Characterisation and optimisation of Azolla with silver nitrate mixture as insecticides against Aedes Aegypti (Dipetra: Culicidae)

The family of mosquitoes (Dipetra:Culicidae) contains several species which act as vectors spreading diseases to human causing a major public health. one of these species, Aedes Aegypti, is widely known due to its responsible in transmitting vector-borne viruses affecting humankind such as chikungunya, Zika and dengue fever. Traditionally, chemical insecticides were used to control the spreading of Ae. aegypti. However, the prolonged use of chemical insecticides has caused significant adverse effects on environmental and the mosquitoes has developed a resistance to insecticides, thus dramatically reducing their efficiency. Therefore, alternative and safer way was needed to combat the spreading of deadly diseases causing by Aedes aegypti. In that context, this research aimed to establish the efficacy of synthesized silver nanoparticles using Azolla microphylla extract (AZO-AgNPs) as insecticides against late third instar larvae of Aedes aegypti. The synthesized nanoparticles were characterized with UV-Visible spectroscopy and Fourier transform infrared spectroscopy. UV-Visible spectrophotometer showed absorbance peak in range of 410 nm to 510 nm. FT-IR analysis show peaks at 3327:91 and 1636.18 cm-1 which shows the presence reductive and capping agents in plant extract. To perform larvicidal test, third instar Ae. aegypti were exposed to 8 concentrations ranging from 20 to 37 ppm. The result shows the values of LC50 is 31.680 ppm while LC90 is 43.610 ppm. These result suggest that synthesized silver nanoparticles using A. microphylla extract (AZO-AgNPs) exhibit noteworthy larvicidal activity and should be further explored as potential source of alternative tools in the fight against insect vectors of human disease.