Pathogenicity of Beauveria Bassiana (deuteromycotina: Hyphomycetes) against the White Grub Laniifera Cyclades (lepidoptera: Pyralidae) under Field and Greenhouse Conditions

The white grub Laniifera cyclades Druce of prickly pear cactus or nopal is a pest that limits the commercial production of Opuntia . The gregarious larvae perforate the cladodes devouring the inner part, thereby forming large galleries until reaching the central axis of the plant; during their movement through the inner part of the cactus, the larvae make orifices to the exterior to expel their excrements. In this investigation, the virulence of strains BbZ3 and BbZ4 of the entomopathogenic fungus Beauveria bassiana was determined by introducing infested cadavers of Galleria mellonella L. through the orifices on the stem pads of the nopal plant. Both stains of B. bassiana were highly pathogenic causing 100% mortality in the larvae of L. cyclades inside the nopal cladodes in the greenhouse as well in the field. BbZ3 was more virulent with a LT50 of 5.1 d in the greenhouse and 6.4 d in the field, while the LT50 of BbZ4 was 6 and 7.5 d, respectively. The application of larval cadavers of G. mellonella infested with the fungus B. bassiana was an effective control strategy against larvae of L. cyclades .