There is more than chitin synthase in insect resistance to benzoylureas: Molecular markers associated with teflubenzuron resistance inSpodoptera frugiperda

AbstractChitin synthesis inhibitors are successfully used in pest control and are an excellent option for use in integrated pest management programs due to their low non-target effects. Reports on field-evolved resistance of lepidopteran pests to chitin synthesis inhibitors and the selection of laboratory resistant strains to these products require a detailed investigation on the resistance mechanisms and on the identification of molecular markers to support the implementation of efficient monitoring and resistance management programs. Teflubenzuron is a chitin synthesis inhibitor highly effective in controlling lepidopteran pests, including nowadays the world widely distributed fall armyworm (FAW),Spodoptera frugiperda(J.E. Smith, 1797) (Lepidoptera: Noctuidae). We report the selection of a laboratory strain ofS. frugiperdaresistant to teflubenzuron, and its use for the characterization of the inheritance of resistance, evaluation of cross-resistance to other chitin-synthesis inhibitors and the identification of a set of single nucleotide polymorphisms (SNPs) for use as candidate molecular markers for monitoring the evolution of resistance ofS. frugiperdato teflubenzuron. The resistance of the selected strain ofS. frugiperdato teflubenzuron was characterized as polygenic, autosomal, and incompletely recessive. The resistance ratio observed was nearly 1,365-fold. Teflubenzuron-resistant strain showed some cross-resistance to lufenuron and novaluron but not to chlorfluazuron. We also detected a set of 72 SNPs that could support monitoring of the resistance frequency to teflubenzuron in field populations. Our data contribute to the understanding of the resistance mechanisms and the inheritance of polygenic resistance ofS. frugiperdato benzoylureas. We also contribute with candidate markers as tools for monitoring the emergence and spread of teflubenzuron resistance inS. frugiperda.