Morphological and molecular systematics of anopheles mosquitoes (diptera: culicidae: anophelinae) of north Kerala

Abstract

Mosquitoes belong to the family Culicidae, which is further subdivided into subfamilies Anophilinae and Culicinae. As the vectors of malaria, species of Anophelinae are considered as the most important of all mosquitoes. The subfamily Anophelinae is comprised of three genera: Anopheles Meigen, which has a nearly worldwide distribution, Bironella Theobald which is found in the Australasian region, and the Neotropical Chagasia Cruz. Nearly 51 species of Anopheles have been recorded from India. An. culicifacies, An. fluviatilis, An. minimus, An. philippinensis, An. stephensi and An. sundaicus, are the primary vectors of malaria in India. Besides, An.subpictus B has been reported to play an important role in malaria transmission in different parts of the county. Several vector species have been reported to exist as species complexes in various parts of the world including India. Hence, their specific identification is very important in planning malaria control strategies. Molecular techniques have been increasingly employed for this purpose in recent years. The present study dealt with morphological and molecular analysis of Anopheles mosquitoes present in different localities of five North Kerala districts. 27 Anopheles species were recorded from Kasaragod, Kannur, Kozhikode, Wayanad, and Malappuram Districts. Out of these 10 species belonged to the subgenus Anopheles, and 17 species to the subgenus Cellia. Of the 27 species, two species, An. sundaicus and An. subpictus B are new records from Kerala. Besides, there are several new records from individual districts. From Kasaragod district, An. fluviatilis, and An. theobaldi were reported for the first time. From Kannur district seven species of Anopheles were reported for the first time viz., An. crawfordi, An. nigerrimus, An. nitidus, An. sinensis, An. theobaldi, An. dirus, and An. sudaicus. Anopheles subpictus B, the most potent malaria vector was reported from Kozhikode district for the first time. The present study also did the redescription of 27 species that had been collected. Molecular analysis of four malarial vector species, Anopheles culicifacies, Anopheles dirus, Anopheles stephensi, and Anopheles subpictus was conducted in the present study. An. culicificies species complex was resolved. The species prevalent in the study area was confirmed as Anopheles culicifacies B. This was the first time such a study was done in Kerala. The study also revealed the presence of Anopheles dirus D in the study area. The molecular analysis of the subpictus complex revealed the presence of Anopheles subpictus B, which is a piece of new information for the entire state.