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For beekeeping to be sustainable, the management of colonies for the production of bee products must be economically viable without endangering the lives of bees, and must include acceptable practices such as the treatment of hives with appropriate products. Occasionally, the use of acaricides to treat the hives against varroosis is uncontrolled and can accumulate in the hives, putting the colonies at risk. In this work, a screening of seven acaricides was carried out in different apiaries in Andalusia (Spain). Their distribution in beeswax, brood, honey, and bees from colonies in different surroundings was evaluated at different times. It was found that beeswax was highly contaminated but honey, brood and bees had acceptable levels, below their respective MRL or LD50, after a certain period following varrocide treatments. Acaricides banned for their use against Varroa, such as chlorfenvinphos, cypermethrin and especially acrinathrin, were found in the hives analysed.

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Pesticide residues in food comprise compounds such as insecticides, fungicides, herbicides, miticides, and plant activators. The insecticides diazinon (O, O-diethyl O-2-isopropyl-6-methylpyrimidin-4-yl phosphorothioate) and malathion (O, O-dimethyl dithiophosphate of diethyl-mercaptosuccinate) are classified as probably carcinogenic (Group 2A) and the fungicides chlorothalonil (2,4,5,6-tetrachloro-1,3-benzenedicarbonitrile) and hexachlorobenzene (pentachlophenyl chloride) as possibly carcinogenic to humans (Group 2B) by the International Agency for Research on Cancer under the World Health Organization. In this study, gas chromatographic and gas chromatography-tandem mass spectrometric analyses were used to determine the concentrations of pesticide residues in agricultural products and assess the effects of chronic human exposure to pesticide residues through the consumption of agricultural products during 2018-2020. Food consumption data were obtained from the Korea National Health and Nutrition Examination Survey of 2016-2018. The chronic exposures determined using mean consumption data for the whole population and mean concentrations of the pesticide residues were 5.15E-11 to 2.08E-05 [lower bound (LB)] and 2.41E-07 to 4.69E-05 mg/kg bw/day [upper bound (UB)], corresponding to 0.00012-2.16% of the hazard index (HA). Exposures to pesticide residues, calculated using the 95th percentile of the consumption data, were 0-8.76E-05 (LB) and 9.26E-07 to 1.56E-04 mg/kg bw/day (UB), corresponding to 0.00045-9.41% of the HA. Based on the result of current exposure assessment, it could be considered that the pesticide residues in agricultural products are properly controlled by the regulatory authorities.

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The aim of this study was to determine the presence of zoocide (insecticide and miticide) residues in hops collected in three hop-growing regions located in the Czech Republic, and to assess their zoocide profiles and residue levels in terms of variability in temperature and precipitation across the 2018-2020 seasons. Furthermore, the weather factors that influenced the occurrence of hop pests are described and discussed. During our 3-year survey, a total of 120 samples of whole-cone hops samples harvested in three hop-growing regions were analysed for the presence of 29 insecticides and miticides using the modified QuEChERS extraction method, followed by liquid chromatography-tandem mass spectrometry and gas chromatography-tandem mass spectrometry. A majority, 119 of 120 samples, contained a residue of at least one of the active substances surveyed in this study, and 34 analysed samples contained multiple residues with three to four zoocides presented. Concerning the most frequently detected zoocide residues, spirotetramat and/or its metabolites were found in 94.2% of the samples at levels ranging from 0.02 to 1.08 mg/kg. Of the other zoocides surveyed, residues of fenpyroximate, hexythiazox, bifenazate and lambda-cyhalothrin were routinely found in hop cone samples. Obtained data were then used for evaluating seasonal and geographical variations in the profile of zoocide residues among the hop-growing regions in the years 2018-2020, and the compliance with legal regulations concerning the use of zoocides on hops was ascertained. The results showed that (1) the profile and levels of zoocide residues found in the samples reflected seasonal prevalence of pest infestation on hop plants; (2) the strategy to control pests (especially aphids) used in most of hop yards was consistent across the seasons; and (3) a concentration of spirotetramat residues less than 1 mg/kg was typical for hops grown in the Czech Republic.

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The active substances coumaphos, tau-fluvalinate and amitraz are among the most commonly employed synthetic miticides to control varroa infestations in apiculture. These compounds can persist inside the beehive matrices and can be detected long time after their application. The present study describes the application of a new passive sampling methodology to assess the dissipation of these miticides as well as the cross-contamination in neighboring beehives. The APIStrips are a recently developed sampling device based on the sorbent Tenax, which shows a remarkable versatility for the sorption of molecules onto its surface. This avoids the need of actively sampling apicultural matrices such as living bees, wax or reserves (honey and pollen), therefore allowing to obtain representative information of the contamination in the beehive environment in one single matrix. The results show that the amitraz-based treatments have the fastest dissipation rate (half-life of 11-14 days), whereas tau-fluvalinate and coumaphos remain inside the beehive environment for longer time periods, with a half-life up to 39 days. In the present study, tau-fluvalinate originated an intense cross-contamination, as opposed to coumaphos and amitraz. This study also demonstrates the contribution of drifting forager bees in the pesticide cross-contamination phenomena. Moreover, the sampling of adult living bees has been compared to the APIStrip-based sampling, and the experimental results show that the latter is more effective and consistent than traditional active sampling strategies. The active substances included in this study do not migrate to the honey from the treated colonies in significant amounts.

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Pesticide residues have been linked to reduced bee health and increased honey bee colony failure. Most research to date has investigated the role of pesticides on individual honey bees, and it is still unclear how trace levels of pesticides change colony viability and productivity over seasonal time scales. To address this question we exposed standard bee colonies to chemical stressors known to have negative effects on individual bees, and measured the productivity of bee colonies across a whole year in two environments: near Tucson Arizona and Sydney Australia. We exposed hives to a trace amount of the neonicotinoid imidacloprid and to the acaricide thymol, and measured capped brood, bee and honey production, as well as the temperature and foraging force of the colonies. The effect of imidacloprid on colony dynamics differed between the two environments. In Tucson we recorded a positive effect of imidacloprid treatment on bee and brood numbers. Thymol was associated with short-term negative effects on bee numbers at both locations, and may have affected colony survival at one location. The overall benefits of thymol for the colonies were unclear. We conclude that long-term and colony-level measures of the effects of agrochemicals are needed to properly understand risks to bees.

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Widespread use of agrochemicals in the U.S. has led to nearly universal contamination of beeswax in honey bee hives. The most commonly found agrochemicals in wax include beekeeper-applied miticides containing tau-fluvalinate, coumaphos, or amitraz, and field-applied pesticides containing chlorothalonil or chlorpyrifos. Wax contaminated with these pesticides negatively affects the reproductive quality of queens and drones. However, the synergistic effects of these pesticides on the growth and survival of incipient colonies remain understudied. We established new colonies using frames with wax foundation that was pesticide free or contaminated with field-relevant concentrations of amitraz alone, a combination of tau-fluvalinate and coumaphos, or a combination of chlorothalonil and chlorpyrifos. Colony growth was assessed by estimating comb and brood production, food storage, and adult bee population during a colony's first season. We also measured colony overwintering survival. We found no significant differences in colony growth or survivorship between colonies established on pesticide-free vs. pesticide-laden wax foundation. However, colonies that had Varroa destructor levels above 3% in the fall were more likely to die over winter than those with levels below this threshold, indicating that high Varroa infestation in the fall played a more important role than initial pesticide exposure of wax foundation in the winter survival of newly established colonies.

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Beeswax from Spain was collected during 2016 to determine pesticide residues incidence. The 35 samples were divided in foundation, old combs, cappings or virgin beeswax to compare pesticide content between groups. Wax was screened for 58 pesticides or their degradation products by QuEChERS extraction and liquid chromatography mass spectrometry (LC-MS/MS). Beeswax was uniformly contaminated with acaricides and, to a much lesser extent, with insecticide and fungicide residues. Virgin followed by cappings were less contaminated than foundation and old combs beeswax. The miticides applied in-hive had a contribution to average pesticide load higher than 95%. Compounds widely used as acaricides, as coumaphos (100%), fluvalinate (86%) and amitraz (83%), were the pesticides most frequently detected with maximum concentrations of 26,858, 3593 and 6884ng·g-1, respectively. Chlorfenvinphos, acrinathrin and flumethrin, also acaricides, were detected in 77, 71 and 54%, respectively. Frequencies of pesticides used in crops were 40% for chlorpyrifos, 29% for dichlofenthion, 9% for malathion, 6% for fenthion-sulfoxide and 3% for azinphos-methyl, carbendazim, ethion, hexythiazox, imazalil and pyriproxyfen. Pesticide assessment in beeswax could be an excellent monitoring tool to establish veterinary treatments applied by beekeepers and environmental contaminants exposure of honey bees.

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ABSTRACT:For a crop protection product to achieve its goal, the product must be applied and remain on the leaves until it is absorbed. This situation may be compromised due to rainfall after spraying, thus necessitating reapplication which increase the overall cost. Application technology research has focused on alternatives and solutions to mitigate this effect through the use of adjuvants. The objective of this research was to evaluate the deposit of spraying liquid on citrus seedlings using the products spirodiclofen, propargite, imidacloprid, lambda cyhalothrin, copper oxychloride, and copper hydroxide with water mixed with the adjuvants polydimethylsiloxane and phosphatidylcholine. Seedlings were subjected to simulated rains of 10mm at intervals of 1, 6, 12 and 24h after spraying, and the remaining deposits of spraying liquid per leaf area were analyzed by spectrophotometry by assessing a metallic marker previously added in the spraying liquids. Variables were subjected to analysis of variance and Tukey's test (P<0.05). The rains that occurred soon after spraying resulted in decreased spraying liquids deposits on citrus leaves. Adjuvant phosphatidylcholine promoted the greatest retention of spraying liquid on citrus leaves after rainfall.

RESUMO:A aplicação de um produto fitossanitário deve assegurar que ocorra sua chegada e permanência das gotas sobre folhas até que sejam absorvidos para manifestação do efeito biológico. Essa situação pode ser comprometida pela ocorrência de chuvas após a pulverização, necessitando de reaplicações que elevam os custos. A tecnologia de aplicação busca alternativas e soluções para amenizar esse efeito, como o uso de adjuvantes. Objetivou-se, neste trabalho, avaliar o depósito de caldas fitossanitárias pulverizadas sobre mudas de citros, com os produtos espirodiclofeno, propargite, imidacloprido, lambida cialotrina, oxicloreto de cobre e hidróxido de cobre apenas com água e em mistura com os adjuvantes polidimetilsiloxano e fosfatidilcoline antes e após chuvas artificais de 10mm, com intervalos de 1, 6, 12 e 24 horas após a pulverização. Os depósitos de caldas remanescentes por área foliar foram analisados por espectrofotometria, considerando um marcador metálico previamente adicionado nas caldas. As variáveis foram submetidas à análise de variância e ao teste de Tukey (P<0,05). As chuvas ocorridas mais próximas do momento das pulverizações resultaram em menores depósitos de calda sobre as folhas de citros. O adjuvante fosfatidilcoline manteve a maior quantidade das caldas sobre folhas de citros, quando da ocorrência de chuvas após a pulverização.