Interaction between predatory mites (Acari: Phytoseiidae) and entomopathogenic fungi in Tetranychus urticae populations

Abstract

The mite Tetranychus urticae Koch is an important pest on several agricultural crops. Resistance to synthetic pesticides has encouraged evaluating more sustainable control strategies. We evaluated the predatory mites Phytoseiulus persimilis Athias Henriot and Neoseiulus californicus McGregor alone or as vectors of entomopathogenic fungi on the mortality of T. urticae. We estimated the susceptibility of the predatory mites and T. urticae to infection by Metarhizium anisopliaesensu stricto (s. str.) (Metchnikoff) Sorokin, Beauveria bassianas. str. Bals. Vuill, Akanthomyces lecanii (Zimm.) Spatafora, Kepler & B. Shrestha and Cordyceps fumosorosea (Wize) Kepler, B. Shrestha & Spatafora. Then, we determined the mortality of T. urticae due to the two predatory mites alone or in combination with the four fungal isolates. T. urticae was more susceptible to fungi than the predatory mites. B. bassiana and M. anisopliae isolates caused the greatest mortality. Greater mortality of T. urticae was achieved when predatory mites were vectoring B. bassiana or M. anisopliae conidia. Combining predatory mites and entomopathogenic fungi has potential for the control of T. urticae.