A project to develop a biological control strategy for locusts and grasshoppers is being conducted in Mexico. Major activities include: surveys of entomopathogenic fungi, laboratory screening of isolates, testing of methods for mass production, and formulation and field evaluation of virulent strains.
The Centro Nacional de Referencia de Control Biológico (CNRCB) has, in its entomopathogen collection, 40 isolates of Metarhizium spp. obtained from the Central American locust (Schistocerca piceifrons piceifrons). The isolates MaaPL16, MaaPL25 and MaPL40 are among the most virulent.
A comparative analysis on Random Amplified Polymorphic DNA patterns between two Mexican isolates of Metarhizium, MaPL40 and MaPL32, and an Australian isolate of Metarhizum anisopliae var. acridum (FI-985), showed that the Mexican isolates and the Australian isolate have similar DNA fingerprints, suggesting they may belong to the same variety.
Field trials using oil formulations of the MaPL40 and MaPL32 isolates against hopper bands of S. piceifrons piceifrons, applied at a rate of 50g of conidia in oil, 1 l ha−1, provided >90% reduction in the hopper bands 10 d after treatment. Comparative studies between the Mexican and the Australian isolates were conducted over a range of temperatures: results are reported in detail.
