Liriomyza sativae is a serious pest of horticultural and ornamental crops worldwide. The overuse of chemical insecticides has caused resistance and environmental pollution, demanding alternative control methods. Plant essential oils, with their insecticidal activity, serve as promising natural alternatives to synthetic insecticides. This study characterized the chemical composition of Artemisia scoparia essential oil using GC-MS and evaluated its insecticidal and growth inhibitory effects against L. sativae. The results showed that the major components were agropyrene (18.96%), o-cymene (12.60%), and caryophyllene oxide (11.35%). The essential oil of A. scoparia demonstrated significant fumigant toxicity against L. sativae adults, with an LC50 value of 0.40 µL/L air after 8 h of exposure. Sublethal concentrations (LC10 and LC20) prolonged the pre-adult developmental stages and reduced the longevity of female adults. The oviposition period and fecundity were significantly reduced compared to the control group. Additionally, reproductive parameters, including the net reproductive rate (R0), gross reproduction rate (GRR), intrinsic rate of increase (r), and finite rate of increase (λ), were significantly lower than the control group. The results indicate that A. scoparia essential oil has potent fumigant and growth-inhibitory effects on L. sativae, offering a promising and sustainable alternative to chemical insecticides for pest control in agriculture.