Populations of honey bees have declined worldwide in recent years. One suspected cause is the widespread use of pesticides in agriculture. Experiments were conducted to examine potential exposure routes of pesticides to honey bees in the Midsouth. Neonicotinoid seed treatment compounds were studied to determine the rate at which they drift during planting and the rate at which they diminish in crop tissue during crop development. Honey bee foraging activity in Midsouth crops was observed to determine when and at what densities foraging honey bees could be active during pesticide applications. This project was designed to aid in understanding the risks that pesticides could potentially pose to honey bees in the Midsouth.

Spider mites (Acari: Tetranychidae) are an important agricultural pest of many crops and landscape plants. They can reproduce rapidly and quickly develop resistance to many pesticides, making them difficult to manage. Plant water-stress and high temperatures promote spider mite infestations, while spider mite outbreaks can also result from neonicotinoid insecticide applications. Drought is predicted to increase in the Intermountain West due to increases in temperature and reduced frequency of precipitation events in the region, and neonicotinoids are currently one of the most widely used classes of insecticides in field crops. I studied the interactive effect of these two simultaneously occurring abiotic factors on spider mite outbreaks and plant biosynthesis of herbivore-related defense proteins. I also evaluated ways to alleviate spider mite outbreaks with drought-tolerant corn and the exogenous application of plant phytohormones involved in plant resistance toward biotic stressors. I found that plant water-stress increased spider mites and that neonicotinoids exacerbated the effect of water-stress. Although applications of plant hormones did not reduce the effect of water-stress and neonicotinoids, drought tolerant corn showed promise in reducing the effect of water-stress and spider mite outbreaks.

Turfgrass settings, including lawns, golf courses, and sports fields, support many beneficial invertebrates that provide important ecosystem services. These non-target organisms and their associated predation, decomposition, and pollination services can be disrupted by the use of certain insecticides. I compared the ecotoxicity of representatives from three major turf insecticide groups, the neonicotinoids, premix formulations, and the anthranilic diamides, in lab and field realistic settings in order to inform industry initiatives towards environmental sustainability. In lab and field bioassays clothianidin, a neonicotinoid, and a premix clothianidin/pyrethroid spray were acutely toxic to beneficial insects. Populations of predators, springtails, and earthworms, as well as parasitism, predation, and decomposition rates were all reduced. In contrast, chlorantraniliprole, a novel anthranilic diamide with a similar spectrum of pests controlled, had no apparent impact on natural enemies, decomposers, or ecosystem services. This newer class is a good fit for industry initiatives to use relatively less toxic pesticides, with the caveat that golf course superintendents may see secondary pest outbreaks of ants and earthworms. Bumble bee colonies exposed to clothianidin-treated white clover for two weeks suffered acute effects including increased mortality of workers and decreases in the number of honeypots constructed in the hive. When hives were exposed to clothianidin treated clover for six days and then allowed to develop naturally over six weeks they exhibited delayed weight gain and produced no new queens. Colonies exposed to chlorantraniliprole-treated flowers suffered no observable adverse effects. When treated blooms were mowed, colonies exposed to newly-formed blooms exhibited no ill effects. After a single mowing neonicotinoid residues in clover nectar were reduced from > 2000 ng/g, to < 10 ng/g. Residues of imidacloprid were also short-lived in guttation water. Some 50 species of bees and other pollinators were collected from flowering white clover and dandelions in lawns across an urbanization gradient. Such weeds, an underappreciated resource for urban bees, could play a role in pollinator conservation if tolerated and not over-sprayed with broad-spectrum insecticides. Informing the public about the potential benefits these weeds could have for pollinators may help lead to more environmentally conscious management decisions.

Neonicotinoids are broad spectrum insecticides that are widely used to control many insect pests. In Ontario they are applied directly to the seeds of most corn and soy crops, after which they are incorporated into the tissues of the developing plant. While researchers have investigated how these insecticides impact honeybee health, much less attention has been given to the effects of neonicotinoids on wild pollinators. Ground nesting bees face exposure to neonicotinoids both in the soil, where they nest, as well as through other exposure routes (e.g, nectar and pollen of treated plants). I studied whether a higher concentration of neonicotinoid pesticides in soils within and near corn and soy crops is negatively associated with the abundance and diversity of ground nesting bees. To determine whether an association exists between soil neonicotinoid concentration and the abundance of associated ground nesting bee communities, I surveyed 16 eastern Ontario (mainly corn and soy) farms once per month from May to August, 2019, sampling the bee communities, soil pesticide levels, and floral resources. I found a significant interaction between the sampling period and neonicotinoid soil concentrations on ground nesting bee abundance. However, no similar relationship existed for an analysis with non ground nesting bees only. Specifically, I found that high concentrations of soil neonicotinoids were associated with lower expected bee abundances and low seasonal variation, a low concentration of soil neonicotinoids was associated with a high degree of seasonal variation, including spikes of relatively high expected abundances, and that sites with no neonicotinoids were associated with low seasonal variation and moderately high expected bee abundances. The number of floral units at a site was also positively associated with bee abundance, which is consistent with what has been reported in other studies. Diversity data are currently being processed off-site and unavailable at the time of publication. My results provide evidence that there exists the potential for higher risks of neonicotinoid seed treatments to ground nesting bees compared to the non-ground nesting community.

There is growing concern over the environmental and human health impacts of chemical contaminants in agricultural systems. The environmental persistence of veterinary antibiotics applied to agricultural fields during manure fertilization could lead to increased antibiotic resistance. New generation, neonicotinoid pesticides pose a threat to aquatic ecosystem health due high water mobility and increased potential for non-target exposure. The objectives of this research were to develop a sensitive, analytical method for quantification of pirlimycin (PLY) in soils to be used in field research and determine the ability of second-generation neonicotinoids to move through soil when applied as a seed coating using a greenhouse study. Liquid-solid extraction of PLY from soil using (1:6, v/v) ammonium hydroxide/methylene chloride produced good PLY recovery (67-140%). Liquid-chromatography coupled with tandem mass-spectrometry for instrumental analysis provided good sensitivity with minimal matrix interferences. The mass balance distribution of neonicotinoid treatment coated onto corn seeds was determined in plant and soil samples for a single pot after 3 weeks of growth. A large percent (83-87%) of initial pesticide coating applied to seed was un-detected in plant in soil. Of the detected portion of neonicotinoid treatment, between 96-98% was observed to move out into the soil. This suggests the potential for long-range transport of seed-coated neonicotinoids. / Master of Science / There is growing concern over the environmental and human health impacts of chemical contaminants in agricultural systems. The environmental persistence of veterinary antibiotics applied to agricultural fields during manure fertilization could lead to increased antibiotic resistance. New generation, neonicotinoid pesticides pose a threat to aquatic ecosystem health due high water mobility and increased potential for non-target exposure. The objectives of this research were to develop a sensitive, analytical method for quantification of pirlimycin (PLY) in soils to be used in field research and determine the ability of second-generation neonicotinoids to move through soil when applied as a seed coating using a greenhouse study. Liquid-solid extraction of PLY from soil using (1:6, v/v) ammonium hydroxide/methylene chloride produced good PLY recovery (67-140%). Liquid-chromatography coupled with tandem mass-spectrometry for instrumental analysis provided good sensitivity with minimal matrix interferences. The mass balance distribution of neonicotinoid treatment coated onto corn seeds was determined in plant and soil samples for a single pot after 3 weeks of growth. A large percent (83-87%) of initial pesticide coating applied to seed was un-detected in plant in soil. Of the detected portion of neonicotinoid treatment, between 96-98% was observed to move out into the soil. This suggests the potential for long-range transport of seed-coated neonicotinoids.

O presente estudo teve como propósito o desenvolvimento de um método para a determinação e a validação de uma metodologia para a identificação e quantificação de Neonicotinóides em águas superficiais coletadas na região de Bauru, no estado de São Paulo. As técnicas analíticas estudadas para o desenvolvimento deste método foram a cromatografia líquida de alta eficiência acoplada a espectrometria de massas em tandem (HPLC - MS/MS), a cromatografia a gás acoplada a espectrometria de massas (GC/MS) e a cromatografia a gás acoplada ao detector de captura de elétrons (GC/ECD). A classe de pesticidas Neonicotinóides foi escolhida para este trabalho por estar relacionada com um súbito desaparecimento de abelhas em colônias de todo o mundo. Este fenômeno é conhecido como colapso de desordem das colônias (Colony Collapse Disorder CCD) e o mesmo é caracterizado por uma rápida perda na população de abelhas adultas. Os Neonicotinóides utilizados neste estudo foram os compostos Clotianidina, Imidacloprido e Tiametoxam que foram proibidos na sua utilização como pesticidas na Europa pelo regulamento de execução nº 540/2011. As amostras foram concentradas utilizando as técnicas de extração em fase sólida (SPE) e extração líquido líquido (LLE) e injetadas no HPLC MS/MS, GC/MS e GC/ECD. As técnicas de GC/ECD e GC/MS não foram satisfatórias para a determinação na matriz água, pois, o limite de detecção (10 mg L-1), esta acima do valor máximo permitido na legislação da agência de proteção ambiental americana (0,6 &mu;g L-1). A técnica de HPLC MS/MS utilizando o modo de monitoramento de reações múltiplas (MRM) provou se adequada para este estudo por obter limites de quantificação entre 5,89 a 8,06 &mu;g L-1 e uma linearidade entre 0,9963 e 0,9993 para os três compostos. / The present study aimed to develop a method for the determination and validation of a method for the identification and quantification of Neonicotinoids in surface waters collected in the Bauru region, in the state of São Paulo. The analytical techniques studied for the development of this method were the high performance liquid chromatography with tandem mass spectrometry (HPLC - MS / MS), gas chromatography with mass spectrometry (GC / MS) and gas chromatography with electron capture detector (GC / ECD). The class of pesticides Neonicotinoids was chosen for this work because it is related to a sudden disappearance of bees in colonies around the world. This phenomenon is known as Colony Collapse Disorder (CCD) and it is characterized by a rapid loss in the population of adult bees. The Neonicotinoids used in this study were the compounds Clothianidin, Imidacloprid and Thiamethoxam which were banned in their use as pesticides in Europe by Implementing Regulation No. 540/2011. The samples were concentrated using solid phase extraction (SPE) and liquid liquid extraction (LLE) techniques and injected into HPLC-MS / MS, GC / MS and GC / ECD. The GC / ECD and GC / MS techniques were not satisfactory for determination in the water matrix because the detection limit (10 mg L-1) is above the maximum allowed by the US Environmental Protection Agency (0.6 &mu;g L-1). The HPLC - MS / MS technique using the multiple reaction monitoring (MRM) proved to be adequate for this study because it obtained quantification limits between 5.89 and 8.06 &mu;g L-1 and a linearity between 0.9963 and 0.9999 for the three compounds.

Made available in DSpace on 2017-07-25T19:31:03Z (GMT). No. of bitstreams: 1 Fernanda Wagner.pdf: 2201127 bytes, checksum: 1f084a627bdbb8e6aed48d44eac35a00 (MD5) Previous issue date: 2017-04-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Soybean is one of the most cultivated crops in the country, and the stink bugs of the largest losses in productivity. The Neotropical brown stink bug Euschistus heros cause severe damage to soybeans, however the green belly stink bug Dichelops melacanthus cause severe damage to corn and wheat, and can also attack soybeans. For its control, seed treatment can be performed, as in the case of D. melacanthus, or sprays with insecticides. The objective of this work was to determine the feasibility of conducting ingestion biossays in E. heros and D. melacanthus, as well as to determine the mode of action of the insecticides used to control the E. heros stink bug. The feasibility of ingestion bioassays on E. heros and D. melacanthus with systemic inseticides was investigated, as well a topical bioassay with synergistic substances on E. heros to determine the mode of action of the most common recommended insecticides. The insects used in the bioassays were collected in Cândido Mota-SP, Palmital-SP, Pedrinhas Paulista-SP and Sertaneja-PR. The data obtained were analyzed by ANOVA and Probit analysis. The CL50 for E. heros for the thiametoxam + lambda cyhalothrin mixture was (0.038 + 0.028 μg iamL-1) and for D. melacanthus (0.219 + 0.164 μg de i.a.mL-1). In ingestion trials, this mixture achieved high mortality compared to the other active ingredients tested. When inoculation with the insecticide thiametoxam and the synergist piperonyl butoxide (PBO) agent was performed, the mortalities were significantly higher in the four populations tested indicating that the monooxygenases would be detoxifying the insecticide. Likewise, imidacloprid caused higher mortality when applied with the same synergist, indicating detoxification by monooxygenase enzymes. In the same way, treatments with pyrethroids (lambda-cyhalothrin and beta-cyfluthrin) and PBO caused higher or faster mortalities than the insecticide applied alone. When treatments with acephate and acephate plus diethyl maleate were performed, E. heros mortalities were faster with the synergist diethyl maleate, indicating detoxification of the insecticide by glutathione-S-transferases enzymes, mainly in the population of Sertaneja-PR. / A soja é uma das culturas mais cultivadas no país, sendo os percevejos da família Pentatomidae responsáveis por parte das maiores perdas em produtividade. O percevejo marrom, Euschistus heros, causa danos severos em soja. Por outro lado, o percevejo barriga-verde, Dichelops melacanthus, causa danos intensos em milho e trigo, podendo atacar também a soja. Para seu controle, podem ser realizadas pulverizações com inseticidas ou o tratamento de sementes, como no caso de D. melacanthus. O objetivo deste trabalho, foi determinar a viabilidade de realizar bioensaios de ingestão em E. heros e D. melacanthus, assim como determinar o modo de ação dos inseticidas utilizados para o controle do percevejo E. heros. Os insetos utilizados para o ensaio de ingestão eram provenientes do laboratório e nos ensaios de aplicação tópica, foram realizadas coletas de campo em: Cândido Mota, SP, Palmital, SP, Pedrinhas Paulista, SP e Sertaneja, PR. Os dados obtidos foram analisados por ANOVA e análise de Probit. A CL50 de E. heros para a mistura thiametoxam + lambda cialotrina calculada foi de (0,038 + 0,028 μg de i.a.mL-1) e para D. melacanthus (0,219 + 0,164 μg de i.a.mL-1), respectivamente. Nos ensaios de ingestão, essa mistura causou mortalidade elevada em comparação aos outros ingredientes ativos testados. Quando foi realizada a inoculação com o inseticida thiametoxam e o agente sinergista butóxido de piperonila (PBO) as mortalidades foram significativamente maiores nas quatro populações testadas indicando que as enzimas monooxigenases estariam realizando a detoxificação do inseticida. Da mesma forma, o imidacloprido causou maior mortalidade quando aplicado com o mesmo sinergista, indicando detoxificação por enzimas monooxigenases e/ou esterases. Os tratamentos com os piretróides (lambda-cialotrina e beta-ciflutrina) e o PBO causaram mortalidades superiores ou mais rápidas que o inseticida aplicado isoladamente. Quando foram realizados os tratamentos com acefato e acefato mais dietil maleato, as mortalidades de E. heros foram mais rápidas com o sinergista dietil maleato, indicando o envolvimento de enzimas glutationa-S-transferases, no processo de detoxificação, principalmente com níveis mais elevados na população de Sertaneja-PR.

Designed for the protection of major agricultural crops, neonicotinoids are the fastest-growing class of insecticides used against a broad spectrum of insect pests. Although neonicotinoid toxicity toward non-target organisms (e.g., bees, aquatic insects) has been well-studied, less is known about their distribution of use, transport, and fate in North American agroecosystems. This is especially true of neonicotinoid interactions with wetlands in the Canadian Prairies. Between 2009 and 2012, neonicotinoid use as a seed treatment increased by 30% across the Canadian Prairies. During spring 2012 to spring 2013, I sampled water and sediment from 136 wetlands situated in a range of crop types across central Saskatchewan to determine the extent of neonicotinoid contamination. Wetlands situated in oat, canola, and barley fields consistently contained higher neonicotinoid concentrations in water than in grasslands, but no single crop influenced overall detections. Neonicotinoid detections in water varied from 16% (fall 2012) to 91% (spring 2013) with peak concentrations up to 3110 ng/L found in summer. I found numerous detections of neonicotinoids in spring, after ice-off, but before seeding. Through sampling snow, snow meltwater, and soil particulates from previously treated (clothianidin) and untreated fields, meltwater showed the strongest relationship to initial spring concentrations in wetland water. Neonicotinoid concentrations increased with time in shallow temporary wetlands which appeared most at risk for annual contamination. While snowmelt contamination influenced water concentrations in spring, peak concentrations in wetlands were consistently found during summer sampling completed in 2012-2014. Rapid wetland assessments completed on 238 wetlands (summer of 2012 and 2013) revealed key ecological, hydrological and landscape features that influenced neonicotinoid detections and peak concentrations in Prairie wetlands. The results of my exploratory analysis indicated that plant community composition is a key indicator and/or driver of both detection and concentration of neonicotinoids in Prairie wetlands. In particular, specific shallow marsh plants were commonly associated with either higher (e.g., Scirpus validus) or lower (e.g., Mentha arvensis) neonicotinoid concentrations in natural wetlands suggesting wetland macrophytes in this zone may be either indicators of agricultural disturbance intensity or differentially capable of accumulating the insecticide in its tissue. Therefore, in 2014, I conducted an outdoor microcosm experiment to evaluate thiamethoxam uptake from water by Typha latifolia and Alisma triviale using two concentrations over a 7-day period. Experimental results found some trace positive detections but no quantifiable accumulation of the insecticide in plant tissues. This is despite the fact that results of my 2015 field study found species of Typha, Alisma and Equisetum had neonicotinoids more frequently detected in their tissues, at concentrations ranging from 1.01-8.44 ug/kg. My findings demonstrate that neonicotinoid distribution and fate in Canadian Prairie agroecosystems is driven by interactions between ecological, hydrological, and landscape characteristics. Consequently, these drivers regulate neonicotinoid exposure and persistence in ecologically important regional wetlands. In order to effectively conserve these critical waterbodies, conservation planning should consider the importance of maintaining naturally diverse vegetation zones to mitigate insecticide exposure to wetland-dependant organisms.

abstract: This dissertation is focused on environmental releases from U.S. wastewater infrastructure of recently introduced, mass-produced insecticides, namely neonicotinoids as well as fipronil and its major degradates (sulfone, sulfide, amide, and desulfinyl derivatives), jointly known as fiproles. Both groups of compounds recently have caught the attention of regulatory agencies worldwide due to their toxic effects on pollinators and on aquatic invertebrates at very low, part-per-trillion levels (Chapter 1). Mass balance studies conducted for 13 U.S. wastewater treatment plants (WWTPs) showed ubiquitous occurrence (3-666 ng/L) and persistence of neonicotinoids (Chapter 2). For the years 2001 through 2016, a longitudinal nationwide study was conducted on the occurrence of fiproles, via analysis of sludge as well as raw and treated wastewater samples. Sludge analysis revealed ubiquitous fiprole occurrence since 2001 (0.2-385 µg/kg dry weight) and a significant increase (2.4±0.3-fold; p<0.005) to elevated levels found both in 2006/7 and 2015/6. This study established a marked persistence of fiproles during both wastewater and sludge treatment, while also identifying non-agricultural uses as a major source of fiprole loading to wastewater (Chapter 3). Eight WWTPs were monitored in Northern California to assess pesticide inputs into San Francisco Bay from wastewater discharge. Per-capita-contaminant-loading calculations identified flea and tick control agents for use on pets as a previously underappreciated source term dominating the mass loading of insecticides to WWTPs in sewage and to the Bay in treated wastewater (Chapter 4). A nationwide assessment of fipronil emissions revealed that pet products, while representing only 22±7% of total fipronil usage (2011-2015), accounted for 86±5% of the mass loading to U.S. surface waters (Chapter 5). In summary, the root cause for considerable annual discharges into U.S. surface waters of the neonicotinoid imidacloprid (3,700-5,500 kg/y) and of fipronil related compounds (1,600-2,400 kg/y) is domestic rather than agricultural insecticide use. Reclaimed effluent from U.S. WWTPs contained insecticide levels that exceed toxicity benchmarks for sensitive aquatic invertebrates in 83% of cases for imidacloprid and in 67% of cases for fipronil. Recommendations are provided on how to limit toxic inputs in the future. / Dissertation/Thesis / Doctoral Dissertation Civil, Environmental and Sustainable Engineering 2017

O presente estudo teve como propósito o desenvolvimento de um método para a determinação e a validação de uma metodologia para a identificação e quantificação de Neonicotinóides em águas superficiais coletadas na região de Bauru, no estado de São Paulo. As técnicas analíticas estudadas para o desenvolvimento deste método foram a cromatografia líquida de alta eficiência acoplada a espectrometria de massas em tandem (HPLC - MS/MS), a cromatografia a gás acoplada a espectrometria de massas (GC/MS) e a cromatografia a gás acoplada ao detector de captura de elétrons (GC/ECD). A classe de pesticidas Neonicotinóides foi escolhida para este trabalho por estar relacionada com um súbito desaparecimento de abelhas em colônias de todo o mundo. Este fenômeno é conhecido como colapso de desordem das colônias (Colony Collapse Disorder CCD) e o mesmo é caracterizado por uma rápida perda na população de abelhas adultas. Os Neonicotinóides utilizados neste estudo foram os compostos Clotianidina, Imidacloprido e Tiametoxam que foram proibidos na sua utilização como pesticidas na Europa pelo regulamento de execução nº 540/2011. As amostras foram concentradas utilizando as técnicas de extração em fase sólida (SPE) e extração líquido líquido (LLE) e injetadas no HPLC MS/MS, GC/MS e GC/ECD. As técnicas de GC/ECD e GC/MS não foram satisfatórias para a determinação na matriz água, pois, o limite de detecção (10 mg L-1), esta acima do valor máximo permitido na legislação da agência de proteção ambiental americana (0,6 &mu;g L-1). A técnica de HPLC MS/MS utilizando o modo de monitoramento de reações múltiplas (MRM) provou se adequada para este estudo por obter limites de quantificação entre 5,89 a 8,06 &mu;g L-1 e uma linearidade entre 0,9963 e 0,9993 para os três compostos. / The present study aimed to develop a method for the determination and validation of a method for the identification and quantification of Neonicotinoids in surface waters collected in the Bauru region, in the state of São Paulo. The analytical techniques studied for the development of this method were the high performance liquid chromatography with tandem mass spectrometry (HPLC - MS / MS), gas chromatography with mass spectrometry (GC / MS) and gas chromatography with electron capture detector (GC / ECD). The class of pesticides Neonicotinoids was chosen for this work because it is related to a sudden disappearance of bees in colonies around the world. This phenomenon is known as Colony Collapse Disorder (CCD) and it is characterized by a rapid loss in the population of adult bees. The Neonicotinoids used in this study were the compounds Clothianidin, Imidacloprid and Thiamethoxam which were banned in their use as pesticides in Europe by Implementing Regulation No. 540/2011. The samples were concentrated using solid phase extraction (SPE) and liquid liquid extraction (LLE) techniques and injected into HPLC-MS / MS, GC / MS and GC / ECD. The GC / ECD and GC / MS techniques were not satisfactory for determination in the water matrix because the detection limit (10 mg L-1) is above the maximum allowed by the US Environmental Protection Agency (0.6 &mu;g L-1). The HPLC - MS / MS technique using the multiple reaction monitoring (MRM) proved to be adequate for this study because it obtained quantification limits between 5.89 and 8.06 &mu;g L-1 and a linearity between 0.9963 and 0.9999 for the three compounds.