Determination of lambda-cyhalothrin and imidacloprid resistance and synergistic activity of diatomaceous earth in Leptinotarsa decemlineata Say, 1824 (Coleoptera: Chrysomelidae) populations

In this study conducted in 2020, the resistance of Leptinotarsa decemlineata Say, 1824 (Coleoptera: Chrysomelidae) populations collected from Karapınar, Çumra, Seydişehir, Güneysınır and Doğanhisar Districts of Konya Province, Turkey to lambda-cyhalothrin and imidacloprid was investigated. Insecticides were applied topically to fourth instar larvae. In addition, the synergistic efficiency of diatomaceous earth (DE) was investigated by applying imidacloprid plus DE (2% w/v) with the same methodology in the Karapınar population. As a result of the research, the resistance rate of all populations was found to be higher in imidacloprid than in lambda-cyhalothrin. The highest LD50 was found in the Çumra (0.212 µg/larvae) and Karapınar (0.456 µg/larvae) population for lambda-cyhalothrin and imidacloprid respectively. The highest synergism ratio was determined as 1.93 after 48 hours in imidacloprid plus DE application. As a result of the research, it is considered that the use of DE will make a great contribution to the control and resistance management of the imidacloprid resistant potato beetle.