Vegetable and Mineral Oil Formulations of Metarhizium anisopliae var. acridum to Control the Central American Locust (Schistocerca piceifrons piceifrons Walker) (Orthoptera: Acrididae)

In 1993, the National Center for Biological Control in Mexico started a research project testing native isolates of Metarhizium spp. against the Central American locust Schistocerca piceifrons piceifrons. The M. anisopliae var. acridum isolate MaPL40 was formulated in various vegetable and mineral oils and at both 7 and 270C; a formulation in citroline oil remained viable the longest. When applied to nymphs of S. p. piceifrons, the Median Lethal Time (MLT) was less for citroline oil formulations of M. anisopliae than aqueous suspension formulations, providing 100% mortality within 7 days.