Effects of neonicotinoid insecticide formulations and their components on Daphnia magna – the role of active ingredients and co-formulants

AbstractImidacloprid (Imid), a systemic neonicotinoid insecticide, is broadly used worldwide. It is reported to contaminate aquatic systems. This study was proposed to evaluate oxidative stress and genotoxicity of Imid on Nile tilapia (Oreochromis niloticus) and the protective effect of ascorbic acid (Asc). O. niloticus juveniles (30.4 ± 9.3 g, 11.9 ± 1.3 cm) were divided into six groups (n = 10/replicate). For 21 days, two groups were exposed to sub-lethal concentrations of Imid (8.75 ppm, 1/20 of 72 h-LC50 and 17.5 ppm, 1/10 of 72 h-LC50); other two groups were exposed to Asc (50 ppm) in combination with Imid (8.75 and 17.5 ppm); one group was exposed to Asc (50 ppm) in addition to a group of unexposed fish which served as controls. Oxidative stress was assessed in the liver where the level of enzymatic activities including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in addition to mRNA transcripts and, Lipid peroxidation (LPO) were evaluated. Moreover, mitotic index (MI) and comet assay were performed, in addition, the erythrocytic micronucleus (MN), and nuclear abnormalities (NA) were observed to assess genotoxicity in fish. Imid exposure induced significant (p ˂ 0.05) changes in the antioxidant profile of the juveniles' liver by increasing the activities and gene expression of SOD, CAT and GPX as well as elevating the levels of LPO. DNA strand breaks in gill cells, erythrocytes and hepatocytes along with erythrocytic MN and NA were also significantly elevated in Imid-exposed groups. MI showed a significant (p ˂ 0.05) decrease associated with Imid exposure. Asc administration induced a significant amelioration towards the Imid toxicity (8.75 and 17.5 ppm). A significant protective potency against the genotoxic effects of Imid was evidenced in Asc co-treated groups. Collectively, results highlight the importance of Asc as a protective agent against Imid-induced oxidative stress and genotoxicity in O. niloticus juveniles.

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Uncovering the most effective active ingredients of antismoking public service announcements: The role of actor and message characteristics

Nicotine & Tobacco Research ◽

10.1093/ntr/ntp045 ◽

2009 ◽

Vol 11 (5) ◽

pp. 547-552 ◽

Cited By ~ 11

Author(s):

William G. Shadel ◽

Craig S. Fryer ◽

Shannah Tharp-Taylor

Keyword(s):

Public Service ◽

Public Service Announcements ◽

Active Ingredients

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BIOLOGICAL CONTROL OF WHITEFLY BY SPECIES OF LADYBUG Delphastus spp.

Revista Mundi Engenharia Tecnologia e Gestão (ISSN 2525-4782) ◽

10.21575/25254782rmetg2020vol5n71122 ◽

2020 ◽

Vol 5 (7) ◽

Author(s):

Greissi Tente Giraldi ◽

Julio César Guerreiro ◽

Cawana Parrow Augusto ◽

Thainara Ferreira Alves Pessoa ◽

Luiz Gustavo Dos Santos ◽

...

Keyword(s):

Biological Control ◽

Natural Enemies ◽

Crop Productivity ◽

Insect Population ◽

Staple Food ◽

Active Ingredients ◽

Pest Population ◽

Critical Damage

Whitefly complex is one of the most severe pests affecting different crops of significant agricultural interest. It causes critical damage to plants, and hence considerably affect crop productivity and the related commercials. This insect has been managed using insecticides; however, there have been reports of resistance of this insecticide to various active ingredients, making it difficult to reduce this pest’s population. Hence, other ways of handling this insect population have been investigated, including through biological control. Several past studies have reported the existence of natural enemies of the whitefly, including coccinellids such as those belonging to the genus Delphastus have gained much attention. These coccinellids are predators and hence perform the important role of controlling pest population. Moreover, the whitefly is a staple food in certain diets.

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Uptake and impacts of polyvinylpyrrolidone (PVP) capped metal oxide nanoparticles on Daphnia magna: role of core composition and acquired corona

Environmental Science Nano ◽

10.1039/c8en00063h ◽

2018 ◽

Vol 5 (7) ◽

pp. 1745-1756 ◽

Cited By ~ 16

Author(s):

S. M. Briffa ◽

F. Nasser ◽

E. Valsami-Jones ◽

I. Lynch

Keyword(s):

Metal Oxide ◽

Daphnia Magna ◽

Metal Oxide Nanoparticles ◽

Oxide Nanoparticles ◽

Core Composition

A key hypothesis in nanosafety assessment is that the NP core chemistry and eco-corona are primary factors controlling toxicity.

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Neonicotinoids: Spreading, Translocation and Aquatic Toxicity

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17062006 ◽

2020 ◽

Vol 17 (6) ◽

pp. 2006 ◽

Cited By ~ 4

Author(s):

Mária Mörtl ◽

Ágnes Vehovszky ◽

Szandra Klátyik ◽

Eszter Takács ◽

János Győri ◽

...

Keyword(s):

Acetylcholine Receptors ◽

Environmental Fate ◽

Aquatic Toxicity ◽

Helix Pomatia ◽

Affecting Factors ◽

Active Ingredients ◽

Coating Materials ◽

Maize Seeds ◽

Neonicotinoid Insecticide ◽

Snail Helix Pomatia

Various environmental and ecotoxicological aspects related to applications of neonicotinoid insecticides are assessed. Dosages of neonicotinoids applied in seed coating materials were determined and are compared to other applications (spray and granule). Environmental levels in soils and affecting factors in translocation are discussed. Excretion of neonicotinoids via guttation from coated maize seeds up to two months upon emergence, as well as cross-contamination of plants emerged from non-coated seeds or weeds nearby have been demonstrated. Contamination of surface waters is discussed in scope of a worldwide review and the environmental fate of the neonicotinoid active ingredients and the formulating surfactant appeared to be mutually affected by each other. Toxicity of neonicotinoid active ingredients and formulations on Daphnia magna completed with some investigations of activity of the detoxifying glutathione S-transferase enzyme demonstrated the modified toxicity due to the formulating agents. Electrophysiological results on identified central neurons of the terrestrial snail Helix pomatia showed acetylcholine antagonist (inhibitory) effects of neonicotinoid insecticide products, but no agonist (ACh-like) effects were recorded. These data also suggested different molecular targets (nicotinergic acetylcholine receptors and acetylcholine esterase enzyme) of neonicotinoids in the snail central nervous system.

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The role of spore morphology in horizontal transmission of a microsporidium of Daphnia

Parasitology ◽

10.1017/s0031182018000392 ◽

2018 ◽

Vol 145 (11) ◽

pp. 1452-1457 ◽

Cited By ~ 3

Author(s):

Hadas Urca ◽

Frida Ben-Ami

Keyword(s):

Daphnia Magna ◽

Horizontal Transmission ◽

Spore Morphology ◽

Infection Rates ◽

Microsporidian Parasite ◽

Parasite Isolate ◽

Theoretical Predictions ◽

Host Mortality ◽

Host Clone

AbstractThe microsporidian parasite Hamiltosporidium tvaerminnensis can infect Daphnia magna both horizontally (through environmental spores) and vertically (through parthenogenetic and sexually produced eggs). The spores of H. tvaerminnensis come in three distinguishable morphologies, which are thought to have different roles in the transmission of the parasite. In this study, we examined the role of the two most common spore morphologies (i.e. oval-shaped spores and pear-shaped spores) in horizontal transmission of H. tvaerminnensis. To this end, we infected hosts with solutions consisting of either mostly oval- or mostly pear-shaped spores, and quantified infection rates, parasite-induced host mortality and mean number of parasite spores produced per host. We found that spore morphology by itself did not influence infection rates and parasite-induced host mortality. Instead, host clone and parasite isolate interacted with spore morphology in shaping infection outcome and mortality. Thus, there appear to be strong genotype-by-genotype (G × G) interactions in this system. While there is no dispute that H. tvaerminnensis can transmit both vertically and horizontally, our findings do not support theoretical predictions that different spore morphologies hold different roles in horizontal transmission of H. tvaerminnensis.

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