Three months of Aedes aegypti control with a novel infusion bag formulation of Chilodonella uncinata in domestic water-storage container in Delhi

摘要

The efficacy of Chilodonella uncinata formulation, a naturally occurring protozoan biolarvicide, was evaluated in 40 liter domestic water-storage tub, one of the most common and preferred larval habitat of the dengue vector Aedes aegypti, in NCT Delhi. The formulation used contained base material as sterilized sand to entrap (3.5x104 cells/ml) of the active ingredient, wrapped in infusion bag in dosages (10.0g; 20.0g) introduced in large water-storage tub during September 2016. Test mosquito larvae were added as and when available during >7 weeks period and all supplied by wild mosquitoes laying eggs in another disused plastic container kept nearby. Inhibition of adult emergence (IE) was measured in Ae. aegypti both in experimental and untreated control tub. While all pupae formed in untreated control tub metamorphosed into adu only one pupa managed to emerge as viable adult mosquito out of 9 pupae formed in treated experimental tub over 3 months follow-up period (September to December 2016), indicating IE in treated tub fluctuated between 75% and 100% for this period. Thus 30g formulation of this biolarvicide provided control of Ae. aegypti in water-storage tub during dengue transmission season in Delhi that normally extends from August to November.