High throughput barcode sequencing of arthropods at scale
Open questions in island biology arArthropods offer high potential for structured sampling to obtain data-rich site-based community data, through the use of multiple complementary sampling methods (Montgomery, Belitz, Guralnick, & Tingley, 2021). For nearly all sampling methods, sorting of samples and classification to species are likely to be substantial challenges, and thus a limitation to sampling at scale. For many groups, regional taxonomic knowledge is incomplete, and for those groups that benefit from a robust taxonomic framework, sorting and species assignment may still be complicated by a lack of specific taxonomic expertise. Molecular barcode-based sequencing tools have already helped to overcome the challenges of taxonomic assignment and facilitate new species discovery and monitoring (e.g. deWaard et al., 2019; Hebert, Cywinska, Ball, & DeWaard, 2003; Ronquist et al., 2020), and there are broader benefits for the characterisation of diverse arthropod communities using high throughput sequencing (HTS) barcoding (Hajibabaei, Baird, Fahner, Beiko, & Golding, 2016). HTS can be employed at the scale of individual specimens or bulk community samples (see Kennedy et al. (2020) and sections below), and both can greatly reduce existing limitations for identifying and understanding biodiversity patterns and processes across entire arthropod assemblages on islands. Additionally, even in the absence of a local reference library, when HTS barcoding is coupled with the use of the universal mitochondrial DNA (mtDNA) barcode region (Andújar, Arribas, Yu, Vogler, & Emerson, 2018), taxonomic assignment is aided by the more than eight million barcode sequences within the BOLD repository.