First record of a new Frankliniella occidentalis (Pergande, 1895) (Thysanoptera: Thripidae) genetic lineage in Australia

Western Flower Thrips (WFT, Frankliniella occidentalis (Pergande, 1895)), is one of the major pests of crops worldwide.WFT was first detected in Australia in 1993 and is now present in all Australian states.Previous genetic studies detected two distinct WFT genetic lineages outside Australia known as the "lupin" strain and the "greenhouse" strain.Until now the genetic diversity and presence of different WFT genetic lineages in Australia was unknown.During recent thrips surveys of ornamental plant nurseries in Victoria, Australia, two WFT genetic lineages were detected, based on comparative analysis of the mitochondrial cytochrome oxidase I (COI), internal transcribed spacer 2 (ITS2) and the nuclear 28S rRNA genes.These two Victorian WFT genetic lineages appear to be identical morphologically and have no genetic differences in the ITS2 and 28S rRNA genes sequences but have a significant COI genetic difference (up to 4.63%).Our study confirms the presence of the "greenhouse" lineage in Victoria, which was found on a range of plant species at several locations and describes the first detection of a unique lineage that was only observed on Lotus berthelotii Masf.(Fabaceae), named hereafter "Aus_Lotus_COI", at one location.Both lineages were found to co-exist on L. berthelotii, with the "greenhouse" lineage more abundant (9/12 specimens) than "Aus_Lotus_COI" (3/12 specimens) collected from this host at the time of survey (March-June 2021).