Structural Features of Coumarin-1,2,4-Triazole Hybrids Important for Insecticidal Effects Against Drosophila melanogaster and Orius laevigatus (Fieber)

Although the present use of pesticides in plant protection has limited the occurrence and development of plant diseases and pests, resistance to pesticides and their environmental and health hazards indicates an urgent need for new active ingredients in plant protection products. Recently synthesized coumarin-1,2,4-triazole hybrid compounds have been proven effective against plant pathogenic fungi and safe for soil-beneficial bacteria. <i>Drosophila melanogaster</i>, the common fruit fly, has been used as a model organism for scientific research. Additionally, it is considered a pest since it damages fruits and serves as a carrier for various plant diseases. On the contrary, <i>Orius laevigatus</i> is a beneficial true bug that biologically controls harmful arthropods in agricultural production. In the present study, we performed an adulticidal bioassay against <i>D. melanogaster</i> and <i>O. laevigatus</i> using coumarin-1,2,4-triazole hybrids. Quantitative structure-activity relationship studies (QSARs) and in silico ecotoxicity evaluation elucidated the structural features underlying the compounds' insecticidal activity. The derivative of 4-methylcoumarin-1,2,4-triazole with a 3-bromophenyl group showed great insecticidal potential. A molecular docking study indicated that the most active compound probably binds to glutamate-gated chloride channels.