Samuel Pineda, Raquel Alatorre, Marcela-lnés Schneider, Ana-Mabel Martinez
Southwestern Entomologist 32 (1), 43-52, (1 March 2007) https://doi.org/10.3958/0147-1724-32.1.43
Entomopatogenic fungi are a promising alternative for the control of agricultural pests. We evaluated the pathogenicity of three isolates of Paecilomyces fumosoroseus (Wize) Brown and Smith (Pf1, Pf2, and Pf3) and six isolates of Lecanicillium (= Verticillium) lecanii (Zimmermann) Zare and Gams (VI1, VI2, VI3, VI4, VI5, and VI10) on eggs, second, third, and fourth nymphal instars of the greenhouse whitefly, Trialeurodes vaporariorum (Westwood). Three of the nine isolates (Pf1, VI3, and VI5) produced 11–26% infections of eggs, while the remaining isolates had no significant effect (Pf3 and VI10) or were unable (Pf2, VI1, VI2, and VI4) to infect this developmental stage. Pf1, Pf2, and Pf3 caused homogeneous pathogenicity in all nymphal instars tested, while L. lecanii isolates showed high variability. Pf1, Pf2, and Pf3 were usually the most pathogenic, but their activity correlated inversely with increasing nymphal instars. The pathogenicity (number of living nymphs recovered from treated plots) of Pf2 on T. vaporariorum nymphs was evaluated on zucchini squash plants in two experimental trials. Survival of whitefly nymphs decreased by 19 and 28% after the first and second fungal applications, respectively, in one trial, and by 62 and 71% in the other trial. Based on these results, we concluded that the use of fungal preparations based on the Pf2 isolate could be feasible for controlling T. vaporariorum.