Investigations of the dual role of entomopathogenic fungi in grapevine: direct and indirect control of Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae)

This study evaluated the efficacy of five entomopathogenic fungi (EPF) strains (Purpureocillium lilacinum CB2, Metarhizium anisopliae Bp1e, Metarhizium robertsii Bp1k, Beauveria bassiana Cg1k, and Penicillium citrinum CaS1d) as biocontrol agents against the vine mealybug Planococcus ficus (Signoret), an important pest in viticulture. Direct pathogenicity assays and endophytic colonisation of grapevine (Vitis vinifera L. cv. ‘Riesling’) were investigated. M. robertsii Bp1k demonstrated the highest virulence, reducing P. ficus survival to 34.1% after 14 days from the treatment. Differently, P. citrinum CaS1d exhibited moderate pathogenicity but superior endophytic colonisation, with a 93% re-isolation rate from vine leaves 3 days post-inoculation. However, endophytic colonisation by both strains did not significantly affect the survival or development of P. ficus. These findings underline the potential of EPF for direct pest control and their capacity to establish endophytic relationships within vine, suggesting their promising role in sustainable pest management strategies in grapevine cultivation.