Morpho molecular studies for differentiation of species and complexes of culex diptera culicidae

Abstract

Culex pipiens group has received a great deal of attention due to its medical significance and is thought to be a possible vector of numerous arboviral diseases such as West Nile fever, Zika fever, filariasis, St. Louis encephalitis, and Western horse encephalitis. During present investigations, eight species i.e., Culex quinquefasciatus, Cx. pipiens, Cx. vagans, Cx. hutchinsoni and Cx. theileri, Cx. univittatus, Cx. perexiguus, Cx. fuscocephala have been recorded from different ecological habitats of Chandigarh and its surrounding areas. Of which, two were new records i.e., Cx. pipiens from Chandigarh Cx. perexiguus from India. The seasonal dynamicity of these eight species was correlated with the change in temperature, relative humidity and rainfall over the study period of four years (June 2017-November 2019, June 2020-November 2020). The taxonomic keys, illustrations and descriptions of all the eight species based on all morphological attributes including external genitalia of the adults have been studied. The detailed taxonomic description of female genitalia of Cx. univittatus and Cx. theileri has been provided for the very first time in study. Culex quinquefasciatus has been observed with thirteen intraspecific variants which were further distinguished on the basis of ventral and dorsal arm of phallosome of male genitalia. For further confirmation these morphologically treated species and their variants were further switched to molecular characterization by using mitochondrial genes viz., CO I, Cyt b and nuclear genes viz., Ace 2 and ITS 2, which were proved to be very useful to separate genetically diversified and evolutionary related species within close members of the pipiens group. All specimens were examined to detect sequence similarity i.e., multiple sequence alignment, bioinformatics like nucleotide composition, codon usage bias,transition, transversion substitution,evolutionary divergence, and phylogeny trees including Maximum likelihood and neighbour-joining with bootstrap values were calculated.