Effect of Isaria fumosorosea Conidial Formulations on Mortality and Reproduction of Trialeurodes vaporariorum in Greenhouse Tomato

Abstract

Greenhouse whitefly, Trialeurodes vaporariorum, is a major sap-feeding pest of tomato that causes direct feeding damage and indirect losses through honeydew production and sooty mold development. The present study evaluated the effect of conidial formulations of Isaria fumosorosea on mortality and reproductive performance of T. vaporariorum under greenhouse tomato conditions. Different concentrations of fungal conidial suspensions were applied to whitefly-infested tomato plants, and observations were recorded on nymphal mortality, adult emergence, fecundity, egg hatchability, and population suppression over time. The results demonstrated that I. fumosorosea conidial formulations significantly increased mortality of immature stages of T. vaporariorum in a dose-dependent manner. Treated populations exhibited reduced adult emergence, decreased fecundity, and lower egg hatch rates compared to untreated controls. Infected individuals showed typical mycosis symptoms including reduced mobility, cuticular discoloration, and fungal outgrowth under favorable humidity conditions. Higher conidial concentrations resulted in faster mortality and greater suppression of population growth. Environmental conditions within the greenhouse, particularly high relative humidity, enhanced fungal infection efficiency and sporulation. The reproductive potential of surviving whiteflies was markedly reduced, indicating sublethal effects of the entomopathogenic fungus on pest biology. The findings highlight the strong biocontrol potential of I. fumosorosea against T. vaporariorum in protected cultivation systems. This study provides valuable insights into fungal-based pest management strategies and supports the integration of entomopathogenic fungi into sustainable greenhouse tomato production systems for effective whitefly control.