title: Morphological and molecular characterization of the ecological, biological and behavioural variants of the JE vector Culex tritaeniorhynchus: an assessment of its taxonomic status.
abstract: OBJECTIVE
  Culex tritaeniorhynchus (Diptera: Culicidae), an important vector of Japanese encephalitis belongs to the Culex vishnui subgroup which includes two other vector species namely, Cx. Vishnui and Cx. pseudovishnui. Many varieties and types of Cx. tritaeniorhynchus have been reported, besides populations that exhibit behavioural and biological differences. This study was undertaken to find out whether Cx. tritaeniorhynchus populations exhibiting behavioural and biological variations, and those from different geographical areas, are comprised of more than one taxon or belong to a single taxon.
  
  
  METHODS
  Morphological characterization was done by examining 153 morphological and morphometric characters in the larval (75), pupal (60) and adult stages (18) of five geographical populations of Cx. tritaeniorhynchus. Molecular characterization was done by PCR amplification of mitochondrial cytochrome c oxidase (COI) gene sequences (DNA barcodes) and another hypervariable genetic marker, the ribosomal DNA (16S). One-way ANOVA, principal component analysis (PCA) and discriminant factor analysis (DFA) were done for statistical analyses using the statistical package SPSS IBM version 19.0.
  
  
  RESULTS
  Morphological characterization showed that no intraspecific differentiation can be made among the five geographical populations of Cx. tritaeniorhynchus. Molecular characterization done by DNA barcoding also showed that the COI sequences of all the five populations of Cx. tritaeniorhynchus grouped into a single taxonomic clade plus the genetic differentiation among these was non-significant and the overall gene flow among the populations was very high. Analysis of the ribosomal DNA also confirmed that the Cx. tritaeniorhynchus populations belonged to a single taxon.
  
  
  CONCLUSIONS
  Culex tritaeniorhynchus is a taxon that does not involve cryptic species.
authors: Vector Control Research Centre (ICMR), Indira Nagar, Puducherry, India.
authors: A R
authors: AR
authors: Rajavel
authors: N Pradeep
authors: NP
authors: Kumar
authors: R
authors: R
authors: Natarajan
authors: P
authors: P
authors: Vanamail
authors: A
authors: A
authors: Rathinakumar
authors: P
authors: P
authors: Jambulingam
mesh_terms: D000818:Animals; D001483:Base Sequence; D003465:Culex / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics / Q000502:physiology; D058893:DNA Barcoding, Taxonomic; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004463:Ecology; D003576:Electron Transport Complex IV / Q000235:genetics; D004672:Encephalitis, Japanese / Q000635:transmission*; D005260:Female; D006801:Humans; D007303:Insect Vectors / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics / Q000502:physiology; D007814:Larva; D008297:Male; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial; D004275:DNA, Ribosomal; D003576:Electron Transport Complex IV