Compatibility levels of fipronil with entomopathogenic fungi

Abstract

The present study evaluated the compatibility of the insecticide fipronil with entomopathogenic fungi, in vitro. The compatibility betwee fipronil and entomopathogenic fungi was based on vegetative growth and sporulation of seven isolates of fungi. The studied isolates were three from Beauveria bassiana, one from Cordyceps fumosorosea, and three from Metarhizium anisopliae, and four concentrations of fipronil (0.2, 0.4, 0.6, and 0.8 g L-1), added in PDA (potato-dextrose-agar) culture medium. After 15 days, the colony diameter was measured and the spores were recorded. There was a reduction in the vegetative growth of the isolates at concentration of 0.8 g L-1 of fipronil. For the isolates of B. bassiana and M. anisopliae, there was a decrease in spore production when added the concentrations above 0.4 g L-1 of fipronil; and for C. fumosorosea, spore production decreased when fipronil concentrations were greater than 0.6 g L-1. The insecticide fipronil was classified as “compatible” in terms of toxicity in vitro for tested fungi isolates depending on its concentration. The combination of the insecticide fipronil with the entomopathogenic fungi isolates tested is possible at concentrations below 0.6 g L-1.