Synergistic Control of Bemisia tabaci Using Nesidiocoris tenuis and Orius laevigatus and Its Effects on Tomato Yield.

The whitefly Bemisia tabaci is a major pest of greenhouse-grown tomato, causing significant yield and quality losses worldwide. This study evaluated the population dynamics of B. tabaci on tomato crops maintained at a maximum temperature of 24 ± 1 °C and assessed the effectiveness of two generalist predators, Nesidiocoris tenuis and Orius laevigatus, applied individually or in combination under greenhouse conditions in Saudi Arabia. Whitefly populations increased progressively throughout the study, reaching peak densities of 32.24 eggs and 124.00 ± 7.78 nymphs per leaf. Predator release significantly reduced B. tabaci populations at both the egg and nymphal stages. N. tenuis showed greater efficacy against eggs, achieving a 67.44% reduction, whereas O. laevigatus was slightly more effective against nymphs, with a 63.30% reduction. Notably, the combined release of both predators resulted in the greatest suppression of whitefly populations, reducing egg and nymphal densities by 79.50% and 78.02%, respectively, suggesting additive or synergistic interactions between the two predators. The dual-predator treatment also significantly improved yield-related parameters, including fruit number, fruit size, and total yield per plant, without adversely affecting fruit quality. In addition, vitamin C content increased under the combined predator treatment. These findings demonstrate that the integration of N. tenuis and O. laevigatus enhances biological control efficacy and supports sustainable integrated pest management strategies for greenhouse tomato production.