Spatial distribution and molecular characterization of Anopheles nivipes and Anopheles philippinensis (Diptera: Culicidae) in north-east India

Anopheles philippinensis-nivipes species of mosquitoes are considered secondary malaria vectors in the north-east India. However, difficulty in separating An. philippinensis and An. nivipes accurately on the basis of morphological identification, due to the overlapping female wing characters, has led to the paucity of information on their spatial distribution and vectorial importance, essential for understanding malaria disease epidemiology in areas under their influence. In view of this a study was undertaken to generate authentic information on distribution of An. philippinensis and An. nivipes in the north-east India using molecular tools. Between the two, An. nivipes was recorded as the dominant species in Assam, and Nagaland states whereas An. philippinensis was found predominant in the state of Mizoram and Arunachal Pradesh. Species differentiation based on female wing characters proved wrong in about 74% specimens of An. philippinensis but found accurate in case of An. nivipes. No intra-specific variation in second internal transcribed spacer (ITS2) region of ribosomal DNA(r-DNA) in either An. nivipes or An. philippinensis from different geographical areas of north-east India was noted.

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► We studied spatial distribution of Anopheles philippinensis and Anopheles nivipes in NE India.
► An. nivipes was found predominant in NE India.
► Discordance between molecular and morphological identification was 74% in An. philippinensis.
► The concordance was 100% in An. nivipes between morphological & molecular identification.
► No intraspecific variation was found in r-DNA ITS2 region of both the species in NE India.
► Variations in ITS2 of An. nivipes from NE India with neighbouring countries were observed.