Eco-Friendly Management of Acanthoscelides obtectus Through Individual and Combined Applications of 1,8-Cineole and Diatomaceous Earth

With growing concerns about chemical insecticides, there is also growing interest in safer, natural alternatives. This study investigated the individual and combined effects of two promising eco-friendly alternatives, diatomaceous earth (DE) and 1,8-cineole, a plant-based essential oil component, on adults of Acanthoscelides obtectus under laboratory conditions. Against the maximum doses of both products (DE 800 ppm, 1,8-cineole 5 ppm), A. obtectus showed 100% mortality within the first 24 h. Although mortality at lower doses (DE 25, 50, 100 ppm, 1,8-cineole 0.600, 1.2 ppm) began from the first day, it was not as effective. In the combined application of 200 ppm DE and 2.5 ppm 1,8-cineole, the mortality rate was 73.33 +/- 8.81%, representing the most effective outcome achieved with the application of relatively low doses of DE and 1,8-cineole. No F1 progeny was observed at any dose of DE or in the combined applications. In contrast, F1 progeny occurred only at three doses of 1,8-cineole (0.150, 0.300, and 0.600 ppm); however, the number of eggs and emerging adults was markedly lower than in the control group and showed a statistically significant difference. Overall, the results obtained from DE alone and DE + 1,8-cineole applications were more effective.