title: Predation by Asian bullfrog tadpoles, Hoplobatrachus tigerinus, against the dengue vector, Aedes aegypti, in an aquatic environment treated with mosquitocidal nanoparticles.
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 LC50 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.
authors.affiliation: Division of Entomology, Department of Zoology, School of Life sciences, Bharathiar University, Coimbatore, 641 046, Tamil Nadu, India.
authors.forename: Kadarkarai
authors.initials: K
authors.lastname: Murugan
authors.forename: Vishwanathan
authors.initials: V
authors.lastname: Priyanka
authors.forename: Devakumar
authors.initials: D
authors.lastname: Dinesh
authors.forename: Pari
authors.initials: P
authors.lastname: Madhiyazhagan
authors.forename: Chellasamy
authors.initials: C
authors.lastname: Panneerselvam
authors.forename: Jayapal
authors.initials: J
authors.lastname: Subramaniam
authors.forename: Udaiyan
authors.initials: U
authors.lastname: Suresh
authors.forename: Balamurugan
authors.initials: B
authors.lastname: Chandramohan
authors.forename: Mathath
authors.initials: M
authors.lastname: Roni
authors.forename: Marcello
authors.initials: M
authors.lastname: Nicoletti
authors.forename: Abdullah A
authors.initials: AA
authors.lastname: Alarfaj
authors.forename: Akon
authors.initials: A
authors.lastname: Higuchi
authors.forename: Murugan A
authors.initials: MA
authors.lastname: Munusamy
authors.forename: Hanem F
authors.initials: HF
authors.lastname: Khater
authors.forename: Russell H
authors.initials: RH
authors.lastname: Messing
authors.forename: Giovanni
authors.initials: G
authors.lastname: Benelli
mesh_terms: D000330:Aedes / Q000502:physiology*; D000818:Animals; D019306:Artemisia / Q000737:chemistry; D007306:Insecticides / Q000737:chemistry / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D053768:Metal Nanoparticles / Q000737:chemistry*; D009032:Mosquito Control / Q000379:methods; D010936:Plant Extracts / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry; D011235:Predatory Behavior / Q000502:physiology*; D011892:Rana catesbeiana / Q000502:physiology*; D012834:Silver / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D007306:Insecticides; D010936:Plant Extracts; D012834:Silver