Virulence of several isolates of the entomopathogenic fungi Beauveria bassiana (Bals.) Vuill., Metarhizium anisopliae (Metsch.) Sor. and Paecilomyces fumosoroseus (Wize) Brown & Smith were evaluated on adult weevils of Anthonomus fulvipes Boheman at dose of 108 spores/mL under laboratory conditions. The study was complemented by testing one isolate each of M. anisopliae and P. fumosoroseus against adult weevils on organically grown Barbados cherry trees at dose of 2 × 1015 spores/ha. All fungi species showed high virulence against A. fulvipes adults, with mortality ranging from 92% to 100%. LT50 values varied 2.7 to 4.8 d. The M. anisopliae isolate 10, and the P. fumosoroseus isolate 1 were selected for field evaluation because laboratory insect cadavers presented the best sporulation. After applying the fungi to the trees, total weevil captures were 38, 56, and 100 for the P. fumosoroseus, M. anisopliae, and the check (untreated) plots, respectively. Statistical differences in fruit damage were detected among treatments: M. anisopliae and P. fumosoroseus treatments showed an average of 50% of undamaged fruits, whereas in the control plots presented 36% of undamaged fruits. Laboratory and field experiments suggest that entomopathogenic fungi have a potential as microbial control agents against the weevil A. fulvipes in organically grown Barbados cherry trees.
Biological insect control using Metarhizium anisopliae: morphological, molecular, and ecological aspects