Isolation of Native Strains of Entomopathogenic Fungi from Agricultural Soils of Northeastern Mexico and their Virulence on Spodoptera exigua (Lepidoptera: Noctuidae)

Spodoptera exigua Hübner (Lepidoptera: Noctuidae) is considered a polyphagous pest distributed worldwide with wide range of hosts, and also serious plague for vegetables ornamentals. The objective this study was to explore the occurrence entomopathogenic fungi in agricultural soils from Mexico evaluate its virulence effect on life cycle S. exigua. Selected isolates (HEB1 γ01) were used perform toxicity bioassays neonatal larvae exigua; additionally, GHA (Beauveria bassiana), Pfr-612 (Cordyceps fumosorosea), Ma, 2 HIB-11 HIB-12 (Metarhizium anisopliae) included obtain median lethal concentration (LC50) time (LT50). Also, surviving individuals followed up after treatment document effects application. belong different species, which are Beauveria bassiana (Bals.-Criv.) Vuill. (Hypocreales: Cordycipitaceae) Cordyceps fumosorosea (Wize) Kepler, B. Shrestha & Spatafora (formerly Isaria fumosorosea). In tests, isolate Metarhizium anisopliae (Metschnikoff) Sorokin showed better mortality results against than other evaluated LC50 3.17 × 106 conidia per mL. LT50 oscillated between 3 5 d had lowest (3.15 d). During monitoring biological treatment, greatest interruption metamorphosis caused by strain, while Ma strain one that induced slightest cycle. These show feasibility using strains M. control larval stages their possible formulation use, as well opening way exploration research mechanisms or metabolites involved due application fungi, specifically bassiana.