IMBIV   05474
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA VEGETAL
Unidad Ejecutora - UE
artículos
Título:
Parasitism of Aphids (Hemiptera: Aphididae) in Relation to of Alfalfa Fields (Medicago sativa L.) Characteristics in Argentine Pampas
Autor/es:
ZUMOFFEN, L.; SALTO, C.; SALVO, A.
Revista:
AGRICULTURE, ECOSYSTEMS AND ENVIRONMENT
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2012 vol. 159 p. 49 - 54
ISSN:
0167-8809
Resumen:
Conservation is the strategy of biological control recommended for developed countries given its low cost and potential sustainability. Alfalfa is a perennial crop, one of the most relevant forage resources for cattle in Argentine Pampas, and aphids (Hemiptera Aphididae), one of the main pest insects in alfalfa, frequently attacked by a rich fauna of aphidiinae parasitoids (Hymenoptera: Braconidae). The aim of this study was to identify possible field characteristics influencing the parasitism rates of aphids in alfalfa, in order to recommend simple methods of environmental manipulation to enhance the action of parasitoids. 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 stems cuttings. The influence of size of fields, 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 low percentage of natural borders, whereas impact by parasitoids was highe in older crops and in those fields with big percentage of natural borders. . The relative importance of characteristics of fields on parasitism of aphids is discussed.