Agroecological Management of Sphenarium Purpurascens with Vegetable Extracts and Entomopathogenic Fungi in Amaranth, Puebla-Mexico

Abstract

Among the most important pests of amaranth (Amaranthus hypochondriacus L.) is Sphenarium purpurascens Charpentier, 1845 (Orthoptera: Pyrgomorphidae) which causes damage to the plant, decreased performance and economic losses, with chemical products being the main control method. The objective of this work was to evaluate the effect of aqueous extracts of Ricinus communis and Capsicum frutensis combined with two entomopathogenic fungi; one commercial and one native to Puebla-Mexico, alternated with the application of soap, in laboratory and field conditions. Bioassays were carried out to evaluate the compatibility of aqueous extracts with the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana at concentrations of 25, 50 and 75 % in conidia, in addition, six treatments with five repetitions were tested in a randomized block experimental design in the field. Los bioensayos de laboratorio presentaron diferencias significativas en el desarrollo micelial y tasa de crecimiento, donde se observó un estímulo positivo en el crecimiento de M. anisopliae por parte de los extractos vegetales. In the field, the H+Ch+M treatment registered the least damage (12.9%), least infestation (1.1%) and best seed production (1,353.7 kg/Ha). The effect of aqueous extracts combined with M. anisopliae, alternated with soap applications, proved to be an effective strategy in the integrated management of Sphenarium purpurascens, in amaranth cultivation in Puebla, Mexico.