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1.
Arq. Inst. Biol ; 87: e1132018, 2020. tab, graf
Article in English | ID: biblio-1130106

ABSTRACT

This study evaluates the effects of combinations of pyrethroids and neonicotinoids on the control of stink bugs at different stages of soybean crop development. The experiment was set up in a factorial randomized block design (4×6: 4 treatments and 6 stages) with 4 repetitions. The following treatments were tested during the V6/V7, R2, R4, R5.1, R5.5 and R 6 phenological stages: 1 ­ control (no application), 2 ­ thiamethoxam + λ-cyhalothrin, 3 ­ acetamiprid + α-cypermethrin, and 4 ­ dinotefuran + α-cypermethrin. Infestation, number of damaged seeds, number of pods, number of pods per plant, and yield (kg/ha) were evaluated. Stink bug infestations were smaller when applications commenced during the vegetative stages (V6-V8). Pod numbers and yields were highest in the dinotefuran + α-cypermethrin treatment with applications from V6/V8 to R4. The active ingredients dinotefuran + α-cypermethrin reduced stink bug populations and increased yields and could therefore be considered in integrated pest management (IPM) programs for soybean crops.(AU)


O objetivo deste trabalho foi avaliar o efeito de combinações de piretroides com neonicotinoides no controle de percevejos em diferentes estádios de desenvolvimento da cultura da soja. O delineamento experimental foi em blocos randomizados, em esquema fatorial 4×6 (4 tratamentos e 6 estádios) com 4 repetições. Os produtos utilizados foram: 1 ­ testemunha (sem aplicação), 2 ­ tiametoxam + λ-cialotrina, 3 ­ acetamiprida + α-cipermetrina, e 4 ­ dinotefuran + α-cipermetrina, e as aplicações foram realizadas a partir dos estádios fenológicos V6/V7,R2, R4, R5.1, R5.5 e R6. Avaliaram-se a infestação, número de grãos danificados, número de vagens, número de vagens por planta e produtividade (kg/ha). A infestação de percevejo foi menor quando se iniciou a aplicação precocemente nos estádios vegetativos (V6-V8).O número de vagens e produtividade foi superior no tratamento dinotefuran + α-cipermetrina nos estádios V6/V8 até R4. Os ingredientes ativos dinotefuran + α-cipermetrina apresentaram resultados positivos na redução da população de percevejo e proporcionaram incremento no rendimento de grão, podendo ser utilizado como opção em programa de manejo integrado de pragas (MIP) na cultura da soja.(AU)


Subject(s)
Soybeans , Pest Control , Cimicidae , Pyrethrins , Neonicotinoids , Fungi
2.
An. acad. bras. ciênc ; 90(1): 239-245, Mar. 2018. tab
Article in English | LILACS | ID: biblio-886915

ABSTRACT

ABSTRACT This study evaluated the in vitro toxicity and motor activity changes in African-derived adult honey bees (Apis mellifera L.) exposed to lethal or sublethal doses of the insecticides fipronil and imidacloprid. Mortality of bees was assessed to determine the ingestion and contact lethal dose for 24 h using probit analysis. Motor activities in bees exposed to lethal (LD50) and sublethal doses (1/500th of the lethal dose) of both insecticides were evaluated in a behavioral observation box at 1 and 4 h. Ingestion and contact lethal doses of fipronil were 0.2316 ? 0.0626 and 0.0080 ? 0.0021 μg/bee, respectively. Ingestion and contact lethal doses of imidacloprid were 0.1079 ? 0.0375 and 0.0308 ? 0.0218 μg/bee, respectively. Motor function of bees exposed to lethal doses of fipronil and imidacloprid was impaired; exposure to sublethal doses of fipronil but not imidacloprid impaired motor function. The insecticides evaluated in this study were highly toxic to African-derived A. mellifera and caused impaired motor function in these pollinators.


Subject(s)
Animals , Pyrazoles/toxicity , Bees/drug effects , Neonicotinoids/toxicity , Insecticides/toxicity , Motor Activity/drug effects , Nitro Compounds/toxicity , Bees/physiology , Behavior, Animal/drug effects , Lethal Dose 50
3.
Pesqui. vet. bras ; 37(4): 307-312, Apr. 2017. graf, ilus
Article in Portuguese | ID: biblio-895416

ABSTRACT

Este estudo avaliou a toxicidade aguda e crônica de um inseticida a base de tiametoxam para peixes da espécie Pacamã (Lophisiolurus alexandri), avaliando a CL50%, além de alterações histopatológicas hepáticas em animais expostos por 96 horas e 15 dias ao inseticida. Para tanto foram utilizados 120 alevinos submetidos a cinco diferentes concentrações do inseticida (30, 60, 120, 240 e 480mg/L) por 15 dias, com dois tempos amostrais, 96 horas e 15 dias. Não houve mortalidade significativa durante todo o período experimental, no entanto os animais apresentaram alterações como vacuolização citoplasmática, congestão e necrose. A CL50% foi determinada como superior a 100mg/L, considerada praticamente não tóxico. A necrose foi a alteração melhor evidenciada nos animais expostos, com o aumento da ocorrência nos animais do teste de toxicidade crônica.(AU)


This research evaluated acute and chronic toxicity of a thiamethoxam insecticide for Pacamã (Lophisiolurus alexandri), assessing the LC50 and liver histopathological changes in animals exposed for 96 hours and 15 days. Therefore, were used 120 fingerlings subjected to five different concentrations (30, 60, 120, 240 and 480mg/L) for 15 days with two sampling times, 96 hours and 15 days. There was no significant mortality during the experimental period, however the animals showed changes as vacuolation, congestion and necrosis. The LC50 was determined as greater than 100mg/L, considered practically non-toxic. Necrosis was the more significant change in exposed animals, with increasing occurrence in chronic toxicity test.(AU)


Subject(s)
Animals , Catfishes , Agrochemicals/adverse effects , Neonicotinoids/adverse effects , Agro Toxic Maximum Allowable Limit on Food , Lethal Dose 50
4.
Med. U.P.B ; 35(1): 41-46, ene.-jun. 2016.
Article in Spanish | LILACS, COLNAL | ID: biblio-837067

ABSTRACT

Las intoxicaciones por plaguicidas son la segunda causa de intoxicación en Colombia. Los neonicotinoides son un nuevo grupo de insecticidas que actúa a través de los receptores nicotínicos. Las principales manifestaciones clínicas que se han asociado con dicha intoxicación son alteraciones neurológicas y autonómicas. En este reporte se presentan dos casos de pacientes que ingirieron tiametoxan e imidacloprid y presentaron compromiso del sensorio y de sus signos vitales, por lo que se acudió a manejo en unidad de cuidados intensivos. El objetivo de este reporte es sensibilizar sobre el creciente uso de estos plaguicidas y la necesidad de identificarlos para hacer un diagnóstico diferencial con otras sustancias, realizar un uso adecuado de ayudas diagnósticas y un manejo inicial pertinente para asegurar la vía área y corregir alteraciones hemodinámicas para prevenir complicaciones.


Pesticide poisoning is the second cause of poisoning in Colombia. Neonicotinoids are a new group of insecticides that act through nicotinic receptors. The main clinical manifestations that have been associated with such poisoning are neurological and autonomic disturbances. In this paper, we present two cases in which two patients ingested thiamethoxan and imidacloprid, showing neurologic compromise and affecting their vital signs, requiring management in the intensive care unit. The aim of this article is to raise awareness about the growing use of such pesticides and identify the need to make a differential diagnosis with other insecticides, making appropriate use of diagnostic aids and appropriate initial management of the airway and correcting the abnormalities in their hemodynamic profile to prevent complications.


As intoxicações por praguicidas são a segunda causa de intoxicação na Colômbia. Os neonicotinóides são um novo grupo de inseticidas que atua através dos receptores nicotínicos. As principais manifestações clínicas que se há associado com dita intoxicação são alterações neurológicas e autonómicas. Neste reporte se apresentam dois casos de pacientes que ingeriram tiametoxan e imidacloprid e apresentaram compromisso do sensório e de seus signos vitais, pelo que se acudiu ao manejo em unidade de tratamentos intensivos. O objetivo deste reporte é sensibilizar sobre o crescente uso destes praguicidas e a necessidade de identificá-los para fazer um diagnóstico diferencial com outras substâncias, realizar um uso adequado de ajudas diagnósticas e um manejo inicial pertinente para assegurar a via área e corrigir alterações hemodinâmicas para prevenir complicações.


Subject(s)
Humans , Animals , Neonicotinoids , Pesticides , Poisoning , Receptors, Nicotinic , Neurotoxicity Syndromes
5.
Article in Chinese | WPRIM | ID: wpr-237678

ABSTRACT

The paper is aimed to establish a method of residue analysis for thiamethoxam and to study its degradation dynamic and final residue and its standard of safe application of thiamethoxam on Lonicera japonica. Samples extracted with methanol by ultrasonication were purified with dichloromethane by liquid-liquid extraction and SPE column and analysed by HPLC-UV. The results showed that average rate was 84.91%-94.44% and RSD 1.74%-4.96% with addition of thiamethoxam in respectively diverse concentration, which meets inspection requirement of pesticide residue. Two kinds of dosages of thiamethoxam were treated- varying from recommended dosage (90 g x hm(-2)) to high dosage (135 g x hm(-2)), Results of two years test showed that thiamethoxam was degraded more than 90% seven days after application and the half - life period of thiamethoxam was 1.54-1.66 d. The digestion rate of thiamethoxam was fast in the L. japonica. The recommended MRL of thiamethoxam in the L. japonica is 0.1 mg x kg(-1), the dosage of 25% thiamethoxam WDG from 90-135 g x hm(-2) is sprayed less than three times a year on L. japonica and 14 days is proposed for the safety interval of the last pesticide application's and harvest's date.


Subject(s)
Agriculture , Methods , Reference Standards , Chromatography, High Pressure Liquid , Flowers , Chemistry , Parasitology , Half-Life , Insect Control , Methods , Reference Standards , Insecticides , Chemistry , Lonicera , Chemistry , Parasitology , Neonicotinoids , Nitro Compounds , Chemistry , Oxazines , Chemistry , Pesticide Residues , Chemistry , Plant Diseases , Parasitology , Thiazoles , Chemistry
6.
Article in Chinese | WPRIM | ID: wpr-324184

ABSTRACT

<p><b>OBJECTIVE</b>The dermal absorption of Imidacloprid was studied to understand the effects of concentrations and skin reservoir on pesticide risk assessment in in vitro absorption studies.</p><p><b>METHODS</b>By using Franz diffusion cell and the transdermal barrier of viable Wistar rat abdomen skin or frozen ones, the imidacloprid content in the receptor fluid and skin was determined by LC/MS/MS method, and the absorption effects were compared between two concentrations of Imidacloprid solutions and two types of skin, respectively.</p><p><b>RESULTS</b>All percentages reported are % of applied dose. In vitro studies using viable skin, the Imidacloprid content in the receptor fluid of high and low concentration was 6.8%, 6.6% respectively; and 10.7%, 1.3% in skin, thus total absorption was 17.5% and 7.9%. And in vitro studies using both viable and frozen skin under the same concentration circumstances, the Imidacloprid content in the receptor fluid of viable and frozen skin was 6.6% and 0.7% respectively, in skin was 1.3% and 10.7%, and total absorption was 7.9% and 11.4%.</p><p><b>CONCLUSION</b>Comparison of these in vitro results showed that either concentrations or skin reservoir had an effect on the dermal absorption. During 6h exposure, the high concentration in viable skin had the maximum dermal absorption value, which was the worst-case exposure estimate, also the best single estimate for pesticide risk assessment.</p>


Subject(s)
Administration, Cutaneous , Animals , Imidazoles , Pharmacokinetics , In Vitro Techniques , Male , Neonicotinoids , Nitro Compounds , Pharmacokinetics , Rats , Rats, Wistar , Skin , Metabolism , Skin Absorption
7.
Chinese Journal of Biotechnology ; (12): 943-951, 2011.
Article in Chinese | WPRIM | ID: wpr-324483

ABSTRACT

To produce high-affinity monoclonal antibodies against pesticide imidacloprid, we synthesized the haptens 1-[(6-Carboxylethylthio-3-pyridinyl) methyl] -N-nitro-imidazolidinimine (named as H1) and 1-[(6-Chloro-3-pyridinyl) methyl]-3-carboxylpropyl-N-nitro-2-imidazolidinimine (termed as H2). And then the haptens were coupled to bovine serum albumin (BSA) and ovalbumin (OVA) for immunogen (H1-BSA) and coating antigen (H2-OVA) respectively by NHS ester method. BALB/c mice were immunized with H1-BSA conjugate. We obtained two hybridoma cell lines 2F11/A9 and 2G6/G12 secreting antibody specific for imidacloprid from the conventional hybridoma technology. The result showed that the subtypes of obtained monoclonal antibodies were IgG3 and IgG1, respectively, and the titers of ascites were up to 1:128 000. The indirect competitive ELISA indicated the IC50 values of 5.3 and 28.3 ng/mL with detection limits of 1.1 ng/mL and 7.7 ng/mL, respectively. Two monoclonal antibodies had no apparent cross reactivity with six analogous compounds. Thus, two prepared monoclonal antibodies had a very high affinity and specificity, and it could be used to develop ELISA for rapid determination of imidacloprid residue and laid a solid foundation for research and development of products for immunoassay.


Subject(s)
Animals , Antibodies, Monoclonal , Antibody Specificity , Hybridomas , Metabolism , Imidazoles , Allergy and Immunology , Insecticides , Allergy and Immunology , Mice , Mice, Inbred BALB C , Neonicotinoids , Nitro Compounds , Allergy and Immunology
8.
Article in Chinese | WPRIM | ID: wpr-283411

ABSTRACT

<p><b>OBJECTIVE</b>To establish residue analysis method of imidacloprid in Ephedra sinica by HPLC.</p><p><b>METHOD</b>Imidacloprid was extracted with dichloromethane, cleaned up with chromatography column, then separated on Spherisorb C18 column by using Methanol-water (20:80), detected at 270 nm.</p><p><b>RESULT AND CONCLUSION</b>The limit of detection (LOD) and limit quantification (LOQ) were 0.4 x 10(-9) g and 0.02 mg x kg(-1), mean recovery and related standard deviation (RSD) were 85.37%-90.65% and 2.23%-3.45%. It is concluded that the method could satisfy the pesticide residue analysis demands in sensitivity, accuracy and precision.</p>


Subject(s)
Chromatography, High Pressure Liquid , Methods , Ephedra sinica , Chemistry , Imidazoles , Insecticides , Neonicotinoids , Nitro Compounds , Pesticide Residues , Plants, Medicinal , Chemistry , Reproducibility of Results
9.
Article in English | WPRIM | ID: wpr-229683

ABSTRACT

<p><b>OBJECTIVE</b>To investigate how acetamiprid, a new insecticide, affects the activity of superoxide dismutase (SOD), catalase (CAT), and ATPase and the SOD isozyme patterns in two G bacteria, E. coli K12 and Pse.FH2, and one G+ bacterum, B. subtilis.</p><p><b>METHODS</b>The SOD, CAT, and ATPase specific activities of cell lysates were determined spectrophotometrically at 550 nm, 240 nm, and 660 nm, respectively, with kits A001, A016, and A007. SOD isozyme patterns were detected by native PAGE analysis.</p><p><b>RESULTS</b>SOD and CAT activities in the tested bacteria increased significantly in a concentration-dependent manner after different concentrations of acetamiprid were applied. The activity of SOD in B. subtilis and Pse.FH2 was stimulated and reached the highest level after treatment with 100 mg/L acetamiprid for 0.5 h. For Pse.FH2, there was another stimulation of SOD activity after acetamiprid application for about 8.0 h and the second stimulation was stronger than the first. The stimulation by acetamiprid showed a relative lag for E. coli K12. Acetamiprid seemed to exhibit a similar effect on CAT activity of the two G bacteria and had an evident influence on ATPase activity in the three bacteria within a relatively short period. Only one SOD isozyme was detectable in Pse.FH2 and B. subtilis, while different isozyme compositions in E. coli could be detected by native PAGE analysis.</p><p><b>CONCLUSION</b>Acetamiprid causes a certain oxidative stress on the three bacteria which may not only elevate SOD and CAT activities but also generate new SOD isozymes to antagonize oxidative stress. However, this oxidative stress lasts for a relatively short time and does not cause a long-term damage.</p>


Subject(s)
Adenosine Triphosphatases , Metabolism , Bacillus , Bacteria , Catalase , Metabolism , Escherichia coli , Insecticides , Pharmacology , Isoenzymes , Metabolism , Neonicotinoids , Pseudomonas , Pyridines , Pharmacology , Superoxide Dismutase , Metabolism
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