Invasive Species Compendium

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Abstract

Biology and bionomical aspects of invasive Aedes albopictus circulating in Odisha.

Abstract

Aedes albopictus is an indigenous species in India and is believed to have originated in the tropical forest of South-east Asia. In general, it breeds outdoors. It is more prevalent in periurban areas and is associated with dengue fever. We undertook a study in selected districts of Odisha to identify the distribution of various breeding sources. The usefulness of indices in the immature stage of the mosquito was assessed to identify risk-prone areas for transmission of dengue and chikungunya. The results showed predominance of Ae. albopictus in all the districts studied in Odisha. Cuttack district accounted for the highest proportion of positive containers (15.7%) followed by Balasore (13.7%), Bhadrak and Jajpur (12.1%). Considering the various indices used for the prediction of dengue, Cuttack, Jajpur, Bhadrak and Balasore districts were found to be at high endemic risk. Earthen pots were found to be the most preferred breeding habitat with the highest container productivity of 29.6 and associated risk factor of 25.67. There was a significant difference in the mean larval development time in subpopulations of Ae. albopictus from the study districts. In all the subpopulations from the study districts, female mosquitoes emerged approximately a day after the emergence of male mosquitoes. A significant difference was also observed in the fecundity values, in terms of the total number of eggs, as long-living females could lay a larger number of eggs during their lifetime (P=0.00068). The higher values of adult indices indicated the high risk association of this species of mosquito with the spread of dengue and likelihood of an epidemic. This study updates the current status of preferred breeding habitats and vector distribution in different districts of Odisha. The differences in Ae. albopictus subpopulations reported here indicate a higher risk for acquiring dengue among the human populations settled in dengue-endemic districts of Odisha.