Simultaneous identification of multiple thrips species (Thysanoptera: Thripidae) from sticky traps using DNA metabarcoding.

More than 130 thrips (Insecta, Thysanoptera) species are significant pests of agricultural crops, 16 of which are known vectors of economically important plant viruses from the Orthotospovirus genus (Bunyavirales: Tospoviridae). It is important to monitor and identify which thrips species are present in production systems so that appropriate controls can be deployed to prevent and manage thrips damage and virus spread. To overcome the challenges of traditional thrips monitoring using sticky traps and morphological identification, a DNA metabarcoding assay was developed, for accurate, high-throughput, and scalable identification of multiple thrips species. For this, a curated mitochondrial cytochrome c oxidase I (COI) database of thrips, based on combined morphological and molecular identification of 70 specimens, was developed and highlighted the importance of combined morphological and molecular identification with the correction of misidentified sequences present on public databases. The metabarcoding method can identify an individual target species within a thrips DNA mixture at a relative abundance of 0.1%, and it successfully identified up to nine different thrips species collected from sticky traps, weeds, and ornamental plants, even up to 2 years after they were collected and kept on sticky traps. Metabarcoding from sticky traps has potential to greatly increase the efficiency of monitoring thrips and represents a significant biosecurity advance for the horticulture industry.