Ocurrencia natural de hongos entomophthorales de áfidos plaga de Medicago sativa L. en Argentina

Four species of entomophthoroid fungi, Pandora neoaphidis (Entomophthorales: Entomophthoraceae), Zoophthora radicans (Entomophthorales: Entomophthoraceae), Entomophthora planchoniana (Entomophthorales: Entomophthoraceae) and Neozygites fresenii (Neozygitales: Neozygitaceae) were found to infect Aphis craccivora, Therioaphis trifolii, and Acyrthosiphon pisum and unidentified species of Acyrthosiphon on lucerne in Argentina. Samples were collected from five sites (Ceres, Rafaela, Sarmiento, Monte Vera and Bernardo de Irigoyen) in the province of Santa Fe. In this study, Zoophthora radicans was the most important pathogen and was recorded mainly on Acyrthosiphon sp. Zoophthora radicans was successfully isolated and maintained in pure cultures. This study is the first report of entomophthoroid fungi infecting lucerne (Medicago sativa L.) aphids in Argentina.Centro de Estudios Parasitológicos y de Vectore

Ocurrencia natural de hongos entomophthorales de áfidos plaga de Medicago sativa L. en Argentina

Four species of entomophthoroid fungi, Pandora neoaphidis (Entomophthorales: Entomophthoraceae), Zoophthora radicans (Entomophthorales: Entomophthoraceae), Entomophthora planchoniana (Entomophthorales: Entomophthoraceae) and Neozygites fresenii (Neozygitales: Neozygitaceae) were found to infect Aphis craccivora, Therioaphis trifolii, and Acyrthosiphon pisum and unidentified species of Acyrthosiphon on lucerne in Argentina. Samples were collected from five sites (Ceres, Rafaela, Sarmiento, Monte Vera and Bernardo de Irigoyen) in the province of Santa Fe. In this study, Zoophthora radicans was the most important pathogen and was recorded mainly on Acyrthosiphon sp. Zoophthora radicans was successfully isolated and maintained in pure cultures. This study is the first report of entomophthoroid fungi infecting lucerne (Medicago sativa L.) aphids in Argentina.Centro de Estudios Parasitológicos y de Vectore

Ocurrencia natural de hongos entomophthorales de áfidos plaga de Medicago sativa L. en Argentina

Four species of entomophthoroid fungi, Pandora neoaphidis (Entomophthorales: Entomophthoraceae), Zoophthora radicans (Entomophthorales: Entomophthoraceae), Entomophthora planchoniana (Entomophthorales: Entomophthoraceae) and Neozygites fresenii (Neozygitales: Neozygitaceae) were found to infect Aphis craccivora, Therioaphis trifolii, and Acyrthosiphon pisum and unidentified species of Acyrthosiphon on lucerne in Argentina. Samples were collected from five sites (Ceres, Rafaela, Sarmiento, Monte Vera and Bernardo de Irigoyen) in the province of Santa Fe. In this study, Zoophthora radicans was the most important pathogen and was recorded mainly on Acyrthosiphon sp. Zoophthora radicans was successfully isolated and maintained in pure cultures. This study is the first report of entomophthoroid fungi infecting lucerne (Medicago sativa L.) aphids in Argentina.Centro de Estudios Parasitológicos y de Vectore

Diversidad y grupos funcionales de insectos en cultivos de arroz y sus bordes bajo manejo convencional y agroecológico en Santa Fe, Argentina

El arroz es el cereal de mayor producción considerado el alimento base para el 50% de la población mundial. Los objetivos del trabajo fueron i) conocer la diversidad de insectos que presentan los cultivos de arroz y sus bordes ii) caracterizar grupos funcionales según el rol ecosistémico que cumplen los insectos en cultivos de arroz y sus bordes con diferente tipo de manejo iii) analizar las interacciones de los grupos funcionales con la vegetación de los bordes. Los muestreos se realizaron durante un ciclo de producción primavera-verano (2017-2018), en cultivos de arroz con prácticas de manejo convencional (MC) y agroecológico (MA). Se capturaron 1005 ejemplares pertenecientes a 244 especies y morfoespecies. Los bordes presentaron mayor riqueza, abundancia y diversidad de Shannon en relación al cultivo, siendo el MA destacado por la presencia de los cinco grupos funcionales. En ambos manejos, se presenció Sepedonea sp., Protodictya sp. y Eryopis connexa (L.) como controladores de gasterópodos e insectos plagas. Se registraron 397 interacciones insecto-planta en MA y 175 en MC. Se destaca la importancia de los bordes y las prácticas MA en el cultivo de arroz para favorecer la conservación de entomofauna y potenciar los servicios ecosistémicos que éstos brindan a los sistemas productivos.Ecosystem services provided by insects, such as pollination and pest control, are essential for food production and agricultural health. The aims of this work were to 1) compare insect diversity in rice crops and their containment edges in two farms under different management systems (conventional and agroecological), 2) characterize functional groups of insects in rice crops and their containment edges, under different management systems, and 3) analyze the interactions of functional groups of insects with vegetation in the containment edges. Sampling was conducted during a rice production cycle in the spring-summer 2017-2018 in farms under conventional management practices (EMC) and agroecological management (EMA) in an area of intensive rice production (San Javier Department, Santa Fe, Argentina). A total of 1008 insects belonging to 236 species and morphospecies were captured using entomological nets. Containment edges exhibited higher richness, abundance and diversity than crops, with the EMA standing out for the presence of all five functional groups. On both farms, Sepedonea sp., Protodictya sp. and Eryopis connexa (L.), known control agents of gastropods and insect pests, were recorded. A total of 397 insect-plant interactions were registered in agroecological containment edges, and only 175 in conventional ones. The results obtained in this work make a novel contribution to the knowledge of insects present in containment edges and in rice crops. This work provides knowledge on the diversity, composition and distribution of the insect community, as well as data on the floral offer of the vegetation growing in containment edges and its relationship with the entomofauna.EEA RafaelaFil: Ghiglione, Carla. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias. Cátedra de Entomología; ArgentinaFil: Zumoffen, Leticia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela. Agencia de Extensión Rural Monte Vera; ArgentinaFil: Zumoffen, Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Dalmazzo, Maria de los Milagros. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias. Cátedra de Entomología; ArgentinaFil: Dalmazzo, Maria de los Milagros. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Strasser, Ruth. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias. Cátedra de Entomología; ArgentinaFil: Attademo, Andres M. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Ecotoxicología; ArgentinaFil: Attademo, Andres M. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Movement of parasitoids (Aphidiinae) for the biocontrol of aphids aphid pests in brasicaceas

El objetivo de este estudio fue evaluar si los márgenes de vegetación espontánea aportan un ingreso de parasitoides (Aphidiinae) en los cultivos hortícolas y que factores afectan dicho movimiento. En la localidad de Ángel Gallardo se seleccionaron tres cultivos (brócoli, coliflor y repollo) y por cada especie hortícola se eligieron dos lotes que presenten vegetación marginal. En el margen de cada lote se colocaron dos trampas pegajosas para la intercepción de insectos en vuelo y se registró el número de parasitoides que ingresaron y egresaron al cultivo. Al mismo tiempo, mediante transectas se cuantificó el número de áfidos plagas en los cultivos y en la vegetación se contabilizó la abundancia de áfidos huésped y flores así como la riqueza. Estos factores más las variables microclimáticas de temperatura y velocidad el viento fueron evaluados. Se analizó mediante modelos lineales generalizados mixtos. Se detectó una mayor cantidad de insectos moviéndose desde la frontera hacia los cultivos. Al mismo tiempo, este movimiento se incrementó con la disponibilidad de flores y áfidos huésped mientras que, la riqueza de la vegetación espontánea y las variables microclimáticas no tuvieron efecto en la dispersión de los afidiinos. Se destaca la importancia de los márgenes vegetales como fuente de recursos para que los parasitoides colonicen los cultivos en número y momento adecuado para un control de plagas exitoso.The objective of the study was to evaluate the factors associated with the bidirectional movement of Aphidians between horticultural crops and their marginal vegetation. Three brassicaceae crops (broccoli, cauliflower and cabbage) were selected in the locality of Ángel Gallardo and two lots with marginal vegetation were selected for each horticultural species. In the margin of each lot, two sticky traps were placed for the interception of insects in flight and the number of parasitoids that entered the crop, counted. At the same time, the number of aphid pests in the crops was quantified by means of transects and the abundance of host aphids and flowers as well as richness was counted in the vegetation. These factors plus the microclimatic variables of temperature and wind speed were evaluated using generalized mixed linear models. A greater number of insects were detected moving from the border to the crops. At the same time, this movement increased with the availability of flowers and host aphids whereas, the richness of the spontaneous vegetation and the microclimatic variables had no effect on the dispersion of the aphidiinae. The importance of the plant margins as a source of resources for the parasitoids to colonize the crops in number and at the right time for successful pest control is emphasized.Fil: Zumoffen, Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Santa Fe. Estacion Experimental Agropecuaria Rafaela. Agencia de Extension Rural Monte Vera.; ArgentinaFil: Pacini, Adriana Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Merke, Julieta. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Gatti, Mariano Adrián. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Santa Fe. Estacion Experimental Agropecuaria Rafaela. Agencia de Extension Rural Monte Vera.; ArgentinaFil: Dalmazzo, Maria de Los Milagros. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias. Departamento de Ciencias Naturales. Cátedra de Entomología; Argentin

Bidirectional movement of aphid parasitoids (Braconidae: Aphidiinae) between crops and non-crop plants in agroecosystems of central Argentina

The movement of predators and parasitoidsbetween natural and cultivated habitats is a common processin agroecosystems, which may be afected by diferentbiotic and abiotic factors, mostly related to the availabilityof resources. Here, through a broad approach, we aimedto obtain an overview of factors afecting the bidirectional movement of aphid parasitoids (Braconidae: Aphidiinae)across cultivated habitats and their natural vegetated borders.Using bidirectional fight traps, we measured the numberof parasitoids moving from borders to crops and viceversa, in felds of three common crop species (alfalfa, oatand wheat) in the Pampean region, Santa Fe, Argentina. Theefects of the abundance of aphid prey, abundance and richnessof fowers in both habitats, as well as temperature andwind speed on parasitoid movement, were assessed throughgeneralized mixed models, considering sampling date andfeld as random factors. The relationship between parasitismpercentages and parasitoid movement from the bordersto the crops was explored separately for three pest aphidspecies: Aphis craccivora Koch, Rhopalosiphum padi (L.)and Schizaphis graminum (Rondani). Overall, we found aprevalence of parasitoids moving in the border-crop direction,mainly in wheat and alfalfa crops. Aphid abundancein the arrival habitat afected parasitoid movement in bothdirections. A link between parasitoid movement and parasitismpercentages was observed for the aphid species S.graminum in wheat, suggesting a benefcial role of naturalvegetation in pest control.Fil: Zumoffen, Leticia. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Signorini, Marcelo. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Salvo, Silvia Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin

Parasitism of aphids (Hemiptera: Aphididae) in relation to of alfalfa fields (Medicago sativa L.) caracteristics in Argentine Pampas

Alfalfa is a perennial crop and is one of the most relevant forage resources for cattle in the Argentine Pampas, with aphids (Hemiptera Aphididae) one of the main pest insects in alfalfa, being frequently attacked by a rich fauna of aphidiinae parasitoids (Hymenoptera: Braconidae). The aim of this study was to identify the possible field characteristics that influence the parasitism rates of aphids in alfalfa, in order to recommend simple methods of environmental manipulation to enhance the action of parasitoids. The abundance of aphids and their parasitism were estimated fortnightly, over a period of seven months in fourteen alfalfa fields located near the city of Rafaela, Santa Fe, through the collection of stem cuttings. The influence of field size, age of crop, and percentage of borders with spontaneous vegetation, on aphid abundance and their parasitism rates, were assessed through general lineal models with repeated measures. Greater aphid populations were observed in fields with a low percentage of natural borders, whereas the impact by parasitoids was higher in older crops and in those fields with a high percentage of natural borders. The relative importance of the characteristics of fields on parasitism of aphids is discussed, bearing in mind that conservation is the strategy of biological control recommended for developed countries given its low cost and potential sustainability.Fil: Zumoffen, Leticia. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Salto, C.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Salvo, Silvia Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin

Study of the associations of aphids-entomophagous in Foeniculum vulgare (Umbelliferae) and Conyza bonariensis (Asteraceae) in the central region of Santa Fe, Argentina

El objetivo del presente trabajo fue estudiar las asociaciones áfidos-entomófagos en Foeniculum vulgare (Miller) y Conyza bonariensis L., a fin de implementar el Control Biológico Conservativo (CBC) en agroecosistemas de la región central de la provincia de Santa Fe. Se realizaron estudios, a campo, de la entomofauna presente mediante la observación directa de las plantas; las mismas se llevaron a cabo con una frecuencia semanal. En invernáculo, se procedió a la identificación de las especies cuando esta no fue posible a campo. La especie de áfido encontrada fue Hyadaphis foeniculi (Passerini) (Homoptera: Aphididae), colonizando a F. vulgare y se destacó Uroleucon (Lambersius) sp. (Homoptera: Aphididae) en C. bonariensis. Entre los enemigos naturales, se destacaron los parasitoides y depredadores en F. vulgare y C. bonariensis, respectivamente. Para el estudio de las relaciones áfidos - enemigos naturales, se calcularon los coeficientes de correlación; los valores indicaron una relación entre H. foeniculi y Diaretiella rapae (M’Intosh) (Hymenoptera: Braconidae) (0,63) y entre Uroleucon (Lambersius) sp. y coccinélidos (Coleoptera: Coccinellidae)(0,43). Las especies vegetales estudiadas son muy importantes para mantener los distintos grupos de entomófagos en los agroecosistemas y su utilización en programas de CBC de pulgones plaga es posible, contribuyendo así a reducir las aplicaciones de insecticidas en cultivos.The objective of this work was to study the aphids-entomophagous associations in Foeniculum vulgare (Miller) and Conyza bonariensis L. in order to implement Conservative Biological Control (CBC) in agroecosystems of the central region of Santa Fe Province. Direct observation on plants was conducted on a weekly basis, from February to May 2008. The identification of species was carried out in the greenhouse when it was not possible to do it in the field. The aphid species identified on F. vulgare was Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae), and on C. bonariensis predominated Uroleucon (Lambersius) sp. (Hemiptera: Aphididae). Parasitoids and predators were also important. The relationships between aphids and natural enemies were estimated by correlation analysis. These coefficients indicated a relationship between H. foeniculi and Diaeretiella rapae (M’Intosh) (Hymenoptera: Braconidae) (0.63) and between U. (Lambersius) sp. and coccinellids (Coleoptera: Coccinellidae) (0.43). It was concluded that these plants are very important in order to keep different groups of entomophagous in agroecosystems, and their use in CBC aphid pest programs is possible, helping to reduce insecticide applications in crops.Fil: Manfrino, Romina Guadalupe. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Salto, Cesar. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Zumoffen, Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; Argentin