The entomopathogenic fungus Metarhizium brunneum Petch for the control of whiteflies in protected cultivation

Abstract: Among the IPM approach for whitefly control, the use of entomopathogenic fungi
(EF), as a potential substitute to synthetic insecticides, is currently increasing its interest
worldwide. About 20 EF species are nowadays extensively focused for their detrimental effects on whiteflies; and Beauveria bassiana, Cordyceps fumosorosea and Lecanicillium muscarium are the most promising ones. In Sicily, a recent survey conducted within the European project VIRTIGATION showed how microbial control is highly used in protected crops, representing an important pillar of IPM strategies and being worth to be improved and developed. Within this context, here we report the results of an experiment carried out in Sicily, aimed at evaluating the efficacy of a Metarhizium brunneum-based wettable powder (WP) mycoinsecticide formulation in controlling whiteflies on eggplant cultivated under greenhouse. In this test, three doses of the above mycoinsecticide (i. e.: 1, 1.5 and 2 kg/ha) have been compared to a negative (untreated plants) and to a positive control (B. bassiana-based mycoinsecticide in OD – oil dispersion – formulation). The tested formulation showed interesting performance, with a higher efficacy observed in the surveys conducted at 21 and 28 days after the first application on both adults and nymphs of the whitefly, regardless of the dose applied. Moreover, it has revealed a greater and more persistent efficacy than the positive control, making the M. brunneum-based formulation meritorious of further investigations for its inclusion in IPM strategies to be adopted for whitefly control.