200 research outputs found
Exigências térmicas para o desenvolvimento de Acanthoscelides obtectus em grãos de feijão.
O objetivo deste trabalho foi avaliar as exigências térmicas para machos e fêmeas de A. obtectus.Resumo
Suscetibilidade de ninfas da Bemisia tabaci Genn. (Hemiptera: Aleyrodidae) biótipo B ao óleo de mamona Ricinus communis L.
O objetivo deste trabalho foi verificar a suscetibilidade de ninfas de primeiro e segundo instar da Bemisia tabaci biótipo B ao óleo comercial de mamona Azevedo ®. Foi avaliada a concentração letal (CL) do óleo testado a0,5, 1,0, 1,5 e 2,0% (v/v).Pôster - pós-graduação
Harvesting the power of fungal entomopathogens for controlling arthropod pests in Brazil.
Here we summarize our progress in innovative liquid fermentation and formulation technologies that produce stable, infective fungal propagules for use in biocontrol of arthropod pests
Within-host competition between two entomopathogenic fungi and a granulovirus in Diatraea saccharalis (Lepidoptera: Crambidae).
Abstract: We provide insights into how the interactions of two entomopathogenic fungi and a virus play a role in virulence, disease development, and pathogen reproduction for an economically important insect crop pest, the sugarcane borer Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae). In our model system, we highlight the antagonistic effects of the co-inoculation of Beauveria bassiana and granulovirus (DisaGV) on virulence, compared to their single counterparts. By contrast, combinations of Metarhizium anisopliae and B. bassiana, or M. anisopliae and DisaGV, have resulted in additive effects against the insect. Intriguingly, most cadavers that were derived from dual or triple infections, produced signs/symptoms of only one species after the death of the infected host. In the combination of fungi and DisaGV, there was a trend where a higher proportion of viral infection bearing conspicuous symptoms occurred, except when the larvae were inoculated with M. anisopliae and DisaGV at the two highest inoculum rates. Co-infections with B. bassiana and M. anisopliae did not affect pathogen reproduction, since the sporulation from co-inoculated larvae did not differ from their single counterparts
Liquid culture production of microsclerotia and submerged conidia by Trichoderma harzianum active against damping-off disease caused by Rhizoctonia solani.
Media and culturing protocols were identified that supported the formation of submerged conidia and microsclerotia (MS) by Trichoderma harzianum Rifai strain T-22 using liquid culture fermentation. Liquid media with a higher carbon concentration (36 g L -1) promoted MS formation at all C:N ratios tested. Hyphae aggregated to form MS after 2 d growth and after 7 d MS were fully melanized. This is the first report of MS formation by T. harzianum or any species of Trichoderma. Furthermore, submerged conidia formation was induced by liquid culture media, but yields, desiccation tolerance, and storage stability varied with C:N ratio and carbon rate. Air-dried MS granules (<4 % moisture) retained excellent shelf life under cool and unrefrigerated storage conditions with no loss in conidial production. A low-cost complex nitrogen source based on cottonseed flour effectively supported high MS yields. Amending potting mix with dried MS formulations reduced or eliminated damping-off of melon seedlings caused by Rhizoctonia solani. Together, the results provide insights into the liquid culture production, stabilization process, and bioefficacy of the hitherto unreported MS of T. harzianum as a potential biofungicide for use in integrated management programs against soilborne diseases
Técnica de produção do fungo entomopatogênico Metarhizium anisopliae para uso em controle biológico.
Introdução. Desenvolvimento metodológico. Inóculo inicial. Produção do fungo em arroz. Secagem em estufa elétrica. Extração dos conídios secos. Secagem final e armazenamento. Lista de materiais e equipamentos utilizados. Referências.bitstream/item/91059/1/seriedocumentos-289.pd
Interação de Beauveria bassiana e óleo de mamona na mortalidade de ninfas de Bemisia tabaci biótipo B.
Fungos entomopatogênicos e inseticidas vegetais são considerados a lternativas promissoras aos inseticidas sintéticos no manejo da mosca-branca. A utilização associada destas estratégias pode potencializar a eficiência de controle da praga. Neste sentido, foi estudada a mistura de Beuveria bassiana com o óleo de mamona Azevedo® na mortalidade de ninfas de Bemisia tabaci biótipo B
Insecticidal Activity of the Granulosis Virus in Combination with Neem Products and Talc Powder Against the Potato Tuberworm Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae)
The potato tuberworm Phthorimaea operculella (Zeller) is an important agricultural pest that causes significant economic losses to potato growers worldwide. The addition of an effective method of biological control for the potato tuberworm is greatly needed, and is currently unavailable in Brazil. The granulosis virus (Baculoviridae) is a promising biological control agent to protect post-harvest potatoes and in storage from the potato tuberworm. However, the control measure must be economically feasible. Liquid suspensions of a granulosis virus applied alone or in mixture with two commercial neem oil-based products (DalNeem (TM) and NeemAzal (TM)), and a dry powder formulation of viral granules were evaluated for control of potato tuberworm larvae by treating potato tubers under laboratory conditions. High larval mortality (86.7%) was achieved when DalNeem and virus were applied together at 4 mg of azadirachtin/L and 10(4) occlusion bodies (OBs)/mL, respectively. This combination resulted in a parts per thousand yen50% efficacy in relation to their counterparts alone. Conversely, NeemAzal did not enhance virus effectiveness against larvae of the potato tuberworm. The talc-based virus formulation was used for dusting seed tubers at different concentrations and resulted in 100% larval mortality at 5 x 10(8) OBs/g. Formulated and unformulated virus provided 50% mortality at 166 OBs/g and at 5.0 x 10(5) OBs/mL, respectively. As a result, talc-based virus formulation had a better control efficiency on potato tuberworm than the aqueous virus suspension. The granulosis virus combined with DalNeem at low rates or formulated with talc powder is a viable option to control the potato tuberworm under storage conditions.CAPES (Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES
Optimization of microesclerotia production by Trichoderma asperellum.
The Trichoderma genus, despite its widespread use for decades as a biological control in agriculture, has only recently been gaining a share in the biopesticide market, thanks to its versatility in controlling diseases and acting as a plant growth enhancer. Most Trichoderma's commercial products have aerial conidia as active ingredient, but recent studies report the production of another propagule, more robust for formulation and application under field conditions - the microsclerotia (MS). Thus, our objective was to evaluate the nutritional conditions that favor the greater production of MS, using two cultures of T. asperellum with known antagonistic activity. For this, we used the fractional factorial design approach in which we evaluated 5 variables: Carbon source, Carbon concentration, C:N ratio, Strain, Nitrogen source, all influencing the production of MS. The results indicated that all variables were statistically significant to MS production. In the best condition tested, we obtained values higher than 104 MS mL-1. In conclusion that the conditions found for the production of MS, using sucrose and lyscell, with carbon concentration 20 g L-1 and C:N ratio (10:1) and isolate TR 356, are inexpensive carbon and nitrogen sources may allow us to scale-up this biofungicide
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