Discovery of novel (N-aryl-4-methylpiperidinyl)pyrazoles: a new class of potent lepidopteran insecticides.

BACKGROUND: Insects of the order Lepidoptera are among the most destructive global pests, causing billions of dollars in damage annually. A new class of N-arylpyrazole-4-methylpiperidines with potent activity on lepidopteran species has been discovered. RESULTS: In a high-throughput insecticide screen compound 1 was identified to possess modest activity on the lepidopteran insect Plutella xylostella. Optimization of 1 to compound 42 resulted in a compound with excellent activity on Spodoptera exigua, Spodoptera frugiperda, and Helicoverpa zea with median lethal concentrations values of 2.8, 1.4, and 12.5 ppm respectively. Although the mode of action remains unknown, these compounds do not appear to work by many of the known biochemical mechanisms of insect control. CONCLUSION: N-Arylpyrazole-4-methylpiperidines represent a new class of insecticides with excellent activity on a broad spectrum of lepidopteran pests. Studies to date indicate the potential for a novel mode of action; however, the target site is unknown at present. © 2023 Society of Chemical Industry.

Mesoionic insecticides: a novel class of insecticides that modulate nicotinic acetylcholine receptors.

BACKGROUND: As the world population grows towards 9 billion by 2050, it is projected that food production will need to increase by 60%. A critical part of this growth includes the safe and effective use of insecticides to reduce the estimated 20-49% loss of global crop yields owing to pests. The development of new insecticides will help to sustain this protection and overcome insecticide resistance. RESULTS: A novel class of mesoionic compounds has been discovered, with exceptional insecticidal activity on a range of Hemiptera and Lepidoptera. These compounds bind to the orthosteric site of the nicotinic acetylcholine receptor and result in a highly potent inhibitory action at the receptor with minimal agonism. The synthesis, biological activity, optimization and mode of action will be discussed. CONCLUSION: Triflumezopyrim insect control will provide a powerful tool for control of hopper species in rice throughout Asia. Dicloromezotiaz can provide a useful control tool for lepidopteran pests, with an underexploited mode of action among these pests. © 2016 Society of Chemical Industry.