Lethal and Sub-Lethal Effects of Beauveria bassiana on Feeding Behavior and Oviposition of Trialeurodes vaporariorum

Abstract

Lethal and sub-lethal effects of Beauveria bassiana on feeding behavior and oviposition of Trialeurodes vaporariorum were evaluated to understand its biocontrol potential beyond direct mortality. Laboratory bioassays were conducted under controlled conditions using different fungal concentrations applied to host plants infested with adult whiteflies. Mortality was assessed alongside behavioral parameters including feeding activity, settling preference, and egg-laying patterns. Results demonstrated significant dose-dependent mortality of adult whiteflies following exposure to B. bassiana. Sub-lethal effects were evident even at lower concentrations, where infected insects exhibited reduced feeding intensity, prolonged probing time, and disrupted host selection behavior. Oviposition was markedly suppressed in treated populations, with females laying fewer eggs and showing altered preference for treated leaf surfaces. These behavioral disruptions were associated with fungal infection progression and reduced physiological fitness of adults. The study also observed decreased egg hatchability in treated groups, suggesting indirect effects on reproductive success. Overall, B. bassiana exerted strong dual-action effects by causing mortality and impairing key biological functions of T. vaporariorum. The findings highlight the importance of considering sub-lethal impacts when evaluating entomopathogenic fungi in integrated pest management programs. These results support the use of B. bassiana as an effective biological control agent capable of reducing population growth and reproductive potential of greenhouse whitefly in protected cultivation systems.