Macrocyclic lactones: A soil bacterium metabolite category for the management of different types of insecticide resistance

Among the major types of resistance, metabolic and KDR have garnered much attention due to their prevalence among insect groups especially public health pests. All three major disease vector genera in mosquitoes (Anopheles, Culex, and Aedes) have both forms of resistance. Other public health insect groups like bed bugs also show this variability in evolving resistance types. Recent research has also shown that the gonotrophic cycle of the targeted insect pest could compound resistance selection and evolution. Regardless of the pest or resistance type, the major factor facilitating evolution of resistance is repeated use of single mode of action. Macrocyclic lactones (ML) such as ivermectin have a long track record with safety and efficacy in the pharmaceutical industry. But these molecules are at least 4 times larger than traditional pesticide molecules, and this has dictated the delivery mode to be consumption rather than absorption. Even if higher absorption can be achieved with better formulation technologies, the issue of a single mode of action (MoA) guarantees the evolution of insect resistance. Incorporation of different MoAs with macrocyclic lactones further compounds the formulation challenges of working with this unique active ingredient class. The presentation will outline challenges in leveraging MLs against different mosquito resistance types and their chances of success in combating pesticide resistance.