Culex quinquefasciatus is an intermediate host of several human pathogens and serve as a vector of filariasis worldwide. Recently, there are increasing efforts to develop new and effective nanoparticles to control mosquito vectors. The green synthesis of ZnO-CuO nanoporous composite using Gum Arabic (Acacia senegalensis) was successfully carried out with Gum Arabic and the composite was characterized by UV-Visible, FTIR, and SEM/EDX techniques. Three different larval instars (1^st, 2^nd, and 3^rd) of Culex quinquefasciatus were exposed to various concentrations (10, 20, 25 mg/l) of the ZnO-CuO nanocomposite for 24 h. The LC₅₀ values for the 1^st, 2^nd, and 3^rd instars were found to be 4.702, 5.459, and 5.459, respectively, while the LC₉₀ values were 22.923, 33.922, and 33.922, respectively. The correlation coefficient values for the three instars were found to be 0.982, 0.941, and 0.941, respectively, and these indicate concentration-dependent larvicidal activity. The novel ZnO-CuO nanoporous composite could serve as a new nanolarvicide against the filariasis-transmitting vector.