Blog
About

  • Record: found
  • Abstract: found
  • Article: found
Is Open Access

Neem oil increases the efficiency of the entomopathogenic fungus Metarhizium anisopliae for the control of Aedes aegypti (Diptera: Culicidae) larvae

Read this article at

Bookmark
      There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

      Abstract

      Background

      Entomopathogenic fungi are potential candidates for use in integrated vector management and many isolates are compatible with synthetic and natural insecticides. Neem oil was tested separately and in combination with the entomopathogenic fungus Metarhizium anisopliae against larvae of the dengue vector Aedes aegypti. Our aim was to increase the effectiveness of the fungus for the control of larval mosquito populations.

      Methods

      Commercially available neem oil was used at concentrations ranging from 0.0001 to 1 %. Larval survival rates were monitored over a 7 day period following exposure to neem. The virulence of the fungus M. anisopliae was confirmed using five conidial concentrations (1 × 10 5 to 1 × 10 9 conidia mL −1) and survival monitored over 7 days. Two concentrations of fungal conidia were then tested together with neem (0.001 %). Survival curve comparisons were carried out using the Log-rank test and end-point survival rates were compared using one-way ANOVA.

      Results

      1 % neem was toxic to A. aegypti larvae reducing survival to 18 % with S 50 of 2 days. Neem had no effect on conidial germination or fungal vegetative growth in vitro. Larval survival rates were reduced to 24 % (S 50 = 3 days) when using 1 × 10 9 conidia mL −1. Using 1 × 10 8 conidia mL −1, 30 % survival (S 50 = 3 days) was observed. We tested a “sub-lethal” neem concentration (0.001 %) together with these concentrations of conidia. For combinations of neem + fungus, the survival rates were significantly lower than the survival rates seen for fungus alone or for neem alone. Using a combination of 1 × 10 7 conidia mL −1 + neem (0.001 %), the survival rates were 36 %, whereas exposure to the fungus alone resulted in 74 % survival and exposure to neem alone resulted in 78 % survival. When using 1 × 10 8 conidia mL −1, the survival curves were modified, with a combination of the fungus + neem resulting in 12 % survival, whilst the fungus alone at this concentration also significantly reduced survival rates (28 %).

      Conclusions

      The use of adjuvants is an important strategy for maintaining/increasing fungal virulence and/or shelf-life. The addition of neem to conidial suspensions improved virulence, significantly reducing larval survival times and percentages.

      Related collections

      Most cited references 30

      • Record: found
      • Abstract: found
      • Article: not found

      Botanical insecticides, deterrents, and repellents in modern agriculture and an increasingly regulated world.

      Botanical insecticides have long been touted as attractive alternatives to synthetic chemical insecticides for pest management because botanicals reputedly pose little threat to the environment or to human health. The body of scientific literature documenting bioactivity of plant derivatives to arthropod pests continues to expand, yet only a handful of botanicals are currently used in agriculture in the industrialized world, and there are few prospects for commercial development of new botanical products. Pyrethrum and neem are well established commercially, pesticides based on plant essential oils have recently entered the marketplace, and the use of rotenone appears to be waning. A number of plant substances have been considered for use as insect antifeedants or repellents, but apart from some natural mosquito repellents, little commercial success has ensued for plant substances that modify arthropod behavior. Several factors appear to limit the success of botanicals, most notably regulatory barriers and the availability of competing products (newer synthetics, fermentation products, microbials) that are cost-effective and relatively safe compared with their predecessors. In the context of agricultural pest management, botanical insecticides are best suited for use in organic food production in industrialized countries but can play a much greater role in the production and postharvest protection of food in developing countries.
        Bookmark
        • Record: found
        • Abstract: not found
        • Article: not found

        Properties and potential of natural pesticides from the neem tree, Azadirachta indica.

         H Schmutterer (1989)
          Bookmark
          • Record: found
          • Abstract: found
          • Article: not found

          Can fungal biopesticides control malaria?

          Recent research has raised the prospect of using insect fungal pathogens for the control of vector-borne diseases such as malaria. In the past, microbial control of insect pests in both medical and agricultural sectors has generally had limited success. We propose that it might now be possible to produce a cheap, safe and green tool for the control of malaria, which, in contrast to most chemical insecticides, will not eventually be rendered useless by evolution of resistance. Realizing this potential will require lateral thinking by biologists, technologists and development agencies.
            Bookmark

            Author and article information

            Affiliations
            [ ]Department of Entomology and Plant Pathology, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ CEP 28013-602 Brazil
            [ ]Departamento de Bioquímica, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, Brazil
            Contributors
            simoneazgomes@yahoo.com.br
            biodepaula@yahoo.com.br
            anderson.ribeirorj@yahoo.com.br
            catiadepaula@gmail.com
            jonathan_bastos@outlook.com
            capsilva@ccb.ufsc.br
            richardiansamuels@gmail.com
            Journal
            Parasit Vectors
            Parasit Vectors
            Parasites & Vectors
            BioMed Central (London )
            1756-3305
            30 December 2015
            30 December 2015
            2015
            : 8
            26715150 4696216 1280 10.1186/s13071-015-1280-9
            © Gomes et al. 2015

            Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License ( http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

            Funding
            Funded by: FAPERJ
            Award ID: E26/102.353/2013
            Award Recipient :
            Categories
            Research
            Custom metadata
            © The Author(s) 2015

            Parasitology

            virulence, phytochemical, natural insecticide, fungus, vector, dengue, biological control

            Comments

            Comment on this article