Solis Perez, Ofelia1, Castillo Gutierrez, Antonio2, Peña Chora, Guadalupe3, Alvear Garcia Andres4, Serrano Morales, Miguel Mizraim5; Suarez Rodriguez Ramon1, Hernandez Velazquez,
1Research Center in Biotechnology. Universidad Autónoma del Estado de Morelos,
Campus Chamilpa. Avenida Universidad 1001. 62209, Chamilpa, Cuernavaca, Morelos, Mexico.
2School of Higher Studies of Xalostoc. Universidad Autónoma del Estado de Morelos, Av. Nicolás, Bravo S/N Parque Industrial Cuautla, Ayala, Morelos, México. C.P. 62715.
3Research Center for Biological. Campus Chamilpa.
4Faculty of Agricultural Sciences. Campus Chamilpa.
5Faculty of Biological Sciences. Campus Chamilpa.
Phyllophaga spp. cause severe damage to maize, sorghum, wheat, sugarcane, bean, amaranth and peanut in Mexico, Central America and the USA. Control measures for white grubs have depended mainly on persistent chemicals. An ecologically safe strategy is the use of entomopathogens in combating soil pests, which is based on the identification of a complex of pest species and their native pathogens and to subsequently select the microorganism with the greatest potential for this purpose. The objective of this study was to determine the pathogenicity, virulence and the interaction between native strains of Metarhizium anisopliae and Beauveria bassiana from Morelos State against P. vetula. The fungal isolates of M. anisopliae and B. bassiana showed differential pathogenicity against P. vetula. The M. anisopliae isolates were more pathogenic than those of B. bassiana. M. anisopliae isolates from a Phyllophaga sp. host were more pathogenic (46.66 to 73.33%) than those from an insect tramp, G. mellonella (00.00 to 20%). The mortality caused by the most highly pathogenic isolate of M. anisopliae, HI-019, (86.06%) decreased significantly (P ˂ 0.05) when the inoculation was simultaneous with B. bassiana HI-113 (61.06%), but the mortality was statistically the same as that when the grubs were inoculated with only B. bassiana (52.73%). The estimated LC50 values of M. anisopliae isolates Ma17 and Ma19 against P. vetula larvae were 4.749 × 107 conidia/mL and 7.684 × 108 conidia/mL, respectively, which are statistically equivalent.
Keywords: white grub, bioassay, entomopathogenic fungi, lethal concentration.