Investigating the effects of glyphosate on the bumblebee proteome and microbiota

Cullen, Merissa G.; Bliss, Liam; Stanley, Dara A.; Carolan, James C.

doi:10.1016/j.scitotenv.2022.161074

Cited by 22 publications

(13 citation statements)

References 139 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This set of DEGs might be part of a general molecular response to neonicotinoids in bumble bees and could be used to identify gene expression signatures of exposure in similar studies or in field scenarios. This may extend beyond neonicotinoids, with some DEGs from our analysis potentially representing general responses to xenobiotics, as similar effects have been seen in response to non-insecticide pesticides 116 , 117 . Despite the clear overall patterns of gene expression differences in larvae following imidacloprid exposure, we see relatively high expression variation across samples from the same treatment that are from different source colonies (Supplementary Figs.…”

Section: Discussionmentioning

confidence: 83%

Gene expression in bumble bee larvae differs qualitatively between high and low concentration imidacloprid exposure levels

Martín-Blázquez

Calhoun

Sadd

et al. 2023

Sci Rep

View full text Add to dashboard Cite

Neonicotinoid pesticides negatively impact bumble bee health, even at sublethal concentrations. Responses to the neonicotinoid imidacloprid have been studied largely at individual adult and colony levels, focusing mostly on behavioral and physiological effects. Data from developing larvae, whose health is critical for colony success, are deficient, particularly at the molecular level where transcriptomes can reveal disruption of fundamental biological pathways. We investigated gene expression of Bombus impatiens larvae exposed through food provisions to two field-realistic imidacloprid concentrations (0.7 and 7.0 ppb). We hypothesized both concentrations would alter gene expression, but the higher concentration would have greater qualitative and quantitative effects. We found 678 genes differentially expressed under both imidacloprid exposures relative to controls, including mitochondrial activity, development, and DNA replication genes. However, more genes were differentially expressed with higher imidacloprid exposure; uniquely differentially expressed genes included starvation response and cuticle genes. The former may partially result from reduced pollen use, monitored to verify food provision use and provide additional context to results. A smaller differentially expressed set only in lower concentration larvae, included neural development and cell growth genes. Our findings show varying molecular consequences under different field-realistic neonicotinoid concentrations, and that even low concentrations may affect fundamental biological processes.

show abstract

Section: Discussionmentioning

confidence: 83%

Gene expression in bumble bee larvae differs qualitatively between high and low concentration imidacloprid exposure levels

Martín-Blázquez

Calhoun

Sadd

et al. 2023

Sci Rep

View full text Add to dashboard Cite

show abstract

“…Alternatively, glyphosate may not directly affect a bumblebee’s ability to detect sucrose or scent, but may indirectly affect their motivation and desire to feed, as also found for other pesticides such as imidacloprid ( Cresswell et al, 2012 , 2014 ) and clothianidin ( Thompson et al, 2015 ). Some research also suggests that glyphosate can have an effect on the honeybee gut microbiome ( Motta et al, 2018 ; Cullen et al, 2023 ). Therefore, bumblebees exposed to glyphosate may be more likely to become full or have digestion issues resulting in a reduced appetite and therefore reduced motivation to respond.…”

Section: Discussionmentioning

confidence: 99%

“…Some initial evidence suggests that these co-formulants may also affect bees ( Straw et al, 2022 ) as they can have the ability to cause changes in microbiota or changes at the physiological level (e.g. Straw and Brown, 2021 ; Cullen et al, 2023 ). However, we have very little understanding of the mechanisms behind this, and so testing the impacts of both formulations and active ingredients is important because it may aid understanding of the role of co-formulants in pesticidal effects.…”

Section: Introductionmentioning

confidence: 99%

Contrasting effects of fungicide and herbicide active ingredients and their formulations on bumblebee learning and behaviour

Thompson

Stanley

2023

Journal of Experimental Biology

Self Cite

View full text Add to dashboard Cite

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 like 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 active ingredient and commercial formulations of both compounds (Roundup biactive and Proline, respectively). We found that learning was not impaired by either formulation but, of the bees which 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.

show abstract

“…Recently, three studies have found limited, and at times somewhat conflicting, results of chronic glyphosate exposure in bumblebees, using both glyphosate as an active ingredient and glyphosate-based formulations 29 , 45 , 46 . In Bombus impatiens , both glyphosate and the formulation were found to impact microbiome composition, notably Snodgrassella abundance 29 .…”

Section: Introductionmentioning

confidence: 99%

“…In Bombus impatiens , both glyphosate and the formulation were found to impact microbiome composition, notably Snodgrassella abundance 29 . In Bombus terrestris , both glyphosate and the formulation altered cellular and physiological processes, including processes associated with oxidative stress regulation and cellular adhesion 45 , 46 . Further, either highly limited or no impacts on gut bacterial composition were observed 45 , 46 , although some impacts on fungal species were observed.…”

Section: Introductionmentioning

confidence: 99%

No impacts of glyphosate or Crithidia bombi, or their combination, on the bumblebee microbiome

Straw

Mesnage

Brown

et al. 2023

Sci Rep

View full text Add to dashboard Cite

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.

show abstract

Investigating the effects of glyphosate on the bumblebee proteome and microbiota

Cited by 22 publications

References 139 publications

Gene expression in bumble bee larvae differs qualitatively between high and low concentration imidacloprid exposure levels

Gene expression in bumble bee larvae differs qualitatively between high and low concentration imidacloprid exposure levels

Contrasting effects of fungicide and herbicide active ingredients and their formulations on bumblebee learning and behaviour

No impacts of glyphosate or Crithidia bombi, or their combination, on the bumblebee microbiome

Contact Info

Product

Resources

About