A set of genetic markers distinguish between Phytoseiulus persimilis populations that differ in their suitability to mass rearing on alternative diet

Abstract: The mass rearing technique of the predatory mite Phytoseiulus persimilis has
undergone a revolution in the recent years, when the diet used to rear this specialist predator
changed from spider mites to alternative prey. One component of the new technique developed is better suitability of the predatory mite population to reproduce on the alternative prey. The current work tested whether we can differentiate between the new selectively bred population, to other commercial and wild populations, that feed on spider mites using genetic markers. We sequenced a pool of several hundreds of predatory mites using Next Generation Sequencing (NGS), assembled a draft genome of the species, and compared sequences of mites originating from different populations to this genome. This process resulted in 34 Single Nucleotid Polymorphisms (SNPs) across the genome that differed between the selected population that is better suited to alternative diet, and other populations. The results were validated by sequencing new samples from various populations using NGS and comparing them to the predicted SNPs. Additionally, specific primers for each marker were designed for PCR reactions and new samples were taken for validation using this method as well. All markers were found to be stable enough to differentiate between the selected population and others by at least one method. We conclude that it is possible to distinguish between the commercially selected population for alternative food and other populations.