Piecing together an integrative taxonomic puzzle

microsatellite, wing shape and aedeagus length analyses of Bactrocera dorsalis s.l. (Diptera: Tephritidae) find no evidence of multiple lineages in a proposed contact zone along the Thai/Malay Peninsula

Matthew N. Krosch*, Mark K. Schutze, Karen F. Armstrong, Yuvarin Boontop, Laura M. Boykin, Toni A. Chapman, Anna Englezou, Stephen L. Cameron, Anthony R. Clarke

*Corresponding author for this work

Research output: Contribution to journalArticle

62 Citations (Scopus)

Abstract

Bactrocera dorsalis (Hendel) and B. papayae Drew & Hancock represent a closely related sibling species pair for which the biological species limits are unclear; i.e. it is uncertain if they are truely two biological species, or one biological species which has been incorrectly split taxonomically. The geographical ranges of the two taxa are thought to abut or overlap on or around the Isthmus of Kra, a recognised biogeographic barrier located on the narrowest portion of the Thai Peninsula. We collected fresh material of B. dorsalis s.l. (i.e. B. dorsalis s.s.+ B. papayae) in a northsouth transect down the Thai Peninsula, from areas regarded as being exclusively B. dorsalis s.s., across the Kra Isthmus, and into regions regarded as exclusively B. papayae. We carried out microsatellite analyses and took measurements of male genitalia and wing shape, both used previously to separate the taxa. No significant population structuring was found in the microsatellite analysis, consistent with one, predominantly panmictic population. Both morphological datasets showed consistent, clinal variation along the transect, without disjunction. No evidence supported historical vicariance driven by the Isthmus of Kra, and no dataset supported the current taxonomy of two species. Rather, within and across the area of range overlap or abutment between the two species, only continuous morphological and genetic variation was recorded. Recognition that morphological traits previously used to separate these taxa are continuous, and that there is no genetic evidence for population segregation in the region of suspected species overlap, is consistent with a growing body of literature that reports no evidence of biological differentiation between these taxa.

Original languageEnglish
Pages (from-to)2-13
Number of pages12
JournalJournal of Entomology Series B, Taxonomy
Volume38
Issue number1
DOIs
Publication statusPublished - Jan 2013
Externally publishedYes

Keywords

  • ORIENTAL FRUIT-FLY
  • MITOCHONDRIAL-DNA SEQUENCES
  • POPULATION-STRUCTURE
  • PHYLOGENETIC-RELATIONSHIPS
  • SPECIES IDENTIFICATION
  • COMPLEX DIPTERA
  • PAPAYAE DIPTERA
  • HENDEL DIPTERA
  • FLIES
  • SOFTWARE

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