Abstract: Using triolein, the main active component of vegetable oils, as the target compound, a novel green pesticide was developed, and its formulation performance, insecticidal activity, and growth-regulating effects on crops were evaluated. The optimal hydrophilic-lipophilic balance (HLB) was determined through emulsifier screening and compounding, and the emulsification system was optimized to prepare a 90% triolein emulsion. The toxicity of the emulsion against adult whiteflies (Bemisia tabaci) was evaluated using the immersion method, its repellent activity was tested with a Y-tube olfactometer, and its growth-promoting effects on tomato seedlings were investigated through pot experiments. The results showed that the optimal HLB for triolein was 8.5. A composite emulsifier consisting of AEO3, NP4, and Tween-80 at a mass ratio of 1∶1∶0.015, added at a concentration of 10%, produced an emulsion with excellent emulsification properties. The emulsion exhibited significant contact toxicity against adult whiteflies, with an LC₅₀ of 167.16 mg/L, which was significantly lower than that of the control SK mineral oil (LC₅₀ = 354.54 mg/L). In addition, the emulsion showed a repellent effect against whiteflies, with repellency rates of 76.00% and 64.37% at 1 hour and 1 day after application, respectively, and no significant differences were observed between the triolein emulsion and the SK mineral oil control at any time point. At a concentration of 5.00 mg/L, triolein consistently promoted the growth of tomato seedlings, with both the relative growth rate of plant height and the net increase in stem diameter being significantly higher than those of the blank control after multiple treatments. In contrast, the same concentration of SK mineral oil significantly inhibited the net increase in tomato stem diameter.

Key words: triolein, botanical pesticide, emulsifier, Bemisia tabaci, tomato