Mycosynthesis of Silver Nanoparticles (Trichoderma viride, Trichoderma longibrachiatum) and their Mosquito Larvicidal Efficacy on Dengue Vectors and Acute Toxicity on Moina macrocopa

Abstract

Current study is based on the larvicidal effect of mycosynthesized siver nanopartices (AgNPs) from Trichoderma longibrachiatum (Tl-AgNPs) and Trichoderma viride (Tv-AgNPs) on Aedes aegypti and Aedes albopictus dengue vectors and non-targeted aquatic crustacean, Moina macrocopa. Mosquito larvae were exposed to each test concentration (10 to 50 mg L-1) of Tl-AgNPs and Tv-AgNPs separately with three replicates containing 25 larvae each. The AgNPs characterization confirmed the formation of Tl-AgNPs and Tv-AgNPs in the UV-Vis spectrum with the surface plasmon resonance (SPR) band at 430 nm, existence of biomolecules and stabilizing agents on the AgNPs in FTIR spectroscopy and the presence of spherical shape AgNPs in a size range of 15-20 nm in TEM. The total larval exposure period was 48 h in order to evaluate 24 and 48 h larval mortalities and the toxicity effects on Moina macrocopa were also evaluated. LC50 were recorded as 14.68 mg L-1,14.05 mg L-1 after 24 h and 13.4 mg L-1, 12.94 mg L-1 after 48 h of exposure to A. aegypti and A. albopictus, respectively for Tl-AgNPs. The LC50 for Tv AgNPs were recorded as 12.08 mg L-1,14.05 mg L-1 after 24 h and 13.4 mg L-1, 12.94 mg L-1 after 48 h exposure for A. aegypti and A. albopictus, respectively. The Tv-AgNPs are reported to be more toxic for M. macrocopa after 48 h exposure with LC50 0.167 ppm, LC90 0.291 ppm for Tl-AgNPs and LC50 0.155, LC90 0.248 ppm for Tv-AgNPs. This study concludes Tl- AgNPs and Tv-AgNPs could be used as potential larvicide for dengue vector control. Results confirmed that Tv-AgNPs are more effective than Tl-AgNPs in controlling mosquito larvae. However, there is a potential threat to other non-targeted organisms in the practical aspects of this treatment.