Abstract
The bio-prospecting of bioactive phytochemicals from invasive flora presents a sustainable paradigm for the ecologically conscious management of major invasive pest S. invicta. Ageratina adenophora, while recognized for its allelopathic insecticidal properties, exhibits poorly characterized toxicological profiles and mechanistic underpinnings against S. invicta, warranting systematic investigation to elucidate its mode of action. This study elucidates the bioactive insecticidal compounds of A. adenophora and their toxicological impacts on S. invicta, including behavioral, metabolic, and enzymatic perturbations, via liquid chromatography-mass spectrometry (LC-MS) profiling. The ethanol extracts of the roots, stems, and leaves of A. adenophora have shown control effects on S. invicta, with an LC(50) (50% lethal concentration) of 331.847, 188.256, and 166.253 mg/mL at 48 h, respectively. Metabolite profiling of A. adenophora revealed that safranal and dihydrocoumarin are relatively high in plant leaves, and they showed significant insecticidal activity and behavioral inhibitory effects on S. invicta with LC(50) 349.042 mg/L and 118.336 mg/L at 48 h, respectively. Notably, these two bioactive compounds disrupted the normal energy production through glucose metabolism and the citrate cycle, which eventually led to the death of S. invicta. Further, these two compounds also activated the detoxification metabolic pathway of S. invicta. These findings provide a theoretical basis for the use of these bioactive compounds in the integrated management of S. invicta and may lead to the development of a new biopesticide.