Pathogenicity of Two Entomopathogenic Fungi on Trialeurodes vaporariorum and Field Evaluation of a Paecilomyces fumosoroseus Isolate

Abstract

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...