Fabrication of nano-mosquitocides using chitosan from crab shells: Impact on non-target organisms in the aquatic environment

Abstract

Mosquitoes are arthropods of huge medical and veterinary relevance, since they vector pathogens and parasites of public health importance, including malaria, dengue and Zika virus. Currently, nanotechnology is considered a potential eco-friendly approach in mosquito control research. We proposed a novel method of biofabrication of silver nanoparticles (AgNP) using chitosan (Ch) from crab shells. Ch-AgNP nanocomposite was characterized by UV-vis spectroscopy, FTIR, SEM, EDX and XRD. Ch-AgNP were tested against larvae and pupae of the malaria vector Anopheles stephensi obtaining LC50 ranging from 3.18 ppm (I) to 6.54 ppm (pupae). The antibacterial properties of Ch-AgNP were proved against Bacillus subtilis, Klebsiella pneumoniae and Salmonella typhi, while no growth inhibition was reported in assays conducted on Proteus vulgaris. Concerning non-target effects, in standard laboratory considtions the predation efficiency of Danio rerio zebrafishes was 68.8% and 61.6% against I and II instar larvae of A. stephensi, respectively. In a Ch-AgNP-contaminated environment, fish predation was boosted to 89.5% and 77.3%, respectively. Quantitative analysis of antioxidant enzymes SOD, CAT and LPO from hepatopancreas of fresh water crabs Paratelphusa hydrodromous exposed for 16 days to a Ch-AgNP-contaminated aquatic environment were conducted. Notably, deleterious effects of Ch-AgNP contaminating aquatic enviroment on the non-target crab P. hydrodromous were observed, particularly when doses higher than 8-10ppm are tested. Overall, this research highlights the potential of Ch-AGNP for the development of newer control tools against young instar populations of malaria mosquitoes, also highlighting some risks concerned the employ of nanoparticles in aquatic environments.

Artemisia absinthium-borne compounds as novel larvicides: effectiveness against six mosquito vectors and acute toxicity on non-target aquatic organisms

“…This is particularly true for studies focused on mosquito vectors. However, recent research showed that in some cases ultra-low doses of green-synthesized nanocomposites may boost the predation efficiency of natural enemies (e.g., copepods, tadpoles, and mosquito fishes) against mosquito young instars (e.g., Murugan et al 2015aMurugan et al ,b,c, 2016aSubramaniam et al 2015Subramaniam et al , 2016. As regards to genotoxicity, Murugan et al (2016c) recently reported no significant damages of Carassius auratus erythrocytes post-treatment with graphene quantum dots at doses lower than 25 ppm.…”

“…These problems highlighted the needing of new pest control alternatives, acceptable for the environment and human health (Benelli 2016a, b;Pavela and Benelli 2016). Among the existing alternative tools aimed at decreasing pest populations, the use of pesticides based on plant extracts is currently one of the most promising (Amer and Mehlhorn 2006a, b, c, d;Dubey 2011;Benelli 2016c;Govindarajan et al 2016a, b, c, d).…”

“…Among the existing alternative tools aimed at decreasing pest populations, the use of pesticides based on plant extracts is currently one of the most promising (Amer and Mehlhorn 2006a, b, c, d;Dubey 2011;Benelli 2016c;Govindarajan et al 2016a, b, c, d). Essential oils and related main compounds are also an environmentally interesting tool because they are biodegradable and have minimal side effects on non-target organisms, as well as on the environment (Govindarajan 2010;Govindarajan et al 2012Govindarajan et al , 2013Pavela 2014Pavela , 2015Benelli 2015b, c Govindarajan andBenelli 2016a, b).…”

Nanofabrication of Graphene Quantum Dots with High Toxicity Against Malaria Mosquitoes, Plasmodium falciparum and MCF-7 Cancer Cells: Impact on Predation of Non-target Tadpoles, Odonate Nymphs and Mosquito Fishes

“…For each instar, 200 mosquitoes were introduced with 1 fish, 1 dragonfly nymph or 1 tadpole in a 500-mL glass beaker filled with 250 mL of dechlorinated water plus the desired concentration of GQDs (i.e. 1/3 of the LC 50 calculated against the tested larval instar of A. stephensi, [57]. Mosquito larvae were replaced daily with new ones.…”

Do Chenopodium ambrosioides-Synthesized Silver Nanoparticles Impact Oryzias melastigma Predation Against Aedes albopictus Larvae?

“…The synthetic methods used for the preparation of AgNP rely to some toxic chemical used as reducing agents such as NaBH 4 , citrate or ascorbate. On the other hand, in plant-mediated reducing processes leading to the production of nanoparticles, no chemical reagent or surfactant template is required, which consequently enables the bioprocess with the advantage of being eco-friendly [13,[87][88][89][90].…”