The Scirtothrips dorsalis Species Complex: Endemism and Invasion in a Global Pest

PLoS One. 2015 Apr 20;10(4):e0123747. doi: 10.1371/journal.pone.0123747. eCollection 2015.

Abstract

Invasive arthropods pose unique management challenges in various environments, the first of which is correct identification. This apparently mundane task is particularly difficult if multiple species are morphologically indistinguishable but accurate identification can be determined with DNA barcoding provided an adequate reference set is available. Scirtothrips dorsalis is a highly polyphagous plant pest with a rapidly expanding global distribution and this species, as currently recognized, may be comprised of cryptic species. Here we report the development of a comprehensive DNA barcode library for S. dorsalis and seven nuclear markers via next-generation sequencing for identification use within the complex. We also report the delimitation of nine cryptic species and two morphologically distinguishable species comprising the S. dorsalis species complex using histogram analysis of DNA barcodes, Bayesian phylogenetics, and the multi-species coalescent. One member of the complex, here designated the South Asia 1 cryptic species, is highly invasive, polyphagous, and likely the species implicated in tospovirus transmission. Two other species, South Asia 2, and East Asia 1 are also highly polyphagous and appear to be at an earlier stage of global invasion. The remaining members of the complex are regionally endemic, varying in their pest status and degree of polyphagy. In addition to patterns of invasion and endemism, our results provide a framework both for identifying members of the complex based on their DNA barcode, and for future species delimiting efforts.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bayes Theorem
  • Electron Transport Complex IV / genetics
  • Genetic Loci
  • Genetic Variation
  • Genetics, Population
  • Internationality*
  • Introduced Species*
  • Phylogeny
  • Phylogeography
  • Sequence Analysis, DNA
  • Species Specificity
  • Thysanoptera / genetics*

Substances

  • Electron Transport Complex IV

Grants and funding

This research was partially funded by the Floriculture and Nursery Research Initiative, http://www.ars.usda.gov/research/projects/projects.htm?ACCN_NO=402626. Additional funding was provided internally by the USDA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.