Larvicidal Activity of Curcuma longa and Cymbopogon citratus Essential Oils Based Floating Hydrogel Nurdles Against Aedes aegypti.

Mosquitoes are the primary vectors of different diseases like dengue fever, chikungunya, zika virus, and yellow fever. Essential oils (EOs) are the natural alternatives of synthetic larvicides. This study was aimed to encapsulate the Curcuma longa and Cymbopogon citratus EOs in hydrogel nurdles, and to evaluate their larvicidal activities against Aedes aegypti. The EOs were extracted by hydro-distillation method and their components were analyzed by using GC-MS analysis. Hydrogel nurdles were characterized using dynamic light scattering (DLS) for size distribution, Zeta potential for surface charge, UV-vis spectrophotometry for optical properties, FT-IR for chemical composition, swelling studies for absorbency and floatability tests for buoyancy behavior. The plant essential oil (EO) filled hydrogel nurdles were stable and exhibited significant larvicidal activity (p < 0.001) against Ae. Aegypti, with C. longa EO (LC50 = 146.86 ppm, LC90 = 290.50 ppm) and C. citratus EO (LC50 = 246.17 ppm; LC90 = 516.36 ppm) as compared to pure EO of C. longa (LC50 = 47.70 ppm, LC90 = 90.51 ppm) and C. citratus (LC50 = 95.69 ppm; LC90 = 160.94 ppm). The present study concluded that EOs filled hydrogel nurdles offers promising and effective larvicides against Ae. aegypti larvae.