Sublethal neonicotinoid exposure attenuates the effects of electromagnetic fields on honey bee flight and learning

2021 · Mixed · Low evidence

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MixedLow evidencePaper 1038

Study snapshot

Publicationmanual · 2021

Study typeanimal

Reported directionMixed

Evidence ratingLow

Abstract

Sublethal neonicotinoid exposure attenuates the effects of electromagnetic fields on honey bee flight and learning S. Shepherd, M.A.P. Lima, E.E. Oliveira, S.M. Sharkh, H. Aonuma, C.W. Jackson, P.L. Newland. Sublethal neonicotinoid exposure attenuates the effects of electromagnetic fields on honey bee flight and learning, Environmental Advances. Volume 4. 2021. 100051. doi:10.1016/j.envadv.2021.100051. Abstract Many environmental stressors are currently implicated in the decline of flying insects in general, and important pollinator species such as the honey bee. Recent studies have shown that extremely low frequency electromagnetic fields (ELF EMFs) affect many aspects of insect behaviour and cognition which raises the potential that ELF EMFs could interact with other environmental stressors such as neonicotinoid insecticides to have even greater impact on the decline of flying insects. Here we analysed the effects of individual and combined exposure of the honey bee to 50 Hz EMFs and sublethal exposure to clothianidin, in a tethered flight assay and an olfactory appetitive learning assay. Clothianidin was significantly toxic to bees and exposure to field-realistic levels (2.00 ng/bee) led to 25% mortality. Exposure to ELF EMFs alone led to a significant increase in wingbeat frequency at levels above 100 µT. Prior exposure to clothianidin attenuated the effects of EMFs on wingbeat frequency. Exposure to EMFs alone reduced learning of a proboscis extension reflex (PER). Prior exposure to low doses of clothianidin attenuated the effects of EMFs on PER. These results indicate no evidence of synergy between clothianidin and ELF EMFs as environmental stressors but suggest the potential for EMFs to affect the same susceptible fraction of the bee population that have been affected by clothianidin. Results lay the foundation to further explore the interactions of ELF EMFs with other environmental stressors and consider the key factors that may make bees susceptible to ELF EMFs. Open access paper: sciencedirect.com

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeanimal

Effect directionmixed

PopulationHoney bee

Sample sizeNot supplied

ExposureELF

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

In honey bees, exposure to 50 Hz EMFs increased wingbeat frequency at field levels above 100 µT and reduced PER learning. Sublethal clothianidin exposure (2.00 ng/bee; reported as field-realistic) caused 25% mortality and attenuated the EMF-associated changes in wingbeat frequency and PER learning; the authors report no evidence of synergy between clothianidin and ELF EMFs.

Outcomes measured

Wingbeat frequency (tethered flight assay)
Olfactory appetitive learning (proboscis extension reflex, PER)
Mortality (clothianidin toxicity)

Limitations

Sample size not reported in the provided abstract/metadata
Exposure duration/timing details for EMF and clothianidin not specified in the provided abstract/metadata
Findings are from tethered flight and olfactory learning assays; generalizability to free-flight/field conditions not stated

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "ELF",
    "source": null,
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": "Honey bee",
  "sample_size": null,
  "outcomes": [
    "Wingbeat frequency (tethered flight assay)",
    "Olfactory appetitive learning (proboscis extension reflex, PER)",
    "Mortality (clothianidin toxicity)"
  ],
  "main_findings": "In honey bees, exposure to 50 Hz EMFs increased wingbeat frequency at field levels above 100 µT and reduced PER learning. Sublethal clothianidin exposure (2.00 ng/bee; reported as field-realistic) caused 25% mortality and attenuated the EMF-associated changes in wingbeat frequency and PER learning; the authors report no evidence of synergy between clothianidin and ELF EMFs.",
  "effect_direction": "mixed",
  "limitations": [
    "Sample size not reported in the provided abstract/metadata",
    "Exposure duration/timing details for EMF and clothianidin not specified in the provided abstract/metadata",
    "Findings are from tethered flight and olfactory learning assays; generalizability to free-flight/field conditions not stated"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "honey bee",
    "insect",
    "extremely low frequency",
    "ELF EMF",
    "50 Hz",
    "microtesla",
    "wingbeat frequency",
    "learning",
    "proboscis extension reflex",
    "PER",
    "clothianidin",
    "neonicotinoid",
    "combined exposure",
    "environmental stressors"
  ],
  "suggested_hubs": [
    {
      "slug": "elF-emf-wildlife",
      "weight": 0.86,
      "reason": "Animal study assessing behavioral/cognitive effects of 50 Hz ELF EMFs in honey bees."
    },
    {
      "slug": "pesticides-interactions",
      "weight": 0.78,
      "reason": "Examines combined exposure and interaction between ELF EMFs and the neonicotinoid clothianidin."
    }
  ]
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1016/j.envadv.2021.100051
PubMed: Not supplied

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