogen is limited by uncertainty about the insect's host plant(s) outside of the growing season. We identified 1,978 polymorphic loci among psyllids separated spatiotemporally on potato or in patches of bittersweet nightshade (S. dulcumara), a weedy plant proposed to be the source of potato-colonizing psyllids. A subset of the psyllids on potato exhibited genetic similarity to insects on nightshade, consistent with regular movement between these two host plants. However, a second subset of potato-collected psyllids was genetically distinct from those collected on bittersweet nightshade; this suggests that a currently unrecognized source, i.e., other nightshade patches or a third host-plant species, could be contributing to psyllid populations in potato. Oftentimes, dispersal of vectors of pathogens must be tracked at a fine scale in order to understand, predict, and manage disease spread. We demonstrate that emerging sequencing technologies that detect genome-wide SNPs of a vector can be used to infer such localized movement.

  15. Effect of silicon application to Eucalyptus camaldulensis on the population of Glycaspis brimblecombei (Hemiptera: Aphalaridae

    Directory of Open Access Journals (Sweden)

    Dalva Luiz de Queiroz

    2016-06-01

    Full Text Available The use of silicon in forestry has increased recently as it is directly related to improved resistance to insect pests. The red gum lerp psyllid, Glycaspis brimblecombei, occurs in all eucalypt producing regions in Brazil. Two field experiments were conducted to study the effect of silicon applied to Eucalyptus camaldulensis on the psyllid population. In the first experiment, the applications were made via soil (calcium silicate and leaves (potassium silicate in a nine months old E. camaldulensis plantation. In the second experiment, we evaluated silicon on seedlings, incorporating it into the substrate (soil or applying it on leaves (foliar. Monthly, for 24 months, the number of psyllid eggs and immatures were counted on leaf samples. The plant height was measured at 9, 12, 16 and 24 months (experiment 1 and at 4, 8, 12 and 24 months (experiment 2 after application. The numbers of eggs and immatures were lower in periods of higher precipitation, indicating less psyllid attack during the rainy season. The psyllid population was lower in treatments with application of silicon both foliar and via soil compared to control. No significant differences were found in the height of E. camaldulensis plants.

  16. The effects of plant cover on population of pear psylla (Cacopsylla pyricola and its predators

    Directory of Open Access Journals (Sweden)

    Mohammad Saeed Emami

    2017-01-01

    Full Text Available Cacopsylla pyricola (Förster, 1848 (Hemiptera: Psyllidae is a serious pest of pear in all pear growing areas. In the scope of an integrated pest management, a two consecutive years study was carried out to determine the effects of plant cover on pear psyllid population and its predators. Two treatments including plant cover and bare ground were applied in a randomized complete block design with three replicates. The sampling of the pest and its predators were done weekly by beating technique and leaf sampling. The data were subjected to analysis of variance (ANOVA. The results showed that plant cover had significant effect on the increase of predators on the trees (P < 0.001. The psyllid specialist predator, Anthocoris nemoralis (Fabricius, 1794, had the highest population among the pear psyllid predators (0.29 per sample. Plant cover had no significant effect on reducing the population of eggs, nymphs and adults of the pear psyllid. Despite the increase in the population of predators led by plant cover, lack of their effectiveness to reduce the pear psyllid population is discussed.

  17. Detection of citrus huanglongbing-associated 'Candidatus Liberibacter asiaticus' in citrus and Diaphorina citri in Pakistan, seasonal variability, and implications for disease management.

    Science.gov (United States)

    Razi, Muhammad F; Keremane, Manjunath L; Ramadugu, Chandrika; Roose, Mikeal; Khan, Iqrar A; Lee, Richard F

    2014-03-01

    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 August) and autumn (September to November) in contrast to reports from Florida, where the bacterium was detectable at very high levels during October to November. We hypothesize that hot summer temperatures in Pakistan may interfere with acquisition and replication of 'Ca. L. asiaticus' in psyllids and may lead to dead or non transmissible 'Ca. L. asiaticus' in plants. Psyllid counts were very low in both summer and winter, showed a population peak ('Ca. L. asiaticus'-positive vectors) in spring, and showed a larger peak ('Ca. L. asiaticus'-free psyllids) in autumn. Natural thermotherapy during hot summers and a low vector population during environmental extremes may have played a major role in long-term survival of the citrus industry in Pakistan. These results may be useful in developing management strategies for U.S. citrus industries in Texas and California.

  18. The Use of an Invasive Species Habitat by a Small Folivorous Primate: Implications for Lemur Conservation in Madagascar

    Science.gov (United States)

    Eppley, Timothy M.; Donati, Giuseppe; Ramanamanjato, Jean-Baptiste; Randriatafika, Faly; Andriamandimbiarisoa, Laza N.; Rabehevitra, David; Ravelomanantsoa, Robertin; Ganzhorn, Jörg U.

    2015-01-01

    The lemurs of Madagascar are among the most threatened mammalian taxa in the world, with habitat loss due to shifting cultivation and timber harvest heavily contributing to their precarious state. Deforestation often leads to fragmentation, resulting in mixed-habitat matrices throughout a landscape where disturbed areas are prone to invasion by exotic plants. Our study site, the Mandena littoral forest (southeast Madagascar), is a matrix of littoral forest, littoral swamp, and Melaleuca swamp habitats. Here, Melaleuca quinquenervia has invaded the wetland ecosystem, creating a mono-dominant habitat that currently provides the only potential habitat corridor between forest fragments. We sought to understand the role of this invasive Melaleuca swamp on the behavioral ecology of a threatened, small-bodied folivore, the southern bamboo lemur (Hapalemur meridionalis). We collected botanical and behavioral data on four groups of H. meridionalis between January and December 2013. Our results confirm Melaleuca swamp as an important part of their home range: while lemurs seasonally limited activities to certain habitats, all groups were capable of utilizing this invasive habitat for feeding and resting. Furthermore, the fact that Hapalemur use an invasive plant species as a dispersal corridor increases our knowledge of their ecological flexibility, and may be useful in the conservation management of remaining threatened populations. PMID:26536667

  19. The Use of an Invasive Species Habitat by a Small Folivorous Primate: Implications for Lemur Conservation in Madagascar.

    Science.gov (United States)

    Eppley, Timothy M; Donati, Giuseppe; Ramanamanjato, Jean-Baptiste; Randriatafika, Faly; Andriamandimbiarisoa, Laza N; Rabehevitra, David; Ravelomanantsoa, Robertin; Ganzhorn, Jörg U

    2015-01-01

    The lemurs of Madagascar are among the most threatened mammalian taxa in the world, with habitat loss due to shifting cultivation and timber harvest heavily contributing to their precarious state. Deforestation often leads to fragmentation, resulting in mixed-habitat matrices throughout a landscape where disturbed areas are prone to invasion by exotic plants. Our study site, the Mandena littoral forest (southeast Madagascar), is a matrix of littoral forest, littoral swamp, and Melaleuca swamp habitats. Here, Melaleuca quinquenervia has invaded the wetland ecosystem, creating a mono-dominant habitat that currently provides the only potential habitat corridor between forest fragments. We sought to understand the role of this invasive Melaleuca swamp on the behavioral ecology of a threatened, small-bodied folivore, the southern bamboo lemur (Hapalemur meridionalis). We collected botanical and behavioral data on four groups of H. meridionalis between January and December 2013. Our results confirm Melaleuca swamp as an important part of their home range: while lemurs seasonally limited activities to certain habitats, all groups were capable of utilizing this invasive habitat for feeding and resting. Furthermore, the fact that Hapalemur use an invasive plant species as a dispersal corridor increases our knowledge of their ecological flexibility, and may be useful in the conservation management of remaining threatened populations.

  20. The Use of an Invasive Species Habitat by a Small Folivorous Primate: Implications for Lemur Conservation in Madagascar.

    Directory of Open Access Journals (Sweden)

    Timothy M Eppley

    Full Text Available The lemurs of Madagascar are among the most threatened mammalian taxa in the world, with habitat loss due to shifting cultivation and timber harvest heavily contributing to their precarious state. Deforestation often leads to fragmentation, resulting in mixed-habitat matrices throughout a landscape where disturbed areas are prone to invasion by exotic plants. Our study site, the Mandena littoral forest (southeast Madagascar, is a matrix of littoral forest, littoral swamp, and Melaleuca swamp habitats. Here, Melaleuca quinquenervia has invaded the wetland ecosystem, creating a mono-dominant habitat that currently provides the only potential habitat corridor between forest fragments. We sought to understand the role of this invasive Melaleuca swamp on the behavioral ecology of a threatened, small-bodied folivore, the southern bamboo lemur (Hapalemur meridionalis. We collected botanical and behavioral data on four groups of H. meridionalis between January and December 2013. Our results confirm Melaleuca swamp as an important part of their home range: while lemurs seasonally limited activities to certain habitats, all groups were capable of utilizing this invasive habitat for feeding and resting. Furthermore, the fact that Hapalemur use an invasive plant species as a dispersal corridor increases our knowledge of their ecological flexibility, and may be useful in the conservation management of remaining threatened populations.

  1. Acquired natural enemies of the weed biological control agent Oxyops vitiosa (Coleoptera: Curculionidae)

    Science.gov (United States)

    The Australian curculionid Oxyops vitiosa Pascoe was introduced into Florida during 1997 as a biological control agent of the invasive tree Melaleuca quinquenervia (Cav.) S.T. Blake. Populations of the weevil increased rapidly and became widely distributed throughout much of the invasive tree’s adve...

  2. In chemico evaluation of tea tree essential oils as skin sensitizers. Impact of the chemical composition on aging and generation of reactive species

    Science.gov (United States)

    Tea tree oil (TTO) is a popular skin remedy obtained from the leaves of Melaleuca alternifolia, M. linariifolia or M dissitiflora. Due to the commercial importance ofTTO, substitution or adulteration with other tea tree species (such as cajeput, niaouli, manuka and kanuka oils) is common and may p...

  3. Determining the Antimicrobial Actions of Tea Tree Oil

    OpenAIRE

    S. Grant Wyllie; Warmington, John R.; Gustafson, John E.; Markham, Julie L.; Mann, Cindy M.; Cox, Sean D.

    2001-01-01

    Research into the mode of action of the essential oil of Melaleuca alternifolia (Tea tree oil) is briefly reviewed. Its mode of action is interpreted in terms of the membrane-toxicity of its monoterpenoid components and different approaches for determining cell membrane damage are discussed.

  4. Determining the Antimicrobial Actions of Tea Tree Oil

    Directory of Open Access Journals (Sweden)

    S. Grant Wyllie

    2001-01-01

    Full Text Available Research into the mode of action of the essential oil of Melaleuca alternifolia (Tea tree oil is briefly reviewed. Its mode of action is interpreted in terms of the membrane-toxicity of its monoterpenoid components and different approaches for determining cell membrane damage are discussed.

  5. Search for potential vectors of ‘Candidatus Liberibacter solanacearum’: population dynamics in host crops

    Energy Technology Data Exchange (ETDEWEB)

    Teresani, G.; Hernández, E.; Bertolini, E.; Siverio, F.; Marroquín, C.; Molina, J.; Hermoso de Mendoza, A.; Cambra, M.

    2015-07-01

    ‘Candidatus Liberibacter solanacearum’ has recently been reported to be associated with vegetative disorders and economic losses in carrot and celery crops in Spain. The bacterium is a carrot seedborne pathogen and it is transmitted by psyllid vector species. From 2011 to 2014 seasonal and occasional surveys in carrot, celery and potato plots were performed. The sticky plant method was used to monitor the arthropods that visited the plants. The collected arthropods were classified into Aphididae and Cicadellidae, and the superfamily Psylloidea was identified to the species level. The superfamily Psylloidea represented 35.45% of the total arthropods captured on celery in Villena and 99.1% on carrot in Tenerife (Canary Islands). The maximum flight of psyllid species was in summer, both in mainland Spain and the Canary Islands, reaching a peak of 570 specimens in August in Villena and 6,063 in July in Tenerife. The main identified psyllid species were as follows: Bactericera trigonica Hodkinson, B. tremblayi Wagner and B. nigricornis Förster. B. trigonica represented more than 99% of the psyllids captured in the Canary Islands and 75% and 38% in 2011 and 2012 in Villena, respectively. In addition, Trioza urticae Linnaeus, Bactericera sp., Ctenarytaina sp., Cacopsylla sp., Trioza sp. and Psylla sp. were captured. ‘Ca. L. solanacearum’ targets were detected by squash real-time PCR in 19.5% of the psyllids belonging to the different Bactericera species. This paper reports at least three new psyllid species that carry the bacterium and can be considered as potential vectors. (Author)

  6. Search for potential vectors of ‘Candidatus Liberibacter solanacearum’: population dynamics in host crops

    Directory of Open Access Journals (Sweden)

    Gabriela Teresani

    2015-03-01

    Full Text Available Candidatus Liberibacter solanacearum’ has recently been reported to be associated with vegetative disorders and economic losses in carrot and celery crops in Spain. The bacterium is a carrot seedborne pathogen and it is transmitted by psyllid vector species. From 2011 to 2014 seasonal and occasional surveys in carrot, celery and potato plots were performed. The sticky plant method was used to monitor the arthropods that visited the plants. The collected arthropods were classified into Aphididae and Cicadellidae, and the superfamily Psylloidea was identified to the species level. The superfamily Psylloidea represented 35.45% of the total arthropods captured on celery in Villena and 99.1% on carrot in Tenerife (Canary Islands. The maximum flight of psyllid species was in summer, both in mainland Spain and the Canary Islands, reaching a peak of 570 specimens in August in Villena and 6,063 in July in Tenerife. The main identified psyllid species were as follows: Bactericera trigonica Hodkinson, B. tremblayi Wagnerand B. nigricornis Förster. B. trigonica represented more than 99% of the psyllids captured in the Canary Islands and 75% and 38% in 2011 and 2012 in Villena, respectively. In addition, Trioza urticae Linnaeus, Bactericera sp.,Ctenarytaina sp., Cacopsylla sp., Trioza sp. and Psylla sp. were captured. ‘Ca. L. solanacearum’ targets were detected by squash real-time PCR in 19.5% of the psyllids belonging to the different Bactericera species. This paper reports at least three new psyllid species that carry the bacterium and can be considered as potential vectors.

  7. First record of Diaphorina citri (Hemiptera: Psyllidae) in Ecuador infesting urban citrus and orange jasmine trees.

    Science.gov (United States)

    Cornejo, J F; Chica, E J

    2014-01-01

    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 our knowledge, this is the first report of D. citri in Ecuador and the Pacific coastal plain of South America.

  8. Comparison of DNA extraction methods for detection of citrus huanglongbing in Colombia

    Directory of Open Access Journals (Sweden)

    Jorge Evelio Ángel

    2014-04-01

    Full Text Available Four DNA citrus plant tissue extraction protocols and three methods of DNA extraction from vector psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae were compared as part of the validation process and standardization for detection of huanglongbing (HLB. The comparison was done using several criterias such as integrity, purity and concentration. The best quality parameters presented in terms of extraction of DNA from plant midribs tissue of citrus, were cited by Murray and Thompson (1980 and Rodríguez et al. (2010, while for the DNA extraction from psyllid vectors of HLB, the best extraction method was suggested by Manjunath et al.(2008.

  9. A new species of Tamarixia Mercet (Hymenoptera, Eulophidae), parasitoid of Trioza aguacate Hollis & Martin (Hemiptera, Triozidae) in Mexico.

    Science.gov (United States)

    Yefremova, Zoya; González-Santarosa, Graciela; Lomeli-Flores, J Refugio; Bautista-Martínez, Néstor

    2014-01-01

    Tamarixia aguacatensis Yefremova, sp. n. (Hymenoptera: Eulophidae: Tetrastichinae) is described from Mexico as a parasitoid of the avocado psyllid, Trioza aguacate Hollis & Martin (Hemiptera: Triozidae). Trioza aguacate is a serious pest of avocado, Persea americana Miller. A key to the species of Tamarixia Mercet in Mexico is given.

  10. A new species of Tamarixia Mercet (Hymenoptera, Eulophidae, parasitoid of Trioza aguacate Hollis & Martin (Hemiptera, Triozidae in Mexico

    Directory of Open Access Journals (Sweden)

    Zoya Yefremova

    2014-01-01

    Full Text Available Tamarixia aguacatensis Yefremova, sp. n. (Hymenoptera: Eulophidae: Tetrastichinae is described from Mexico as a parasitoid of the avocado psyllid, Trioza aguacate Hollis & Martin (Hemiptera: Triozidae. Trioza aguacate is a serious pest of avocado, Persea americana Miller. A key to the species of Tamarixia Mercet in Mexico is given.

  11. A new species of Tamarixia Mercet (Hymenoptera, Eulophidae), parasitoid of Trioza aguacate Hollis & Martin (Hemiptera, Triozidae) in Mexico

    Science.gov (United States)

    Yefremova, Zoya; González-Santarosa, Graciela; Lomeli-Flores, J. Refugio; Bautista-Martínez, Néstor

    2014-01-01

    Abstract Tamarixia aguacatensis Yefremova, sp. n. (Hymenoptera: Eulophidae: Tetrastichinae) is described from Mexico as a parasitoid of the avocado psyllid, Trioza aguacate Hollis & Martin (Hemiptera: Triozidae). Trioza aguacate is a serious pest of avocado, Persea americana Miller. A key to the species of Tamarixia Mercet in Mexico is given. PMID:24478580

  12. Visualization of ‘Candidatus Liberibacter asiaticus’ cells in citrus seed coats with fluorescence in situ hybridization and transmission electron microscopy

    Science.gov (United States)

    ‘Candidatus Liberibacter asiaticus’ is bacterium implicated as the causal agent of the economically damaging disease of citrus called huanglongbing (HLB). The bacterium is spread by movement of infected citrus propagation material and by the Asian citrus psyllid, Diaphorina citri Kuwayama. Seed tr...

  13. Control of Huanglongbing (HLB) disease with reference to its ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-01

    Sep 1, 2009 ... After extraction of the juice, the skin and fruit pulp can be used as livestock .... nery or commercial grove care companies to accomplish chemical ... on psyllid vectors, the effect of this practice on HLB ... tic pesticides a year.

  14. Zoophthora radicans (Entomophthorales), fungal pathogen of Bagrada hilaris and Bactericera cockerelli (Hemiptera: Pentatomidae & Triozidae)in Mexico: Prevalence, bioassays, & environmental influences on conidial morphology

    Science.gov (United States)

    The Bagrada bug, Bagrada hilaris, and the potato/tomato psyllid, Bactericera cockerelli, are key pests of horticulture in western North America. In 2014 and 2015, adult and juvenile B. hilaris and B. cockerelli killed by fungi in the genus Zoophthora were detected at separate localities near Saltill...

  15. First Report of Candidatus Liberibacter solanacearum in Pepper Plants in Mexico

    Science.gov (United States)

    Bell pepper (Capsicum annuum) plants exhibiting symptoms that resemble those of potato psyllid damage and/or ‘Candidatus Liberibacter solanacearum’ infection were observed in La Cruz de Elota, Sinaloa, México in March 2009. The plants had chlorotic or pale green leaves and exhibited leaf cupping, sh...

  16. Repellency of a kaolin particle film to potato payllid, Bactericera cockerelli (Hemiptera: Psyllidae) on tomato under laboratory and field conditions

    Science.gov (United States)

    The potato psyllid, Bactericera cockerelli, is a vector of “Candidatus Liberibacter solanacearum,” the bacterium causing several diseases in solanaceous crops. Laboratory and field no-choice and choice experiments were conducted to evaluate repellency of kaolin particle film on adults of B. cockerel...

  17. Formic and acetic acids in degradation products of plant volatiles elicit olfactory and behavorial responses from an insect vector

    Science.gov (United States)

    The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae) vectors the bacterial pathogen presumed to be the etiological agent of citrus greening disease, Huanglongbing (HLB), a major threat to citrus industry worldwide. We studied antennal and behavioral responses of Diaphorina citri...

  18. First report of 'Candidatus Liberibacter solanacearum' associated with psylllid-affected tobacco in Honduras

    Science.gov (United States)

    Tobacco plants with symptoms resembling those associated with the psyllid Bactericera cockerelli and the bacterium “Candidatus Liberibacter solanacearum” (Lso) were observed in April of 2012 in heavily B. cockerelli-infested commercial fields in the Department of El-Paraíso, Honduras; all cultivars ...

  19. Use of the entomopathogenic fungi Metarhizium anisopliae, Cordyceps bassiana and Isaria fumosorosea to control Diaphorina citri (Hemiptera: Psylidae) in Persian lime under field conditions

    Science.gov (United States)

    The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is a destructive insect pest in the citriculture, because it is an efficient vector of the proteobacteria, ‘Candidatus Liberibacter asiaticus’ (Las), ‘Ca. L. Africanus’ (Laf), and ‘Ca. L. Americanus’ (Lam). These bacteria c...

  20. Constitutive and herbivore-induced volatiles in pear, alder and hawthorn trees

    NARCIS (Netherlands)

    Scutareanu, P.; Bruin, de J.; Posthumus, M.A.; Drukker, B.

    2003-01-01

    Qualitative and quantitative differences among pear cultivars were found in constitutive and Cacopsylla-induced volatiles, depending on experimental treatment of the trees (i.e., uninfested and partly or completely infested by psyllids). Blend differences were also found between pear cultivars and w

  1. An improved method of DNA extraction from Diaphorina citri for HLB detection

    Science.gov (United States)

    Huanglongbing (HLB) is a devastating disease of citrus that is transmitted by two citrus psyllids. Diaphorina citri transmits Candidatus Liberibacter asiaticus (Las) and Ca. L. americanus (Lam), and Trioza erytreae transmits Ca. L. africanus (Laf). Ca. Liberibacter species can be detected in DNA ex...

  2. Ca. Liberibacter asiaticus genes orthologous with pSymA-borne genes of Sinorhizobium meliloti: suggested roles in eukaryotic host interactions

    Science.gov (United States)

    ‘Ca. Liberibacter asiaticus,’ is a psyllid-vectored, obligate phytopathogen associated with citrus huanglongbing disease. Sinorhizobium meliloti strain 1021, a nitrogen-fixing, root-nodulating bacterial microsymbiont of alfalfa, has a 3.5 Mbp circular chromosome and two megaplasmids including 1.3 Mb...

  3. Biocuration and improvement of the Diaphorina citri draft genome assembly with long reads, optical maps and long-range scaffolding

    Science.gov (United States)

    The Asian citrus psyllid (Diaphorina citri Kuwayama) is the insect vector of the bacterium Candidatus Liberibacter asiaticus (CLas), the causal agent for the citrus greening or Huanglongbing disease which threatens citrus industry worldwide. This vector is the primary target of approaches to stop th...

  4. Effect of vector control and foliar nutrition on the quality of orange juice affected by Huanglongbing: Sensory evaluation

    Science.gov (United States)

    A 3-year study was undertaken to establish the effect of field nutritional sprays, combined or not with insecticide treatments against Asian Citrus psyllid, on the fruit quality of ‘Valencia’ orange trees affected by the greening disease Huanglongbing (HLB). Four replicated plots were harvested, jui...

  5. Host plant affects morphometric variation of Diaphorina citri (Hemiptera: Liviidae)

    Science.gov (United States)

    The Asian citrus psyllid (ACP), due to its potential to vector the pathogen causing citrus greening disease or huanglongbing, is one of the most serious citrus pests worldwide. While optimal plant cultivars for ACP oviposition and development have been determined, little is known of the influence of...

  6. Developing resistance to HLB

    Science.gov (United States)

    Huanglongbing (HLB) disease of citrus is caused by Candidatus Liberibacter asiaticus (CLas) a bacterium that is transmitted among citrus trees by its insect vector, the Asian citrus psyllid (ACP). HLB has had negative impact on citrus production in the far east for over one hundred years, but not c...

  7. Characterization of a recombinant Cathepsin B-Like cysteine peptidase from Diaphorina citri Kuwayama (Hemiptera: Liviidae): A putative target control of citrus huanglongbing

    Science.gov (United States)

    Huanglongbing (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) spread by the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae). Among the control strategies for H...

  8. Population ecology and phenology of Diaphorina citri (Hemiptera: Psyllidae) in two Florida citrus groves

    Science.gov (United States)

    Studies were conducted during 2005 and 2006 to assess population densities and phenology of the psyllid Diaphorina citri Kuwayama in citrus within east central Florida. Young, irrigated grapefruit and mature, non-irrigated orange trees were sampled weekly for eggs, nymphs and adults on flush shoots;...

  9. Characterization of management and environmental factors associated with regional variations in potato zebra chip occurrence

    Science.gov (United States)

    Potato zebra chip (ZC) disease, putatively caused by the bacterial pathogen ‘Candidatus Liberibacter solanacearum’, which is vectored by the potato psyllid (Bactericera cockerelli), has caused widespread damage to the US potato production ever since its first discovery in south Texas in 2000. In t...

  10. The complete mitochondrial genome sequence of Bactericera cockerelli and its comparison with three other psylloidea species

    Science.gov (United States)

    Potato-tomato psyllid (Bactericera cockerelli) is an important pest of potatoes, tomato and peppers. A toxin secreted by nymphs results in serious phytotoxemia in some host plants. Over the past few years, B. cockerelli was shown to transmit “Candidatus Liberibacter solanacearum”, the putative bacte...

  11. The complete mitochondrial genome sequence of Diaphorina citri (Hemiptera: Psyllidae)

    Science.gov (United States)

    The first complete mitochondrial genome (mitogenome) sequence of Asian citrus psyllid, Diaphorina citri (Hemiptera: Psyllidae), from Guangzhou, China is presented. The circular mitogenome is 14,996 bp in length with an A+T content of 74.5%, and contains 13 protein-coding genes (PCGs), 22 tRNA genes ...

  12. Variations in Zebra Chip disease expression and tuber biochemistry in response to vector density

    Science.gov (United States)

    This study examined effects of the number of ‘Candidatus Liberibacter solanacearum’ (Lso)-positive psyllids feeding on potatoes to Lso titers, zebra chip disease (ZC) symptom severity, and levels of amino acids, carbohydrates, and phenolics in tubers harvested weeks later. Red La Soda and Russet Nor...

  13. Attraction of Diaphorina citri (Hemiptera: Liviidae) to colored light

    Science.gov (United States)

    The most devasting disease of citrus, huanglongbing (HLB), is spread by the insect vector the Asian Citrus Psyllid (ACP). Although ACP are known to respond to visual cues, previous studies have not documented the specific wavelengths of light attractive to ACP. The objectives of this study were to...

  14. Within-orchard edge effects of the azimuth of the sun on Diaphorina citri adults in mature orchards

    Science.gov (United States)

    Huanglongbing (HLB) has been considered the most devastating disease of citrus. The bacterium and vector associated with HLB in Florida are ‘Candidatus Liberibacter asiaticus’ and Diaphorina citri (Asian citrus psyllid), respectively. D. citri is positively phototropic, and higher populations have b...

  15. Low-level detection of Candidatus Liberibacter solanacearum in extracted Bactericera cockerelli (Hemiptera: Triozidae) DNA by 454 pyrosequencing

    Science.gov (United States)

    Accurate detection and quantification of Candidatus Liberibacter solanacearum, the putative causal agent of zebra chip disease of potato (Solanum tuberosum), in the potato psyllid, Bactericera cockerelli, has become necessary to better understand the biology of the disease cycle. Studies on the tran...

  16. Effects of temperature, photoperiod, and rainfall on morphometric variation of Diaphorina citri (Hemiptera: Liviidae)

    Science.gov (United States)

    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 artifi...

  17. Broad sprectrum potential of Isaria fumosorosea on insect pests of citrus

    Science.gov (United States)

    Use of entomopathogenic fungi, Isaria fumosorosea, Ifr, =Paecilomyces fumosoroseus, successfully increased insect pest mortality. Spraying the Ifr containing product, PFR97 TM, on citrus seedlings was used to screen efficacy for the management of Asian citrus psyllid, Diaphorina citri; glassy-winge...

  18. Characterization and correlation of EPG waveforms of Bactericera cockerelli (Hemiptera: Triozidae): variability in waveform appearance in relation to applied signal

    Science.gov (United States)

    The potato psyllid, Bactericera cockerelli, was recently shown to be a vector of “Candidatus Liberibacter solanacearum” (Lso), a phloem-limited bacterium that is the putative causal agent of “Zebra Chip” in potato and unnamed diseases in other solanaceous species. Despite its importance, very little...

  19. Low incidence of Candidatus Liberibacter asiaticus in Diaphorina citri and its host plant Murraya paniculata

    Science.gov (United States)

    Huanglongbing (HLB) is one of the most devastating diseases of citrus worldwide. Candidatus Liberibacter asiaticus is the prevalent species of three HLB-associated Liberibacter species, which is vectored by the psyllid Diaphorina citri. The vector and the bacteria have host plants outside Citrus, ...

  20. Feasibility of Using the Optical Sensing Techniques for Early Detection of Huanglongbing in Citrus Seedlings

    Directory of Open Access Journals (Sweden)

    Alireza Pourreza

    2017-04-01

    Full Text Available A vision sensor was introduced and tested for early detection of citrus Huanglongbing (HLB. This disease is caused by the bacterium Candidatus Liberibacter asiaticus (CLas and is transmitted by the Asian citrus psyllid. HLB is a devastating disease that has exerted a significant impact on citrus yield and quality in Florida. Unfortunately, no cure has been reported for HLB. Starch accumulates in HLB infected leaf chloroplasts, which causes the mottled blotchy green pattern. Starch rotates the polarization plane of light. A polarized imaging technique was used to detect the polarization-rotation caused by the hyper-accumulation of starch as a pre-symptomatic indication of HLB in young seedlings. Citrus seedlings were grown in a room with controlled conditions and exposed to intensive feeding by CLas-positive psyllids for eight weeks. A quantitative polymerase chain reaction was employed to confirm the HLB status of samples. Two datasets were acquired; the first created one month after the exposer to psyllids and the second two months later. The results showed that, with relatively unsophisticated imaging equipment, four levels of HLB infections could be detected with accuracies of 72%–81%. As expected, increasing the time interval between psyllid exposure and imaging increased the development of symptoms and, accordingly, improved the detection accuracy.

  1. Gut content analysis of a phloem-feeding insect, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae)

    Science.gov (United States)

    Potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae) is a key pest of potato (Solanum tuberosum L., Solanales: Solanaceae) and a vector of "Candidatus Liberibacter solanacearum," the pathogen associated with zebra chip disease. In addition to its presence on cultivated crops, the p...

  2. Wolbachia infection differs among divergent mitochondrial haplotypes of Bactericera cockerelli (Hemiptera: Triozidae)

    Science.gov (United States)

    Four mitochondrial (cytrochrome oxidase I) haplotypes of the potato psyllid, Bactericera cockerelli (S'ulc) (Hemiptera: Triozidae), have been identified in North America: western, central, northwestern,and southwestern. A recent study found that females of the northwestern haplotype mated by males o...

  3. Survey of endosymbionts in the Diaphorina citri metegenome and assembly of a Wolbachia wDi draft genome

    Science.gov (United States)

    Diaphorina citri, the Asian citrus psyllid,(Hemiptera) is the insect vector of Candidatus Liberibacter asiaticus, the presumed cause of citrus greening disease, known as huanglongbing. Sequencing of the Diaphorina citri metagenome has been initiated to gain better understanding of the biology of D. ...

  4. Aero-allergens in canine atopic dermatitis in southeastern Australia based on 1000 intradermal skin tests.

    Science.gov (United States)

    Mueller, R S; Bettenay, S V; Tideman, L

    2000-06-01

    To determine the most relevant aero-allergens involved in canine atopic dermatitis in southeastern Australia and provide information about these aero-allergens to the general practitioner. Dogs presented to the Animal Skin & Allergy Clinic with history and clinical signs of atopic dermatitis were injected intradermally with 38 different allergens and negative and positive control. Intradermal skin tests in 1000 dogs were retrospectively evaluated. One third of all patients reacted to the house dust mite Dermatophagoides farinae. Allergens reacting in more than 15% of the patients were wheat (Triticum aestivum), sweet vernal (Anthoxanthum odoratum), English couch (Agropyron repens), yellow dock (Rumex crispus), Mexican tea (Chenopodium ambrosioides), plantain (Plantago lanceolata), melaleuca (Melaleuca quinquenervia) and peppercorn (Schimus spp). House dust mites are the most common allergens in canine atopic dermatitis in southeastern Australia and D farinae is involved most frequently. However, a number of grass, weed and tree pollens also are involved regularly.

  5. Repellency effect of forty-one essential oils against Aedes, Anopheles, and Culex mosquitoes.

    Science.gov (United States)

    Amer, Abdelkrim; Mehlhorn, Heinz

    2006-09-01

    Since ancient times, plant products were used in various aspects. However, their use against pests decreased when chemical products became developed. Recently, concerns increased with respect to public health and environmental security requiring detection of natural products that may be used against insect pests. In this study, 41 plant extracts and 11 oil mixtures were evaluated against the yellow fever mosquito, Aedes aegypti (Linnaeus), the malaria vector, Anopheles stephensi (Liston), and the filariasis and encephalitis vector, Culex quinquefasciatus (Say) (Diptera: Culicidae) using the skin of human volunteers to find out the protection time and repellency. The five most effective oils were those of Litsea (Litsea cubeba), Cajeput (Melaleuca leucadendron), Niaouli (Melaleuca quinquenervia), Violet (Viola odorata), and Catnip (Nepeta cataria), which induced a protection time of 8 h at the maximum and a 100% repellency against all three species. This effect needs, however, a peculiar formulation to fix them on the human skin.

  6. Komponen minyak atsiri dari daun tiga jenis tumbuhan famili Myrtaceae asal Desa Soa dan Desa Sota Merauke

    Directory of Open Access Journals (Sweden)

    Yuliasri Jamal

    1997-12-01

    Full Text Available An isolation of the leaves of Asteromyrtus sp., Melaleuca leucaleucadendron, M.angustifolia and M.leucadendon Var. latifolia by steam distillation yielded 1.36, 1.02, 1.32 and 0.97 % essential oils respectively. Their constituents were analyzed using two combination techniques, gas chromathography and mass spectroscophy (GCMS. Based on their compositin, the essensial oils of Asteromyrtus sp., Melaleuca leucaleucadendron, M.angustifolia were considered acceptable for commercial essential oil production because of their potential source of cineole (65.11, 60.03. 82.43 % respectively, while M.leucadendon Var. latifolia was vey interesting source of methyleugenol (97.03% which attractant activity.

  7. Induced release of a plant-defense volatile 'deceptively' attracts insect vectors to plants infected with a bacterial pathogen.

    Directory of Open Access Journals (Sweden)

    Rajinder S Mann

    Full Text Available 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 attracted to volatiles from pathogen-infected plants more than to those from non-infected counterparts. Las-infected plants were more attractive to D. citri adults than non-infected plants initially; however after feeding, psyllids subsequently dispersed to non-infected rather than infected plants as their preferred settling point. Experiments with Las-infected and non-infected plants under complete darkness yielded similar results to those recorded under light. The behavior of psyllids in response to infected versus non-infected plants was not influenced by whether or not they were carriers of the pathogen. Quantification of volatile release from non-infected and infected plants supported the hypothesis that odorants mediate psyllid preference. Significantly more methyl salicylate, yet less methyl anthranilate and D-limonene, was released by infected than non-infected plants. Methyl salicylate was attractive to psyllids, while methyl anthranilate did not affect their behavior. Feeding on citrus by D. citri adults also induced release of methyl salicylate, suggesting that it may be a cue revealing location of conspecifics on host plants. Infected plants were characterized by lower levels of nitrogen, phosphorus, sulfur, zinc, and iron, as well as, higher levels of potassium and boron than non-infected plants. Collectively, our results suggest that host selection behavior of D. citri may be modified by bacterial infection of plants, which alters release of

  8. [Allergic contact eczema due to 'tea tree' oil].

    Science.gov (United States)

    van der Valk, P G; de Groot, A C; Bruynzeel, D P; Coenraads, P J; Weijland, J W

    1994-04-16

    In four patients, three women aged 45, 29 and 52 years and a man aged 45 years, allergic contact dermatitis due to 'tea tree' oil was diagnosed. The case of the man was published before. 'Tea tree' oils are essential oils distilled from the leaves of myrtaceous trees and shrubs occurring in Australia and South-East Asia. The 'tea tree' oil available in the Netherlands is distilled from the Melaleuca alternifolia and mainly contains eucalyptol. Eucalyptol is probably the most important allergen.

  9. Antimicrobial effect against different bacterial strains and bacterial adaptation to essential oils used as feed additives

    OpenAIRE

    Melo, Antonio Diego Brandão; Amaral, Amanda Figueiredo; Schaefer, Gustavo; Luciano, Fernando Bittencourt; Andrade,Carla de; Costa, Leandro Batista; Rostagno, Marcos Horácio

    2015-01-01

    The aim of this study was to evaluate the antimicrobial activity and determine the minimum bactericidal concentration (MBC) of the essential oils derived from Origanum vulgare (oregano), Melaleuca alternifolia (tea tree), Cinnamomum cassia (cassia), and Thymus vulgaris (white thyme) against Salmonella Typhimurium, Salmonella Enteritidis, Escherichia coli, Staphylococcus aureus and Enterococcus faecalis. The study also investigated the ability of these different bacterial strains to develop ad...

  10. Tea Tree Oil-Induced Transcriptional Alterations in Staphylococcus aureus

    OpenAIRE

    Cuaron, Jesus A.; Dulal, Santosh; Song, Yang; Singh, Atul K; Montelongo, Cesar E.; Yu, Wanqin; Nagarajan, Vijayaraj; Jayaswal, Radheshyam K.; Wilkinson, Brian J; Gustafson, John E.

    2012-01-01

    Tea tree oil (TTO) is a steam distillate of Melaleuca alternifolia that demonstrates broad-spectrum antibacterial activity. This study was designed to document how TTO challenge influences the Staphylococcus aureus transcriptome. Overall, bioinformatic analyses (S. aureus microarray meta-database) revealed that both ethanol and TTO induce related transcriptional alterations. TTO challenge led to the down-regulation of genes involved with energy-intensive transcription and translation, and alt...

  11. Antibacterial Activity of Cinnamaldehyde and Estragole Extracted from Plant Essential Oils against Pseudomonas syringae pv. actinidiae Causing Bacterial Canker Disease in Kiwifruit

    OpenAIRE

    2016-01-01

    Pseudomonas syringae pv. actinidiae (Psa) causes bacterial canker disease in kiwifruit. Antibacterial activity of plant essential oils (PEOs) originating from 49 plant species were tested against Psa by a vapor diffusion and a liquid culture assays. The five PEOs from Pimenta racemosa, P. dioica, Melaleuca linariifolia, M. cajuputii, and Cinnamomum cassia efficiently inhibited Psa growth by either assays. Among their major components, estragole, eugenol, and methyl eugenol showed significant ...

  12. Larvicidal activity of Myrtaceae essential oils and their components against Aedes aegypti, acute toxicity on Daphnia magna, and aqueous residue.

    Science.gov (United States)

    Park, Hye-Mi; Kim, Junheon; Chang, Kyu-Sik; Kim, Byung-Seok; Yang, Yu-Jung; Kim, Gil-Hah; Shin, Sang-Chul; Park, Il-Kwon

    2011-03-01

    The larvicidal activity of 11 Myrtaceae essential oils and their constituents was evaluated against Aedes aegypti L. Of the 11, Melaleuca linariifolia Sm., Melaleuca dissitiflora F. Muell., Melaleuca quinquenervia (Cav.) S. T. Blake, and Eucalyptus globulus Labill oils at 0.1 mg/ml exhibited > or = 80% larval mortality. At this same concentration, the individual constituents tested, allyl isothiocyanate, alpha-terpinene, p-cymene, (+)-limonene, (-)-limonene, gamma-terpinene, and (E)-nerolidol, resulted in > or = 95% mortality. We also tested the acute toxicity of these four active oils earlier mentioned and their constituents against Daphnia magna Straus. M. linariifolia and allyl isothiocyanate was the most toxic to D. magna. Twodays after treatment, residues of M. dissitiflora, M. linariifolia, M. quinquenervia, and E. globulus oils in water were 55.4, 46.6, 32.4, and 14.8%, respectively. Less than 10% of allyl isothiocyanate, alpha-terpinene, p-cymene, (-)-limonene, (+)-limonene, and gamma-terpinene was detected in the water at 2 d after treatment. Our results indicated that oils and their constituents could easily volatilize in water within a few days after application, thus minimizing their effect on the aqueous ecosystem. Therefore, Myrtaceae essential oils and their constituents could be developed as control agents against mosquito larvae.

  13. Threshold Dynamics of a Huanglongbing Model with Logistic Growth in Periodic Environments

    Directory of Open Access Journals (Sweden)

    Jianping Wang

    2014-01-01

    Full Text Available We analyze the impact of seasonal activity of psyllid on the dynamics of Huanglongbing (HLB infection. A new model about HLB transmission with Logistic growth in psyllid insect vectors and periodic coefficients has been investigated. It is shown that the global dynamics are determined by the basic reproduction number R0 which is defined through the spectral radius of a linear integral operator. If R0 1, then the disease persists. Numerical values of parameters of the model are evaluated taken from the literatures. Furthermore, numerical simulations support our analytical conclusions and the sensitive analysis on the basic reproduction number to the changes of average and amplitude values of the recruitment function of citrus are shown. Finally, some useful comments on controlling the transmission of HLB are given.

  14. Prophage-Mediated Dynamics of ‘Candidatus Liberibacter asiaticus’ Populations, the Destructive Bacterial Pathogens of Citrus Huanglongbing

    Science.gov (United States)

    Zhou, Lijuan; Powell, Charles A.; Li, Wenbin; Irey, Mike; Duan, Yongping

    2013-01-01

    Prophages are highly dynamic components in the bacterial genome and play an important role in intraspecies variations. There are at least two prophages in the chromosomes of Candidatus Liberibacter asiaticus’ (Las) Floridian isolates. Las is both unculturable and the most prevalent species of Liberibacter pathogens that cause huanglongbing (HLB), a worldwide destructive disease of citrus. In this study, seven new prophage variants resulting from two hyper-variable regions were identified by screening clone libraries of infected citrus, periwinkle and psyllids. Among them, Types A and B share highly conserved sequences and localize within the two prophages, FP1 and FP2, respectively. Although Types B and C were abundant in all three libraries, Type A was much more abundant in the libraries from the Las-infected psyllids than from the Las-infected plants, and Type D was only identified in libraries from the infected host plants but not from the infected psyllids. Sequence analysis of these variants revealed that the variations may result from recombination and rearrangement events. Conventional PCR results using type-specific molecular markers indicated that A, B, C and D are the four most abundant types in Las-infected citrus and periwinkle. However, only three types, A, B and C are abundant in Las-infected psyllids. Typing results for Las-infected citrus field samples indicated that mixed populations of Las bacteria present in Floridian isolates, but only the Type D population was correlated with the blotchy mottle symptom. Extended cloning and sequencing of the Type D region revealed a third prophage/phage in the Las genome, which may derive from the recombination of FP1 and FP2. Dramatic variations in these prophage regions were also found among the global Las isolates. These results are the first to demonstrate the prophage/phage-mediated dynamics of Las populations in plant and insect hosts, and their correlation with insect transmission and disease

  15. Prophage-mediated dynamics of 'Candidatus Liberibacter asiaticus' populations, the destructive bacterial pathogens of citrus huanglongbing.

    Directory of Open Access Journals (Sweden)

    Lijuan Zhou

    Full Text Available Prophages are highly dynamic components in the bacterial genome and play an important role in intraspecies variations. There are at least two prophages in the chromosomes of Candidatus Liberibacter asiaticus' (Las Floridian isolates. Las is both unculturable and the most prevalent species of Liberibacter pathogens that cause huanglongbing (HLB, a worldwide destructive disease of citrus. In this study, seven new prophage variants resulting from two hyper-variable regions were identified by screening clone libraries of infected citrus, periwinkle and psyllids. Among them, Types A and B share highly conserved sequences and localize within the two prophages, FP1 and FP2, respectively. Although Types B and C were abundant in all three libraries, Type A was much more abundant in the libraries from the Las-infected psyllids than from the Las-infected plants, and Type D was only identified in libraries from the infected host plants but not from the infected psyllids. Sequence analysis of these variants revealed that the variations may result from recombination and rearrangement events. Conventional PCR results using type-specific molecular markers indicated that A, B, C and D are the four most abundant types in Las-infected citrus and periwinkle. However, only three types, A, B and C are abundant in Las-infected psyllids. Typing results for Las-infected citrus field samples indicated that mixed populations of Las bacteria present in Floridian isolates, but only the Type D population was correlated with the blotchy mottle symptom. Extended cloning and sequencing of the Type D region revealed a third prophage/phage in the Las genome, which may derive from the recombination of FP1 and FP2. Dramatic variations in these prophage regions were also found among the global Las isolates. These results are the first to demonstrate the prophage/phage-mediated dynamics of Las populations in plant and insect hosts, and their correlation with insect transmission and

  16. Prophage-mediated dynamics of 'Candidatus Liberibacter asiaticus' populations, the destructive bacterial pathogens of citrus huanglongbing.

    Science.gov (United States)

    Zhou, Lijuan; Powell, Charles A; Li, Wenbin; Irey, Mike; Duan, Yongping

    2013-01-01

    Prophages are highly dynamic components in the bacterial genome and play an important role in intraspecies variations. There are at least two prophages in the chromosomes of Candidatus Liberibacter asiaticus' (Las) Floridian isolates. Las is both unculturable and the most prevalent species of Liberibacter pathogens that cause huanglongbing (HLB), a worldwide destructive disease of citrus. In this study, seven new prophage variants resulting from two hyper-variable regions were identified by screening clone libraries of infected citrus, periwinkle and psyllids. Among them, Types A and B share highly conserved sequences and localize within the two prophages, FP1 and FP2, respectively. Although Types B and C were abundant in all three libraries, Type A was much more abundant in the libraries from the Las-infected psyllids than from the Las-infected plants, and Type D was only identified in libraries from the infected host plants but not from the infected psyllids. Sequence analysis of these variants revealed that the variations may result from recombination and rearrangement events. Conventional PCR results using type-specific molecular markers indicated that A, B, C and D are the four most abundant types in Las-infected citrus and periwinkle. However, only three types, A, B and C are abundant in Las-infected psyllids. Typing results for Las-infected citrus field samples indicated that mixed populations of Las bacteria present in Floridian isolates, but only the Type D population was correlated with the blotchy mottle symptom. Extended cloning and sequencing of the Type D region revealed a third prophage/phage in the Las genome, which may derive from the recombination of FP1 and FP2. Dramatic variations in these prophage regions were also found among the global Las isolates. These results are the first to demonstrate the prophage/phage-mediated dynamics of Las populations in plant and insect hosts, and their correlation with insect transmission and disease development.

  17. Brachygastra mellifica (Hymenoptera: Vespidae): Predation preference and feeding behavior on Diaphorina citri (Hemiptera: Psyllidae) in Mexico

    OpenAIRE

    Reyes-Rosas, M. A.; Loera-Gallardo, J.; López-Arroyo, J. I.; Buck, M.

    2014-01-01

    In previous field studies in Northern Mexico, we found the wasp Brachygastra mellifica (Say 1837) (Hymenoptera: Vespidae) preying voraciously the Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Psyllidae), the vector of the bacteria Ca. Liberibacter spp., the putative agent of Huanglongbing, one of the most devastating citrus disease in the world.   As in Mexico, the ACP management considers the use of pest biological control, the availability of potential agents for the con...

  18. Entomophagous insects associated to Diaphorina citri (Hemiptera: Psyllidae) in citrus orchards with different weed management systems in Papantla, Veracruz, Mexico

    OpenAIRE

    Ortega-Arenas, L. D.; López-López, R.; Lomelí-Flores, J. R.; Cedillo-Portugal, E.; Gómez-Tovar, L.; Salazar-Cruz, J.; Villegas-Monter, A.

    2014-01-01

    Huanglongbing (HLB), one of the most destructive diseases of citrus worldwide, is threatening the survival of the citrus industry in Mexico. Diaphorina citri is the primary vector of HLB; thus, control of the vector it’s vital for disease management. This study was carried out to evaluate the influence of different management systems on the population psyllid density and entomophagous insects associated in orange orchards (Citrus sinensis cv. Valencia) in Papantla, Veracruz, Mexico. Five orch...

  19. Survey of huanglongbing associated with ‘Candidatus Liberibacter’ species in Spain: analyses of citrus plants and Trioza erytreae

    Directory of Open Access Journals (Sweden)

    Felipe SIVERIO

    2017-05-01

    Full Text Available The disease huanglongbing (HLB, caused by the phloem-limited and psyllid-vectored ‘Candidatus Liberibacter’ spp., is threatening the Mediterranean citrus industry. The African psyllid (Trioza erytreae vector of the pathogen was detected in Madeira (Portugal in 1994 and in the Canary Islands (Spain in 2002, and its arrival in 2014 in northwest Spain and Portugal along the Atlantic coast instigated a biological alert, and a contingency management plan was developed. Extensive surveys were conducted in Canary Islands from 2009 to 2015 and in the northwest mainland Spain (Galicia since the first detection of T. erytreae. Symptoms of the psyllid were observed in most sweet orange orchards of five islands in Canary Islands (93% of the inspected plots. In northwest mainland Spain, 65% of the inspected plots up to 2016 showed T. erytreae symptoms. During the surveys, ten leaves/tree from trees showing suspicious symptoms and from symptomless trees, as well as adult psyllids, were collected and analysed by real-time PCR using a universal ‘Ca. Liberibacter’ spp. kit, according to the EPPO standard. Suspected samples from other surveyed Spanish regions free of the vector were also analysed. The few samples that were positive in the screening test were tested by species-specific real-time PCR protocols, and they did not show amplification. These data confirm that the Spanish citrus industry is currently free of the ‘Ca. Liberibacter’ spp., but strict measures to prevent the introduction of this pathogen are required as the presence of T. erytreae increases the risk of its dissemination.

  20. Botanicals, selective insecticides, and predators to control Diaphorina citri (Hemiptera: Liviidae) in citrus orchards.

    Science.gov (United States)

    Khan, Azhar A; Afzal, Muhammad; Qureshi, Jawwad A; Khan, Arif M; Raza, Abubakar M

    2014-12-01

    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 selective insecticides could help to conserve beneficial insects and reduce pest resistance to insecticides. Sprays of Azadirachtin (Neem), Tropane (Datura), Spirotetramat, Spinetoram, and broad-spectrum Imidacloprid were evaluated to control ACP in spring and summer on 10-year-old "Kinow" Citrus reticulata Blanco trees producing new growth. Psyllid populations were high averaging 5-9 nymphs or adults per sample before treatment application. Nymphs or adults were significantly reduced to 0.5-1.5 per sample in all treatments for 3 weeks, average 61%-83% reduction. No significant reduction in ladybeetles Adalia bipunctata, Aneglei scardoni, Cheilomenes sexmaculata, and Coccinella septempunctata was observed. Syrphids, spiders and green lacewings were reduced in treated trees except with Tropane. Studies are warranted to assess impact of these predators on ACP and interaction with insecticides. Observed reduction in ACP populations may not be enough considering its reproductive potential and role in the spread of HLB. Follow-up sprays may be required to achieve additional suppression using rotations of different insecticides. © 2014 Institute of Zoology, Chinese Academy of Sciences.

  1. Green  Control  Citrus  Psyllid  Control  Huanglong  Disease  to  Explore  Effective  Measures%绿色防治柑桔木虱控制黄龙病的有效措施探讨

    Institute of Scientific and Technical Information of China (English)

    洪增米

    2012-01-01

      黄龙病对于柑橘来说是毁灭性的病害,柑桔木虱是传播黄龙病的昆虫。经过长期的生产实践所总结的经验来看,控制黄龙病的关键措施就是防治柑桔木虱。为此应该要合理地利用生物防治、物理防治以及其他一些绿色生态的控制办法,尽量减少化学药品的使用,进一步改善柑橘的生态系统,提高对柑桔木虱的自控能力,控制黄龙病的出现。%  Huanglong disease for citrus it is devastating diseases, citrus psyllid is spread Huanglong disease of insects. Through long-term production practice were summarized experience, control Huanglong disease prevention and control is key measures citrus psyllid. This should be a reasonable use of biological control, physical control and other green ecological control measures, as far as possible to reduce the use of chemical drugs, and further improve the citrus ecological system, improve the citrus psyllid self-control, and control the emergence of huanglong disease.

  2. Detection of 'Candidatus Liberibacter asiaticus' in Diaphorina citri and its importance in the management of citrus huanglongbing in Florida.

    Science.gov (United States)

    Manjunath, K L; Halbert, S E; Ramadugu, C; Webb, S; Lee, R F

    2008-04-01

    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 develop, presumably because of low titer and uneven distribution of the causal bacteria in nonsymptomatic tissues. In the present study, TaqMan based real-time quantitative polymerase chain reaction methodology was developed for detection of 'Ca. L. asiaticus' in D. citri. Over 1,200 samples of psyllid adults and nymphs, collected from various locations in Florida, from visually healthy and HLB symptomatic trees at different times of the year were analyzed to monitor the incidence and spread of HLB. The results showed that spread of 'Ca. L. asiaticus' in an area may be detected one to several years before the development of HLB symptoms in plants. The study suggests that discount garden centers and retail nurseries may have played a significant role in the widespread distribution of psyllids and plants carrying HLB pathogens in Florida.

  3. Genomic sequence of 'Candidatus Liberibacter solanacearum' haplotype C and its comparison with haplotype A and B genomes

    Science.gov (United States)

    Haapalainen, Minna; Schott, Thomas; Thompson, Sarah M.; Smith, Grant R.; Nissinen, Anne I.; Pirhonen, Minna

    2017-01-01

    Haplotypes A and B of ‘Candidatus Liberibacter solanacearum’ (CLso) are associated with diseases of solanaceous plants, especially Zebra chip disease of potato, and haplotypes C, D and E are associated with symptoms on apiaceous plants. To date, one complete genome of haplotype B and two high quality draft genomes of haplotype A have been obtained for these unculturable bacteria using metagenomics from the psyllid vector Bactericera cockerelli. Here, we present the first genomic sequences obtained for the carrot-associated CLso. These two genomic sequences of haplotype C, FIN114 (1.24 Mbp) and FIN111 (1.20 Mbp), were obtained from carrot psyllids (Trioza apicalis) harboring CLso. Genomic comparisons between the haplotypes A, B and C revealed that the genome organization differs between these haplotypes, due to large inversions and other recombinations. Comparison of protein-coding genes indicated that the core genome of CLso consists of 885 ortholog groups, with the pan-genome consisting of 1327 ortholog groups. Twenty-seven ortholog groups are unique to CLso haplotype C, whilst 11 ortholog groups shared by the haplotypes A and B, are not found in the haplotype C. Some of these ortholog groups that are not part of the core genome may encode functions related to interactions with the different host plant and psyllid species. PMID:28158295

  4. Changes in Variable Number of Tandem Repeats in 'Candidatus Liberibacter asiaticus' through Insect Transmission.

    Directory of Open Access Journals (Sweden)

    Hiroshi Katoh

    Full Text Available 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 in the genome. In this study, the VNTR analysis was further validated by assessing the stability of these repeats after multiplication of the pathogen upon host-to-host transmission using a 'Ca. L. asiaticus' strain from Japan. The results showed that some tandem repeats showed detectable changes after insect transmission. To our knowledge, this is the first report to demonstrate that the repeat numbers VNTR 002 and 077 of 'Ca. L. asiaticus' change through psyllid transmission. VNTRs in the recipient plant were apparently unrelated to the growing phase of the vector. In contrast, changes in the number of tandem repeats increased with longer acquisition and inoculation access periods, whereas changes were not observed through psyllid transmission after relatively short acquisition and inoculation access periods, up to 20 and 19 days, respectively.

  5. Método para avaliação e pesquisa da atividade antimicrobiana de produtos de origem natural Evaluation and research method for natural products inhibitory activity

    OpenAIRE

    Janaina F. Packer; Marisa M.S. da Luz

    2007-01-01

    As exigências do mercado consumidor induzem a indústria cosmética a formular produtos seguros cada vez menos agressivos e naturais. Durante a formulação para tais apelos a dificuldade maior encontra-se em conservar o produto final. Com este objetivo avaliamos os óleos: de copaíba, alecrim, melaleuca, alho, andiroba; própolis, e dois ingredientes de origem natural: um ingrediente multifuncional extraído de folhas de oliva e o farnesol que estão disponíveis e são fornecidos à indústria cosmétic...

  6. Método para avaliação e pesquisa da atividade antimicrobiana de produtos de origem natural

    OpenAIRE

    Janaina F. Packer; Luz,Marisa M.S. da

    2007-01-01

    As exigências do mercado consumidor induzem a indústria cosmética a formular produtos seguros cada vez menos agressivos e naturais. Durante a formulação para tais apelos a dificuldade maior encontra-se em conservar o produto final. Com este objetivo avaliamos os óleos: de copaíba, alecrim, melaleuca, alho, andiroba; própolis, e dois ingredientes de origem natural: um ingrediente multifuncional extraído de folhas de oliva e o farnesol que estão disponíveis e são fornecidos à indústria cosmétic...

  7. Método para avaliação e pesquisa da atividade antimicrobiana de produtos de origem natural Evaluation and research method for natural products inhibitory activity

    Directory of Open Access Journals (Sweden)

    Janaina F. Packer

    2007-03-01

    Full Text Available As exigências do mercado consumidor induzem a indústria cosmética a formular produtos seguros cada vez menos agressivos e naturais. Durante a formulação para tais apelos a dificuldade maior encontra-se em conservar o produto final. Com este objetivo avaliamos os óleos: de copaíba, alecrim, melaleuca, alho, andiroba; própolis, e dois ingredientes de origem natural: um ingrediente multifuncional extraído de folhas de oliva e o farnesol que estão disponíveis e são fornecidos à indústria cosmética, com a finalidade de comprovar a ação dos mesmos. O método de escolha foi o de ágar em placa com orifício modificado. As cepas selecionadas foram Staphylococcus aureus (ATCC 6538, Escherichia coli (ATCC 8739, Pseudomonas aeruginosa (ATCC 9027 e Candida albicans (ATCC 10231. Dentre as amostras analisadas os melhores resultados foram obtidos com os óleos de melaleuca e alecrim que apresentaram atividade bacteriostática e fungistática para as quatro cepas em questão.The consumer market requirement induces the cosmetic industry to generate safer and less aggressive products including the natural products. Within the natural products formulation process, the most demanding challenge is the final product conservation. In order to cope with the conservation factor, some natural oils (copaiba, rosemary, melaleuca, garlic, andiroba, propolis and two natural ingredients (one multifunctional ingredient extracted from olive leaves and farnesol which are available and usually supplied to the cosmetic industry, were considered in this analysis. The chosen method was the agar in plaque with modificed hole. The chosen microorganisms were: Staphylococcus aureus (ATCC 6538, Escherichia coli (ATCC 8739, Pseudomonas aeruginosa (ATCC 9027 and Candida albicans (ATCC 10231. The best results were achieved by melaleuca and rosemary oils, which showed bacteriostatic and fungistatic activity against the four microorganisms.

  8. Tea tree oil might combat melanoma.

    Science.gov (United States)

    Bozzuto, Giuseppina; Colone, Marisa; Toccacieli, Laura; Stringaro, Annarita; Molinari, Agnese

    2011-01-01

    In this study we present new data from experiments focused on the antitumor activity of tea tree oil (TTO), an essential oil distilled from Melaleuca alternifolia. TTO proved to be capable of inhibiting the growth of melanoma cells and of overcoming multidrug resistance (MDR), as we reported in our previous study. Moreover, the survival role of the MDR-marker P-glycoprotein appears to be involved in the mechanism of invasion of melanoma cells. The results reported herein indicate that TTO and its main active component, terpinen-4-ol, can also interfere with the migration and invasion processes of drug-sensitive and drug-resistant melanoma cells.

  9. Tea tree oil as a novel antipsoriasis weapon.

    Science.gov (United States)

    Pazyar, Nader; Yaghoobi, Reza

    2012-01-01

    Psoriasis is a clinical skin disease that is characterized by erythematous scaling plaques and involves the extensor site of the extremities, the scalp and other surfaces of the skin. Tea tree oil (TTO) is considered an essential oil, obtained by steam distillation of the leaves and terminal branchlets of Melaleuca alternifolia. Notably,terpinen-4-ol, the major TTO constituent, has been found to have potent anti-inflammatory properties. It is suggested that terpinen-4-ol may be a novel potential agent against psoriasis. This article draws attention to the antipsoriatic effect of TTO and provides a theoretical molecular approach.

  10. Australasian sequestrate fungi 18: Solioccasus polychromus gen. & sp. nov., a richly colored, tropical to subtropical, hypogeous fungus.

    Science.gov (United States)

    Trappe, James M; Castellano, Michael A; Halling, Roy E; Osmundson, Todd W; Binder, Manfred; Fechner, Nigel; Malajczuk, Nicholas

    2013-01-01

    Solioccasus polychromus gen. & sp. nov., the most brightly colored hypogeous fungus known, is described from Papua New Guinea and tropical northern Australia south into subtropical forests along the Queensland coast and coastal mountains to near Brisbane. Phylogenetic analysis of molecular data places it as a sister genus to Bothia in the Boletineae, a clade of predominantly ectomycorrhizal boletes. Ectomycorrhizal trees, such as members of the Myrtaceae (Eucalyptus, Corymbia, Lophostemon, Melaleuca spp.) and Allocasuarina littoralis, were present usually in mixture or in some cases dominant, so we infer some or all of them to be among the ectomycorrhizal hosts of S. polychromus.

  11. 385 新西兰特产:扫帚叶澳洲茶精油

    Institute of Scientific and Technical Information of China (English)

    希雨

    2002-01-01

    @@扫帚叶澳洲茶Leptospermum scoparium J.R.Forst.et G.Forst是新西兰特有植物,当地毛利人称之为马鲁卡(manuka),为花色鲜艳、富含精油的灌木或小乔木,与多脂的桉树属植物及澳大利亚茶树Melaleuca alternifolia(M&B)Cheel同属桃金娘科。该植……

  12. Inhibitory effect of essential oils against Trichosporon ovoides causing Piedra Hair Infection.

    Science.gov (United States)

    Saxena, Seema; Uniyal, Veena; Bhatt, R P

    2012-10-01

    Piedra, is an asymptomatic fungal infection of the hair shaft, resulting in the formation of nodules of different hardness on the infected hair. The infection also known as Trichomycosis nodularis is a superficial fungal infection arising from the pathogen being restricted to the stratum corneum with little or no tissue reaction. The nodules are a concretion of hyphae and fruiting bodies of the fungus. Two varieties of Piedra may be seen, Black Piedra and White Piedra. The fungus Trichosporon ovoides is involved in the occurrence of both types of Piedras. The purpose of this study was to examine the effectiveness of selected essential oils for the control of growth of the fungus and to determine whether the antifungal effect was due to the major compounds of the oils. Two screening methods viz. Agar well diffusion assay and Minimum Inhibitory Concentration were adopted for the study. MIC and MFC were determined by tube dilution method. Essential oils from Eucalyptus, Ocimum basilicum, Mentha piperita, Cymbopogon flexuosus, Cymbopogon winterians, Trachyspermum ammi, Zingiber officinalis, Citrus limon, Cinnamomon zeylanicum, Salvia sclarea, Citrus aurantifolia, Melaleuca alternifolia, Citrus aurantium, Citrus bergamia, Pogostemon pathchouli, Cedrus atlantica, Jasminum officinale, Juniperus communis, Abelmoschus moschatus, Cyperus scariosus, Palargonium graveolens, Boswellia carterii, Rosa damascene, Veteveria zizanoides and Commiphora myrrha were evaluated. The essential oils of Cymbopogon winterians, Mentha piperita, Cinnamomum zeylanicum, Melaleuca alternifolia and Eucalyptus globulus were proved to be most effective against the fungus Trichosporon ovoides.

  13. Histological observation of Gelam (Melaleucacajuputi Powell) in different ecosystems of Terengganu

    Science.gov (United States)

    Mohamad, Masitah; Razak, Shamsul Bahri Abd; Salim, Jamilah Mohd.; Ismail, Salwani

    2015-07-01

    A histological and anatomical comparative analysis of Gelam, Melaleuca cajuputi Powell was conducted to determine the adaptability Gelam (Melaleuca cajuputi Powell, Family = Myrtaceae) in two different micro-ecosystems of Terengganu. The sites sampling chosen were Jambu Bongkok Amenity Forest (Formerly known as Rantau Abang Amenity Forest), a large swamp forests and prominent flooding site in the District of Marang, Terengganu and Taman Penyelidikan Alam, Bukit Kor - a hard top soil area of Marang, Terengganu. The objective of this study is to compare the anatomy and histology features of gelam in these two areas. Results show that gelam from both ecosystems exhibits morphological differences and variations in some tissues (in leaf, petiole, bark, and root anatomy such as in type of epicuticular waxes, bark anatomy, leaf anatomy, vascular bundle, bark fibre pits, vessel, phloem, xylem, cortex, epidermal cells and mesophyll cells). This initial observation may suggest that gelam can adapt well in different micro-ecosystems of Terengganu. Its ability to response well toward Terengganu's different climates and coastal environmental changes could make gelam a viable tree for conservation and landscape program.

  14. Antifungal activity of natural compounds against Candida species isolated from HIV-positive patients

    Institute of Scientific and Technical Information of China (English)

    Dbora Oro; Andria Heissler; Eliandra Mirlei Rossi; Diane Scapin; Patrcia da Silva Malheiros; Everton Boff

    2015-01-01

    To evaluate the antifungal effect of Cinnamomum zeylanicum (C. zeylanicum) and Melaleuca alternifolia essential oils and honey against strains of Candida sp. from HIV-positive patients in order to subsidize new therapeutic strategies for candidiasis. Methods: The study evaluated the antifungal effect of natural antimicrobials against 30 strains of Candida sp. isolated from oral cavities in HIV-infected patients. Then, they were compared to the action of fluconazole and amphotericin B. Antifungal susceptibility was evaluated by the broth macrodilution technique and the minimum inhibitory concentration and the minimum fungicidal concentration were determined. Results: Among all antifungals evaluated in this study, amphotericin B was the one showing the best results; however, all compounds studied here showed inhibitory activities against isolates of Candida sp. Honey (0.031 3 to 64 μg/mL) demonstrated fungistatic activity inhibiting 70% of the isolates. C. zeylanicum essential oil (0.0313 to 64 μg/mL) inhibited 93.3% of the Candida strains and Melaleuca alternifolia essential oil (0.0313 to 64 μg/mL) was able to inhibit 73.3% of them. Conclusions: Therefore, all natural compounds evaluated in this study, especially C. zeylanicum essential oil, may become promising agents for oral candidiasis therapy including in HIV-positive patients.

  15. Inhibitory effect of essential oils against Trichosporon ovoides causing Piedra Hair Infection

    Directory of Open Access Journals (Sweden)

    Seema Saxena

    2012-12-01

    Full Text Available Piedra, is an asymptomatic fungal infection of the hair shaft, resulting in the formation of nodules of different hardness on the infected hair. The infection also known as Trichomycosis nodularis is a superficial fungal infection arising from the pathogen being restricted to the stratum corneum with little or no tissue reaction. The nodules are a concretion of hyphae and fruiting bodies of the fungus. Two varieties of Piedra may be seen, Black Piedra and White Piedra. The fungus Trichosporon ovoides is involved in the occurrence of both types of Piedras. The purpose of this study was to examine the effectiveness of selected essential oils for the control of growth of the fungus and to determine whether the antifungal effect was due to the major compounds of the oils. Two screening methods viz. Agar well diffusion assay and Minimum Inhibitory Concentration were adopted for the study. MIC and MFC were determined by tube dilution method. Essential oils from Eucalyptus, Ocimum basilicum, Mentha piperita, Cymbopogon flexuosus, Cymbopogon winterians, Trachyspermum ammi, Zingiber officinalis, Citrus limon, Cinnamomon zeylanicum, Salvia sclarea, Citrus aurantifolia, Melaleuca alternifolia, Citrus aurantium, Citrus bergamia, Pogostemon pathchouli, Cedrus atlantica, Jasminum officinale, Juniperus communis, Abelmoschus moschatus, Cyperus scariosus, Palargonium graveolens, Boswellia carterii, Rosa damascene, Veteveria zizanoides and Commiphora myrrha were evaluated. The essential oils of Cymbopogon winterians, Mentha piperita, Cinnamomum zeylanicum, Melaleuca alternifolia and Eucalyptus globulus were proved to be most effective against the fungus Trichosporon ovoides.

  16. Antifungal activity of natural compounds against Candida species isolated from HIV-positive patients

    Institute of Scientific and Technical Information of China (English)

    Débora; Oro; Andréia; Heissler; Eliandra; Mirlei; Rossi; Diane; Scapin; Patrícia; da; Silva; Malheiros; Everton; Boff

    2015-01-01

    Objective: To evaluate the antifungal effect of Cinnamomum zeylanicum(C. zeylanicum) and Melaleuca alternifolia essential oils and honey against strains of Candida sp. from HIV-positive patients in order to subsidize new therapeutic strategies for candidiasis.Methods: The study evaluated the antifungal effect of natural antimicrobials against 30 strains of Candida sp. isolated from oral cavities in HIV-infected patients. Then, they were compared to the action of fl uconazole and amphotericin B. Antifungal susceptibility was evaluated by the broth macrodilution technique and the minimum inhibitory concentration and the minimum fungicidal concentration were determined.Results: Among all antifungals evaluated in this study, amphotericin B was the one showing the best results; however, all compounds studied here showed inhibitory activities against isolates of Candida sp. Honey(0.031 3 to 64 μg/m L) demonstrated fungistatic activity inhibiting 70% of the isolates. C. zeylanicum essential oil(0.031 3 to 64 μg/m L) inhibited 93.3% of the Candida strains and Melaleuca alternifolia essential oil(0.031 3 to 64 μg/m L) was able to inhibit 73.3% of them.Conclusions: Therefore, all natural compounds evaluated in this study, especially C. zeylanicum essential oil, may become promising agents for oral candidiasis therapy including in HIV-positive patients.

  17. In vitro antibacterial effect of exotic plants essential oils on the honeybee pathogen Paenibacillus larvae, causal agent of American foul brood

    Energy Technology Data Exchange (ETDEWEB)

    Fuselli, S. R.; Garcia de la Rosa, S. B.; Eguaras, M. J.; Fritz, R.

    2010-07-01

    Chemical composition and antimicrobial activity of exotic plants essential oils to potentially control Paenibacillus larvae, the causal agent of American foul brood disease (AFB) were determined. AFB represents one of the main plagues that affect the colonies of honeybees Apis mellifera L. with high negative impact on beekeepers worldwide. Essential oils tested were niaouli (Melaleuca viridiflora) and tea tree (Melaleuca alternifolia) from Myrtaceae, and citronella grass (Cymbopogon nardus) and palmarosa (Cymbopogon martinii) from Gramineae. The components of the essential oils were identified by SPME-GC/MS analysis. The antimicrobial activity of the oils against P. larvae was determined by the broth micro dilution method. In vitro assays of M. viridiflora and C. nardus oils showed the inhibition of the bacterial strains at the lowest concentrations tested, with minimal inhibitory concentration (MIC) mean value about 320 mg L{sup -}1 for both oils, respectively. This property could be attributed to the kind and percentage of the components of the oils. Terpinen-4-ol (29.09%), {alpha}-pinene (21.63%) and limonene (17.4%) were predominant in M. viridiflora, while limonene (24.74%), citronelal (24.61%) and geraniol (15.79%) were the bulk of C. nardus. The use of these essential oils contributes to the screening of alternative natural compounds to control AFB in the apiaries; toxicological risks and other undesirable effects would be avoided as resistance factors, developed by the indiscriminate use of antibiotics. (Author) 40 refs.

  18. High nymphal host density and mortality negatively impact parasitoid complex during an insect herbivore outbreak.

    Science.gov (United States)

    Hall, Aidan A G; Johnson, Scott N; Cook, James M; Riegler, Markus

    2017-08-26

    Insect herbivore outbreaks frequently occur and this may be due to factors that restrict top-down control by parasitoids, for example, host-parasitoid asynchrony, hyperparasitisation, resource limitation and climate. Few studies have examined host-parasitoid density relationships during an insect herbivore outbreak in a natural ecosystem with diverse parasitoids. We studied parasitisation patterns of Cardiaspina psyllids during an outbreak in a Eucalyptus woodland. First, we established the trophic roles of the parasitoids through a species-specific multiplex PCR approach on mummies from which parasitoids emerged. Then, we assessed host-parasitoid density relationships across three spatial scales (leaf, tree and site) over one year. We detected four endoparasitoid species of the family Encyrtidae (Hymenoptera); two primary parasitoid and one heteronomous hyperparasitoid Psyllaephagus species (the latter with female development as a primary parasitoid and male development as a hyperparasitoid), and the hyperparasitoid Coccidoctonus psyllae. Parasitoid development was host-synchronised, although synchrony between sites appeared constrained during winter (due to temperature differences). Parasitisation was predominantly driven by one primary parasitoid species and was mostly inversely host-density dependent across the spatial scales. Hyperparasitisation by C. psyllae was psyllid-density dependent at the site scale, however, this only impacted the rarer primary parasitod. High larval parasitoid mortality due to density dependent nymphal psyllid mortality (a consequence of resource limitation) compounded by a summer heat wave was incorporated in the assessment and resulted in density independence of host-parasitoid relationships. As such, high larval parasitoid mortality during insect herbivore outbreaks may contribute to the absence of host density dependent parasitisation during outbreak events. This article is protected by copyright. All rights reserved. This article

  19. The phloem-sap feeding mealybug (Ferrisia virgata carries 'Candidatus Liberibacter asiaticus' populations that do not cause disease in host plants.

    Directory of Open Access Journals (Sweden)

    Marco Pitino

    Full Text Available '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 acquire and retain Las bacteria. The bacterial titers were positively correlated with the feeding acquisition time on Las-infected leaf discs, with a two-weeks feeding period resulting in Ct values ranging from 23.1 to 36.1 (8.24 × 10(7 to 1.07 × 10(4 Las cells per mealybug. We further discovered that the prophage/phage populations of Las in the mealybugs were different from those of Las in psyllids based on Las prophage-specific molecular markers: infected psyllids harbored the Las populations with prophage/phage FP1 and FP2, while infected mealybugs carried the Las populations with the iFP3 being the dominant prophage/phage. As in the psyllids, Las bacteria were shown to move through the insect gut wall to the salivary glands after being ingested by the mealybug based on a time-course quantitative polymerase chain reaction (qPCR assay of the dissected digestive systems. However, Las populations transmitted by the mealybugs did not cause disease in host plants. This is the first evidence of genetic difference among Las populations harbored by different insect vectors and difference among Las populations with respect to whether or not they cause disease in host plants.

  20. The Phloem-Sap Feeding Mealybug (Ferrisia virgata) Carries ‘Candidatus Liberibacter asiaticus’ Populations That Do Not Cause Disease in Host Plants

    Science.gov (United States)

    Pitino, Marco; Hoffman, Michele T.; Zhou, Lijuan; Hall, David G.; Stocks, Ian C.; Duan, Yongping

    2014-01-01

    ‘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 acquire and retain Las bacteria. The bacterial titers were positively correlated with the feeding acquisition time on Las-infected leaf discs, with a two-weeks feeding period resulting in Ct values ranging from 23.1 to 36.1 (8.24×107 to 1.07×104 Las cells per mealybug). We further discovered that the prophage/phage populations of Las in the mealybugs were different from those of Las in psyllids based on Las prophage-specific molecular markers: infected psyllids harbored the Las populations with prophage/phage FP1 and FP2, while infected mealybugs carried the Las populations with the iFP3 being the dominant prophage/phage. As in the psyllids, Las bacteria were shown to move through the insect gut wall to the salivary glands after being ingested by the mealybug based on a time-course quantitative polymerase chain reaction (qPCR) assay of the dissected digestive systems. However, Las populations transmitted by the mealybugs did not cause disease in host plants. This is the first evidence of genetic difference among Las populations harbored by different insect vectors and difference among Las populations with respect to whether or not they cause disease in host plants. PMID:24465578

  1. Coleoptera, Coccinellidae, Harmonia axyridis (Pallas, 1773: New record in Minas Gerais, southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Rezende, M. Q.

    2010-01-01

    Full Text Available Harmonia axyridis is a voracious aphid predator, which has been used in biological control programs in severalcountries. Due to its fast spreading, H. axyridis is becoming widely distributed across the world. Recently, it was detectedin Viçosa, Minas Gerais, southeastern Brazil. This region shows climatic similarity to its native region and it may facilitatethe establishment of H. axyridis. The species was found in some home gardens feeding on aphids and psyllids. The presenceof the lady beetle in the state of Minas Gerais confirms its high spreading potential in Brazil, reinforcing the necessity forfurther studies on the possible impacts and control methods of its populations.

  2. [First record of Platycorypha nigrivirga Burckhardt (Hemiptera: Psylloidea), in Tipuana tipu (Benth.), from Brazil].

    Science.gov (United States)

    Santana, Dalva L Q; Burckhardt, Daniel; Aguiar, António M F

    2006-01-01

    The occurrence of Platycorypha nigrivirga Burckhardt (Hemiptera: Psyllidae, Acizzinae), is reported for the first time, in Brazil. The psyllid was observed causing injuries on leaves and shoots of Tipuana tipu (Benth.), in urban areas of Paraná State. P. nigrivirga are tiny sap-sucking insects that feed on phloem and cause curling, stains and fall of leaves. The excrements of these insects accumulate on the leaves propitiating fungus growth on the leaves, or they fall in great amount on the cars dirtying them as if they were sparkling of white and sticky ink.

  3. Molecular test to assign individuals within the Cacopsylla pruni complex.

    Directory of Open Access Journals (Sweden)

    Jean Peccoud

    Full Text Available Crop protection requires the accurate identification of disease vectors, a task that can be made difficult when these vectors encompass cryptic species. Here we developed a rapid molecular diagnostic test to identify individuals of Cacopsyllapruni (Scopoli, 1763 (Hemiptera: Psyllidae, the main vector of the European stone fruit yellows phytoplasma. This psyllid encompasses two highly divergent genetic groups that are morphologically similar and that are characterized by genotyping several microsatellite markers, a costly and time-consuming protocol. With the aim of developing species-specific PCR primers, we sequenced the Internal Transcribed Spacer 2 (ITS2 on a collection of C. pruni samples from France and other European countries. ITS2 sequences showed that the two genetic groups represent two highly divergent clades. This enabled us to develop specific primers for the assignment of individuals to either genetic group in a single PCR, based on ITS2 amplicon size. All previously assigned individuals yielded bands of expected sizes, and the PCR proved efficient on a larger sample of 799 individuals. Because none appeared heterozygous at the ITS2 locus (i.e., none produced two bands, we inferred that the genetic groups of C. pruni, whose distribution is partly sympatric, constitute biological species that have not exchanged genes for an extended period of time. Other psyllid species (Cacopsylla, Psylla, Triozidae and Aphalaridae failed to yield any amplicon. These primers are therefore unlikely to produce false positives and allow rapid assignment of C. pruni individuals to either cryptic species.

  4. Citrus huanglongbing: a newly relevant disease presents unprecedented challenges.

    Science.gov (United States)

    Wang, Nian; Trivedi, Pankaj

    2013-07-01

    Citrus huanglongbing (HLB) is one of the oldest citrus diseases and has been known for over a century. HLB is caused by 'Candidatus Liberibacter' spp. that are phloem-limited, fastidious α-proteobacteria and infect hosts in different Kingdoms (i.e., Animalia and Plantae). When compared with well-characterized, cultivatable plant-pathogenic Gram-negative bacteria, the interactions of uncultured insect-vectored plant-pathogenic bacteria, including 'Ca. Liberibacter' spp., with their hosts remain poorly understood. 'Ca. Liberibacter' spp. have been known to cause HLB, which has been rapidly spreading worldwide, resulting in dramatic economic losses. HLB presents an unprecedented challenge to citrus production. In this review, we focus on the most recent research on citrus, 'Candidatus Liberibacter asiaticus', and psyllid interactions, specifically considering the following topics: evolutionary relationships among 'Ca. Liberibacter' spp., genetic diversity, host range, genome analysis, transmission, virulence mechanisms, and the ecological importance of HLB. Currently, no efficient management strategy is available to control HLB, although some promising progress has been made. Further studies are needed to understand citrus, 'Ca. L. asiaticus', and psyllid interactions to design innovative management strategies. Although HLB has been problematic for over a century, we can only win the battle against HLB with a coordinated and deliberate effort by the citrus industry, citrus growers, researchers, legislatures, and governments.

  5. Complete genome sequence of citrus huanglongbing bacterium, 'Candidatus Liberibacter asiaticus' obtained through metagenomics.

    Science.gov (United States)

    Duan, Yongping; Zhou, Lijuan; Hall, David G; Li, Wenbin; Doddapaneni, Harshavardhan; Lin, Hong; Liu, Li; Vahling, Cheryl M; Gabriel, Dean W; Williams, Kelly P; Dickerman, Allan; Sun, Yijun; Gottwald, Tim

    2009-08-01

    Citrus huanglongbing is the most destructive disease of citrus worldwide. It is spread by citrus psyllids and is associated with a low-titer, phloem-limited infection by any of three uncultured species of alpha-Proteobacteria, 'Candidatus Liberibacter asiaticus', 'Ca. L. americanus', and 'Ca. L. africanus'. A complete circular 'Ca. L. asiaticus' genome has been obtained by metagenomics, using the DNA extracted from a single 'Ca. L. asiaticus'-infected psyllid. The 1.23-Mb genome has an average 36.5% GC content. Annotation revealed a high percentage of genes involved in both cell motility (4.5%) and active transport in general (8.0%), which may contribute to its virulence. 'Ca. L. asiaticus' appears to have a limited ability for aerobic respiration and is likely auxotrophic for at least five amino acids. Consistent with its intracellular nature, 'Ca. L. asiaticus' lacks type III and type IV secretion systems as well as typical free-living or plant-colonizing extracellular degradative enzymes. 'Ca. L. asiaticus' appears to have all type I secretion system genes needed for both multidrug efflux and toxin effector secretion. Multi-protein phylogenetic analysis confirmed 'Ca. L. asiaticus' as an early-branching and highly divergent member of the family Rhizobiaceae. This is the first genome sequence of an uncultured alpha-proteobacteria that is both an intracellular plant pathogen and insect symbiont.

  6. β-caryophyllene emitted from a transgenic Arabidopsis or chemical dispenser repels Diaphorina citri, vector of Candidatus Liberibacters.

    Science.gov (United States)

    Alquézar, Berta; Volpe, Haroldo Xavier Linhares; Magnani, Rodrigo Facchini; de Miranda, Marcelo Pedreira; Santos, Mateus Almeida; Wulff, Nelson Arno; Bento, Jose Mauricio Simões; Parra, José Roberto Postali; Bouwmeester, Harro; Peña, Leandro

    2017-07-17

    Production of citrus, the main fruit tree crop worldwide, is severely threatened by Huanglongbing (HLB), for which as yet a cure is not available. Spread of this bacterial disease in America and Asia is intimately connected with dispersal and feeding of the insect vector Diaphorina citri, oligophagous on rutaceous host plants. Effective control of this psyllid is an important component in successful HLB management programs. Volatiles released from the non-host guava have been shown to be repellent to the psyllid and to inhibit its response to citrus odour. By analysing VOC emission from guava we identified one volatile compound, (E)-β-caryophyllene, which at certain doses exerts a repellent effect on D. citri. Non-host plant rejection mediated by (E)-β-caryophyllene is demonstrated here by using Arabidopsis over-expression and knock-out lines. For the first time, results indicate that genetically engineered Arabidopsis plants with modified emission of VOCs can alter the behaviour of D. citri. This study shows that transgenic plants with an inherent ability to release (E)-β-caryophyllene can potentially be used in new protection strategies of citrus trees against HLB.

  7. Development of rapid, sensitive and non-radioactive tissue-blot diagnostic method for the detection of citrus greening.

    Science.gov (United States)

    Nageswara-Rao, Madhugiri; Miyata, Shin-Ichi; Ghosh, Dilip; Irey, Mike; Garnsey, Stephen M; Gowda, Siddarame

    2013-01-01

    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 management of HLB disease requires rapid and sensitive detection early in the infection followed by eradication of the source of pathogen and the vector. The polymerase chain reaction (PCR) based method is most commonly employed for screening the infected/suspected HLB plants and psyllids. This is time consuming, cumbersome and not practical for screening large number of samples in the field. To overcome this, we developed a simple, sensitive, non-radioactive, tissue-blot diagnostic method for early detection and screening of HLB disease. Digoxigenin labeled molecular probes specific to 'Ca. L. asiaticus' nucleotide sequences have been developed and used for the detection of the pathogen of the HLB disease. The copy number of the target genes was also assessed using real-time PCR experiments and the optimized real-time PCR protocol allowed positive 'Ca. L. asiaticus' detection in citrus samples infected with 'Ca. L. asiaticus' bacterium.

  8. Modeling huanglongbing transmission within a citrus tree.

    Science.gov (United States)

    Chiyaka, Christinah; Singer, Burton H; Halbert, Susan E; Morris, J Glenn; van Bruggen, Ariena H C

    2012-07-24

    The citrus disease huanglongbing (HLB), associated with an uncultured bacterial pathogen, is threatening the citrus industry worldwide. A mathematical model of the transmission of HLB between its psyllid vector and citrus host has been developed to characterize the dynamics of the vector and disease development, focusing on the spread of the pathogen from flush to flush (a newly developing cluster of very young leaves on the expanding terminal end of a shoot) within a tree. This approach differs from that of prior models for vector-transmitted plant diseases where the entire plant is the unit of analysis. Dynamics of vector and host populations are simulated realistically as the flush population approaches complete infection. Model analysis indicates that vector activity is essential for initial infection but is not necessary for continued infection because infection can occur from flush to flush through internal movement in the tree. Flush production, within-tree spread, and latent period are the most important parameters influencing HLB development. The model shows that the effect of spraying of psyllids depends on time of initial spraying, frequency, and efficacy of the insecticides. Similarly, effects of removal of symptomatic flush depend on the frequency of removal and the time of initiation of this practice since the start of the epidemic. Within-tree resistance to spread, possibly affected by inherent or induced resistance, is a major factor affecting epidemic development, supporting the notion that alternate routes of transmission besides that by the vector can be important for epidemic development.

  9. Costs and benefits of insecticide and foliar nutrient applications to huanglongbing-infected citrus trees.

    Science.gov (United States)

    Tansey, James A; Vanaclocha, Pilar; Monzo, Cesar; Jones, Moneen; Stansly, Philip A

    2017-05-01

    The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Psyllidae), vectors Candidatus Liberibacter asiaticus, which causes huanglongbing (HLB). In Florida, HLB incidence is approaching 100% statewide. Yields have decreased and production costs have increased since 2005. Despite this, some growers are maintaining a level of production and attribute this in part to aggressive psyllid control and foliar nutrition sprays. However, the value of these practices is debated. A replicated field study was initiated in 2008 in a commercial block of 'Valencia' sweet orange trees to evaluate individual and combined effects of foliar nutrition and ACP control. Results from 2012-2016 are presented. Insecticides consistently reduced ACP populations. However, neither insecticide nor nutrition applications significantly influenced HLB incidence or PCR copy number in mature trees. In reset trees, infection continued to build and reached 100% in all treatments. Greatest yields (kg fruit ha(-1) ) and production (kg solids ha(-1) ) were obtained from trees receiving both insecticides and foliar nutrition. All treatments resulted in production and financial gains relative to controls. However, material and application costs associated with the nutrition component offset these gains, resulting in lesser benefits than insecticides applied alone. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  10. Evolutionary conservation of candidate osmoregulation genes in plant phloem sap-feeding insects.

    Science.gov (United States)

    Jing, X; White, T A; Luan, J; Jiao, C; Fei, Z; Douglas, A E

    2016-06-01

    The high osmotic pressure generated by sugars in plant phloem sap is reduced in phloem-feeding aphids by sugar transformations and facilitated water flux in the gut. The genes mediating these osmoregulatory functions have been identified and validated empirically in the pea aphid Acyrthosiphon pisum: sucrase 1 (SUC1), a sucrase in glycoside hydrolase family 13 (GH13), and aquaporin 1 (AQP1), a member of the Drosophila integral protein (DRIP) family of aquaporins. Here, we describe molecular analysis of GH13 and AQP genes in phloem-feeding representatives of the four phloem-feeding groups: aphids (Myzus persicae), coccids (Planococcus citri), psyllids (Diaphorina citri, Bactericera cockerelli) and whiteflies (Bemisia tabaci MEAM1 and MED). A single candidate GH13-SUC gene and DRIP-AQP gene were identified in the genome/transcriptome of most insects tested by the criteria of sequence motif and gene expression in the gut. Exceptionally, the psyllid Ba. cockerelli transcriptome included a gut-expressed Pyrocoelia rufa integral protein (PRIP)-AQP, but has no DRIP-AQP transcripts, suggesting that PRIP-AQP is recruited for osmoregulatory function in this insect. This study indicates that phylogenetically related SUC and AQP genes may generally mediate osmoregulatory functions in these diverse phloem-feeding insects, and provides candidate genes for empirical validation and development as targets for osmotic disruption of pest species. © 2016 The Authors. Insect Molecular Biology published by John Wiley & Sons Ltd on behalf of The Royal Entomological Society.

  11. Roles of olfactory cues, visual cues, and mating status in orientation of Diaphorina citri Kuwayama (Hemiptera: Psyllidae) to four different host plants.

    Science.gov (United States)

    Wenninger, Erik J; Stelinski, Lukasz L; Hall, David G

    2009-02-01

    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 L.), and Murraya paniculata L. Jack. Responses varied by plant species, psyllid sex and mating status, and the presence of a visual cue. Evidence of attraction generally was stronger in females and in mated individuals of both sexes relative to virgins. The presence of a visual cue typically enhanced attractiveness of olfactory cues; in no case did unmated individuals show evidence of attraction to host plant odors in the absence of avisual cue. In the absence of visual cues, mated females and males showed evidence of attraction only to odors from sour orange and navel orange, respectively. Psyllids exhibited anemotactic responses when assayed with plant odors alone but showed strong evidence of attraction only when olfactory and visual cues were combined, suggesting that olfactory cues facilitate orientation to host plants but may be insufficient alone. Antennal responses to citrus volatiles were confirmed by electroantennogram. The results reported here provide evidence that D. citri uses olfactory and visual cues in orientation to host plants and suggest the possibility of using plant volatiles in monitoring and management of this pest.

  12. Unique features of a Japanese 'Candidatus Liberibacter asiaticus' strain revealed by whole genome sequencing.

    Directory of Open Access Journals (Sweden)

    Hiroshi Katoh

    Full Text Available Citrus greening (huanglongbing is the most destructive disease of citrus worldwide. It is spread by citrus psyllids and is associated with phloem-limited bacteria of three species of α-Proteobacteria, namely, 'Candidatus Liberibacter asiaticus', 'Ca. L. americanus', and 'Ca. L. africanus'. Recent findings suggested that some Japanese strains lack the bacteriophage-type DNA polymerase region (DNA pol, in contrast to the Floridian psy62 strain. The whole genome sequence of the pol-negative 'Ca. L. asiaticus' Japanese isolate Ishi-1 was determined by metagenomic analysis of DNA extracted from 'Ca. L. asiaticus'-infected psyllids and leaf midribs. The 1.19-Mb genome has an average 36.32% GC content. Annotation revealed 13 operons encoding rRNA and 44 tRNA genes, but no typical bacterial pathogenesis-related genes were located within the genome, similar to the Floridian psy62 and Chinese gxpsy. In contrast to other 'Ca. L. asiaticus' strains, the genome of the Japanese Ishi-1 strain lacks a prophage-related region.

  13. Spatial Distribution of Adults of Triozoida limbata (Enderlein) (Hemiptera: Triozidae) in Guava Plants.

    Science.gov (United States)

    Marcelino, M C S; Barbosa, J C

    2016-04-01

    The psyllid Triozoida limbata (Enderlein) (Hemiptera: Triozidae) is a major pest in guava, feeding primarily on new shoots. Despite its importance, there are no studies on the spatial distribution of T. limbata on guava. Such studies are needed to establish sequential sampling plans for decision making in pest control. Thus, an experiment was carried out in a 9-year-old commercial guava orchard divided into 100 sampling units or plots. Double-sided yellow sticky traps were placed on one plant per plot (sample unit) to capture and monitor T. limbata adults from April 2011 to May 2012. To determine the insect distribution in the area, we calculated the variance-to-mean ratio index (I), the Morisita index (I δ ), Green's coefficient (Cx), and the k exponent of the negative binomial distribution. Most of the samples showed that the adults had a moderate to highly aggregated distribution. Statistical models were also used to study the pest spatial distribution by fitting the number of adults captured to the Poisson and negative binomial distributions. The negative binomial distribution model best fitted the data of the number of adult psyllids captured by the traps, which is consistent with an aggregated distribution.

  14. Effect of silicon application to Eucalyptus camaldulensis on the population of Glycaspis brimblecombei (Hemiptera: Aphalaridae

    Directory of Open Access Journals (Sweden)

    Dalva Luiz de Queiroz

    2016-06-01

    Full Text Available The use of silicon in forestry has increased recently as it is directly related to improved resistance to insect pests. The red gum lerp psyllid, Glycaspis brimblecombei, occurs in all eucalypt producing regions in Brazil. Two field experiments were conducted to study the effect of silicon applied to Eucalyptus camaldulensis on the psyllid population. In the first experiment, the applications were made via soil (calcium silicate and leaves (potassium silicate in a nine months old E. camaldulensis plantation. In the second experiment, we evaluated silicon on seedlings, incorporating it into the substrate (soil or applying it on leaves (foliar. Monthly, for 24 months, the number of psyllid eggs and immatures were counted on leaf samples. The plant height was measured at 9, 12, 16 and 24 months (experiment 1 and at 4, 8, 12 and 24 months (experiment 2 after application. The numbers of eggs and immatures were lower in periods of higher precipitation, indicating less psyllid attack during the rainy season. The psyllid population was lower in treatments with application of silicon both foliar and via soil compared to control. No significant differences were found in the height of E. camaldulensis plants. O uso do silício na área florestal tem aumentado recentemente, pois o elemento está relacionado a uma melhoria na resistência a insetos pragas. O psilídeo de concha, Glycaspis brimblecombei é encontrado em todas as regiões produtoras de eucalipto no Brasil. O efeito do silício aplicado em Eucalyptus camaldulensis, na população do psilídeo, foi estudado em dois ensaios. No primeiro experimento, as aplicações foram via solo (silicato de cálcio e foliar (silicato de potássio em uma plantação de nove meses. No segundo experimento, este mineral foi aplicado em mudas de eucalipto, no substrato ou sobre as folhas. Mensalmente, durante 24 meses, ovos e imaturos de G. brimblecombei foram amostrados nas folhas. A altura das plantas foi medida

  15. In vitro effect of essential oils and isolated mono- and sesquiterpenes on Leishmania major and Trypanosoma brucei.

    Science.gov (United States)

    Mikus, J; Harkenthal, M; Steverding, D; Reichling, J

    2000-05-01

    The effect of different essential oils as well as of isolated mono- and sesquiterpenes on the viability of bloodstream forms of Trypanosoma brucei, promastigotes of Leishmania major and human HL-60 cells was evaluated using the Almar Blue assay. Of the 12 essential oils and 8 terpenes investigated, only three essential oils, Melissa officinalis (balmmint) oil, Thymus vulgaris (thyme) oil, and Melaleuca alternifolia (tea tree) oil were about 50-fold and 80-fold more toxic to bloodstream forms of T. brucei than to HL-60 cells, respectively. Terpinen-4-ol, the main compound of the Australian tea tree oil, was even 1000-fold more toxic to trypanosomes than to the human cells. On the other hand, none of the essential oils and terpenes tested were more toxic to promastigotes of L. major than to HL-60 cells.

  16. [Peculicidal activity of plant essential oils and their based preparations].

    Science.gov (United States)

    Lopatina, Iu V; Eremina, O Iu

    2014-01-01

    The peculicidal activity of eight plant essential oils in 75% isopropyl alcohol was in vitro investigated. Of them, the substances that were most active against lice were tea tree (Melaleuca), eucalyptus, neem, citronella (Cymbopogon nardus), and clove (Syzygium aromaticum) oils; KT50 was not more than 3 minutes on average; KT95 was 4 minutes. After evaporating the solvent, only five (tea tree, cassia, clove, anise (Anisum vulgare), and Japanese star anise (Illicium anisatum) oils) of the eight test botanical substances were active against lice. At the same time, KT50 and KT95 showed 1.5-5-fold increases. Citronella and anise oils had incomplete ovicidal activity. Since the lice were permethrin-resistant, the efficacy of preparations based on essential oils was much higher than permethrin.

  17. Effects of Iodine Doping on Optoelectronic and Chemical Properties of Polyterpenol Thin Films

    Science.gov (United States)

    Bazaka, Kateryna; Jacob, Mohan V.

    2017-01-01

    Owing to their amorphous, highly cross-liked nature, most plasma polymers display dielectric properties. This study investigates iodine doping as the means to tune optoelectronic properties of plasma polymer derived from a low-cost, renewable resource, i.e., Melaleuca alternifolia oil. In situ exposure of polyterpenol to vapors of electron-accepting dopant reduced the optical band gap to 1.5 eV and increased the conductivity from 5.05 × 10−8 S/cm to 1.20 × 10−6 S/cm. The increased conductivity may, in part, be attributed to the formation of charge-transfer complexes between the polymer chain and halogen, which act as a cation and anion, respectively. Higher levels of doping notably increased the refractive index, from 1.54 to 1.70 (at 500 nm), and significantly reduced the transparency of films.

  18. TEA TREE OIL: AS A PROMISING ANTIMICROBIAL AGENT (UMUT VAAT EDEN BİR ANTİMİKROBİYAL: TEA TREE OIL (ÇAY AĞACI YAĞI))

    OpenAIRE

    TEZGÜL ÇAKIR, Nalan; KALEAĞASI, Sakine; KÖKDİL, Gamze

    2005-01-01

    Tea tree oil (TTO, Çay ağacı yağı), Avusturalya’da doğal olarak yetişen Melaleuca alternifolia(Myrtaceae)’nın yapraklarından buhar distilasyonu ile elde edilen bir uçucu yağdır ve Avusturalya’da 80 yılıaşkın süredir topikal antiseptik olarak kullanılmaktadır. Yapılan araştırmalar yağın yüksek terpinen-4-oliçeriğine atfedilen geniş spektrumlu antimikrobiyal aktiviteye sahip olduğunu doğrulamaktadır. Son yıllardayapılmış klinik denemeler ümit vericidir. Son onbeş yılda tea tre oil, doğal kaynak...

  19. Effect of Australian tea tree oil on Gyrodactylus spp. infection of the three-spined stickleback Gasterosteus aculeatus.

    Science.gov (United States)

    Steverding, Dietmar; Morgan, Edward; Tkaczynski, Patrick; Walder, Foster; Tinsley, Richard

    2005-08-09

    Gyrodactylus spp. infections of commercially farmed fishes are responsible for significant economic losses. Existing treatments have proved uneconomic, stressful to the fishes, and ecologically damaging. Essential oils are naturally occurring compounds that exhibit a wide range of anti-microbial and anti-fungal activities. This study explored the possibility of using Australian tea tree (Melaleuca alternifolia) oil (TTO) to treat Gyrodactylus spp. infection on the three-spined stickleback Gasterosteus aculeatus. In the presence of 0.01 % Tween 80 as an emulsifier, TTO treatments at concentrations between 3 and 30 ppmv (parts per million by volume) lowered the prevalence and significantly reduced the parasite burden of sticklebacks naturally infected with Gyrodactylus spp. In addition, Tween 80 alone exhibited parasiticidal activity against Gyrodactylus spp. These findings show the potential of TTO in combination with Tween 80 as an effective treatment of Gyrodactylus spp. infection of fishes.

  20. A review of applications of tea tree oil in dermatology.

    Science.gov (United States)

    Pazyar, Nader; Yaghoobi, Reza; Bagherani, Nooshin; Kazerouni, Afshin

    2013-07-01

    Tea tree oil (TTO) is an essential oil, steam-distilled from the Australian native plant, Melaleuca alternifolia. It has a minimum content of terpinen-4-ol and a maximum content of 1, 8-cineole. Terpinen-4-ol is a major TTO component which exhibits strong antimicrobial and anti-inflammatory properties. Tea tree oil exerts antioxidant activity and has been reported to have broad-spectrum antimicrobial activity against bacterial, viral, fungal, and protozoal infections affecting skin and mucosa. Several studies have suggested the uses of TTO for the treatment of acne vulgaris, seborrheic dermatitis, and chronic gingivitis. It also accelerates the wound healing process and exhibits anti-skin cancer activity. This review opens up new horizons for dermatologists in the use of this herbal agent.

  1. Antibacterial Activity of Cinnamaldehyde and Estragole Extracted from Plant Essential Oils against Pseudomonas syringae pv. actinidiae Causing Bacterial Canker Disease in Kiwifruit

    Science.gov (United States)

    Song, Yu-Rim; Choi, Min-Seon; Choi, Geun-Won; Park, Il-Kwon; Oh, Chang-Sik

    2016-01-01

    Pseudomonas syringae pv. actinidiae (Psa) causes bacterial canker disease in kiwifruit. Antibacterial activity of plant essential oils (PEOs) originating from 49 plant species were tested against Psa by a vapor diffusion and a liquid culture assays. The five PEOs from Pimenta racemosa, P. dioica, Melaleuca linariifolia, M. cajuputii, and Cinnamomum cassia efficiently inhibited Psa growth by either assays. Among their major components, estragole, eugenol, and methyl eugenol showed significant antibacterial activity by only the liquid culture assay, while cinnamaldehyde exhibited antibacterial activity by both assays. The minimum inhibitory concentrations (MICs) of estragole and cinnamaldehyde by the liquid culture assay were 1,250 and 2,500 ppm, respectively. The MIC of cinnamaldehyde by the vapor diffusion assay was 5,000 ppm. Based on the formation of clear zones or the decrease of optical density caused by these compounds, they might kill the bacterial cells and this feature might be useful for managing the bacterial canker disease in kiwifruit. PMID:27493612

  2. Antibacterial Activity of Cinnamaldehyde and Estragole Extracted from Plant Essential Oils against Pseudomonas syringae pv. actinidiae Causing Bacterial Canker Disease in Kiwifruit

    Directory of Open Access Journals (Sweden)

    Yu-Rim Song

    2016-08-01

    Full Text Available Pseudomonas syringae pv. actinidiae (Psa causes bacterial canker disease in kiwifruit. Antibacterial activity of plant essential oils (PEOs originating from 49 plant species were tested against Psa by a vapor diffusion and a liquid culture assays. The five PEOs from Pimenta racemosa, P. dioica, Melaleuca linariifolia, M. cajuputii, and Cinnamomum cassia efficiently inhibited Psa growth by either assays. Among their major components, estragole, eugenol, and methyl eugenol showed significant antibacterial activity by only the liquid culture assay, while cinnamaldehyde exhibited antibacterial activity by both assays. The minimum inhibitory concentrations (MICs of estragole and cinnamaldehyde by the liquid culture assay were 1,250 and 2,500 ppm, respectively. The MIC of cinnamaldehyde by the vapor diffusion assay was 5,000 ppm. Based on the formation of clear zones or the decrease of optical density caused by these compounds, they might kill the bacterial cells and this feature might be useful for managing the bacterial canker disease in kiwifruit.

  3. Biological control of weeds: research by the United States Department of Agriculture-Agricultural Research Service: selected case studies.

    Science.gov (United States)

    Quimby, Paul C; DeLoach, C Jack; Wineriter, Susan A; Goolsby, John A; Sobhian, Rouhollah; Boyette, C Douglas; Abbas, Hamed K

    2003-01-01

    Research by the USDA-Agricultural Research Service (ARS) on biological control of weeds has been practiced for many years because of its inherent ecological and economic advantages. Today, it is further driven by ARS adherence to Presidential Executive Order 13112 (3 February 1999) on invasive species and to USDA-ARS policy toward developing technology in support of sustainable agriculture with reduced dependence on non-renewable petrochemical resources. This paper reports examples or case studies selected to demonstrate the traditional or classical approach for biological control programs using Old World arthropods against Tamarix spp, Melaleuca quinquenervia (Cav) ST Blake and Galium spurium L/G aparine L, and the augmentative approach with a native plant pathogen against Pueraria lobata Ohwi = P montana. The examples illustrated various conflicts of interest with endangered species and ecological complexities of arthropods with associated microbes such as nematodes.

  4. In vitro synergic efficacy of the combination of Nystatin with the essential oils of Origanum vulgare and Pelargonium graveolens against some Candida species.

    Science.gov (United States)

    Rosato, Antonio; Vitali, Cesare; Piarulli, Monica; Mazzotta, Manuela; Argentieri, Maria Pia; Mallamaci, Rosanna

    2009-10-01

    In this study we investigated a synergistic effect between the essential oils Origanum vulgare, Pelargonium graveolens and Melaleuca alternifolia and the antifungal compound Nystatin. Nystatin is considered a drug of choice in the treatment of fungal infections, but it can cause some considerable problems through its side effects, such as renal damage. Finding a new product that can reduce the Nystatin dose via combination is very important. Our findings showed an experimental occurrence of a synergistic interaction between two of these essential oils and Nystatin. The essential oil O. vulgare appeared to be the most effective, inhibiting all the Candida species evaluated in this study. Some combinations of Nystatin and P. graveolens essential oil did not have any synergistic interactions for some of the strains considered. Associations of Nystatin with M. alternifolia essential oil had only an additive effect.

  5. Effects of Iodine Doping on Optoelectronic and Chemical Properties of Polyterpenol Thin Films

    Directory of Open Access Journals (Sweden)

    Kateryna Bazaka

    2017-01-01

    Full Text Available Owing to their amorphous, highly cross-liked nature, most plasma polymers display dielectric properties. This study investigates iodine doping as the means to tune optoelectronic properties of plasma polymer derived from a low-cost, renewable resource, i.e., Melaleuca alternifolia oil. In situ exposure of polyterpenol to vapors of electron-accepting dopant reduced the optical band gap to 1.5 eV and increased the conductivity from 5.05 × 10−8 S/cm to 1.20 × 10−6 S/cm. The increased conductivity may, in part, be attributed to the formation of charge-transfer complexes between the polymer chain and halogen, which act as a cation and anion, respectively. Higher levels of doping notably increased the refractive index, from 1.54 to 1.70 (at 500 nm, and significantly reduced the transparency of films.

  6. UJI VIABILITAS DAN SKARIFIKASI BENIH BEBERAPA POHON ENDEMIK HUTAN RAWA GAMBUT KALIMANTAN TENGAH Seed Viability Test and Seed Scarification for Specifically Trees of Peat Swamp Forest Central of Kalimantan

    Directory of Open Access Journals (Sweden)

    Siti Maimunah

    2016-09-01

    Full Text Available Rehabilitasi hutan gambut di Indonesia mengalami banyak kendala baik secara teknis maupun biologis jenis pohon yang digunakan seperti sifat benih yang rekalsitran. Penelitian ini bertujuan untuk memberikan acuan baku tentang indeks viabilitas benih untuk jenis-jenis yang tumbuh di hutan rawa gambut. Penelitian ini adalah penelitian dasar sebagai penelitian pendahuluan saja untuk bisa dikembangkan lagi dalam penelitian-penelitian lanjutan.Jenis endemik rawa gambut Kalimantan Tengah yang diujikan dalam penelitian ini adalah Tumih (Combretocarpus rotundatus, Pulai rawa (Alstonia pneumatophora, Geronggang rawa(Cratoxylum arborescens dan Galam (Melaleuca leucadendron. Hasil penelitian menunjukkan bahwa besarnya indeks viabilitas dipengaruhi oleh tingkat kemasakan buah dan ketepatan cara skarifikasi benihnya. Tumih dan pulai adalah jenis yang direkomendasikan untuk dikembangkan di lahan gambut terdegradasi. Kata kunci : Benih rekalsitran, Indeks viabilitas benih, skarifikasi benih

  7. Rhamnolipids as emulsifying agents for essential oil formulations: antimicrobial effect against Candida albicans and methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Haba, Ester; Bouhdid, Samira; Torrego-Solana, Noelia; Marqués, A M; Espuny, M José; García-Celma, M José; Manresa, Angeles

    2014-12-10

    This work examines the influence of essential oil composition on emulsification with rhamnolipids and their use as therapeutic antimicrobial agents against two opportunistic pathogens, methicillin-resistant Staphylococcus aureus (MRSA) and Candida albicans. Rhamnolipids, produced by Pseudomonas aeruginosa, with waste frying oil as the carbon source, were composed of eight rhamnolipid homologues. The rhamnolipid mixture was used to produce emulsions containing essential oils (EOs) of Melaleuca alternifolia, Cinnamomum verum, Origanum compactum and Lavandula angustifolia using the titration method. Ternary phase diagrams were designed to evaluate emulsion stability, which differed depending on the essential oil. The in vitro antimicrobial activity of the EOs alone and the emulsions was evaluated. The antimicrobial activity presented by the essential oils alone increased with emulsification. The surface properties of rhamnolipids contribute to the positive dispersion of EOs and thus increase their availability and antimicrobial activity against C. albicans and S. aureus. Therefore, rhamnolipid-based emulsions represent a promising approach to the development of EO delivery systems.

  8. Water use patterns of estuarine vegetation in a tidal creek system.

    Science.gov (United States)

    Wei, Lili; Lockington, David A; Poh, Seng-Chee; Gasparon, Massimo; Lovelock, Catherine E

    2013-06-01

    Water availability is a key determinant of the zonation patterns in estuarine vegetation, but water availability and the use of different water sources over space and time are not well understood. We have determined the seasonal water use patterns of riparian vegetation over an estuarine ecotone. Our aim was to investigate how the water use patterns of estuarine vegetation respond to variations in the availability of tidal creek water and rain-derived freshwater. The levels of natural stable isotopes of oxygen and hydrogen were assessed in the stem of the mangrove Avicennia marina (tall and scrub growth forms), Casuarina glauca and Melaleuca quinquenervia that were distributed along transects from river/creek-front towards inland habitats. The isotopic composition of plant tissues and the potential water sources were assessed in both the wet season, when freshwater from rainfall is present, and the dry season, when mangrove trees are expected to be more dependent on tidal water, and when Casuarina and Melaleuca are expected to be dependent on groundwater. Our results indicate that rainwater during the wet season contributes significantly to estuarine vegetation, even to creek-side mangroves which are inundated by tidal creek water daily, and that estuarine vegetation depends primarily on freshwater throughout the year. In contrast, high intertidal scrub mangroves were found to use the greatest proportion of tidal creek water, supplemented by groundwater in the dry season. Contrary to prediction, inland trees C. glauca and M. quinquenervia were found also to rely predominantly on rainwater--even in the dry season. The results of this study reveal a high level of complexity in vegetation water use in estuarine settings.

  9. Cumulative mortality of Aedes aegypti larvae treated with compounds.

    Science.gov (United States)

    Torres, Sandra Maria; Cruz, Nadine Louise Nicolau da; Rolim, Vitor Pereira de Matos; Cavalcanti, Maria Inês de Assis; Alves, Leucio Câmara; Silva Júnior, Valdemiro Amaro da

    2014-06-01

    OBJECTIVE To evaluate the larvicidal activity of Azadirachta indica, Melaleuca alternifolia, carapa guianensis essential oils and fermented extract of Carica papaya against Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae). METHODS The larvicide test was performed in triplicate with 300 larvae for each experimental group using the third larval stage, which were exposed for 24h. The groups were: positive control with industrial larvicide (BTI) in concentrations of 0.37 ppm (PC1) and 0.06 ppm (PC2); treated with compounds of essential oils and fermented extract, 50.0% concentration (G1); treated with compounds of essential oils and fermented extract, 25.0% concentration (G2); treated with compounds of essential oils and fermented extract, 12.5% concentration (G3); and negative control group using water (NC1) and using dimethyl (NC2). The larvae were monitored every 60 min using direct visualization. RESULTS No mortality occurred in experimental groups NC1 and NC2 in the 24h exposure period, whereas there was 100% mortality in the PC1 and PC2 groups compared to NC1 and NC2. Mortality rates of 65.0%, 50.0% and 78.0% were observed in the groups G1, G2 and G3 respectively, compared with NC1 and NC2. CONCLUSIONS The association between three essential oils from Azadirachta indica, Melaleuca alternifolia, Carapa guianensis and fermented extract of Carica papaya was efficient at all concentrations. Therefore, it can be used in Aedes aegypti Liverpool third larvae stage control programs.

  10. Cumulative mortality of Aedes aegypti larvae treated with compounds

    Science.gov (United States)

    Torres, Sandra Maria; da Cruz, Nadine Louise Nicolau; Rolim, Vitor Pereira de Matos; Cavalcanti, Maria Inês de Assis; Alves, Leucio Câmara; da Silva, Valdemiro Amaro

    2014-01-01

    OBJECTIVE To evaluate the larvicidal activity of Azadirachta indica, Melaleuca alternifolia, carapa guianensis essential oils and fermented extract of Carica papaya against Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae). METHODS The larvicide test was performed in triplicate with 300 larvae for each experimental group using the third larval stage, which were exposed for 24h. The groups were: positive control with industrial larvicide (BTI) in concentrations of 0.37 ppm (PC1) and 0.06 ppm (PC2); treated with compounds of essential oils and fermented extract, 50.0% concentration (G1); treated with compounds of essential oils and fermented extract, 25.0% concentration (G2); treated with compounds of essential oils and fermented extract, 12.5% concentration (G3); and negative control group using water (NC1) and using dimethyl (NC2). The larvae were monitored every 60 min using direct visualization. RESULTS No mortality occurred in experimental groups NC1 and NC2 in the 24h exposure period, whereas there was 100% mortality in the PC1 and PC2 groups compared to NC1 and NC2. Mortality rates of 65.0%, 50.0% and 78.0% were observed in the groups G1, G2 and G3 respectively, compared with NC1 and NC2. CONCLUSIONS The association between three essential oils from Azadirachta indica, Melaleuca alternifolia, Carapa guianensis and fermented extract of Carica papaya was efficient at all concentrations. Therefore, it can be used in Aedes aegypti Liverpool third larvae stage control programs. PMID:25119939

  11. Cumulative mortality of Aedes aegypti larvae treated with compounds

    Directory of Open Access Journals (Sweden)

    Sandra Maria Torres

    2014-06-01

    Full Text Available OBJECTIVE To evaluate the larvicidal activity of Azadirachta indica, Melaleuca alternifolia, carapa guianensis essential oils and fermented extract of Carica papaya against Aedes aegypti (Linnaeus, 1762 (Diptera: Culicidae. METHODS The larvicide test was performed in triplicate with 300 larvae for each experimental group using the third larval stage, which were exposed for 24h. The groups were: positive control with industrial larvicide (BTI in concentrations of 0.37 ppm (PC1 and 0.06 ppm (PC2; treated with compounds of essential oils and fermented extract, 50.0% concentration (G1; treated with compounds of essential oils and fermented extract, 25.0% concentration (G2; treated with compounds of essential oils and fermented extract, 12.5% concentration (G3; and negative control group using water (NC1 and using dimethyl (NC2. The larvae were monitored every 60 min using direct visualization. RESULTS No mortality occurred in experimental groups NC1 and NC2 in the 24h exposure period, whereas there was 100% mortality in the PC1 and PC2 groups compared to NC1 and NC2. Mortality rates of 65.0%, 50.0% and 78.0% were observed in the groups G1, G2 and G3 respectively, compared with NC1 and NC2. CONCLUSIONS The association between three essential oils from Azadirachta indica, Melaleuca alternifolia, Carapa guianensis and fermented extract of Carica papaya was efficient at all concentrations. Therefore, it can be used in Aedes aegypti Liverpool third larvae stage control programs.

  12. Dynamics of Land Cover/Land Use Changes in the Mekong Delta, 1973–2011: A Remote Sensing Analysis of the Tran Van Thoi District, Ca Mau Province, Vietnam

    Directory of Open Access Journals (Sweden)

    Hanh Tran

    2015-03-01

    Full Text Available The main objective of this study is to assess the spatio-temporal dynamics of land cover/land use changes in the lower Mekong Delta over the last 40 years with the coastal Tran Van Thoi District of Ca Mau Province, Vietnam as a case study. Land cover/land use change dynamics are derived from moderate to high spatial resolution (Landsat and SPOT satellite imagery in six time intervals ranging from 1973 to 2011. Multi-temporal satellite images were collected, georeferenced, classified using per-pixel method, validated, and compared in post classification for the land use/land cover change detection in decades. Seven major land cover/land use classes were obtained, including cultivated lands, aquaculture ponds, mangrove forest, melaleuca forest, built up areas, bare lands, and natural water bodies. The accuracies of the land cover/land use maps for 1973, 1979, 1989, 1995, 2004, and 2011 were 81%, 82%, 86%, 87%, 89%, and 89%, respectively. The results show that the area of cultivated lands reduced over the period 1973–2011, however, it still represents the dominant land use in the case study. Aquaculture ponds were almost absent in 1973 but greatly increased from 1995 to 2004, to represent 20% of the land surface in 2011. Overall, from 1973 to 2011, bare lands, cultivated lands, mangrove forest, and melaleuca forest decreased by 104 km2, 77 km2, 61 km2, and 5 km2, respectively. In contrast, aquaculture lands and built up areas increased by 123 km2 and 120 km2, respectively. Temporal analysis highlights that these changes took place mostly between 1995 and 2004. This study is a first step to identify the main drivers of land use changes in this delta region, which include economical policies as well as demographic, socio-economic, and environmental changes.

  13. Atividade inseticida de óleos essenciais e fixos sobre Callosobruchus maculatus (FABR., 1775 (Coleoptera: Bruchidae em grãos de caupi [Vigna unguiculata (L. WALP.] Insecticide activity of essential and fixed oils in Callosobruchus maculatus (FABR., 1775 (Coleoptera: Bruchidae in cowpea grains [Vigna unguiculata (L. WALP.

    Directory of Open Access Journals (Sweden)

    Adriana Carla Ribeiro Lopes Pereira

    2008-06-01

    Full Text Available O caruncho, Callosobruchus maculatus (Fabr., é considerado a praga mais importante do caupi, Vigna unguiculata (L. Walp., armazenado em regiões tropicais e subtropicais. Visando minimizar os efeitos indesejáveis dos inseticidas químicos sintéticos, o controle dessa praga com óleos de origem vegetal vem se constituindo numa alternativa promissora, de baixo custo e segura para os aplicadores e consumidores. Foram testados os óleos essenciais [(Cymbopogon martini (Roxb. J.F. Watson], Piper aduncum L., Piper hispidinervum C.DC., Melaleuca sp., Lippia gracillis Shauer e fixos (Helianthus annuus L, Sesamum indicum L, Gossypium hirsutum L., Glycine max (L. Merr. e Caryocar brasiliense Camb., em grãos de caupi, cv. Sempre Verde. Os óleos foram utilizados nas concentrações 10, 20, 30, 40 e 50mL/20g, correspondendo a 0,5, 1,0, 1,5, 2,0 e 2,5 L/t e impregnados aos grãos no interior de recipientes de plástico, com auxílio de pipetador automático e agitados manualmente durante dois minutos. Parcelas de 20g de caupi foram infestadas com oito fêmeas de C. maculatus, com 0 a 48 h de idade. Cada óleo foi testado, separadamente, em delineamento inteiramente casualisado com seis repetições. Os óleos essenciais de C. martini, P. aduncum e L. gracillis causaram 100% de mortalidade em todas as concentrações, P. hispidinervum a partir de 1,5 L/t e Melaleuca sp. nas concentrações de 2,0 e 2,5 L/t. A redução do número de ovos viáveis e de insetos emergidos foi de 100% para todos os óleos essenciais, exceto Melaleuca sp. Por outro lado, os óleos fixos, apesar de apresentarem baixa mortalidade em todas as concentrações testadas, reduziram em praticamente 100% o número de ovos viáveis e de insetos emergidos.The weevil Callosobruchus maculatus (Fabr. is considered the most important pest of cowpea, Vigna unguiculata (L. Walp., stored in tropical and subtropical regions. Focusing to minimize the undesired effects of synthetic chemical

  14. Spatial distribution of Diaphorina citri Kuwayama (Hemiptera: Psyllidae in citrus orchards Distribuição espacial de Diaphorina citri Kuwayama (Hemiptera: Psyllidae em pomares de citros

    Directory of Open Access Journals (Sweden)

    Marilia Gregolin Costa

    2010-10-01

    Full Text Available The psyllid Diaphorina citri Kuwayama is one of the most important pests of citrus, mainly because it is the vector of the bacterium that causes huanglongbing (HLB or 'Greening' disease. To study the spatial distribution of nymphs and adults of this pest, an experiment was carried out in two 'Valencia' sweet orange orchards, four and 12 years of age, established in Matão, central area of São Paulo state, Brazil. The following dispersion indices were used to study pest aggregation in the citrus plants: variance/mean relationship (I, index of Morisita (Iδ, coefficient of Green (Cx, the exponent of negative binomial distribution, common k (c and Taylor's Power Law for each sampling. The negative binomial distribution was more representative of the spatial distribution of this psyllid, for both nymphs and adults. For most samplings, psyllid nymphs found in branches and adults caught in traps had an aggregated distribution.O psilídeo Diaphorina citri Kuwayama tornou-se nos últimos anos uma das mais importantes pragas na cultura de citros, principalmente pelos prejuízos causados às plantas por ser o transmissor da bactéria causadora da doença Huanglongbing (HLB ou 'Greening'. Com a finalidade de estudar a distribuição espacial de ninfas e adultos desta praga, instalaram-se experimentos em duas áreas de citros com histórico de ocorrência de HLB, no município de Matão (região central do Estado de São Paulo, em plantas de laranja 'Valência', com quatro e 12 anos de idade. Para estudo da agregação da população nas plantas, foram utilizados os seguintes índices de dispersão: razão variância/média (I, índice de Morisita (Iδ, coeficiente de Green (Cx e expoente da distribuição binomial negativa, k comum (c e lei da potência de Taylor para cada amostragem. A distribuição binomial negativa foi o modelo mais adequado para representar a distribuição espacial do psilídeo, tanto para ninfas como para adultos. Na maioria das

  15. The Long and the Short of Mate Attraction in a Psylloid: do Semiochemicals Mediate Mating in Aacanthocnema dobsoni Froggatt?

    Science.gov (United States)

    Lubanga, Umar K; Drijfhout, Falko P; Farnier, Kevin; Steinbauer, Martin J

    2016-02-01

    Mating is preceded by a series of interdependent events that can be broadly categorized into searching and courtship. Long-range signals convey species- and sex-specific information during searching, while short-range signals provide information specific to individuals during courtship. Studies have shown that cuticular hydrocarbons (CHCs) can be used for mate recognition in addition to protecting insects from desiccation. In Psylloidea, four species rely on semiochemicals for long-range mate attraction. Psyllid mating research has focused on long-range mate attraction and has largely ignored the potential use of cuticular hydrocarbons (CHCs) as mate recognition cues. This study investigated whether CHCs of Aacanthocnema dobsoni have semiochemical activity for long- and short-range communication prior to mating. Using a solid sampler for solvent-less injection of whole psyllids into coupled gas chromatography/mass spectrometry, we found quantitative, sex- and age-related differences in CHC profiles. Males had higher proportions of 2-MeC28, 11,15-diMeC29, and n-C33 alkanes, while females had higher proportions of 5-MeC27, 3-MeC27, 5,15-diMeC27, n-C29 and n-C30 alkanes. In males and females, 84 and 68 % of CHCs varied with age, respectively. Y-tube olfactometer bioassays provided no evidence that males or females responded to odors emanating from groups of conspecifics of the opposite sex. Tests of male and female psyllids for attraction to branchlets previously occupied by conspecifics showed no evidence of attraction to possible semiochemical residues. Our short-range chemoreception bioassay showed that males were as indifferent to freshly killed individuals of either sex with intact CHC profiles as to those treated with hexane (to remove CHCs). Aacanthocnema dobsoni utilizes substrate-borne vibrations (SBVs) for communication. Therefore, our results indicate that SBVs are probably more important than semiochemicals for long-range mate attraction. Furthermore

  16. Candidate gene markers for Candidatus Liberibacter asiaticus for detecting citrus greening disease.

    Science.gov (United States)

    Nageswara-Rao, Madhugiri; Irey, Mike; Garnsey, Stephen M; Gowda, Siddarame

    2013-06-01

    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 quick screening of HLB disease. Thirty-two different gene-specific primer pairs, across the Ca. Liberibacter asiaticus genome, were successfully developed. The possibility of these primer pairs for cross-genome amplification across 'Ca. Liberibacter africanus' and 'Ca. Liberibacter americanus' were tested. The applicability of these primer pairs for detection and differentiation of Ca Liberibacter spp. is discussed.

  17. 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

    Directory of Open Access Journals (Sweden)

    Stephen Chan Teck Leong

    2012-01-01

    Full Text Available 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 imidacloprid, nC24HMO, and triazophos/cypermethrin/chlorpyrifos. Levels of HLB as determined by Polymerase Chain Reaction (PCR were 42.2%, 9.4%, 11.4%, and 22.7%, respectively. The effects of nC24HMO and conventional pesticides on the citrus psyllid population and parasitoids in citrus orchard were also determined.

  18. 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.

    Science.gov (United States)

    Leong, Stephen Chan Teck; Abang, Fatimah; Beattie, Andrew; Kueh, Roland Jui Heng; Wong, Sing King

    2012-01-01

    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 imidacloprid, nC24HMO, and triazophos/cypermethrin/chlorpyrifos. Levels of HLB as determined by Polymerase Chain Reaction (PCR) were 42.2%, 9.4%, 11.4%, and 22.7%, respectively. The effects of nC(24)HMO and conventional pesticides on the citrus psyllid population and parasitoids in citrus orchard were also determined.

  19. Occurrence of free fatty acids in the phloem sap of different citrus varieties.

    Science.gov (United States)

    Valim, Maria Filomena; Killiny, Nabil

    2017-06-03

    Candidatus Liberibacter asiaticus is a phloem restricted bacterium that 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 12 citrus varieties with different degrees of tolerance to HLB were extracted with ethyl acetate and analyzed by GC-MS after derivatization with boron trifluoride, a fatty acid-specific reagent. Nine free fatty acids were detected in all varieties. Of the 9 fatty acids detected, only capric acid was significantly different among varieties.

  20. Candidate gene markers for Candidatus Liberibacter asiaticus for detecting citrus greening disease

    Indian Academy of Sciences (India)

    Madhugiri Nageswara-Rao; Mike Irey; Stephen M Garnsey; Siddarame Gowda

    2013-06-01

    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 quick screening of HLB disease. Thirty-two different gene-specific primer pairs, across the Ca. Liberibacter asiaticus genome, were successfully developed. The possibility of these primer pairs for cross-genome amplification across `Ca. Liberibacter africanus’ and `Ca. Liberibacter americanus’ were tested. The applicability of these primer pairs for detection and differentiation of Ca Liberibacter spp. is discussed.

  1. The Influence of Learning on Host Plant Preference in a Significant Phytopathogen Vector, Diaphorina citri.

    Science.gov (United States)

    Stockton, Dara G; Martini, Xavier; Patt, Joseph M; Stelinski, Lukasz L

    2016-01-01

    Although specialist herbivorous insects are guided by innate responses to host plant cues, host plant preference may be influenced by experience and is not dictated by instinct alone. The effect of learning on host plant preference was examined in the Asian citrus psyllid, Diaphorina citri; vector of the causal agent of citrus greening disease or huanglongbing. We investigated: a) whether development on specific host plant species influenced host plant preference in mature D. citri; and b) the extent of associative learning in D. citri in the form of simple and compound conditioning. Learning was measured by cue selection in a 2-choice behavioral assay and compared to naïve controls. Our results showed that learned responses in D. citri are complex and diverse. The developmental host plant species influenced adult host plant preference, with female psyllids preferring the species on which they were reared. However, such preferences were subject to change with the introduction of an alternative host plant within 24-48 hrs, indicating a large degree of experience-dependent response plasticity. Additionally, learning occurred for multiple sensory modalities where novel olfactory and visual environmental cues were associated with the host plant. However, males and females displayed differing discriminatory abilities. In compound conditioning tasks, males exhibited recognition of a compound stimulus alone while females were capable of learning the individual components. These findings suggest D. citri are dynamic animals that demonstrate host plant preference based on developmental and adult experience and can learn to recognize olfactory and visual host plant stimuli in ways that may be sex specific. These experience-based associations are likely used by adults to locate and select suitable host plants for feeding and reproduction and may suggest the need for more tailored lures and traps, which reflect region-specific cultivars or predominate Rutaceae in the area

  2. The complete genome sequence of 'Candidatus Liberibacter solanacearum', the bacterium associated with potato zebra chip disease.

    Directory of Open Access Journals (Sweden)

    Hong Lin

    Full Text Available Zebra Chip (ZC is an emerging plant disease that causes aboveground decline of potato shoots and generally results in unusable tubers. This disease has led to multi-million dollar losses for growers in the central and western United States over the past decade and impacts the livelihood of potato farmers in Mexico and New Zealand. ZC is associated with 'Candidatus Liberibacter solanacearum', a fastidious alpha-proteobacterium that is transmitted by a phloem-feeding psyllid vector, Bactericera cockerelli Sulc. Research on this disease has been hampered by a lack of robust culture methods and paucity of genome sequence information for 'Ca. L. solanacearum'. Here we present the sequence of the 1.26 Mbp metagenome of 'Ca. L. solanacearum', based on DNA isolated from potato psyllids. The coding inventory of the 'Ca. L. solanacearum' genome was analyzed and compared to related Rhizobiaceae to better understand 'Ca. L. solanacearum' physiology and identify potential targets to develop improved treatment strategies. This analysis revealed a number of unique transporters and pathways, all potentially contributing to ZC pathogenesis. Some of these factors may have been acquired through horizontal gene transfer. Taxonomically, 'Ca. L. solanacearum' is related to 'Ca. L. asiaticus', a suspected causative agent of citrus huanglongbing, yet many genome rearrangements and several gene gains/losses are evident when comparing these two Liberibacter. species. Relative to 'Ca. L. asiaticus', 'Ca. L. solanacearum' probably has reduced capacity for nucleic acid modification, increased amino acid and vitamin biosynthesis functionalities, and gained a high-affinity iron transport system characteristic of several pathogenic microbes.

  3. Vector control and foliar nutrition to maintain economic sustainability of bearing citrus in Florida groves affected by huanglongbing.

    Science.gov (United States)

    Stansly, Philip A; Arevalo, H Alejandro; Qureshi, Jawwad A; Jones, Moneen M; Hendricks, Katherine; Roberts, Pamela D; Roka, Fritz M

    2014-03-01

    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 foliar nutrition. Insecticides were sprayed during tree dormancy and when psyllid populations exceeded a nominal threshold. A mixture consisting primarily of micro- and macro-nutrients was applied three times a year corresponding to the principal foliar flushes. Differences in ACP numbers from five- to 13-fold were maintained in insecticide treated and untreated plots. Incidence of HLB estimated by polymerase chain reaction (PCR), rose from 30% at the beginning of the study to 95% in only 18 months. Highest yields all four years were seen from trees receiving both foliar nutrition and vector control. Production for these trees in the fourth year was close to the pre-HLB regional average for 10 year old 'Valencia' on 'Swingle'. Nevertheless, at current juice prices, the extra revenue generated from the combined insecticide and nutritional treatment did not cover the added treatment costs. This experiment demonstrated that vector control, especially when combined with enhanced foliar nutrition, could significantly increase yields in a citrus orchard with high incidence of HLB. Economic thresholds for both insecticide and nutrient applications are needed under different market and environmental conditions. © 2013 Society of Chemical Industry.

  4. The complete genome sequence of 'Candidatus Liberibacter solanacearum', the bacterium associated with potato zebra chip disease.

    Science.gov (United States)

    Lin, Hong; Lou, Binghai; Glynn, Jonathan M; Doddapaneni, Harshavardhan; Civerolo, Edwin L; Chen, Chuanwu; Duan, Yongping; Zhou, Lijuan; Vahling, Cheryl M

    2011-04-28

    Zebra Chip (ZC) is an emerging plant disease that causes aboveground decline of potato shoots and generally results in unusable tubers. This disease has led to multi-million dollar losses for growers in the central and western United States over the past decade and impacts the livelihood of potato farmers in Mexico and New Zealand. ZC is associated with 'Candidatus Liberibacter solanacearum', a fastidious alpha-proteobacterium that is transmitted by a phloem-feeding psyllid vector, Bactericera cockerelli Sulc. Research on this disease has been hampered by a lack of robust culture methods and paucity of genome sequence information for 'Ca. L. solanacearum'. Here we present the sequence of the 1.26 Mbp metagenome of 'Ca. L. solanacearum', based on DNA isolated from potato psyllids. The coding inventory of the 'Ca. L. solanacearum' genome was analyzed and compared to related Rhizobiaceae to better understand 'Ca. L. solanacearum' physiology and identify potential targets to develop improved treatment strategies. This analysis revealed a number of unique transporters and pathways, all potentially contributing to ZC pathogenesis. Some of these factors may have been acquired through horizontal gene transfer. Taxonomically, 'Ca. L. solanacearum' is related to 'Ca. L. asiaticus', a suspected causative agent of citrus huanglongbing, yet many genome rearrangements and several gene gains/losses are evident when comparing these two Liberibacter. species. Relative to 'Ca. L. asiaticus', 'Ca. L. solanacearum' probably has reduced capacity for nucleic acid modification, increased amino acid and vitamin biosynthesis functionalities, and gained a high-affinity iron transport system characteristic of several pathogenic microbes.

  5. The Complete Genome Sequence of ‘Candidatus Liberibacter solanacearum’, the Bacterium Associated with Potato Zebra Chip Disease

    Science.gov (United States)

    Lin, Hong; Civerolo, Edwin L.; Chen, Chuanwu; Duan, Yongping; Zhou, Lijuan; Vahling, Cheryl M.

    2011-01-01

    Zebra Chip (ZC) is an emerging plant disease that causes aboveground decline of potato shoots and generally results in unusable tubers. This disease has led to multi-million dollar losses for growers in the central and western United States over the past decade and impacts the livelihood of potato farmers in Mexico and New Zealand. ZC is associated with ‘Candidatus Liberibacter solanacearum’, a fastidious alpha-proteobacterium that is transmitted by a phloem-feeding psyllid vector, Bactericera cockerelli Sulc. Research on this disease has been hampered by a lack of robust culture methods and paucity of genome sequence information for ‘Ca. L. solanacearum’. Here we present the sequence of the 1.26 Mbp metagenome of ‘Ca. L. solanacearum’, based on DNA isolated from potato psyllids. The coding inventory of the ‘Ca. L. solanacearum’ genome was analyzed and compared to related Rhizobiaceae to better understand ‘Ca. L. solanacearum’ physiology and identify potential targets to develop improved treatment strategies. This analysis revealed a number of unique transporters and pathways, all potentially contributing to ZC pathogenesis. Some of these factors may have been acquired through horizontal gene transfer. Taxonomically, ‘Ca. L. solanacearum’ is related to ‘Ca. L. asiaticus’, a suspected causative agent of citrus huanglongbing, yet many genome rearrangements and several gene gains/losses are evident when comparing these two Liberibacter. species. Relative to ‘Ca. L. asiaticus’, ‘Ca. L. solanacearum’ probably has reduced capacity for nucleic acid modification, increased amino acid and vitamin biosynthesis functionalities, and gained a high-affinity iron transport system characteristic of several pathogenic microbes. PMID:21552483

  6. Zoophthora radicans (Entomophthorales), a fungal pathogen of Bagrada hilaris and Bactericera cockerelli (Hemiptera: Pentatomidae and Triozidae): Prevalence, pathogenicity, and interplay of environmental influence, morphology, and sequence data on fungal identification.

    Science.gov (United States)

    Torres Acosta, Reyna Ivonne; Humber, Richard A; Sánchez-Peña, Sergio R

    2016-09-01

    The exotic bagrada bug or painted bug, Bagrada hilaris, and the native potato/tomato psyllid, Bactericera (=Paratrioza) cockerelli, are key pests of horticulture in western North America. In 2014-2015, adult and juvenile B. hilaris and B. cockerelli killed by fungi in the genus Zoophthora were detected near Saltillo, northeastern Mexico. We report the field prevalence and observations of Zoophthora on these hosts. The morphology and growth characteristics of field-collected specimens and pure in vitro cultures, as well as molecular markers (ITS1 and ITS4) were analyzed to identify these Zoophthora populations. Although there were morphological spore differences detected among field collections from both insect hosts, the fungi causing these mycoses can be identified as the same species (Zoophthora radicans), according to morphometric data from in vitro cultures (where differences observed in field material were attenuated) and sequence data (96-99% identity for ITS1 and 4). These results underscore the plasticity of field collections and in vitro cultures, and the relevance of comprehensive morphological and molecular analysis from cultures under standard conditions. Dose-response bioassays were conducted with one Z. radicans strain against bagrada bug nymphs. Exposure to conidial showers from cultures induced 30-90% mortality. This is the first report of a natural enemy of bagrada bug in Mexico, and the first published report of entomophthoralean fungi naturally attacking bagrada bugs and potato psyllids. Z. radicans should be further investigated as a tool in the biological control of hemipterans. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Competition between honeydew producers in an ant-hemipteran interaction may enhance biological control of an invasive pest.

    Science.gov (United States)

    Tena, A; Hoddle, C D; Hoddle, M S

    2013-12-01

    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 honeydew producers may hinder or favor the establishment of D. citri and its biological control with Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) in citrus via competition or mutualism for ants, respectively. In the field, L. humile and D. citri are engaged in a mutualistic relationship. Ants harvest solid honeydew secreted by psyllid nymphs and tended more than 55% of observed D. citri colonies. Linepithema humile displayed a preference hierarchy when tending honeydew producers infesting citrus. It responded equally or less intensively to D. citri than to other honeydew-producing species. Consequently, the mutualism between L. humile and D. citri was affected by the presence of other honeydew-producing species, and the percentage of D. citri colonies tended by L. humile. The number of ants per D. citri colony also decreased as the number of other honeydew producers increased. Diaphorina citri density was also affected by the presence of other honeydew producers. Both colony size and the number of D. citri nymphs counted per tree decreased as the number of other honeydew producers increased. Our results indicate that competition between honeydew producers for the mutualist ant L. humile may hinder the establishment of D. citri by possibly facilitating increased biological control.

  8. Genetic diversity of Candidatus Liberibacter asiaticus based on two hypervariable effector genes in Thailand.

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    Thamrongjet Puttamuk

    Full Text Available Huanglongbing (HLB, also known as citrus greening, is one of the most destructive diseases of citrus worldwide. HLB is associated with three species of 'Candidatus Liberibacter' with 'Ca. L. asiaticus' (Las being the most widely distributed around the world, and the only species detected in Thailand. To understand the genetic diversity of Las bacteria in Thailand, we evaluated two closely-related effector genes, lasAI and lasAII, found within the Las prophages from 239 infected citrus and 55 infected psyllid samples collected from different provinces in Thailand. The results indicated that most of the Las-infected samples collected from Thailand contained at least one prophage sequence with 48.29% containing prophage 1 (FP1, 63.26% containing prophage 2 (FP2, and 19.38% containing both prophages. Interestingly, FP2 was found to be the predominant population in Las-infected citrus samples while Las-infected psyllids contained primarily FP1. The multiple banding patterns that resulted from amplification of lasAI imply extensive variation exists within the full and partial repeat sequence while the single band from lasAII indicates a low amount of variation within the repeat sequence. Phylogenetic analysis of Las-infected samples from 22 provinces in Thailand suggested that the bacterial pathogen may have been introduced to Thailand from China and the Philippines. This is the first report evaluating the genetic variation of a large population of Ca. L. asiaticus infected samples in Thailand using the two effector genes from Las prophage regions.

  9. Pengaruh Jenis Mangsa dan Suhu pada Perkembangan Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae dan Peranannya dalam Pengendalian Diaphorina citri Kuwayama (Hemiptera: Psyllidae

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    Tris Haris Ramadhan

    2008-07-01

    Full Text Available Diaphorina citri Kuwayama (Hemiptera: Psyllidae is the vector of citrus greening (Huanglongbing bacterium and the most serious impediment to citrus culture. Classical biological control of this psyllid vector should contribute to suppress their population. This research was conducted to determine the performance of Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae when they were fed with D. citri. The larval performance index of M. sexmaculatus on D. citri compared with Aphis craccivora Koch (Hemiptera: Aphididae diet was 1.3.M. sexmaculatus fed with D. citri had lower fitness than those fed with A. craccivora as shown by longer larval stadium, lower adult dry weight, less number of egg produced and lower percentage of egg hatched. M. sexmaculatus grew best at the temperature of 27oC. Employing the exclusion procedure under field condition,M. sexmaculatus could reduce the population of D. citri up to 90%. These findings showed that theM. sexmaculatus could be a potential predator in reducing D. citri, particularly when the more preferred prey A. craccivora was not present.   Diaphorina citri Kuwayama (Hemiptera: Psyllidae merupakan kelompok Psyllid yang menularkan penyebab penyakit Huanglongbing yang sangat berbahaya pada tanaman jeruk. Pengendalian hayati klasik telah banyak memberikan kontribusi dalam pengendalian di lapangan. Penelitian ini dilakukan untuk melihat penampilan Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae dengan pakan D. citri. Indeks penampilan larva M. sexmaculatus dengan pakan D. citri dibandingkan dengan Aphis craccivora Koch (Hemiptera: Aphididae adalah 1,3. M. sexmaculatus yang diberi pakan D. citri menunjukkan penurunan kebugaran dibandingkan jika diberi pakan A. craccivora seperti yang ditunjukkan dengan stadium larva lebih lama, penurunan berat kering serangga dewasa, telur yang dihasilkan lebih sedikit, dan penurunan jumlah telur yang menetas. Menggunakan metode eksklusi pada kondisi

  10. The Influence of Learning on Host Plant Preference in a Significant Phytopathogen Vector, Diaphorina citri.

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    Dara G Stockton

    Full Text Available Although specialist herbivorous insects are guided by innate responses to host plant cues, host plant preference may be influenced by experience and is not dictated by instinct alone. The effect of learning on host plant preference was examined in the Asian citrus psyllid, Diaphorina citri; vector of the causal agent of citrus greening disease or huanglongbing. We investigated: a whether development on specific host plant species influenced host plant preference in mature D. citri; and b the extent of associative learning in D. citri in the form of simple and compound conditioning. Learning was measured by cue selection in a 2-choice behavioral assay and compared to naïve controls. Our results showed that learned responses in D. citri are complex and diverse. The developmental host plant species influenced adult host plant preference, with female psyllids preferring the species on which they were reared. However, such preferences were subject to change with the introduction of an alternative host plant within 24-48 hrs, indicating a large degree of experience-dependent response plasticity. Additionally, learning occurred for multiple sensory modalities where novel olfactory and visual environmental cues were associated with the host plant. However, males and females displayed differing discriminatory abilities. In compound conditioning tasks, males exhibited recognition of a compound stimulus alone while females were capable of learning the individual components. These findings suggest D. citri are dynamic animals that demonstrate host plant preference based on developmental and adult experience and can learn to recognize olfactory and visual host plant stimuli in ways that may be sex specific. These experience-based associations are likely used by adults to locate and select suitable host plants for feeding and reproduction and may suggest the need for more tailored lures and traps, which reflect region-specific cultivars or predominate

  11. 深圳25种植物提取物抑菌效果的研究%Inhibitory Effects on Bacteria of 25 Plant Essential Oils in Shenzhen

    Institute of Scientific and Technical Information of China (English)

    江娟娟; 黄丹璇; 胡彧

    2012-01-01

    Inhibition of escherichia coli and staphylococcus aureus, in the air is studied by extracting 25 plants volatiles essential oil. The results show different inhibitory effects with different plants. Plants with better inhibition effect for escherichia coli and staphylococcus aureus include Pittosporum tobira, Syzygium jambos (L.) Alston, Murraya exotica L., Melaleuca leucadendra Linn, Ghccsmis peniaphylla (Retz) Correa, and Cinnamomum camphora (L.) Presl. For escherichia coli, the three plants with highest inhibition effect are Liquidambar formosana Hance, Cinnamomum camphora (L.) Presl, and Syzygium jambos (L.) Alston. Inhibition effect among 25 essential oils of plant was ranked in the order as follows: Melaleuca leucadendra Linn , Thymus mongolicus , Syzygium jambos (L.) Alston and so on. Besides, antibacterial effect of volatiles essential oil of 25 fragrant plants in Shenzhen has been achieved, which can help to decide on fragrant plants in gardens.%萃取提取25种园林植物提取物,用平板纸片法测定这些提取物对大肠杆菌、金黄色葡萄球菌的抑制效果.结果表明:不同植物的提取物对这2种细菌的抑制效果不同.其中,对大肠杆菌和金黄色葡萄球菌抑菌效果较好的有:海桐、蒲桃、百里香、白千层、山小橘、香樟.对大肠杆菌抑制效果最好的前3种植物是枫香、香樟和蒲桃,对金黄色葡萄球菌抑制效果最好的前3种植物是白千层、百里香和蒲桃.结果为保健生态园林植物选择提供依据.

  12. 柑橘黄龙病疫情监测与防控技术研究%Study on Monitoring and Control Technology of Citrus Huanglongbing in Citrus Orchards

    Institute of Scientific and Technical Information of China (English)

    汪恩国; 李达林

    2012-01-01

    为了研究柑橘黄龙病传播介体种群消长规律和疫情动态,破解柑橘黄龙病防控问题,以主栽的早熟‘宫川’品种为重点在古城和大田柑橘园设立2个柑橘木虱监测点,采用定点定人定树定枝定时方法对柑橘木虱进行系统监测;以乡镇为单位每年在10-11月的果实显症期对全市柑橘园柑橘黄龙病进行全境式普查.结果表明,柑橘木虱季节性消长规律主要呈三峰型曲线变化,其峰期主要在6月下旬至7月下旬、8月中旬至9月中旬、10月上旬至11月上旬,其年度之间和果园之间总体趋势基本一致,但其峰值峰次差异却较大,主要受初见期、基数和气温等三要素影响所致,并建立柑橘木虱时序成若虫数量与其气温关系模型:D=0.018 T+17.365(n=36,r=0.3563*).针对柑橘木虱传播柑橘黄龙病的特征特性,摸索集成了“一挖两治”防控策略和“三防五关”防控技术.经过3年的全面应用,将柑橘黄龙病发病面积持续控制在5%以内,2008-2010年将加权平均株发病率分别控制在0.084%、0.077%、0.051%,基本达到了持续控制效果,保障了临海市柑橘产业持续健康发展.%In order to explore the epidemics of Huanglongbing and the regulation of its vector Citrus psyllid, and improve monitoring and control techniques, data of general investigation of disease epidemic of Huanglongbing from October to November in the Citrus orchard all over communities of Linhai County from 2003 to 2010 and the annual population dynamics of vector Citrus psyllid was collected by applied specific citrus tree timing method in 2 systemic monitoring points in Gucheng and Datian early-maturing Citrus orchard during 2008-2010. The results showed that the seasonal population dynamics of Citrus psyllid could be described by trimodal curve, its peaks mainly appeared at late June to late July, mid-August to mid-September and early October to early November. The tend between

  13. A Holocene pollen and diatom record from Vanderlin Island, Gulf of Carpentaria, lowland tropical Australia

    Science.gov (United States)

    Prebble, Matiu; Sim, Robin; Finn, Jan; Fink, David

    2005-11-01

    Sedimentary, palynological and diatom data from a dunefield lake deposit in the interior of Vanderlin Island in the Gulf of Carpentaria are presented. Prior to the formation of present perennial lake conditions, the intensified Australian monsoon associated with the early Holocene marine transgression allowed Cyperaceae sedges to colonise the alluvial margins of an expansive salt flat surrounded by an open Eucalyptus woodland. As sea level stabilised between 7500 and 4500 cal yr B.P. coastal dunes ceased to develop allowing dense Melaleuca forest to establish in a Restionaceae swamp. Dune-sand input into the swamp was diminished further as the increasingly dense vegetation prevented fluvial and aeolian transported sand arriving from coastal sources. This same process impounded the drainage basin allowing a perennial lake to form between 5500 and 4000 cal yr B.P. Myriophyllum and other aquatic taxa colonised the lake periphery under the most extensive woodland recorded for the Holocene. The palynological data support an effective precipitation model proposed for northern Australia that suggests more variable conditions in the late Holocene. A more precise measure of effective precipitation change is provided by diatom-based inferences that indicate few changes in lake hydrology. Such interpretations are explained in terms of palynological sensitivity to adjustments in local fire regimes where regional precipitation change may only be recorded indirectly through fire promoting mechanisms, including intensified ENSO periodicity and human impact.

  14. Reduction of mouth malodour and volatile sulphur compounds in intensive care patients using an essential oil mouthwash.

    Science.gov (United States)

    Hur, Myung-Haeng; Park, Joohyang; Maddock-Jennings, Wendy; Kim, Dong Oak; Lee, Myeong Soo

    2007-07-01

    The aim of this study was to explore the effect of an essential oil solution on levels of malodour and production of volatile sulphur compounds (VSC) in patients nursed in intensive care unit (ICU). Thirty two patients received 3 min of oral cleaning using an essential oil solution (mixture of tea tree, Melaleuca alternifolia, peppermint, Mentha piperita and lemon, Citrus limon) on the first day, and Tantum (benzydamine hydrochloride) on the second day. Two trained nurses measured the level of malodour with a 10 cm visual analogue scale (VAS) and VSC with a Halimeter before (Pre), 5 min after (Post I) and 1 h following treatment (Post II). The level of oral malodour was significantly different following the essential oil session, and differed significantly between two sessions at Post I (p essential oil, p essential oil session than Tantum at the Post II (p essential oil mixture of diluted tea tree, peppermint and lemon may be an effective method to reduce malodour and VSC in intensive care unit patients. Copyright 2007 John Wiley & Sons, Ltd.

  15. The expulsive and attractive effects of 16 species of plants on Golden Apple Snails(Ampullaria gigas Spix)%16种植物对福寿螺的趋避效果研究

    Institute of Scientific and Technical Information of China (English)

    徐武兵; 钟秋华; 李林峰; 郭荣荣; 章家恩; 罗明珠

    2010-01-01

    于实验室内通过自制的八边形分室趋避试验装置观察研究了16种植物对福寿螺(A mpullaria gigas Spix)的趋避效果.结果表明:福寿螺具有沿壁爬行的偏好性,沿壁爬行的福寿螺数量平均为非沿壁爬行福寿螺数的3.77倍.同时发现,在所选的16种植物中,白千层(Melaleuca leucadendra L)、扶桑(Hibiscus rosa-sinensis L.)2种植物对福寿螺有较大的吸引作用;金叶假连翘(Duranta repens cv.Dwarf Yellow)、木麻黄(Casuarina equisetifolia L)、红龙草(A lternanthera dentata cv.Ruliginosa)、鸭脚木[Schefflera octophylla(Lour.)Harms]、剑麻(Agave Sisalana Perrine)5种植物对福寿螺有一定的驱赶作用.

  16. EFFETS DES HUILES ESSENTIELLES SUR LES QUALITES HYGIENIQUES ET ORGANOLEPTIQUES DE LA BOISSON "BISSAP"

    Directory of Open Access Journals (Sweden)

    S.A. ADISSO

    2011-01-01

    Full Text Available This study was conducted in a conservation perspective. Thus, we have submitted 6 samples of "hibiscus" beverage taken from different Market in Cotonou Benin to microbiological and sensory analysis. The microbiological parameters studied (total mesophilic flora (total, total and thermotolerant coliforms (E. coli, staphylococci (Staphylococcus aureus, Salmonella, yeasts and moulds have given widely varying results for beverages analyzed immediately after purchase. In order to evaluate the effect of essential oils from Ocimum basilicum L. (Lamiaceae and Melaleuca leucadendron L. (Myrtaceae on mesophilic and fungal flora, a low dose of oils is added to a sample of the drink containing the sought germs and has stored at 26 ± 1°C or 4 ± 1°C. This study showed that the samples preserved with essential oils have retained their original color with natural flavors for eight days as opposed to controls not treated with essential oils, and are fermented rapidly. The degree of inhibition of mesophilic and fungal flora in different mixtures ranged from 22.87 to 99.59%. Therefore the oils have had a microbiostatic effect on germs initially contained in the drink. However,bactericidal and fungicidal effects of low doses of essential oils have been observed in vitro on strains isolated from the drinking. These results provide a basis for the conservation of Hibiscus "drink.

  17. Evaluation of commercial essential oil samples on the growth of postharvest pathogen Monilinia fructicola (G. Winter) Honey.

    Science.gov (United States)

    Lazar-Baker, E E; Hetherington, S D; Ku, V V; Newman, S M

    2011-03-01

    To assess the effect of several commercial essential oils samples Australian lemon myrtle (Backhousia citriodora), cinnamon bark (Cinnamomum zeylanicum), oregano (Origanum vulgare), thyme oil (Thymus vulgaris), clove bud (Eugenia caryophyllata), valerian (Valeriana officinalis) and Australian tea tree oil (Melaleuca alternifolia) on mycelium growth and spore germination of Monilinia fructicola. The effectiveness of lemon myrtle essential oil as a fumigant for the control of brown rot in nectarines was evaluated. Monilinia fructicola exhibited a different level of sensitivity to each tested essential oil with results suggesting that the essential oils provide excellent control of the pathogen with respect to mycelium growth and spore germination at very low concentrations, whereas for others higher concentrations are needed to reduce significant fungal growth. In vivo application of lemon myrtle essential oil effectively reduced the incidence of M. fructicola on noninoculated fruit. Fumigation of nectarines following inoculation did not reduce the incidence of brown rot in comparison with the inoculated control treatment. No evidence of phytotoxicity on the fruit was recorded. Lemon myrtle essential oil exhibited the strongest antifungal activity against M. fructicola, in vitro and to a lesser extent, under in vivo conditions. The results demonstrate that lemon myrtle essential oil, in particular, has potential as an antifungal agent to control M. fructicola. © 2011 NSW Industry & Investment, Australia. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

  18. The antimicrobial activity of four commercial essential oils in combination with conventional antimicrobials.

    Science.gov (United States)

    van Vuuren, S F; Suliman, S; Viljoen, A M

    2009-04-01

    Due to the emergence of multi-drug resistance, alternatives to conventional antimicrobial therapy are needed. This study aims to investigate the in vitro pharmacological interactions between essential oils (considered valuable as natural therapeutic treatments) and conventional antimicrobials (ciprofloxacin/amphotericin B) when used in combination. Interactions of the essential oils (Melaleuca alternifolia, Thymus vulgaris, Mentha piperita and Rosmarinus officinalis) when combined with ciprofloxacin against Staphylococcus aureus indicate mainly antagonistic profiles. When tested against Klebsiella pneumoniae the isobolograms show antagonistic, synergistic and additive interactions depending on the combined ratio. The R. officinalis/ciprofloxacin combination against K. pneumoniae displayed the most favourable synergistic pattern. The interactions of M. alternifolia (tea tree), T. vulgaris (thyme), M. piperita (peppermint) and R. officinalis (rosemary) essential oils with amphotericin B indicate mainly antagonistic profiles when tested against Candida albicans. While a number of interactions show complete antagonism, others show varied (synergistic, additive and/or antagonistic) interactions, thus the efficacy is dependent on the ratio in which the two components co-exist. The predominant antagonistic interactions noted here, suggests that some natural therapies containing essential oils should be used with caution when combined with antibiotics.

  19. Exploring the Anti-Burkholderia cepacia Complex Activity of Essential Oils: A Preliminary Analysis

    Directory of Open Access Journals (Sweden)

    Isabel Maida

    2014-01-01

    Full Text Available In this work we have checked the ability of the essential oils extracted from six different medicinal plants (Eugenia caryophyllata, Origanum vulgare, Rosmarinus officinalis, Lavandula officinalis, Melaleuca alternifolia, and Thymus vulgaris to inhibit the growth of 18 bacterial type strains belonging to the 18 known species of the Burkholderia cepacia complex (Bcc. These bacteria are opportunistic human pathogens that can cause severe infection in immunocompromised patients, especially those affected by cystic fibrosis (CF, and are often resistant to multiple antibiotics. The analysis of the aromatograms produced by the six oils revealed that, in spite of their different chemical composition, all of them were able to contrast the growth of Bcc members. However, three of them (i.e., Eugenia caryophyllata, Origanum vulgare, and Thymus vulgaris were particularly active versus the Bcc strains, including those exhibiting a high degree or resistance to ciprofloxacin, one of the most used antibiotics to treat Bcc infections. These three oils are also active toward both environmental and clinical strains (isolated from CF patients, suggesting that they might be used in the future to fight B. cepacia complex infections.

  20. Identity and specificity of the fungi forming mycorrhizas with the rare mycoheterotrophic orchid Rhizanthella gardneri.

    Science.gov (United States)

    Bougoure, Jeremy; Ludwig, Martha; Brundrett, Mark; Grierson, Pauline

    2009-10-01

    Fully subterranean Rhizanthella gardneri (Orchidaceae) is obligately mycoheterotrophic meaning it is nutritionally dependent on the fungus it forms mycorrhizas with. Furthermore, R. gardneri purportedly participates in a nutrient sharing tripartite relationship where its mycorrhizal fungus simultaneously forms ectomycorrhizas with species of Melaleuca uncinata s.l. Although the mycorrhizal fungus of R. gardneri has been morphologically identified as Thanatephorus gardneri (from a single isolate), this identification has been recently questioned. We sought to clarify the identification of the mycorrhizal fungus of R. gardneri, using molecular methods, and to identify how specific its mycorrhizal relationship is. Fungal isolates taken from all sites where R. gardneri is known to occur shared almost identical ribosomal DNA (rDNA) sequences. The fungal isolate rDNA most closely matched that of other Ceratobasidiales species, particularly within the Ceratobasidium genus. However, interpretation of results was difficult as we found two distinct ITS sequences within all mycorrhizal fungal isolates of R. gardneri that we assessed. All mycorrhizal fungal isolates of R. gardneri readily formed ectomycorrhizas with a range of M. uncinata s.l. species. Consequently, it is likely that R. gardneri can form a nutrient sharing tripartite relationship where R. gardneri is connected to autotrophic M. uncinata s.l. by a common mycorrhizal fungus. These findings have implications for better understanding R. gardneri distribution, evolution and the ecological significance of its mycorrhizal fungus, particularly in relation to nutrient acquisition.