Surveillance of the Asian tiger mosquito Aedes albopictus Skuse 1894 (Diptera: Culicidae) the dengue vector in rubber plantations of Kanya Kumari district, Tamil Nadu, India

Abstract

Kanyakumari district is endemic for dengue and reconnaissance of Aedes albopictus in relation to rubber plantations is essential. Natural vertical transmission in Aedes albopictus have occurred in the rural areas of Kanyakumari district, Tamil Nadu, India. In the present study, the surveillance of the dengue vector, Aedes albopictus in selected villages of Kalkulam taluk of Kanyakumari, and its impact in the nearby villages was reported from June 2019 to December 2019. A total of 300 houses and 772 containers in the five villages were surveyed of which 90 houses and 83 containers were tested positive for Aedes larval breeding. Abiotic factors, particularly rainfall assumed an indispensable role in Aedes larval breeding, other than temperature, relative humidity, and light intensity. House, Container and Breteau indices computed for the total surveyed villages were 1.88, 0.72, and 1.83 respectively. The occurrence of Aedes albopictus larval instars (I, II, III and IV) in the coconut shells of rubber plantations examined at 15 per each village were 6.30 ±0.24, 11.50 ±0.80, 14.66 ±0.52, and 7.62 ±0.38 in Anaiady; 5.30 ±0.12, 10.08 ±1.82, 15.18 ±1.50, and 6.90 ±0.14 in Kottarai; 8.68 ±0.86, 9.60 ±0.76, 12.02 ±0.98, and 5.20 ±0.60 in Manacaud; 9.20 ±0.84, 12.60 ±0.36, 14.08 ±2.16, and 6.20 ±0.34 in Pullani; 46.14 ±4.54, 20.14 ±1.88, 20.71 ±3.76, and 34.28 ±4.94 in Thiruvattar; and 8.16 ±0.65, 13.80 ±0.92, 16.25 ±1.80, and 4.80 ±0.26 in Vadakkanadu respectively. Age and sex wise distribution of people in the study area showed men and women of different age groups were affected with the most affected between 20 and 30 years followed by 10 and 20 years. The people residing in and around the rubber plantation were drastically affected by mosquito menace, and as preventive measures coconut husks were burnt (76%). Studies on bionomics of this vector mosquito is essential, since it is slowly displacing Aedes aegypti from its habitats. The significant presence of vegetation, particularly rubber plantations are responsible for the prevalence of Aedes albopictus in the study area.