Made available in DSpace on 2014-06-11T19:22:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-22Bitstream added on 2014-06-13T18:07:55Z : No. of bitstreams: 1 souza_gsf_me_botfca.pdf: 3983066 bytes, checksum: 0ecc95aedf49bb3a0b687a39cac24ced (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo do presente trabalho foi avaliar a influência de diferentes intervalos de chuva na eficiência de herbicidas aplicados em pós-emergência em quatro espécies de plantas daninhas: Ipomoea grandifolia, Senna obtusifolia, Brachiaria decumbens e Brachiaria plantaginea. O experimento foi conduzido em condições de casa-de-vegetação com uma planta por vaso, com capacidade de 2,5 L. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repetições, disposto em um esquema fatorial 7x8 (sete tratamentos químicos e oito intervalos de chuva) para as espécies dicotiledôneas e 6x8 (seis tratamentos herbicidas e oito intervalos de chuva) para as monocotiledôneas. Os tratamentos testados foram: glyphosate em cinco formulações comerciais (Roundup Original, Roundup WG, Roundup Transorb, Roundup Transorb R e Roundup Ultra) a 1.080 g e.a. ha-1, amonio-glufosinate a 400 g i.a. ha-1 e, apenas para as espécies dicotiledôneas utilizou-se o tratamento com 2,4-D a 1.000 g e.a. ha-1. A simulação de chuva de 20 mm foi realizada em oito intervalos de tempo após a aplicação dos herbicidas (15‟, 30‟, 1h, 2h, 4h, 6h, 8h e sem chuva). Foram realizadas avaliações visuais de controle das plantas aos 3, 7, 14, 21, 28 e 35 dias após a aplicação (DAA) para I. grandifolia,aos 3, 7, 14, 21 e 28 DAA para S. obtusifolia, aos 3, 7, 14 e 21 DAA para B. decumbens e aos 3, 7 e 14 DAA para B. plantaginea. Ao final do período de avaliação de cada espécie determinou-se a massa seca das plantas. Os resultados foram submetidos à análise de variância pelo Teste “F” e as médias dos tratamentos comparadas pelo teste de Tukey a 5% de probabilidade. Para plantas de I. grandifolia a ocorrência de chuvas após 15 minutos da aplicação do herbicida 2,4-D não afetou sua eficiência de controle, já os herbicidas amonio-glufosinate e glyphosate, em todas suas... / The aim of this study was to evaluate the influence of different intervals of rain in the efficiency of herbicides applied post-emergence in four weed species: Ipomoea grandifolia, Senna obtusifolia, Brachiaria decumbens and Brachiaria plantaginea. The experiment was conducted in conditions of green-house with one plant per pot, with a capacity of 2.5 L. The experiment was a completely randomized design with four replications, arranged in a 7x8 factorial arrangement (seven chemical treatments and eight intervals of rain) for dicotyledons and 6x8 (six and eight herbicide treatments rain intervals) for monocotyledons. The treatments were: glyphosate in five formulations (Roundup Original, Roundup WG, Transorb Roundup, Roundup and Roundup Ultra Transorb R) to 1080 g ae ha-1 ammonium-glufosinate at 400 g ai ha-1, and only for dicot species, we used treatment with 2,4-D and 1,000 g ha-1. The simulated rainfall of 20 mm was accomplished in eight intervals of time after herbicide application (15', 30', 1h, 2h, 4h, 6h, 8h and no rain). Visual evaluations of weed control at 3, 7, 14, 21, 28 and 35 days after application (DAA) for I. grandifolia, 3, 7, 14, 21 and 28 DAA for S. obtusifolia, 3, 7, 14 and 21 DAA for B. decumbens and at 3, 7 and 14 DAA for B. plantaginea. At the end of the trial period of each species determined the dry mass of plants. The results were subjected to analysis of variance test by F and the means were compared by Tukey test at 5% probability. For plants I. grandifolia to rainfall after 15 minutes of application of 2,4-D did not affect the efficiency of control because the herbicides glufosinate and glyphosate-ammonium, in all its formulations tested showed reduced efficiency of control when the occurrence of rainfall up to 8 hours after herbicide application and, with the exception of Roundup Original, all herbicides provided greater than 50% reductions in dry mass of ... (Complete abstract click electronic access below)

O capim-amargoso (Digitaria insularis) é uma planta daninha que ganhou importância no cenário agrícola brasileiro recentemente, decorrente da dificuldade natural de se controlar essa espécie de planta daninha e pela descoberta de populações resistentes ao glyphosate. Esse trabalho teve o objetivo de estudar os níveis de resistência apresentados por populações de capim-amargoso dos estados do Paraná e São Paulo e avaliar o controle de proporcionado por aplicações de herbicidas associados ou não a duas formulações de 2,4-D, em plantas perenizadas adultas e após roçada mecânica. No primeiro experimento foram coletadas populações de capim-amargoso em quinze áreas nos estados do Paraná e São Paulo. Foi feita a aplicação de 8 doses crescentes de glyphosate (0; 67,5; 135; 270; 540; 1080; 2160 e 4320 g e.a.ha-1) em 5 repetições para a obtenção da curva de dose resposta. Os dados de controle foram submetidos ao modelo de regressão não-linear do tipo log-logístico para determinação dos parâmetros das curvas de dose-resposta, em seguida foi determinado o fator de resistência para cada população. No segundo e terceiro experimentos foi avaliada a eficácia de controle de capim-amargoso através de 31 associações entre os herbicidas glyphosate, 2,4-D dimethylamine, 2,4-D choline, haloxyfop, clethodim, glufosinate, em plantas perenizadas adultas e após roçada mecânica a 20cm. Existe um cenário de evolução nos casos de resistência de capim-amargoso ao herbicida glyphosate nos estados de São Paulo e Paraná. Grande parte das populações estudadas apresentaram algum nível de resistência ao glyphosate, mas em maioria (67%) baixa resistência. No entanto, a constatação de populações com fatores de resistência muito altos serve como alerta para a necessidade do uso do manejo integrado de plantas daninhas, buscando usar boas práticas agrícolas para que as populações que ainda apresentam baixo nível de resistência não atinjam esse mesmo patamar. É possível afirmar que o controle de plantas adultas de capim-amargoso resistente ao glyphosate é facilitado com a roçada mecânica, podendo atingir resultados semelhantes ao controle das plantas não roçadas, com uma aplicação sequencial. Existem diversas combinações de associações e aplicações sequenciais entre glyphosate, haloxyfop, clethodim e glufosinate, em associação ou não com 2,4-D colina e 2,4-D dimetilamina, capazes de proporcionar controle superior a 90% em plantas de capim-amargoso, roçadas ou não. Independente do tratamento algumas plantas sofreram rebrota, sendo a intensidade dessa importante na ocasião da aplicação sequencial. É recomendado que esse parâmetro seja observado com cautela para tomada de decisão correta, principalmente no caso de roçada mecânica das plantas, prévia a aplicação de herbicidas. Foi possível observar que a nova formulação de 2,4-D colina possui comportamento similar ao 2,4-D dimetilamina em relação a possíveis antagonismos em associações com graminicidas. Isso indica que os conhecimentos anteriores servem como uma boa referência para uso da nova formulação enquanto novos estudos são desenvolvidos. / The sourgrass (Digitaria insularis) is a weed that has gained importance in the Brazilian agricultural scene recently, due to the natural difficulty to control this species of weed and the discovery of populations resistant to glyphosate. The objective of this work was to study the resistance levels of sourgrass populations in the states of Paraná and São Paulo, and to evaluate the control provided by herbicides applications associated or not with two 2,4-D formulations in perennial plants and after mechanical mowing. In the first experiment, sourgrass populations were collected in fifteen areas in the states of Paraná and São Paulo. Eight growing doses of glyphosate (0, 67.5, 135, 270, 540, 1080, 2160 and 4320 g a.a.ha-1) were applied in 5 replicates to obtain the dose response curve. The control data were submitted to the log-logistic nonlinear regression model to determine the parameters of the dose-response curves, after the resistance factor for each population was determined. In the second and third experiments, was evaluated the effectiveness of sourgrass control through 31 associations between herbicides glyphosate, 2,4-D dimethylamine, 2,4-D choline, haloxyfop, clethodim, glufosinate, in adult perennial plants and after mowing at 20cm. There is a scenario of evolution in the cases of sourgrass resistance to glyphosate herbicide in the states of São Paulo and Paraná. Most of the populations studied showed some resistance to glyphosate, but most (67%) low resistance. However, the observation of populations with very high resistance factors serves as an alert to the need of using integrated weed management, seeking to use good agricultural practices, so that populations that still have a low resistance level do not reach this high level. It is possible to affirm that the control of adult plants of sourgrass resistant to glyphosate is facilitated with the mechanical mowing, being able to reach results similar to the control of the non-cropped plants, with a sequential application less. There are several combinations of sequential applications and associations between glyphosate, haloxyfop, clethodim and glufosinate, in association or not with 2,4-D choline and 2,4-D dimethylamine, capable of providing superior control to 90% in sourgrass plants, mowed or not. Regardless of the treatment, some plants regrowth, where the intensity is important at the occasion of the sequential application. It is recommended that this parameter get observed with caution for correct decision making, especially in the case of mechanical mowing of the plants, prior to the application of herbicides. It was possible to observe that the new formulation of 2,4-D choline has similar behavior to 2,4-D dimethylamine in relation to possible antagonisms in combinations with graminicides. This indicates that prior knowledge serves as a good reference for use of the new formulation while new studies are developed.

These studies were conducted on several central Texas agricultural producers?? properties, the Stiles Farm Foundation, the Texas Agricultural Experiment Station, and the Texas A&M University campus. First, an experimental herbicide from Dow AgroSciences, GF-884, was evaluated for effectiveness in controlling three annual and three perennial weed species in production pasture lands and hay meadows. Several rates of GF-884 were examined and evaluated against three registered pasture products and one non-selective herbicide. Next, GF-884 was assessed for tolerance on two common bermudagrass hybrids (Cynodon dactylon (L.) Pers.) at three progressive rates with and without adjuvant. Finally, the herbicides, picloram and fluroxypyr, were applied to common ragweed (Ambrosia artemisiifolia L.) to characterize their individual absorption and translocation and assess any influence one might have on the other. GF-884 applied at rates of 0.91 and 1.14 kg a.e./ha provided >85% and >75% control of the annual and perennial weed species evaluated, respectively. These same rates of GF-884 consistently provided control that was equivalent or better than thatachieved with the registered products. No differences were observed among treatments when shoots from the perennial species were evaluated 12 months following treatment application. The tolerance experiments utilized GF-884 at rates twice that used to evaluate weed control efficacy. These elevated rates did not result in discernable influences on yield or forage quality for either hybrid forage grass when compared to untreated areas. The efficacy and tolerance observations suggest that GF-884 applied at the highest recommended weed control rate can effectively control several annual and perennial weed species without imparting detrimental effects to the hybrid bermudagrass being produced. Finally, in the presence of fluroxypyr, 14C picloram absorption was maintained throughout all sampling intervals. Picloram applied alone, maximized 14C absorption at 6 HAT then declined significantly. At the final sampling, 14C from picloram applied alone was in greater concentration in the treated leaf and the root. Picloram significantly decreased absorption of 14C fluroxypyr. Fluroxypyr alone maintained 14C absorption throughout all samplings, whereas the combination maximized at 12 HAT. Initially, picloram limited 14C translocation, however at 6, 12, and 24 HAT this was not evident.

Tests were conducted for 71 pesticides in weekly bulk (wet + dry) deposition samples collected from May 25 to September 21 over two years at two sites in the City of Winnipeg, Canada. Twenty-one pesticides and their metabolites were detected in this study and 99% of samples collected contained mixtures of two or more pesticides. Malathion and glyphosate were the largest contributors to bulk deposition in 2010 and 2011, respectively. A second study examined the mineralization of 2,4-D and 17β-estradiol using a novel in-field soil microcosm study and a series of laboratory experiments under different temperature incubations. Results indicated that temperature fluctuations do not greatly affect the amount or rate of mineralization relative to the traditionally constant laboratory incubations of 20°C; however long-term freezing of soil reduced potential mineralization over time. This research advances scientific knowledge of agri-chemical fate and provides data for strengthening current environmental policy analysis in Canada.

Tests were conducted for 71 pesticides in weekly bulk (wet + dry) deposition samples collected from May 25 to September 21 over two years at two sites in the City of Winnipeg, Canada. Twenty-one pesticides and their metabolites were detected in this study and 99% of samples collected contained mixtures of two or more pesticides. Malathion and glyphosate were the largest contributors to bulk deposition in 2010 and 2011, respectively. A second study examined the mineralization of 2,4-D and 17β-estradiol using a novel in-field soil microcosm study and a series of laboratory experiments under different temperature incubations. Results indicated that temperature fluctuations do not greatly affect the amount or rate of mineralization relative to the traditionally constant laboratory incubations of 20°C; however long-term freezing of soil reduced potential mineralization over time. This research advances scientific knowledge of agri-chemical fate and provides data for strengthening current environmental policy analysis in Canada.

Pollution of water by herbicides and heavy metals has caused world wide concern because of the adverse effects of these pollutants on the environment, humans and wildlife. This has resulted in tighter legislation being imposed on the levels of these pollutants in drinking water. For example, the European Union (EU) has set the legislation in the drinking water Directive Admissible Concentration for a single herbicide to a maximum of 0.1 ppb. Despite the tight environmental pollution controls, isolated cases of pollutants exceeding their limits are still encountered. This would suggest that research towards the efficient and effective removal of these pollutants will be an on-going process. In this study, sorption of copper and some selected herbicides e.g. atrazine, benazolin and 2,4-dichlorophenoxyacetic acid (2,4-D) was undertaken on a conventional activated carbon and its modified series. A low level detection method was developed using High Performance Liquid Chromatography (HPLC) and this system was used to quantify the sorption capacity of the herbicides. In order to understand the sorption mechanism of the targeted pollutants, physical and chemical characterisation of the adsorbents was undertaken using a variety of techniques. These include, Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared (FT-IR) method, pore size distribution and surface area measurements, elemental analysis, sodium capacity determination, zeta potential and pH titration. The sorption data were presented and analysed by conventional adsorption isotherms. Sorption of the herbicides was favoured on carbon samples with least oxygen content while the uptake of copper was strongest in oxidised carbons. Kinetic experimental data were analysed by a pseudo second order model and the Boyd kinetic model. Molecular structural configurations and the physico-chemical properties of the adsorbent played a crucial role in the sorption behaviour of the herbicides.

To reduce the uncertainty associated with pesticide fate model predictions on the large scale, a rapid method is needed that can generate sorption coefficients (Kd values) with sufficient spatial detail. The feasibility of near-infrared spectroscopy (NIRS) to act as such a method was examined, using weak-acidic (2,4-D), weak-basic (atrazine) and zwitterion (glyphosate) herbicides and the natural steroid estrogen (17β-estradiol). A total of 609 horizons in 140 soil profiles were collected in agricultural fields near Brandon, Manitoba and near Saskatoon, Saskatchewan. In both agricultural fields, Kd values in horizons generally increased in the order of 2,4-D < atrazine < 17β-estradiol < glyphosate. Soil organic carbon content (SOC) followed by the soil pH were the major factors controlling the sorption of 2,4-D, atrazine and 17β-estradiol but glyphosate showed very strong sorption to soil particles regardless of measured SOC and soil pH values. For the chemicals studied, Kd values decreased from A to C horizons regardless of the segment of the slope from which the soil samples were collected, with the exception of glyphosate that showed relatively large Kd values in B-horizons illuviated with clay. Both the Zeiss Corona and the Foss 6500 spectrophotometers produced significantly strong predictive models for soil properties and Kd values of 2,4-D, atrazine and 17β-estradiol. However, models for glyphosate Kd values were weak or not significant. Using a test set approach and either soil spectral or soil properties data as independent variables, partial least squares regressions were successfully developed to estimate Kd values for use in the Pesticide Root Zone Model (PRZM) to calculate the herbicide mass leached. The study concluded that the added benefit of NIRS will be most useful if the pesticides under study have small sorption potentials and short half-lives in soil. Regional approaches to predicting Kd values from NIRS spectral data can also be developed if the calibration model is derived by combining a set of fields where each has a similar statistical population characteristic in Kd values. / February 2016

Orientador: Percília Cardoso Giaquinto / Resumo: As abelhas têm grande importância na polinização; no entanto, o desaparecimento e morte de colônias de Apis mellifera Linnaeus, 1758 (Hymenoptera: Apidae) têm aumentado em várias regiões do mundo, prejudicando a sobrevivência da espécie e a estrutura dos ecossistemas. O uso de agrotóxicos em cultivos agrícolas vem sendo apontado como um dos fatores responsáveis pela intensificação do desaparecimento das abelhas. No presente estudo, avaliou-se a toxicidade, as alterações comportamentais e motoras de abelhas campeiras de A. mellifera expostas aos herbicidas 2,4-D e glifosato, isolados ou associados, por testes de ingestão e contato. Para determinação da dose letal (DL50) foi analisada a mortalidade de abelhas expostas a diferentes doses dos herbicidas por contato e ingestão por 24 horas. A atividade motora das abelhas expostas aos herbicidas glifosato, 2,4-D e associação de ambos foi avaliada 4 e 24 horas após sua exposição utilizando caixa de observação comportamental. As DL50 encontradas dos herbicidas glifosato e 2,4-D foram respectivamente: 273,93 e 127,70 µg/abelha para ingestão e 255,73 e 97,09 µg/abelha para contato. As doses subletais dos herbicidas glifosato e 2,4-D foram, respectivamente: 5,47 e 2,55 µg/abelha para ingestão e 5,11 e 1,94 µg/abelha para contato. A dose letal de 4 horas e subletal de 24 horas foram altamente tóxicas para as abelhas causando alterações locomotoras, as quais em campo podem influenciar o forrageamento das campeiras. Dos testes de doses sub... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Bees are very important for pollination, however, disappearance and death of Apis mellifera hives in many regions of the world has increased, damaging the species survival and ecosystems maintenance. The use of herbicides in agricultural crops has been accused as one of the factors responsible for this disappearance. This study aimed to evaluate the toxicity, behavioral and motor abnormalities on foraging honey bees Apis mellifera exposed to 2,4-D and glyphosate alone and combined. To determine the lethal dose (LD50), bees were exposed to different herbicides doses by contact or ingestion and mortality was analyzed. After 24 hours, the mortality results were analyzed. The glyphosate and 2,4-D LD50 found were, respectively: 273,93 and 127,70 μg/bee for ingestion and 255,73 and 97,09 μg/bee for contact. The sublethal doses for glyphosate and 2,4-D were, respectively: 5,47 and 2,55 μg/bee for ingestion and 5,11 and 1,94 μg/bee for contact. The bee’s motor activity was assessed 4 and 24 hours after herbicides and combination exposure, using a behavioral observation box. The 24 hours lethal and sublethal doses were highly toxic to bees causing locomotors changes, which in the field can influence the bees foraging activity. Only the 4h sublethal herbicide association test showed additive effect, however this fact deserves attention because when carried to the colony, the herbicides can influence other bees behavior and cause weakening or even death of the hive. / Mestre

Orientador: Dagoberto Martins / Banca: Pedro Luis da Costa Aguiar Alves / Banca: Roberto Andreani Junior / Resumo: O objetivo do presente trabalho foi avaliar a influência de diferentes intervalos de chuva na eficiência de herbicidas aplicados em pós-emergência em quatro espécies de plantas daninhas: Ipomoea grandifolia, Senna obtusifolia, Brachiaria decumbens e Brachiaria plantaginea. O experimento foi conduzido em condições de casa-de-vegetação com uma planta por vaso, com capacidade de 2,5 L. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repetições, disposto em um esquema fatorial 7x8 (sete tratamentos químicos e oito intervalos de chuva) para as espécies dicotiledôneas e 6x8 (seis tratamentos herbicidas e oito intervalos de chuva) para as monocotiledôneas. Os tratamentos testados foram: glyphosate em cinco formulações comerciais (Roundup Original, Roundup WG, Roundup Transorb, Roundup Transorb R e Roundup Ultra) a 1.080 g e.a. ha-1, amonio-glufosinate a 400 g i.a. ha-1 e, apenas para as espécies dicotiledôneas utilizou-se o tratamento com 2,4-D a 1.000 g e.a. ha-1. A simulação de chuva de 20 mm foi realizada em oito intervalos de tempo após a aplicação dos herbicidas (15‟, 30‟, 1h, 2h, 4h, 6h, 8h e sem chuva). Foram realizadas avaliações visuais de controle das plantas aos 3, 7, 14, 21, 28 e 35 dias após a aplicação (DAA) para I. grandifolia,aos 3, 7, 14, 21 e 28 DAA para S. obtusifolia, aos 3, 7, 14 e 21 DAA para B. decumbens e aos 3, 7 e 14 DAA para B. plantaginea. Ao final do período de avaliação de cada espécie determinou-se a massa seca das plantas. Os resultados foram submetidos à análise de variância pelo Teste "F" e as médias dos tratamentos comparadas pelo teste de Tukey a 5% de probabilidade. Para plantas de I. grandifolia a ocorrência de chuvas após 15 minutos da aplicação do herbicida 2,4-D não afetou sua eficiência de controle, já os herbicidas amonio-glufosinate e glyphosate, em todas suas ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to evaluate the influence of different intervals of rain in the efficiency of herbicides applied post-emergence in four weed species: Ipomoea grandifolia, Senna obtusifolia, Brachiaria decumbens and Brachiaria plantaginea. The experiment was conducted in conditions of green-house with one plant per pot, with a capacity of 2.5 L. The experiment was a completely randomized design with four replications, arranged in a 7x8 factorial arrangement (seven chemical treatments and eight intervals of rain) for dicotyledons and 6x8 (six and eight herbicide treatments rain intervals) for monocotyledons. The treatments were: glyphosate in five formulations (Roundup Original, Roundup WG, Transorb Roundup, Roundup and Roundup Ultra Transorb R) to 1080 g ae ha-1 ammonium-glufosinate at 400 g ai ha-1, and only for dicot species, we used treatment with 2,4-D and 1,000 g ha-1. The simulated rainfall of 20 mm was accomplished in eight intervals of time after herbicide application (15', 30', 1h, 2h, 4h, 6h, 8h and no rain). Visual evaluations of weed control at 3, 7, 14, 21, 28 and 35 days after application (DAA) for I. grandifolia, 3, 7, 14, 21 and 28 DAA for S. obtusifolia, 3, 7, 14 and 21 DAA for B. decumbens and at 3, 7 and 14 DAA for B. plantaginea. At the end of the trial period of each species determined the dry mass of plants. The results were subjected to analysis of variance test by "F" and the means were compared by Tukey test at 5% probability. For plants I. grandifolia to rainfall after 15 minutes of application of 2,4-D did not affect the efficiency of control because the herbicides glufosinate and glyphosate-ammonium, in all its formulations tested showed reduced efficiency of control when the occurrence of rainfall up to 8 hours after herbicide application and, with the exception of Roundup Original, all herbicides provided greater than 50% reductions in dry mass of ... (Complete abstract click electronic access below) / Mestre

Submitted by Juliana Sartori Lunardi (jusartorilunardi@gmail.com) on 2018-04-26T20:50:59Z No. of bitstreams: 1 Juliana Sartori Lunardi -Dissertação mestrado REPOSITÓRIO.pdf: 1404393 bytes, checksum: 14768aa62b64729cfed9d15a41a9a557 (MD5) / Approved for entry into archive by Sulamita Selma C Colnago null (sulamita@btu.unesp.br) on 2018-04-27T13:47:53Z (GMT) No. of bitstreams: 1 lunardi_js__me_bot_int.pdf: 1404393 bytes, checksum: 14768aa62b64729cfed9d15a41a9a557 (MD5) / Made available in DSpace on 2018-04-27T13:47:53Z (GMT). No. of bitstreams: 1 lunardi_js__me_bot_int.pdf: 1404393 bytes, checksum: 14768aa62b64729cfed9d15a41a9a557 (MD5) Previous issue date: 2018-02-28 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / As abelhas têm grande importância na polinização; no entanto, o desaparecimento e morte de colônias de Apis mellifera Linnaeus, 1758 (Hymenoptera: Apidae) têm aumentado em várias regiões do mundo, prejudicando a sobrevivência da espécie e a estrutura dos ecossistemas. O uso de agrotóxicos em cultivos agrícolas vem sendo apontado como um dos fatores responsáveis pela intensificação do desaparecimento das abelhas. No presente estudo, avaliou-se a toxicidade, as alterações comportamentais e motoras de abelhas campeiras de A. mellifera expostas aos herbicidas 2,4-D e glifosato, isolados ou associados, por testes de ingestão e contato. Para determinação da dose letal (DL50) foi analisada a mortalidade de abelhas expostas a diferentes doses dos herbicidas por contato e ingestão por 24 horas. A atividade motora das abelhas expostas aos herbicidas glifosato, 2,4-D e associação de ambos foi avaliada 4 e 24 horas após sua exposição utilizando caixa de observação comportamental. As DL50 encontradas dos herbicidas glifosato e 2,4-D foram respectivamente: 273,93 e 127,70 µg/abelha para ingestão e 255,73 e 97,09 µg/abelha para contato. As doses subletais dos herbicidas glifosato e 2,4-D foram, respectivamente: 5,47 e 2,55 µg/abelha para ingestão e 5,11 e 1,94 µg/abelha para contato. A dose letal de 4 horas e subletal de 24 horas foram altamente tóxicas para as abelhas causando alterações locomotoras, as quais em campo podem influenciar o forrageamento das campeiras. Dos testes de doses subletais em 4h, foram significativos os de ingestão do 2,4-D e a associação dos herbicidas a qual demonstrou efeito aditivo. A associação dos herbicidas merece atenção, pois em campo essa combinação será tóxica as abelhas. Com este estudo, espera-se contribuir para a compreensão do efeito de herbicidas, assim como auxiliar no estabelecimento de medidas que reduzam a exposição de polinizadores a agrotóxicos prejudiciais. / Bees are very important for pollination, however, disappearance and death of Apis mellifera hives in many regions of the world has increased, damaging the species survival and ecosystems maintenance. The use of herbicides in agricultural crops has been accused as one of the factors responsible for this disappearance. This study aimed to evaluate the toxicity, behavioral and motor abnormalities on foraging honey bees Apis mellifera exposed to 2,4-D and glyphosate alone and combined. To determine the lethal dose (LD50), bees were exposed to different herbicides doses by contact or ingestion and mortality was analyzed. After 24 hours, the mortality results were analyzed. The glyphosate and 2,4-D LD50 found were, respectively: 273,93 and 127,70 μg/bee for ingestion and 255,73 and 97,09 μg/bee for contact. The sublethal doses for glyphosate and 2,4-D were, respectively: 5,47 and 2,55 μg/bee for ingestion and 5,11 and 1,94 μg/bee for contact. The bee’s motor activity was assessed 4 and 24 hours after herbicides and combination exposure, using a behavioral observation box. The 24 hours lethal and sublethal doses were highly toxic to bees causing locomotors changes, which in the field can influence the bees foraging activity. Only the 4h sublethal herbicide association test showed additive effect, however this fact deserves attention because when carried to the colony, the herbicides can influence other bees behavior and cause weakening or even death of the hive. / CNPq: 132451/2016-6. 7