Species Composition of Medically Important Mosquitoes in Selected Areas of Kurunegala, Gampaha, Kegalle and Kandy Districts in Sri Lanka

Abstract

Mosquito borne diseases are one of major health problems in almost all tropical and subtropical countries including Sri Lanka. Knowledge on breeding places and the larval distribution are important parameters for risk assessment and sound mosquito control strategies. Thus, the present study aimed to investigate the diversity and species composition of medically important mosquito immature stages in selected areas of Kurunegala, Gampaha, Kegalle and Kandy districts in Sri Lanka. Larval surveys were conducted in selected areas in each District from June 2017 to September 2018 on monthly basis. The species density and distribution was calculated. A total of 4369 mosquito larvae belong ten species under five Genera (Aedes, Anopheles, Culex, Mansonia and Armigeres) was identified. Aedes aegypti, Ae. albopictus, Anopheles subpictus, An. vagus, Armigeres subalbatus, Culex quinquefasciatus, Cx. tritaeniorynchus, Cx. gelidus, Cx. whitmorei and Mansonia uniformis were encountered as species. Cx. gelidus showed highest density (27.49%, n= 411) in Kurunegala district followed by An. vagus and Ae. aegypti as satellite species (D<1%) and subdominant species (1<D<5%), respectively. In Gampaha district, Mansonia uniformis and Cx. whitmorei were found as a subdominant species. In both Kegalle and Kandy districts, Cx. whitmorei was found as a subdominant species and all the other mosquito species were recorded as dominant species (D>5%). However, Ae. albopictus was a dominant species in both Gampaha and Kandy districts which showed an infrequent distribution (C2; 20.1 – 40%). The presence of medically important mosquitoes in these areas in considerable numbers can cause public health concerns as dengue is one of the major challenges in these areas. Therefore, the study of this nature would be useful to identify the entomological potential for disease transmission and update would be facilitated for implementing appropriate vector control interventions.