The entomopathogenic fungus, Metarhizium anisopliae for the European grapevine moth, Lobesia botrana Den. & Schiff. (Lepidoptera: Tortricidae) and its effect to the phytopathogenic fungus, Botrytis cinerea

The European grapevine moth, Lobesia botrana Den. & Schiff. (Lepidoptera: Tortricidae) and the gray rot fungus(Botrytis cinerea) are two important factors that cause elevated losses of productivity in vineyards globally. TheEuropean grapevine moth is one of the most important pests in vineyards around the world, not only because ofits direct damage to crops, but also due to its association with the gray rot fungus; both organisms are highlydetrimental to the same crop. Currently, there is no effective, economic, and eco-friendly technique that can beapplied for the control of both agents. On the other hand, Metarhizium anisopliae belongs to a diverse group ofentomopathogenic fungi of asexual reproduction and global distribution. Several Metarhizium isolates have beendiscovered causing large epizootics to over 300 insects? species worldwide. In this study, a simple design wasconducted to evaluate the potential of native M. anisopliae isolates as one of biological control agents against L.botrana and as possible growth inhibitors to B. cinerea. Entomopathogenic fungal strains were isolated from aridsoils under vine (Vitis vinifera) culture. Results suggest that the three entomopathogenic strains (CEP413, CEP589,and CEP591) were highly efficient in controlling larval and pupal stages of L. botrana, with mortality rates rangingfrom 81 to 98% (within 4?6 days). Also, growth inhibition over B. cinerea strains resulted in percentages rangedfrom 47 to 64%. Finally, the compatibility of the entomopathogenic strains, with seven commercial fungicides, wasevaluated. The potential of the entomopathogenic fungal strains to act as control agents is discussed.Centro de Estudios Parasitológicos y de Vectore

Dual effects of entomopathogenic fungi on control of the pest Lobesia botrana and the pathogenic fungus Eutypella microtheca on grapevine

Background: Entomopathogenic fungi (EPF) are the natural enemies of insect pests. Nevertheless, research on the use of EPF for simultaneous prevention of pest and disease agents on the same crop is limited. In this study, we explored the potential dual effects of three strains of the EPF Metarhizium anisopliae on the control of detrimental agents of Vitis vinifera L., including different developmental stages (larvae, pupae, and adult) of the insect pest Lobesia botrana and the phytopathogenic fungus Eutypella microtheca. Methods: Laboratory pathogenicity trials were performed to examine the effects of the three M. anisopliae strains on the mortality rate of L. botrana. In addition, field trials were conducted to assess the biocontrol potential of one selected M. anisopliae strain on the larval stage of L. botrana. Moreover, inhibitory effects of the three EPF strains on E. microtheca growth were examined in vitro. Results: All the M. anisopliae strains were highly effective, killing all stages of L. botrana as well as inhibiting the growth of E. microtheca. The in vitro mortality of larvae treated with the strains was over 75%, whereas that of treated pupae and adults was over 85%. The three EPF strains showed similar efficacy against larvae and adult stages; nevertheless, pupal mortality was observed to be strain dependent. Mortality of L. botrana larvae ranged from 64 to 91% at field conditions. Inhibition of E. microtheca growth reached 50% in comparison to the control. Conclusions: Our study showed that M. anisopliae strains were highly effective in ensuring control of two different detrimental agents of V. vinifera L., providing new evidence to support the dual effects of entomopathogenic fungi.Fil: Aguilera Sammaritano, Juan Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Católica de la Santísima Concepción; ChileFil: Caballero, Juan Jose. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Deymié Terzi, María Celina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rosa, Melisa. Universidad Nacional de San Juan; ArgentinaFil: Vazquez, Fabio. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Pappano, Delia Beatriz. Universidad Nacional de San Juan; ArgentinaFil: Lechner, Bernardo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; ArgentinaFil: González Teuber, Marcia. Universidad Católica de la Santísima Concepción; Chil

Entomopathogenic fungi: Are polisporic isolates more pathogenic than monosporic strains?

Currently only monosporic strains from several entomopathogenic fungi have been selected and used for mass production and bioinsecticide manufacturing worldwide. The main reasons for the use of single spore instead of multispore strains are the attenuated virulence and the contaminants of the same species. In this study, different polisporic isolates and their monosporic combinations were tested against Tenebrio molitor (Linnaeus) larvae as an insect model. Isolates were obtained from arid soils. Four Metarhizium sp. (Metschn.) multisporic isolates (CEP413, CEP589, CEP590 and CEP591) were selected for bioassays. Trials were performed to evaluate mortality on three treatments, Full Polisporic (FP), Partial Polisporic (PP) and Pure Monosporic (PM). Cumulative mortality was measured at day 4 post infection. Sporulation percentage was assessed at day 6 post infection. The highest mortality was found at FP treatment (94%), the lowest mortality at day 4 was found at PM-CEP413 (32%). At day 6 the sporulation percentage was higher on FP (94%) and it was different from the rest of the treatments. To elucidate different polisporic and monosporic combinations to improve their effectiveness, may help to expand the use of bioinsecticides based on entomopathogenic fungi.Centro de Estudios Parasitológicos y de Vectore

Entomopathogenic fungi: Are polisporic isolates more pathogenic than monosporic strains?

Currently only monosporic strains from several entomopathogenic fungi have been selected and used for mass production and bioinsecticide manufacturing worldwide. The main reasons for the use of single spore instead of multispore strains are the attenuated virulence and the contaminants of the same species. In this study, different polisporic isolates and their monosporic combinations were tested against Tenebrio molitor (Linnaeus) larvae as an insect model. Isolates were obtained from arid soils. Four Metarhizium sp. (Metschn.) multisporic isolates (CEP413, CEP589, CEP590 and CEP591) were selected for bioassays. Trials were performed to evaluate mortality on three treatments, Full Polisporic (FP), Partial Polisporic (PP) and Pure Monosporic (PM). Cumulative mortality was measured at day 4 post infection. Sporulation percentage was assessed at day 6 post infection. The highest mortality was found at FP treatment (94%), the lowest mortality at day 4 was found at PM-CEP413 (32%). At day 6 the sporulation percentage was higher on FP (94%) and it was different from the rest of the treatments. To elucidate different polisporic and monosporic combinations to improve their effectiveness, may help to expand the use of bioinsecticides based on entomopathogenic fungi.Centro de Estudios Parasitológicos y de Vectore

Control integrado de la polilla de la vid con hongos entomopatógenos

Introducción y Objetivos: La polilla de la Vid Lobesia botrana es la plaga más importante en los cultivos vitícolas de todo el mundo. En la actualidad su control depende del uso de insecticidas químicos. Sin embargo, su uso desmedido ha conducido a la aparición de fracciones poblacionales resistentes a los insecticidas, y ha impactado sobre otros organismos benéficos. Esto pone de manifiesto la necesidad de implementar prácticas de control más amigables con el ambiente, en favor de la sostenibilidad de los agroecosistemas. Bajo estas circunstancias, se encuentra en auge el desarrollo de biocontroladores como parásitos, parasitoides, nemátodos, bacterias, y hongos entomopatógenos. Respecto a estos últimos, los hongos entomopatógenos son considerados importantes agentes naturales de control que limitan las poblaciones de insectos. Por esta razón constituyen una herramienta potencial para ser utilizados en un manejo integrado de plagas en conjunto con dosis reducidas de pesticidas. Materiales y Métodos: Para llevar a cabo estos ensayos, se utilizaron 20 larvas con seis repeticiones por cada tratamiento. Las larvas fueron infectadas individualmente con 2 µL de una formulado correspondiente a distintos tratamientos. Estos fueron: 1-Spinosad 48% en dosis de 0.15 µL/mL), 2- CEP591 en dosis de 1x108 c/mL, 3-Spinosad 48% en dosis de 0.075 µL/mL + CEP591 en dosis de 1x104 c/mL y 4-agua destilada como control. Las larvas tratadas se llevaron a campo y se colocaron sobre racimos de vid los cuales se cubrieron con mallas antiáfidos que se fijaron cuidadosamente al raquis de cada racimo. De esta manera se mantuvo un sistema cerrado de conteo efectivo pero sin alterar las condiciones de temperatura, humedad o intensidad lumínica. Para asegurar la independencia de los tratamientos, éstos se separaron espacialmente por al menos 20 metros. Las plantas seleccionadas para los tratamientos fueron elegidas al azar. Ningún producto químico fue aplicado mientras los tratamientos estuvieron en proceso. A las 96 horas los racimos cerrados junto con las larvas fueron transportados al laboratorio para el conteo de cadáveres. Resultados: Los resultados obtenidos señalan que el análisis de la varianza no detectó diferencias significativas entre la mortalidad obtenida en los tratamientos donde se utilizó el insecticida en su dosis recomendada (98,33 %), el insecticida combinado con la CEP591 en dosis reducida a la mitad (100 %) y el tratamiento con la cepa CEP591 (92,41 %). Además estos 3 tratamientos se diferenciaron del tratamiento control (0%) (H= 15,54; p=0,0005). Conclusiones: Se puede concluir que la cepa (CEP591) de Metarhizium sp. nativa de San Juan, puede resultar efectiva para controlar a L. botrana en condiciones de campo, permitiendo reducir el uso de insecticidas.Fil: Olivieri, Gabriela. Ministerio de Agricultura, Ganadería, Pesca y Alimento. Servicio Nacional de Sanidad y Calidad Agroalimentaria; ArgentinaFil: Deymié Terzi, María Celina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Torrente, Karina Andrea. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Universidad Nacional de San Juan. Facultad de Ingenieria. Departamento de Ingenieria Agronomica; ArgentinaFil: Caballero, Juan Jose. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Herrera, Maria Eugenia. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Mendoza-san Juan. Estacion Experimental Agropecuaria Mendoza. Agencia de Extension Rural Lujan de Cuyo.; ArgentinaFil: Vazquez, Fabio. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Aguilera Samaritano, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaXV Congreso Argentino de Microbiología; XIV Congreso Argentino de Microbiología General; V Congreso Argentino de Microbiología de Alimentos y V Congreso Latinoamericano de Microbiología de Medicamentos y CosméticosCiudad Autónoma de Buenos AiresArgentinaAsociación Argentina de Microbiologí