Efficacy and Toxicity of Bio and Chemical Insecticides Against Field and Laboratory Strains of the Mediterranean Fruit Fly, Ceratitis capitata (Wiedemann)

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) is a serious global agricultural pest, causing significant economic losses to a variety of crops, especially in the vital horticulture sector. This study comprehensively investigates different management strategies for this pest, ranging from the efficacy of entomopathogenic fungi to synthetic and naturally derived insecticides, which were evaluated under laboratory and open field conditions in Egypt during the growing seasons of 2023 and 2024. This study indicated varying susceptibility of field and laboratory fly strains across all tested experiments. Laboratory evaluations of the fungicide, Beauveria bassiana (Bals.-Criv.) Vuill. revealed its time-dependent efficacy against adults of C. capitata. Spinosad, a naturally derived compound, showed significantly higher rapid and acute efficacy against the susceptible fly strain compared to the field strain. Malathion showed significant latent efficacy against the susceptible laboratory strain. Moving to open field conditions, a comparative evaluation of spinosad, malathion, and betacyfluthrin revealed superior performance. Malathion achieved strong initial population reductions, while spinosad achieved balanced performance with effective initial control. Notably, betacyfluthrin demonstrated inconsistent and often negative reductions. spinosad stands out as a highly effective and balanced option for rapid control, and B. bassiana provides excellent long-term biological suppression, reliance on older chemicals such as malathion is negatively impacted by the spread of resistance. Future management protocols should prioritize the rotational use of diverse modes of action, integrate biological and chemical control, and utilize continuous monitoring to adapt to evolving pest dynamics, ensuring sustainable control of C. capitata in agricultural settings.