The objective of this study was to systematically evaluate the pathogenicity of Beauveria bassiana to Bemisia tabaci, the attraction rate of food-based attractants to B. tabaci, and the synergistic efficacy of their combination against B. tabaci under both laboratory and field conditions, and to screen the highly pathogenic B. bassiana strains and optimized attractant formulations for effective whitefly control.

Under controlled laboratory conditions, the pathogenicity of multiple B. bassiana strains against nymphal and adult stages of B. tabaci was assessed using leaf-dip and contact bioassays, respectively. Conidial production per unit area was quantified microscopically using a hemocytometer. Behavioral responses of B. tabaci to plant-derived volatile organic compounds (VOCs) were evaluated in a Y-tube olfactometer assay. An optimized food-based attractant formulation was developed through systematic screening of active components, empirical optimization of component ratios and concentrations, evaluation of solvent compatibility, and assessment of slow-release carrier efficacy. A prototype dual-function device—integrating the selected B. bassiana strain with the optimized attractant—was designed for field deployment. The influence of device hanging height and inter-unit spacing on whitefly attractive effect was rigorously tested under semi-field and field conditions. Finally, conidial acquisition by B. tabaci individuals and subsequent population-level impacts were quantified via standardized cage experiments and longitudinal field monitoring.

At a concentration of 1×10⁸ conidia/mL, strain XJWLMQ-1 caused corrected mortalities of 93.16% and 79.17% against second-instar nymphs and adults of B. tabaci, respectively, with LT₅₀ values of 3.78 and 7.12 d. The conidial production of this strain reached 3.74×10⁸ conidia/cm² on sporulation medium. A compound attractant consisting of (Z)-3-hexenal, linalool, and eugenol at a ratio of 1﹕2﹕1 showed the highest attraction rate (90.0%). A mixed solvent of liquid paraffin and n-hexane combined with a porous silica gel rod as a slow-release carrier exhibited good persistence, maintaining an attraction rate of 60.0% after 84 d. Devices suspended at the top of tomato plants attracted significantly more whiteflies than those placed at the middle of plants or 20 cm above the canopy. Cage experiments showed that B. tabaci could acquire and carry (1.50-4.34) ×10⁴ conidia per adult through contact with the combined application device. Conidial loads carried by adults increased with exposure time and reached a peak of 1.40×10⁵ conidia per adult after 14 d. Two years of field trials demonstrated that the peak densities of B. tabaci adult in the treatment plots were 16.40 and 15.60 individuals per leaf, representing reductions of 36.3% and 37.6%, respectively, compared with the control (P＜0.05).

A highly pathogenic B. bassiana strain XJWLMQ-1 against both nymphs and adults of B. tabaci was screened, and an efficient food attractant formulation consisting of (Z)-3-hexenal, linalool, and eugenol at a ratio of 1﹕2﹕1 was developed. The combined application of B. bassiana and the attractant effectively suppressed B. tabaci populations and showed strong potential for sustainable field application.