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1.
Toxicol Lett ; 322: 32-38, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31923464

RESUMO

Neonicotinoids (NNs), a widely used class of systemic pesticides, are regarded as exhibiting selective toxicity in insects. However, NNs are suspected of exerting adverse effects on mammals as well, including humans. To date, only adult male animal models have been subjected to general toxicity studies of NNs; fetuses have yet to be considered in this context. Here, we focused on the NN clothianidin (CLO) for the first quantitative LC-MS/MS analysis of maternal-to-fetal transfer and residual property of once-daily (single or multiple days), orally administered CLO and its metabolites in mice. The results revealed the presence of CLO and its five metabolites at approximately the same respective blood levels in both dams and fetuses. In the dams, CLO showed a peak value 1 h after administration, after which levels rapidly decreased at 3 and 6 h. In the fetuses of each group, levels of CLO were almost the same as those observed in the corresponding dams. The present results clearly demonstrated rapid passage of CLO through the placental barrier. However, metabolite-dependent differences observed in blood pharmacokinetics and residual levels. This is the first quantitative demonstration of the presence of CLO and its metabolites in fetal mouse blood.


Assuntos
Sangue Fetal/metabolismo , Guanidinas/sangue , Inseticidas/sangue , Troca Materno-Fetal , Neonicotinoides/sangue , Tiazóis/sangue , Animais , Biotransformação , Feminino , Guanidinas/administração & dosagem , Guanidinas/farmacocinética , Guanidinas/toxicidade , Inseticidas/administração & dosagem , Inseticidas/farmacocinética , Inseticidas/toxicidade , Exposição Materna , Camundongos Endogâmicos ICR , Neonicotinoides/administração & dosagem , Neonicotinoides/farmacocinética , Neonicotinoides/toxicidade , Gravidez , Medição de Risco , Tiazóis/administração & dosagem , Tiazóis/farmacocinética , Tiazóis/toxicidade , Toxicocinética
2.
Environ Technol ; 41(5): 539-546, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30051762

RESUMO

The imidacloprid was mineralized by heterogeneous photo-Fenton process in a three-phase fluidized bed reactor using waste iron oxide as catalyst. The effects of catalyst loading, dosage of H2O2 and pH were investigated to determine the optimal experiments conditions. The results revealed that TOC removal efficiency increases with an increase in H2O2 dosage of up to 105.0 mM, an increase in catalyst dosage from 1.0 to 5.0 g L-1, and a decrease in pH from 5.0 to 3.5. Under the optimal conditions, 97.7% TOC removal was achieved in 6 h under 254-nm UV irradiation. Moreover, recycling experiments indicated that the waste iron oxide had a good stability and the TOC removal of pesticide yielded more than 80% under the fourth recycles.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Peróxido de Hidrogênio , Ferro , Neonicotinoides , Nitrocompostos , Oxirredução , Eliminação de Resíduos Líquidos
3.
Ecotoxicol Environ Saf ; 188: 109891, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31740236

RESUMO

The study focuses on degradation efficiency of non-radical activation and radical activation systems of persulfate (PS) to degrade imidacloprid (IMI) by using sodium persulfate (SPS) as PS source. Copper oxide (CuO)-SPS and CuO/biochar (BC)-SPS were selected as PS non-radical activation systems, and pyrite (PyR)-SPS was selected as PS radical activation system. The degradation by CuO-SPS, CuO/BC-SPS and PyR-SPS systems was investigated from acidic to basic conditions (pH 3.0-11.0). Highest degradation by CuO-SPS and CuO/BC-SPS systems was achieved over pH 11.0. In contrast, highest degradation by PyR-SPS system was achieved over pH 3.0, however, PyR-SPS system was also found effective up to pH 9.0. It was found that degradation was more efficient in PS radical activation system, indicating that IMI could be oxidized by radicals rather than by activated PS. Electron paramagnetic resonance (EPR) analysis was carried out to investigate the generation of sulfate (SO4-) and hydroxyl (OH) radicals, which indicated the presence of SO4- and OH in CuO-SPS, CuO/BC and PyR-SPS systems. However, free radical quenching analysis indicated that radicals were main reactive oxygen species for degradation. The lower degradation in PS non-radical activation systems was probably resulted from radicals existed as minor reactive oxygen species. The findings indicated that non-radical oxidation systems showed low reality for degradation and good degradation could be achieved by radical oxidation system. The degradation was also carried out in real waters to investigate the potential applicability of applied systems, which supported PyR-SPS system for effective degradation.


Assuntos
Carvão Vegetal/química , Cobre/química , Radicais Livres/química , Neonicotinoides/análise , Nitrocompostos/análise , Compostos de Sódio/química , Sulfatos/química , Poluentes Químicos da Água/análise , Concentração de Íons de Hidrogênio , Radical Hidroxila/química , Ferro/química , Modelos Teóricos , Oxirredução , Sulfetos/química , Purificação da Água
4.
Chemosphere ; 240: 124926, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31726586

RESUMO

Insect pollinators such as bees and syrphid flies play a crucial role in pollinating many food crops, and their diversity and abundance may be influenced by pesticide application patterns. Over three years, we assessed the ecotoxicological impacts on the diversity and abundance of bees and syrphid flies between reduced-risk pesticide programs and standard, conventional pesticide programs in paired plots at six spatially distinct commercial apple orchards. In particular, we quantified pesticide inputs, environmental impact, and community response of bees and syrphids to these pesticide programs. Relative environmental impacts of reduced-risk versus conventional pesticide programs were calculated using Environmental Impact Quotient analysis, while ecological impacts were characterized by assessing the abundance, richness, and species assemblages of bees and syrphids. Adopting a reduced-risk pesticide program for apple pest management reduced the use (in terms of kg a.i./ha) of organophosphate and pyrethroid insecticides by approximately 97.6% and 100% respectively, but increased the use of neonicotinoid pesticides (acetamiprid, imidacloprid, thiacloprid) by 40.4% compared to the orchards under standard conventional pesticide program. Regardless of pesticide inputs, abundance, richness and species assemblages of bees and syrphids did not differ between reduced-risk and conventional pest management programs. However, the environmental impact of pesticide inputs was reduced by 89.8% in reduced-risk pesticide program. These findings suggest that the implementation of reduced-risk pesticide program may reduce pesticide environmental impact, in addition to being safer to farm workers, without adversely affecting the robust community composition of bees and syrphids in commercial apple orchards in the mid-Atlantic region.


Assuntos
Produtos Agrícolas , Malus , Controle de Pragas/métodos , Praguicidas , Polinização , Animais , Abelhas , Ecotoxicologia , Meio Ambiente , Insetos , Inseticidas , Neonicotinoides , Nitrocompostos , Piretrinas , Tiazinas
5.
Chemosphere ; 240: 124857, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31726599

RESUMO

Colorado potato beetle, Leptinotarsa decemlineata Say (coleoptera: chrysomelidae), is the important pest of potato all over the world. This insect pest is resistant to more than 50 active compounds belonging to various chemical groups. Potential of RNA interference (RNAi) was explored to knock down transcript levels of imidacloprid resistant genes in Colorado potato beetle (CPB) under laboratory conditions. Three important genes belonging to cuticular protein (CP), cytochrome P450 monoxygenases (P450) and glutathione synthetase (GSS) families encoding imidacloprid resistance were targeted. Feeding bio-assays were conducted on various stages of imidacloprid resistant CPB lab population by applying HT115 expressing dsRNA on potato leaflets. Survival rate of insects exposed to CP-dsRNA decreased to 4.23%, 15.32% and 47.35% in 2nd, 3rd and 4th instar larvae respectively. Larval weight and pre-adult duration were also affected due to dsRNAs feeding. Synergism of RNAi with imidacloprid conducted on the 2nd instar larvae, exhibited 100% mortality of larvae when subjected to reduced doses of GSS and CP dsRNAs along with imidacloprid. Utilization of three different dsRNAs against imidacloprid resistant CPB population reveal that dsRNAs targeting CP, P450 and GSS enzymes could be useful tool in management of imidacloprid resistant CPB populations.


Assuntos
Besouros/genética , Resistência a Medicamentos/genética , Genes de Insetos , Inseticidas/farmacologia , Larva/metabolismo , Neonicotinoides/farmacologia , Nitrocompostos/farmacologia , Animais , Besouros/efeitos dos fármacos , Besouros/crescimento & desenvolvimento , Sistema Enzimático do Citocromo P-450/genética , Regulação para Baixo , Resistência a Medicamentos/efeitos dos fármacos , Glutationa Sintase/genética , Larva/efeitos dos fármacos , Larva/genética , Interferência de RNA/efeitos dos fármacos , Solanum tuberosum/crescimento & desenvolvimento
6.
Sci Total Environ ; 700: 134914, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31706094

RESUMO

In the present work, the marine invertebrate Mytilus galloprovincialis was used as model organism to evaluate the toxic effects of the neonicotinoid Calypso 480 SC (CAL) following 20 days of exposure to sub-lethal concentrations of 7.77 mg L-1 (0.1% 96 h-LC50) and 77.70 mg L-1 (1% 96 h-LC50), and a recovery period of 10 days in uncontaminated seawater. Results revealed that exposure to both concentrations of CAL increased significantly mortality rate in the cells of haemolymph and digestive gland, while digestive gland cells were no longer able to regulate cell volume. Exposure significantly reduced haemolymph parameters (Cl-, Na+), affected the enzymatic activities of superoxide dismutase of digestive gland and catalase of gill, and caused also histopathological alterations in digestive gland and gills. Main histological damages detected in mussels were lipofuscin accumulation, focal points of necrosis, mucous overproduction and infiltrative inflammations. Interestingly, alterations persisted after the recovery period in CAL-free water, especially for haemocyte parameters (K+, Na+, Ca2+, lactate dehydrogenase, glucose). A slight recovery of histological conditions was detected. These findings suggested that sub-chronic exposure to the neonicotinoid insecticide caused significant alterations in both cell and tissue parameters of M. galloprovincialis. Considering the ecologically and commercially important role of mussels in coastal waters, a potential risk posed by neonicotinoids to this essential aquatic resource can be highlighted.


Assuntos
Inseticidas/toxicidade , Mytilus/fisiologia , Neonicotinoides/toxicidade , Poluentes Químicos da Água/toxicidade , Animais
7.
Ecotoxicol Environ Saf ; 188: 109921, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31711778

RESUMO

The presence of pesticides in water has emerged as a momentous environmental issue over the past decades. Herein, a terbium doped Ti/PbO2 (denoted as Ti/PbO2-Tb) dimensionally stable Ti/PbO2-Tb anode has been successfully prepared by one-step electrodeposition path for electrocatalytic degradation of imidacloprid (IMD) wastewater with high efficiency. Ti/PbO2-Tb electrode presents higher oxygen evolution potential, lower charge transfer resistance, stronger stability, longer service lifetime and outstanding electrocatalytic activity than Ti/PbO2 electrode. The optimum condition for IMD oxidation is obtained by analyzing the effects of some critical operating parameters including temperature, initial pH, current density and electrolyte concentration. It is proved that 70.05% of chemical oxygen demand and 76.07% of IMD are removed after 2.5 h of degradation under current density of 8 mA cm-2, pH 9, temperature 30 °C and 7.0 g L-1 NaCl electrolyte. In addition, the electrode displays commendable energy saving property as well as favorable reusability. The degradation mechanism of IMD is proposed by analyzing the intermediates identified by LC-MS. The present research provides a feasible strategy to degrade IMD wastewater by Ti/PbO2-Tb electrode.


Assuntos
Técnicas Eletroquímicas/métodos , Neonicotinoides/análise , Nitrocompostos/análise , Térbio/química , Águas Residuárias/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Análise da Demanda Biológica de Oxigênio , Técnicas Eletroquímicas/instrumentação , Eletrodos , Chumbo/química , Oxirredução , Óxidos/química , Titânio/química
8.
Ecotoxicol Environ Saf ; 187: 109779, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31639643

RESUMO

UV-activated persulfate (UV/PS) and peroxymonosulfate (UV/PMS) processes as alternative methods for removal of imidacloprid (IMP) were conducted for the first time. The reaction rate constants between IMP and the sulfate or hydroxyl radical were calculated as 2.33×109  or 2.42×1010 M-1 s-1, respectively. The degradation of IMP was greatly improved by UV/PS and UV/PMS compared with only UV or oxidant. At any given dosage, UV/PS achieved higher IMP removal rate than UV/PMS. The pH range affecting the degradation in the UV/PS and UV/PMS systems were different in the ranges of 6-8 and 9 to 10. SO42-, F- and NO3- had no obvious effect on the degradation in the UV/PS and UV/PMS systems. CO32- and PO43- inhibited the degradation of IMP in the UV/PS system, while they enhanced the degradation in the UV/PMS system. Algae organic matters (AOM) were used to consider the impact of the degradation of IMP for the first time. The removal of IMP were restrained by both AOM and natural organic matters. The higher removal rate of IMP demonstrated that both UV/PS and UV/PMS were suitable for treating the water containing IMP, while UV/PS was cost-effective than UV/PMS based on the total cost calculation. Finally, the degradation pathways of IMP were proposed.


Assuntos
Neonicotinoides/análise , Nitrocompostos/análise , Peróxidos/química , Compostos de Sódio/química , Sulfatos/química , Raios Ultravioleta , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Cinética , Modelos Teóricos , Oxirredução , Peróxidos/efeitos da radiação , Compostos de Sódio/efeitos da radiação , Sulfatos/efeitos da radiação
9.
Chemosphere ; 239: 124799, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31518926

RESUMO

Terrestrial adult stages of freshwater insects may be exposed to pesticides by wind drift, over-spray, contact or feeding. However, studies addressing insecticide effects on freshwater invertebrates focus primarily on the impact of pesticides reaching the streams and potentially harming the aquatic juvenile stages. This is also reflected in the current risk assessment procedures, which do not include testing of adult freshwater insects. In order to assess the potential impact of insecticides on adult stages of freshwater insects, we exposed six common species to the insecticides Karate (lambda-cyhalothrin) and Confidor (imidacloprid). Dose-response relations were established, and LD50 estimates were compared to those of the honey bee, Apis mellifera L. (Hymenoptera: Apidae), which is the standard terrestrial test insect when pesticides are evaluated prior to commercial release. Generally, the tested species were more sensitive to the studied insecticides than the honey bee. In order to examine whether the sensitivity of adult stages of freshwater insects corresponds with the sensitivity of the juvenile stages of the same species, the ranking of the two life stages with respect to the toxicity of Karate was compared, revealing some correspondence, but also some dissimilarities. Our results strongly indicate that terrestrial adult stages of aquatic insects are not adequately protected by current risk assessment procedures.


Assuntos
Insetos/efeitos dos fármacos , Insetos/fisiologia , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Nitrilos/toxicidade , Nitrocompostos/toxicidade , Piretrinas/toxicidade , Animais , Abelhas/efeitos dos fármacos , Dinamarca , Relação Dose-Resposta a Droga , Ecotoxicologia/métodos , Inseticidas/administração & dosagem , Dose Letal Mediana , Neonicotinoides/administração & dosagem , Nitrilos/administração & dosagem , Nitrocompostos/administração & dosagem , Piretrinas/administração & dosagem , Rios , Especificidade da Espécie , Poluentes Químicos da Água/toxicidade
10.
Nat Ecol Evol ; 3(11): 1521-1524, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31666734

RESUMO

Recent research has shown that several managed bee species have specific P450 enzymes that are preadapted to confer intrinsic tolerance to some insecticides including certain neonicotinoids. However, the universality of this finding across managed bee pollinators is unclear. Here we show that the alfalfa leafcutter bee, Megachile rotundata, lacks such P450 enzymes and is >2,500-fold more sensitive to the neonicotinoid thiacloprid and 170-fold more sensitive to the butenolide insecticide flupyradifurone than other managed bee pollinators. These findings have important implications for the safe use of insecticides in crops where M. rotundata is used for pollination, and ensuring that regulatory pesticide risk assessment frameworks are protective of this species.


Assuntos
Inseticidas , 4-Butirolactona/análogos & derivados , Animais , Abelhas , Neonicotinoides , Polinização
11.
Parasit Vectors ; 12(1): 519, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31685011

RESUMO

BACKGROUND: Troglostrongylus brevior is a lungworm of wild felids that recently has been recognized as agent of severe respiratory disease in domestic cats in Mediterranean and Balkan countries. Nevertheless, the information on treatment options for feline troglostrongylosis is still poor. The aim of this pilot field trial was to evaluate the efficacy of the spot-on formulation containing 1% w/v moxidectin and 10% w/v imidacloprid (Advocate® spot-on solution for cats, Bayer Animal Health GmbH) in the treatment of T. brevior infection in naturally infected cats in Greece. METHODS: The trial was a negative control, multicentre, clinical efficacy study conducted according to the standards of Good Scientific Practice (GSP). Sixteen cats in two study sites, naturally infected with T. brevior, were allocated to an untreated control group (G1, n = 8) or a treatment group (G2, n = 8), according to a randomization list. Animals assigned to G2 were treated with Advocate® for cats on days 0 and 28 at the recommended dose rate and animals assigned to G1 received a rescue treatment with the same product on days 56 and 84. Efficacy was assessed on days 28 and 56 in G2 and on days 84 and 112 in G1 by faecal larval counts. The primary efficacy criterion was the absence of T. brevior first-stage larvae (L1) following treatment. Other efficacy parameters were the quantitative comparison of L1 presence before (baseline) and after one or two treatments in both groups. RESULTS: All G2 cats were negative for T. brevior L1 at the first post-treatment evaluation (100% efficacy) while G1 cats were persistently shedding L1. The difference of the mean number of L1 per gram between G2 and G1 was statistically significant (P < 0.001). All G1 cats were negative (100% efficacy) for T. brevior L1 at the first post-rescue-treatment evaluation. Therefore, treatment efficacy at study completion was 100% in both groups in terms of stopping the L1 shedding in the faeces of the animals. No adverse effects were observed during the study. CONCLUSIONS: These results indicate that Advocate® spot-on solution for cats represents an option for treating cats naturally infected with T. brevior.


Assuntos
Doenças do Gato/tratamento farmacológico , Macrolídeos/uso terapêutico , Metastrongyloidea/efeitos dos fármacos , Neonicotinoides/uso terapêutico , Nitrocompostos/uso terapêutico , Infecções Respiratórias/veterinária , Infecções por Strongylida/veterinária , Animais , Doenças do Gato/parasitologia , Gatos , Combinação de Medicamentos , Fezes/parasitologia , Feminino , Grécia , Larva/efeitos dos fármacos , Masculino , Metastrongyloidea/isolamento & purificação , Infecções Respiratórias/tratamento farmacológico , Infecções Respiratórias/parasitologia , Infecções por Strongylida/tratamento farmacológico , Infecções por Strongylida/parasitologia
12.
Environ Pollut ; 255(Pt 1): 113075, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31671311

RESUMO

The widespread use of neonicotinoid insecticides is controversial due to their persistence in the environment and concern for the long-term consequences of their use. We present a simple, low-cost method for the sensitive and efficient extraction from soil of thiamethoxam, clothianidin and imidacloprid, the three neonicotinoid insecticides approved in New Zealand as seed coatings. We have validated this method by applying it to uncontaminated soil samples spiked with environmentally relevant concentrations of the three targets. Absolute recoveries were >80% with instrument detection limits <1 ng g-1 wet soil. We also applied the method to soil samples collected from maize fields in New Zealand's North Island and found imidacloprid in 43 out of 45 samples and clothianidin in every one. Mean imidacloprid concentrations varied from 0.5 to 9.4 ng g-1 (wet weight) and clothianidin from 2.1 to 26.7 ng g-1 (wet weight). Imidacloprid concentrations exceed the New Zealand Environmental Protection Agency's Environmental Exposure Limit of 1 ng g-1 (dry weight) at eight of the nine sites sampled. These results are remarkable because we have detected multiple neonicotinoid residues at every site sampled. Imidacloprid residues appear to persist at significant concentrations at five of our sites from an application at least two years previously. This is only the third study to report the presence of neonicotinoid residues in NZ's environment and the first to show that those residues are persistent in the environment at nominally hazardous concentrations.


Assuntos
Monitoramento Ambiental/métodos , Inseticidas/análise , Neonicotinoides/análise , Resíduos de Praguicidas/análise , Poluentes do Solo/análise , Zea mays/crescimento & desenvolvimento , Animais , Nova Zelândia , Sementes/crescimento & desenvolvimento , Solo/química
13.
Science ; 366(6465): 566-567, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31672878
14.
J Agric Food Chem ; 67(45): 12374-12381, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31613611

RESUMO

The uptake, distribution, metabolism, and degradation of three neonicotinoid insecticides (NIs)-imidacloprid (IMI), acetamiprid (ACE), and thiamethoxam (THI) in different parts of cotton plants were investigated under field conditions. Insecticides were either applied by foliar spraying or root irrigation. Foliar application resulted in high tissue concentration (average tissue concentration ratio, TCR: 46.78-68.61% for leaves and 12.2-31.40% for flowers). The flowers showed high NI residual. The metabolism and trends of NIs in different parts of cotton were reported here for the first time. Metabolites, toxic to bees, were detected in the flowers. The translocation factor was around 0.004 for the spray treatment and 0.2-0.7 for the root irrigation treatment. The average root concentration factors of IMI, ACE, and THI were 0.838, 8.027, and 1.014, respectively, indicating that the three NIs can be transported from the soil to the plant. The high concentrations of NIs and their metabolites in flowers indicate exposure risk to pollinators, such as bees.


Assuntos
Gossypium/metabolismo , Inseticidas/química , Inseticidas/metabolismo , Neonicotinoides/química , Neonicotinoides/metabolismo , Animais , Abelhas/efeitos dos fármacos , Transporte Biológico , Flores/metabolismo , Gossypium/química , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Folhas de Planta/química , Folhas de Planta/metabolismo , Raízes de Plantas/química , Raízes de Plantas/metabolismo
15.
Chem Biodivers ; 16(12): e1900428, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31637808

RESUMO

The present study was performed to assess the HPLC-DAD analysis as well as antioxidant and protective effects of Tunisian Rhanterium suaveolens (Rs) against acetamiprid (ACT) induced oxidative stress on mice erythrocytes. The in vitro assays showed that the methanolic extract of Rs has an impressive antioxidant effect proved by testing the total antioxidant and scavenging activities using BCB, DPPH and ABTS assays, respectively. Moreover, qualitative and quantitative analysis using HPLC-DAD revealed the richness of Rs in polyphenols where p-Coumaric, Apigenin-7-glucoside and Ferulic acid were detected as the most abundant polyphenols. In the in vivo experiment, ACT, used as a toxicity model, was given to mice at a dose of 20 mg/kg. The latter was the origin of hemolytic anemia characterized by a significant decrease in red blood cells, hemoglobin and hematocrit levels and an increase in bilirubin, LDH, osmotic fragility, reticulocytes and white blood cells number. Characteristic erythrocyte morphological alterations were also determined as spherocytosis, schistocytosis and dacryocystitis. The oxidative status of ACT-treated mice was also altered manifested by a significant increase in MDA and GSH levels and a decrease in SOD, CAT and GPx activities. When receiving the Rs methanolic extract at a dose of 300 mg/kg, all the parameters cited above were restored in mice. These remarkable corrections could only confirm the important antioxidant effect and the noticeable protective properties that possess Rs owing to its broad range of secondary bioactive metabolites.


Assuntos
Antioxidantes/análise , Asteraceae/química , Cromatografia Líquida de Alta Pressão/métodos , Neonicotinoides/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/análise , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Asteraceae/metabolismo , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Flavonoides/química , Flavonoides/farmacologia , Camundongos , Extratos Vegetais/química , Polifenóis/química , Polifenóis/farmacologia , Substâncias Protetoras/química , Substâncias Protetoras/farmacologia , Superóxido Dismutase/metabolismo , Tunísia
16.
Environ Entomol ; 48(6): 1418-1424, 2019 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-31630197

RESUMO

Our purpose is to determine whether extremely low concentrations of imidacloprid (2-8 ppb) typically found in field soil 1-3 yr after a crop is grown using seed with a standard imidacloprid seed-coating could impact the fitness of whiteflies, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae). Results of our experiments indicate that imidacloprid-resistant whitefly larvae feeding on cotton seedlings growing in soil with 8.0 ppb imidacloprid are conditioned so that when the same individuals feed on plants treated with imidacloprid as adults their fitness, measured as fecundity, increases 30-70% compared with individuals that were not primed as larvae. This conditioning hormesis stimulates resistant whiteflies more than susceptible whiteflies, which may contribute to the selection of resistant populations.


Assuntos
Hemípteros , Inseticidas , Animais , Hormese , Neonicotinoides , Nitrocompostos
17.
J Agric Food Chem ; 67(43): 12105-12116, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31600056

RESUMO

Sublethal exposure to neonicotinoids affects honey bee olfaction, but few studies have investigated the sublethal effects of the enantioselective neonicotinoid dinotefuran on honey bee olfaction. This study assessed the sublethal olfactory toxicity of dinotefuran enantiomers to honey bees. Compared to R-dinotefuran, S-dinotefuran had higher acute oral toxicity, sucrose sensitivity effects, octopamine concentrations, lower learning ability, and memory effects on honey bees. High-throughput circular RNA sequencing of the honey bee brain revealed that R-dinotefuran caused more gene regulatory changes than S-dinotefuran. Gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses demonstrated that the SERCA, Kca, and Maxik genes may be related to the enantioselective effects of dinotefuran isomers on honey bee olfaction. These results indicated that the current ecotoxicological safety knowledge about chiral dinotefuran effects on honey bees should be amended.


Assuntos
Abelhas/efeitos dos fármacos , Guanidinas/toxicidade , Inseticidas/química , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Animais , Abelhas/fisiologia , Guanidinas/química , Neonicotinoides/química , Nitrocompostos/química , Olfato/efeitos dos fármacos , Estereoisomerismo
18.
Chemosphere ; 235: 1097-1106, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31561300

RESUMO

Neonicotinoid insecticides show high persistence in the environment, and standard biological approaches such as biopurification systems have shown mostly inefficient removal of such compounds. In this work, soil pre-exposed to imidacloprid was used to obtain presumptive imidacloprid-degrading consortia. Cometabolic enrichment yielded a microbial consortium composed of eight bacterial and one yeast strains, capable of degrading not only this compound, but also thiamethoxam and acetamiprid, as demonstrated in cross-degradation assays. The biological removal process was scaled-up to batch stirred tank bioreactors (STBR); this configuration was able to simultaneously remove mixtures of imidacloprid + thiamethoxam or imidacloprid + thiamethoxam + acetamiprid, reaching elimination of 95.8% and 94.4% of total neonicotinoids, respectively. Removal rates in the bioreactors followed the pattern imidacloprid > acetamiprid > thiamethoxam, including >99% elimination of imidacloprid in 6 d and 17 d (binary and ternary mixtures, respectively). A comprehensive evaluation of the detoxification in the STBR was performed using different biomarkers: seed germination (Lactuca sativa), bioluminescence inhibition (Vibrio fischeri), and acute oral tests in honeybees. Overall, ecotoxicological tests revealed partial detoxification of the matrix, with clearer detoxification patterns in the binary mixture. This biological approach represents a promising option for the removal of neonicotinoids from agricultural wastewater; however, optimization of the process should be performed before application in farms.


Assuntos
Inseticidas/isolamento & purificação , Consórcios Microbianos , Neonicotinoides/isolamento & purificação , Purificação da Água/métodos , Agricultura , Animais , Abelhas , Ecotoxicologia/métodos , Inativação Metabólica , Inseticidas/análise , Neonicotinoides/metabolismo , Nitrocompostos/metabolismo , Águas Residuárias/química
19.
Curr Microbiol ; 76(12): 1461-1466, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31552451

RESUMO

Imidacloprid (C9H10ClN5O2) is used as the most recommended type of insecticide in vegetable farming worldwide. Two types of bacteria (Methylobacterium radiotolerans and Microbacterium arthrosphaerae) were isolated from a corn farming field in the Thrace region of Turkey, and then consortia of these bacteria were prepared from equal volumes of 107 CFU/ml for each bacterium type. Imidacloprid remediation studies were carried out during 18 days in soil test units. The water filtered from these soil test units was determined for chemical oxygen demand (COD) and biochemical oxygen demand (BOD5) to determine the optimum concentration of microorganisms to ascertain the best removal efficiency of Imidacloprid. COD removal rates were 98.7%, 96.4% and 51.6% with 80, 40, and 20 ml volumes of the consortia of bacteria, respectively, at the end of 18 days. The BOD5 removal rates were 88.4%, 78.6% and 49.9% in the same volumes of bacteria, respectively. As a result of this study, we have found that this bacterial consortium is very effective for the bioremediation of this insecticide at the two volumes of 40 and 80 ml, both being better than 20 ml.


Assuntos
Actinobacteria/metabolismo , Biodegradação Ambiental , Inseticidas/metabolismo , Methylobacterium/metabolismo , Neonicotinoides/metabolismo , Nitrocompostos/metabolismo , Poluentes do Solo/metabolismo , Análise da Demanda Biológica de Oxigênio , Consórcios Microbianos , Microbiologia do Solo
20.
Bull Environ Contam Toxicol ; 103(4): 507-514, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31529138

RESUMO

Systemic pesticides, such as the neonicotinoid imidacloprid, can be introduced into aquatic ecosystems through contaminated plant material, which is the basis for detrital (brown) aquatic food-webs. With the aim of exemplarily assessing for indirect effects on the level of predators, we first offered imidacloprid contaminated and uncontaminated alder leaves to the stonefly shredder Protonemura sp. for 72 h. Shredder survival, leaf decomposition, body length and biomass were all between 20% and 50% lower under imidacloprid exposure compared to uncontaminated conditions, indicating physiological implications. Subsequently, these shredders were provided as prey to stonefly predators (Isoperla sp.) kept in cages in a stream. Predator biomass and length decreased by up to 11% and 4.3%, respectively, when feeding on imidacloprid exposed prey. Our study hence suggests that plant material contaminated with systemic pesticides can exert adverse effects in aquatic predators when preying on shredders consuming such leaves, which warrants a further consideration of this pathway.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Cadeia Alimentar , Modelos Teóricos , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Praguicidas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/química , Neonicotinoides/análise , Nitrocompostos/análise , Praguicidas/análise , Poluentes Químicos da Água/análise
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