Locusts and grasshoppers infestations pose significant threats to agricultural productivity and food security, particularly in regions like Egypt, where sustainable pest management strategies are urgently needed. This study evaluated the efficacy of three insecticides spinosad, alpha-cypermethrin, and cypermethrin, as potential alternatives to chlorpyrifos, which has been banned for locusts control in Egypt since December 2023. Laboratory trial was conducted to assess mortality rates of the desert locust Schistocerca gregaria (Forsskål, 1775) (Orthoptera, Acrididae), while field trial was conducted to assess mortality rates of the desert locust S. gregaria, the african migratory locust Locusta migratoria Fairmaire & L.J. Reiche, 1849 (Orthoptera, Acrididae), and the grasshopper lamenting grasshopper Eyprepocnemis plorans Charpentier, 1825 (Orthoptera, Acrididae). In laboratory conditions, alpha-cypermethrin and cypermethrin demonstrated superior efficacy, achieving 99.63% and 96.30% mortality, respectively, after 48 hours, while spinosad reached only 74.07% on S. gregaria. Field trials in 2022 and 2023 corroborated these findings, with pyrethroids consistently achieving 96–100% mortality across all species, compared to spinosad’s moderate efficacy (62.96 - 74.07%). Statistical analyses confirmed significant differences between spinosad and the pyrethroids, with no notable variation in susceptibility among the target species.

The study highlights alpha-cypermethrin and cypermethrin as highly effective, fast-acting alternatives to chlorpyrifos, aligning with their neurotoxic mode of action and lower environmental persistence. In contrast, spinosad’s slower lethality limits its utility during acute outbreaks, despite its favorable safety profile. These findings underscore the importance of selecting context-appropriate insecticides for integrated pest management (IPM) programs, balancing efficacy, speed of action, and environmental impact. The results provide critical insights for policymakers and agricultural stakeholders in Egypt and similar regions, advocating for pyrethroid-based strategies to mitigate locust-driven crop losses while adhering to sustainable practices.