Bio-efficacy and dynamic distribution of pymetrozine and cyantraniliprole against Aphis gossypii glover, and their residues in cucumber (Cucumis sativus l.) fruits using the QuEChERS method and LC-ESI-MS/MS

Mixed pesticides are promising alternative approaches for insect pest management and could reduce the risk to the environment. Therefore, their efficiency against pests and their residues in the environment should be investigated. In this study, the efficacy of pymetrozine, cyantraniliprole, and their mixture against Aphis gossypii Glover and their residues in cucumber (Cucumis sativus L.) were studied. The results showed that pymetrozine and cyantraniliprole alone or in combination were more effective than acetamiprid insecticide for reducing A. gosspyii populations up to 15 days following application. Additionally, a residual analytical method for insecticide determination in cucumber fruits, leaves, and soil was optimized and validated. The tested insecticides’ residue extraction was carried out using the QuEChERS method, and the determination was achieved using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The recovery tests were studied at three spiking levels of low concentration (0.01, 0.05, and 0.1 mg · kg–1) with acceptable recovery between 71 and 101% and good precision and expanded uncertainty up to ± 20%. The half-life times of the tested formulations ranged from 8.19 to 10.6 days, while the pre-harvest intervals (PHI) ranged from 8.8 to 23.8 days.