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Rweyemamu EW, Mwatawala MW, Tryphone GM, De Meyer M, Kabota S, Bwire PM. Impact of cucurbit crop management techniques on the foraging behavior of honeybees and hoverflies in Morogoro, Tanzania. BMC Ecol Evol 2024; 24:9. [PMID: 38233768 PMCID: PMC10795283 DOI: 10.1186/s12862-024-02202-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 01/11/2024] [Indexed: 01/19/2024] Open
Abstract
BACKGROUND Poor agricultural practices have drastically threatened insect pollinators' biodiversity. Little is known in Tanzania about how different agricultural practices affect pollinators' foraging behavior. This study investigated the effects of the agroecological zone, season, cucurbit species and management practices on visitation frequency, visitation rate and time spent on cucurbit flowers by five pollinator species viz. Apis mellifera, Eristalinus megacephalus, Mesembrius caffer, Paragus borbonicus and Toxomerus floralis. The experiment was designed as a 5 × 3 × 3 × 2 × 2 factorial arrangement in a Randomized Complete Block Design (RCBD) with four replications. GAMOUR-Agroecology was tested against conventional practices and untreated control. RESULTS This study revealed significant effects of agroecological zone × season × cucurbit species × management practice on pollinators' visitation frequency (p = 0.007) and time spent on flowers (p = 0.005). Also, agroecological zone × season × cucurbit species × pollinator species significantly (p < 0.0001) affected pollinators' visitation frequency. Agroecological zones × season × cucurbit species × cucurbits management practices × pollinators significantly (p = 0.001) affected pollinators' visitation rate. Apis mellifera was the most frequent visitor in Cucurbita moschata plots treated with GAMOUR- Agroecology in the plateau zone, also, visited higher number of Cucumis sativus plots under GAMOUR-Agroecology practices in the mountainous zone during the October-November season. Furthermore, it has been found that pollinators spent much in cucurbit flowers on plots with GAMOUR-Agroecology practices and control. CONCLUSIONS Pollinators' foraging behavior were enhanced by GAMOUR-Agroecology practices. Therefore, this study recommended that cucurbit growers should consider management practices that positively influence pollinator foraging activities for sustainable cucurbit production.
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Affiliation(s)
- Elvillah William Rweyemamu
- Department of Crop Science and Horticulture, Sokoine University of Agriculture (SUA), P.O. Box 3005, Chuo Kikuu, Morogoro, Tanzania.
| | - Maulid Walad Mwatawala
- Department of Crop Science and Horticulture, Sokoine University of Agriculture (SUA), P.O. Box 3005, Chuo Kikuu, Morogoro, Tanzania
| | - George Muhamba Tryphone
- Department of Crop Science and Horticulture, Sokoine University of Agriculture (SUA), P.O. Box 3005, Chuo Kikuu, Morogoro, Tanzania
| | - Marc De Meyer
- Royal Museum for Central Africa, Invertebrates Section and JEMU, Leuvensesteenweg 13, B-3080, Tervuren, Belgium
| | - Sija Kabota
- Department of Crop Science and Horticulture, Sokoine University of Agriculture (SUA), P.O. Box 3005, Chuo Kikuu, Morogoro, Tanzania
- Research, Consultancy and Publication Unit, National Sugar Institute (NSI), P.O. Box 97, Kidatu-, Morogoro, Tanzania
| | - Patroba Masatu Bwire
- Department of Crop Science and Horticulture, Sokoine University of Agriculture (SUA), P.O. Box 3005, Chuo Kikuu, Morogoro, Tanzania
- Tanzania Tobacco Board, P.O. Box 227, Morogoro, Tanzania
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2
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Nouvian M, Foster JJ, Weidenmüller A. Glyphosate impairs aversive learning in bumblebees. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 898:165527. [PMID: 37451452 DOI: 10.1016/j.scitotenv.2023.165527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 07/06/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
Agrochemicals represent prominent anthropogenic stressors contributing to the ongoing global insect decline. While their impact is generally assessed in terms of mortality rates, non-lethal effects on fitness are equally important to insect conservation. Glyphosate, a commonly used herbicide, is toxic to many animal species, and thought to impact a range of physiological functions. In this study, we investigate the impact of long-term exposure to glyphosate on locomotion, phototaxis and learning abilities in bumblebees, using a fully automated high-throughput assay. We find that glyphosate exposure had a very slight and transient impact on locomotion, while leaving the phototactic drive unaffected. Glyphosate exposure also reduced attraction towards UV light when blue was given as an alternative and, most strikingly, impaired learning of aversive stimuli. Thus, glyphosate had specific actions on sensory and cognitive processes. These non-lethal perceptual and cognitive impairments likely represent a significant obstacle to foraging and predator avoidance for wild bumblebees exposed to glyphosate. Similar effects in other species could contribute to a widespread reduction in foraging efficiency across ecosystems, driven by the large-scale application of this herbicide. The high-throughput paradigm presented in this study can be adapted to investigate sublethal effects of other agrochemicals on bumblebees or other important pollinator species, opening up a critical new avenue for the study of anthropogenic stressors.
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Affiliation(s)
- Morgane Nouvian
- Department of Biology, University of Konstanz, Konstanz, Germany; Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany; Zukunftskolleg, University of Konstanz, Konstanz, Germany.
| | - James J Foster
- Department of Biology, University of Konstanz, Konstanz, Germany; Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
| | - Anja Weidenmüller
- Department of Biology, University of Konstanz, Konstanz, Germany; Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
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3
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Straw EA, Mesnage R, Brown MJF, Antoniou MN. No impacts of glyphosate or Crithidia bombi, or their combination, on the bumblebee microbiome. Sci Rep 2023; 13:8949. [PMID: 37268667 DOI: 10.1038/s41598-023-35304-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 05/16/2023] [Indexed: 06/04/2023] Open
Abstract
Pesticides are recognised as a key threat to pollinators, impacting their health in many ways. One route through which pesticides can affect pollinators like bumblebees is through the gut microbiome, with knock-on effects on their immune system and parasite resistance. We tested the impacts of a high acute oral dose of glyphosate on the gut microbiome of the buff tailed bumblebee (Bombus terrestris), and glyphosate's interaction with the gut parasite (Crithidia bombi). We used a fully crossed design measuring bee mortality, parasite intensity and the bacterial composition in the gut microbiome estimated from the relative abundance of 16S rRNA amplicons. We found no impact of either glyphosate, C. bombi, or their combination on any metric, including bacterial composition. This result differs from studies on honeybees, which have consistently found an impact of glyphosate on gut bacterial composition. This is potentially explained by the use of an acute exposure, rather than a chronic exposure, and the difference in test species. Since A. mellifera is used as a model species to represent pollinators more broadly in risk assessment, our results highlight that caution is needed in extrapolating gut microbiome results from A. mellifera to other bee species.
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Affiliation(s)
- Edward A Straw
- Department of Botany, Trinity College Dublin, Dublin, Ireland.
- Centre for Ecology, Evolution and Behaviour, Department of Biological Sciences, School of Life Sciences and the Environment, Royal Holloway University of London, Egham, UK.
| | - Robin Mesnage
- Buchinger Wilhelmi Clinic, Wilhelmi-Beck-Straße 27, 88662, Überlingen, Germany.
- Gene Expression and Therapy Group, King's College London, Faculty of Life Sciences and Medicine, Department of Medical and Molecular Genetics, Guy's Hospital, London, SE1 9RT, UK.
| | - Mark J F Brown
- Centre for Ecology, Evolution and Behaviour, Department of Biological Sciences, School of Life Sciences and the Environment, Royal Holloway University of London, Egham, UK
| | - Michael N Antoniou
- Gene Expression and Therapy Group, King's College London, Faculty of Life Sciences and Medicine, Department of Medical and Molecular Genetics, Guy's Hospital, London, SE1 9RT, UK
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4
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Motta EVS, Moran NA. The effects of glyphosate, pure or in herbicide formulation, on bumble bees and their gut microbial communities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 872:162102. [PMID: 36764553 PMCID: PMC11050743 DOI: 10.1016/j.scitotenv.2023.162102] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 01/29/2023] [Accepted: 02/04/2023] [Indexed: 06/18/2023]
Abstract
The widespread use of glyphosate-based formulations to eliminate unwanted vegetation has increased concerns regarding their effects on non-target organisms, such as honey bees and their gut microbial communities. These effects have been associated with both glyphosate and co-formulants, but it is still unknown whether they translate to other bee species. In this study, we tested whether glyphosate, pure or in herbicide formulation, can affect the gut microbiota and survival rates of the eastern bumble bee, Bombus impatiens. We performed mark-recapture experiments with bumble bee workers from four different commercial colonies, which were exposed to field relevant concentrations of glyphosate or a glyphosate-based formulation (0.01 mM to 1 mM). After a 5-day period of exposure, we returned the bees to their original colonies, and they were sampled at days 0, 3 and 7 post-exposure to investigate changes in microbial community and microbiota resilience by 16S rRNA amplicon sequencing and quantitative PCR. We found that exposure to glyphosate, pure or in herbicide formulation, reduced the relative abundance of a beneficial bee gut bacterium, Snodgrassella, in bees from two of four colonies when compared to control bees at day 0 post-exposure, but this reduction became non-significant at days 3 and 7 post-exposure, suggesting microbiota resilience. We did not find significant changes in total bacteria between control and exposed bees. Moreover, we observed an overall trend in decreased survival rates in bumble bees exposed to 1 mM herbicide formulation during the 7-day post-exposure period, suggesting a potential negative effect of this formulation on bumble bees.
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Affiliation(s)
- Erick V S Motta
- Department of Integrative Biology, University of Texas at Austin, TX, USA.
| | - Nancy A Moran
- Department of Integrative Biology, University of Texas at Austin, TX, USA.
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5
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Botina LL, Barbosa WF, Acosta JPL, Bernardes RC, Cortes JEQ, Pylro VS, Mendonça AC, Barbosa RC, Lima MAP, Martins GF. The impact of early-life exposure to three agrochemicals on survival, behavior, and gut microbiota of stingless bees (Partamona helleri). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-27385-4. [PMID: 37147541 DOI: 10.1007/s11356-023-27385-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 04/28/2023] [Indexed: 05/07/2023]
Abstract
Over the last few decades, agrochemicals have been partially associated with a global reduction in bees' population. Toxicological assessment is therefore crucial for understanding the overall agrochemical risks to stingless bees. Therefore, the lethal and sublethal effects of agrochemicals commonly used in crops (copper sulfate, glyphosate, and spinosad) on the behavior and gut microbiota of the stingless bee, Partamona helleri, were assessed using chronic exposure during the larval stage. When used at the field-recommended rates, both copper sulfate (200 µg of active ingredient/bee; a.i µg bee-1) and spinosad (8.16 a.i µg bee-1) caused a decrease in bee survival, while glyphosate (148 a.i µg bee-1) did not show any significant effects. No significant adverse effects on bee development were observed in any treatment with CuSO4 or glyphosate, but spinosad (0.08 or 0.03 a.i µg bee -1) increased the number of deformed bees and reduced their body mass. Agrochemicals changed the behavior of bees and composition of the gut microbiota of adult bees, and metals such as copper accumulated in the bees' bodies. The response of bees to agrochemicals depends on the class or dose of the ingested compound. In vitro rearing of stingless bees' larvae is a useful tool to elucidate the sublethal effects of agrochemicals.
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Affiliation(s)
- Lorena Lisbetd Botina
- Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG, 36570-900, Brazil.
| | - Wagner Faria Barbosa
- Departamento de Estatística, Universidade Federal de Viçosa, Viçosa, MG, 36570-900, Brazil
| | - João Paulo Lima Acosta
- Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG, 36570-900, Brazil
| | | | | | - Victor Satler Pylro
- Departamento de Biologia, Universidade Federal de Lavras - UFLA, Lavras, MG, 37200-900, Brazil
| | - Adriana Corrêa Mendonça
- Departamento de Ciência de Solos, Universidade Federal de Viçosa, Viçosa, MG, 36570-900, Brazil
| | - Renata Cristina Barbosa
- Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, MG, 36570-900, Brazil
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6
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Cullen MG, Bliss L, Stanley DA, Carolan JC. Investigating the effects of glyphosate on the bumblebee proteome and microbiota. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 864:161074. [PMID: 36566850 DOI: 10.1016/j.scitotenv.2022.161074] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 12/15/2022] [Accepted: 12/16/2022] [Indexed: 06/17/2023]
Abstract
Glyphosate is one of the most widely used herbicides globally. It acts by inhibiting an enzyme in an aromatic amino acid synthesis pathway specific to plants and microbes, leading to the view that it poses no risk to other organisms. However, there is growing concern that glyphosate is associated with health effects in humans and an ever-increasing body of evidence that suggests potential deleterious effects on other animals including pollinating insects such as bees. Although pesticides have long been considered a factor in the decline of wild bee populations, most research on bees has focussed on demonstrating and understanding the effects of insecticides. To assess whether glyphosate poses a risk to bees, we characterised changes in survival, behaviour, sucrose solution consumption, the digestive tract proteome, and the microbiota in the bumblebee Bombus terrestris after chronic exposure to field relevant doses of technical grade glyphosate or the glyphosate-based formulation, RoundUp Optima+®. Regardless of source, there were changes in response to glyphosate exposure in important cellular and physiological processes in the digestive tract of B. terrestris, with proteins associated with oxidative stress regulation, metabolism, cellular adhesion, the extracellular matrix, and various signalling pathways altered. Interestingly, proteins associated with endocytosis, oxidative phosphorylation, the TCA cycle, and carbohydrate, lipid, and amino acid metabolism were differentially altered depending on whether the exposure source was glyphosate alone or RoundUp Optima+®. In addition, there were alterations to the digestive tract microbiota of bees depending on the glyphosate source No impacts on survival, behaviour, or food consumption were observed. Our research provides insights into the potential mode of action and consequences of glyphosate exposure at the molecular, cellular and organismal level in bumblebees and highlights issues with the current honeybee-centric risk assessment of pesticides and their formulations, where the impact of co-formulants on non-target organisms are generally overlooked.
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Affiliation(s)
- Merissa G Cullen
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland.
| | - Liam Bliss
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Dara A Stanley
- School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 2, Ireland; Earth Institute, University College Dublin, Belfield, Dublin 2, Ireland
| | - James C Carolan
- Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
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7
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Thompson LJ, Stout JC, Stanley DA. Contrasting effects of fungicide and herbicide active ingredients and their formulations on bumblebee learning and behaviour. J Exp Biol 2023; 226:297167. [PMID: 36861783 PMCID: PMC10112909 DOI: 10.1242/jeb.245180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 02/14/2023] [Indexed: 03/03/2023]
Abstract
Fungicides and herbicides are two of the most heavily applied pesticide classes in the world, but receive little research attention with regards to their potential impacts on bees. As they are not designed to target insects, the mechanisms behind potential impacts of these pesticides are unclear. It is therefore important to understand their influence at a range of levels, including sublethal impacts on behaviours such as learning. We used the proboscis extension reflex (PER) paradigm to assess how the herbicide glyphosate and the fungicide prothioconazole affect bumblebee olfactory learning. We also assessed responsiveness, and compared the impacts of these active ingredients and their respective commercial formulations (Roundup Biactive and Proline). We found that learning was not impaired by either formulation but, of the bees that displayed evidence of learning, exposure to prothioconazole active ingredient increased learning level in some situations, while exposure to glyphosate active ingredient resulted in bumblebees being less likely to respond to antennal stimulation with sucrose. Our data suggest that fungicides and herbicides may not negatively impact olfactory learning ability when bumblebees are exposed orally to field-realistic doses in a lab setting, but that glyphosate has the potential to cause changes in responsiveness in bees. As we found impacts of active ingredients and not commercial formulations, this suggests that co-formulants may modify impacts of active ingredients in the products tested on olfactory learning without being toxic themselves. More research is needed to understand the mechanisms behind potential impacts of fungicides and herbicides on bees, and to evaluate the implications of behavioural changes caused by glyphosate and prothioconazole for bumblebee fitness.
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Affiliation(s)
- Linzi J Thompson
- School of Agriculture and Food Science, University College Dublin, Dublin 4, Ireland.,Earth Institute, University College Dublin, Dublin 4, Ireland
| | - Jane C Stout
- School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
| | - Dara A Stanley
- School of Agriculture and Food Science, University College Dublin, Dublin 4, Ireland.,Earth Institute, University College Dublin, Dublin 4, Ireland
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8
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Helander M, Lehtonen TK, Saikkonen K, Despains L, Nyckees D, Antinoja A, Solvi C, Loukola OJ. Field-realistic acute exposure to glyphosate-based herbicide impairs fine-color discrimination in bumblebees. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 857:159298. [PMID: 36216073 DOI: 10.1016/j.scitotenv.2022.159298] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 10/02/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Pollinator decline is a grave challenge worldwide. One of the main culprits for this decline is the widespread use of, and pollinators' chronic exposure to, agrochemicals. Here, we examined the effect of a field-realistic dose of the world's most commonly used pesticide, glyphosate-based herbicide (GBH), on bumblebee cognition. We experimentally tested bumblebee (Bombus terrestris) color and scent discrimination using acute GBH exposure, approximating a field-realistic dose from a day's foraging in a patch recently sprayed with GBH. In a 10-color discrimination experiment with five learning bouts, GBH treated bumblebees' learning rate fell to zero by third learning bout, whereas the control bees increased their performance in the last two bouts. In the memory test, the GBH treated bumblebees performed to near chance level, indicating that they had lost everything they had learned during the learning bouts, while the control bees were performing close to the level in their last learning bout. However, GBH did not affect bees' learning in a 2-color or 10-odor discrimination experiment, which suggests that the impact is limited to fine color learning and does not necessarily generalize to less specific tasks or other modalities. These results indicate that the widely used pesticide damages bumblebees' fine-color discrimination, which is essential to the pollinator's individual success and to colony fitness in complex foraging environments. Hence, our study suggests that acute sublethal exposure to GBH poses a greater threat to pollination-based ecosystem services than previously thought, and that tests for learning and memory should be integrated into pesticide risk assessment.
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Affiliation(s)
- Marjo Helander
- Department of Biology, University of Turku, FI-20014 Turku, Finland.
| | - Topi K Lehtonen
- Ecology and Genetics Research Unit, University of Oulu, FI-90570 Oulu, Finland; Natural Resources Institute Finland, FI-90570 Oulu, Finland
| | - Kari Saikkonen
- Biodiversity Unit, University of Turku, FI-20014 Turku, Finland
| | - Léo Despains
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 118 route de Narbonne, F-31062 Toulouse cedex 9, France
| | - Danae Nyckees
- Laboratory of Entomology, Wageningen University, 6700 AA Wageningen, the Netherlands
| | - Anna Antinoja
- Ecology and Genetics Research Unit, University of Oulu, FI-90570 Oulu, Finland
| | - Cwyn Solvi
- Ecology and Genetics Research Unit, University of Oulu, FI-90570 Oulu, Finland
| | - Olli J Loukola
- Ecology and Genetics Research Unit, University of Oulu, FI-90570 Oulu, Finland
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9
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Zioga E, White B, Stout JC. Glyphosate used as desiccant contaminates plant pollen and nectar of non-target plant species. Heliyon 2022; 8:e12179. [DOI: 10.1016/j.heliyon.2022.e12179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/09/2022] [Accepted: 11/30/2022] [Indexed: 12/14/2022] Open
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