title: Morphological and molecular identification of cryptic species in the Sergentomyia bailyi (Sinton, 1931) complex in Sri Lanka.
abstract: The correct identification of sand fly vectors of leishmaniasis is important for controlling the disease. Genetic, particularly DNA sequence data, has lately become an important adjunct to the use of morphological criteria for this purpose. A recent DNA sequencing study revealed the presence of two cryptic species in the Sergentomyia bailyi species complex in India. The present study was undertaken to ascertain the presence of cryptic species in the Se. bailyi complex in Sri Lanka using morphological characteristics and DNA sequences from cytochrome c oxidase subunits. Sand flies were collected from leishmaniasis endemic and non-endemic dry zone districts of Sri Lanka. A total of 175 Se. bailyi specimens were initially screened for morphological variations and the identified samples formed two groups, tentatively termed as Se. bailyi species A and B, based on the relative length of the sensilla chaeticum and antennal flagellomere. DNA sequences from the mitochondrial cytochrome c oxidase subunit I (COI) and subunit II (COII) genes of morphologically identified Se. bailyi species A and B were subsequently analyzed. The two species showed differences in the COI and COII gene sequences and were placed in two separate clades by phylogenetic analysis. An allele specific polymerase chain reaction assay based on sequence variation in the COI gene accurately differentiated species A and B. The study therefore describes the first morphological and genetic evidence for the presence of two cryptic species within the Se. bailyi complex in Sri Lanka and a DNA-based laboratory technique for differentiating them.
authors.affiliation: Department of Zoology,Faculty of Science,University of Jaffna,Jaffna,Sri Lanka.
authors.forename: T
authors.initials: T
authors.lastname: Tharmatha
authors.affiliation: Department of Zoology,Faculty of Science,University of Jaffna,Jaffna,Sri Lanka.
authors.forename: K
authors.initials: K
authors.lastname: Gajapathy
authors.affiliation: Department of Biomedical and Forensic Sciences,Faculty of Science and Technology,Anglia Ruskin University,Cambridge,England.
authors.forename: R
authors.initials: R
authors.lastname: Ramasamy
authors.affiliation: Department of Zoology,Faculty of Science,University of Jaffna,Jaffna,Sri Lanka.
authors.forename: S N
authors.initials: SN
authors.lastname: Surendran
mesh_terms: D000818:Animals; D003576:Electron Transport Complex IV / Q000235:genetics*; D014644:Genetic Variation; D019476:Insect Proteins / Q000235:genetics*; D010802:Phylogeny; D011576:Psychodidae / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics; D017422:Sequence Analysis, DNA; D013188:Sri Lanka
chemical_list: D019476:Insect Proteins; C117108:cytochrome C oxidase subunit II; D003576:Electron Transport Complex IV
keywords: 
                 COI
              ; 
                 COII
              ; 
                 Sergentomyia bailyi
              ; Sri Lanka; antennal flagellomere; cryptic species; sand fly; sensilla chaeticum