Population dynamics and breeding preference of &lt;em&gt;Aedes aegypti&lt;/em&gt; and &lt;em&gt;Ae. albopictus&lt;/em&gt; attributing to dengue threat in Kelaniya medical officer of health area in Sri Lanka

L.D Amarasinghe,P.V.J Nadeeka

doi:10.4038/josuk.v14i2.8046

Abstract

Aedes aegypti and Ae. albopictus are the two species of dengue vector mosquitoes in Sri Lanka. Indoor and outdoor distribution of these species, their population dynamics and breeding preference are important factors determining the dengue transmission. Gampaha district in Sri Lanka reported to have frequent dengue epidemics from recent past, hence this study was conducted. Ovitrap surveillance was conducted to determine the vector species distribution in indoor and outdoor in Kelaniya Medical Officer of Health (MOH) area of the Gampaha district. Larvae were reared until emergence of adults in the laboratory to identify species morphologically. Breeding preference of vector mosquitoes were carried out by physically observing the presence of mosquito larvae in water accumulated receptacles in the area. Aedes aegypti and Ae. albopictus were reported to distribute throughout Kelaniya MOH area as a mixed population. Ae. albopictus is the most abundant species both indoor and outdoor in Kelaniya MOH area compared to Ae. aegypti. Weather factors, rain days and wind positively correlated with Aedes population. High risk areas were identified as Kiribathgoda and Hunupitiya in this study.

Highlights

Among the Aedes species mosquitoes, Ae. aegypti (Linnaeus, 1762) which is a predominantly urban species, and Ae. albopictus (Skuse, 1894) which is a peridomestic species, are the two species of dengue vectors in Sri Lanka (Vitharana et al 1997; Sirisena & Noordeen, 2014)
Results obtained for the ovitrap survaillance over a period of one year showed that Hunupitiya, Kiribathgoda, Peliyagoda and Kelaniya divisions recorded a presence of higher Aedes mosquito populations compared to other two divisions (Figure 3)
Higher egg counts were recorded in outdoor traps than in indoor traps except in Dalugama PHI division in which egg counts in indoor and outdoor ovitraps were not significantly different

Summary

Introduction

Among the Aedes species mosquitoes, Ae. (sub genus stegomyia) aegypti (Linnaeus, 1762) which is a predominantly urban species, and Ae. (sub genus stegomyia) albopictus (Skuse, 1894) which is a peridomestic species, are the two species of dengue vectors in Sri Lanka (Vitharana et al 1997; Sirisena & Noordeen, 2014). (sub genus stegomyia) albopictus (Skuse, 1894) which is a peridomestic species, are the two species of dengue vectors in Sri Lanka (Vitharana et al 1997; Sirisena & Noordeen, 2014) Both these species are prevalent throughout the country in both urban and semi urban areas (Sirisena & Noordeen, 2014). They only need clear water, but not necessarily clean water to complete the life cycle (Lee, 1991) They prefer to breed in low values of turbidity and BOD (Biological Oxygen Demand) which are critical parameters of mosquito breeding water (Dom et al 2016).

Methods

Results

Discussion

Conclusion