Abstract
Aedes aegypti
is a primary vector of dengue and chikungunya. The use of synthetic insecticides to control
Aedes
populations often leads to high operational costs and adverse non-target effects. Botanical extracts have been proposed for rapid extracellular synthesis of mosquitocidal nanoparticles, but their impact against predators of mosquito larvae has not been well studied. We propose a single-step method for the biosynthesis of silver nanoparticles (AgNP) using the extract of
Artemisia vulgaris
leaves as a reducing and stabilizing agent. AgNP were characterized by UV–vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). SEM and XRD showed that AgNP were polydispersed, crystalline, irregularly shaped, with a mean size of 30–70 nm. EDX confirmed the presence of elemental silver. FTIR highlighted that the functional groups from plant metabolites capped AgNP, stabilizing them over time. We investigated the mosquitocidal properties of
A. vulgaris
leaf extract and green-synthesized AgNP against larvae and pupae of
Ae. aegypti
. We also evaluated the predatory efficiency of Asian bullfrog tadpoles,
Hoplobatrachus tigerinus
, against larvae of
Ae. aegypti
, under laboratory conditions and in an aquatic environment treated with ultra-low doses of AgNP. AgNP were highly toxic to
Ae. aegypti
larval instars (I–IV) and pupae, with LC
50
ranging from 4.4 (I) to 13.1 ppm (pupae). In the lab, the mean number of prey consumed per tadpole per day was 29.0 (I), 26.0 (II), 21.4 (III), and 16.7 (IV). After treatment with AgNP, the mean number of mosquito prey per tadpole per day increased to 34.2 (I), 32.4 (II), 27.4 (III), and 22.6 (IV). Overall, this study highlights the importance of a synergistic approach based on biocontrol agents and botanical nano-insecticides for mosquito control.