Extremely Low-Frequency Electromagnetic Fields Entrain Locust Wingbeats

Bioelectromagnetics · 2021 · Mixed · Low evidence

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MixedLow evidencePaper 1180

Study snapshot

PublicationBioelectromagnetics · 2021

Study typeanimal

Reported directionMixed

Evidence ratingLow

Abstract

Extremely Low-Frequency Electromagnetic Fields Entrain Locust Wingbeats Sebastian Shepherd, Christopher W Jackson, Suleiman M Sharkh, Hitoshi Aonuma, Eugenio E Oliveira, Philip L Newland. Extremely Low-Frequency Electromagnetic Fields Entrain Locust Wingbeats. Bioelectromagnetics. 2021 Apr 6. doi: 10.1002/bem.22336. Abstract Extremely low-frequency electromagnetic fields (ELF EMFs) have been shown to impact the behavior and physiology of insects. Recent studies have highlighted the need for more research to determine more specifically how they affect flying insects. Here, we ask how locust flight is affected by acute exposure to 50 Hz EMFs. We analyzed the flights of individual locusts tethered between a pair of copper wire coils generating EMFs of various frequency using high-speed video recording. The mean wingbeat frequency of tethered locusts was 18.92 ± 0.27 Hz. We found that acute exposure to 50 Hz EMFs significantly increased absolute change in wingbeat frequency in a field strength-dependent manner, with greater field strengths causing greater changes in wingbeat frequency. The effect of EMFs on wingbeat frequency depended on the initial wingbeat frequency of a locust, with locusts flying at a frequency lower than 20 Hz increasing their wingbeat frequency, while locusts flying with a wingbeat frequency higher than 20 Hz decreasing their wingbeat frequency. During the application of 50 Hz EMF, the wingbeat frequency was entrained to a 2:5 ratio (two wingbeat cycles to five EMF cycles) of the applied EMF. We then applied a range of ELF EMFs that were close to normal wingbeat frequency and found that locusts entrained to the exact frequency of the applied EMF. These results show that exposure to ELF EMFs lead to small but significant changes in wingbeat frequency in locusts. We discuss the biological implications of the coordination of insect flight in response to electromagnetic stimuli. pubmed.ncbi.nlm.nih.gov

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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

PopulationLocusts (tethered, individual flights)

Sample sizeNot supplied

ExposureELF · acute exposure

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Acute exposure to 50 Hz EMFs significantly increased the absolute change in wingbeat frequency in a field strength-dependent manner. The direction of change depended on initial wingbeat frequency (below 20 Hz increased; above 20 Hz decreased), and wingbeat frequency became entrained to the applied EMF (2:5 ratio at 50 Hz; exact frequency entrainment for ELF EMFs near normal wingbeat frequency).

Outcomes measured

Wingbeat frequency
Entrainment of wingbeat frequency to applied EMF frequency/ratio

Limitations

Sample size not reported in abstract
Field strength values not reported in abstract
Exposure metrics beyond frequency (e.g., magnetic flux density/electric field) not specified in abstract
Tethered flight setup may limit generalizability to free flight

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "ELF",
    "source": "laboratory coils (copper wire coils generating EMFs)",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "acute exposure"
  },
  "population": "Locusts (tethered, individual flights)",
  "sample_size": null,
  "outcomes": [
    "Wingbeat frequency",
    "Entrainment of wingbeat frequency to applied EMF frequency/ratio"
  ],
  "main_findings": "Acute exposure to 50 Hz EMFs significantly increased the absolute change in wingbeat frequency in a field strength-dependent manner. The direction of change depended on initial wingbeat frequency (below 20 Hz increased; above 20 Hz decreased), and wingbeat frequency became entrained to the applied EMF (2:5 ratio at 50 Hz; exact frequency entrainment for ELF EMFs near normal wingbeat frequency).",
  "effect_direction": "mixed",
  "limitations": [
    "Sample size not reported in abstract",
    "Field strength values not reported in abstract",
    "Exposure metrics beyond frequency (e.g., magnetic flux density/electric field) not specified in abstract",
    "Tethered flight setup may limit generalizability to free flight"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "extremely low-frequency",
    "ELF EMF",
    "50 Hz",
    "locust",
    "insect flight",
    "wingbeat frequency",
    "entrainment",
    "behavior"
  ],
  "suggested_hubs": [
    {
      "slug": "elf-emf",
      "weight": 0.9,
      "reason": "Study examines effects of extremely low-frequency EMFs (including 50 Hz) on an animal model."
    }
  ]
}

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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: 10.1002/bem.22336
PubMed: 33822398

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