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

Among the IPM approach for whitefly control, the use of entomopathogenic fungi (EF) as a potential substitute to inorganic insecticide is currently increasing its interest worldwide. About 20 EF species are nowadays extensively focused for their detrimental effects on whiteflies and, Beauveria bassiana (Balsamo-Crivelli) Vuillemin, Cordyceps fumosorosea (Wize) Kepler and Lecanicillium muscarium Zare and Gams 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 in its implementation. Within this context, here we report the results of an experimental activity carried out in Sicily, aimed at evaluate the efficacy of a Metarhizium brunneum-based mycoinsecticide formulation in controlling a whitefly population infesting eggplant cultivated under greenhouse. For the field trials, a "WP" (wettable powder) formulation of a M. brunneum-based mycoinsecticide was used, comparing three doses (i.e.: 1kg/ha, 1.5kg/ha and 2kg/ha), a positive control (untreated plants) and a negative control (B. bassiana-based mycoinsecticide in OD – oil dispersion - formulation). From the obtained results, it has emerged how the tested formulation showed interesting performance for the control of whiteflies on eggplant in protected cultivation. Indeed, from both the field and laboratory collected data, a better efficacy of this formulation has been observed in the surveys conducted at 21 and 28 days after the last application, both against adults and nymphs of the whitefly, regardless of the dose applied. Moreover, it has revealed a greater and more persistent efficacy than the B. bassiana-based formulation, used as negative control, making the M. brunneum-based formulation meritorious of further investigations for its inclusion in IPM strategies to be adopted for the control of whitefly infestations.