Mosquitoes still pose a clear risk to human and animal health. Recently, nanomaterials have been considered one of the cost-effective solutions to this problem. Therefore, alumina nanoparticles (Al) were synthesized using an auto-combustion method, followed by calcination at 600 and 800 °C. Glucose (G) and sucrose (Su) were used as fuels and the combustion was performed at pH 2, 7, and 10. The as-synthesized Al₂O₃ nanoparticles were characterized by XRD, FTIR, SEM, and TEM. Alumina nanoparticles prepared using G and Su fuels at pH 7 and 800 °C (Al-G7-800 and Al-Su7-800) have crystallite sizes of 3.9 and 4.05 nm, respectively. While the samples (Al-G7-600 and Al-Su7-600) synthesized at pH 7 and 600 °C were amorphous. The prepared alumina nanoparticles were applied to the larval and pupal stages of Culex pipiens. The results showed that alumina nanoparticles cause higher mortality in the 1st larval instar than in all other larval instars and pupal stages of Culex pipiens after treatment at a high concentration of 200 ppm. Additionally, the larval duration after treatment with LC₅₀ concentrations of alumina (Al-G7-800 and Al-Su7-800) was 31.7 and 23.6 days, respectively, compared to the control (13.3 days). The recorded data found that the content of glutathione-S-transferase, alkaline/acid phosphatase, β/α-esterase, and total protein were altered upon treatment with the LC₅₀ concentration of alumina (Al-G7-800) nanoparticles. Based on these findings, alumina nanoparticles are a promising candidate as a potential weapon to control pests and mosquitoes.