Exposure to an additional alternating magnetic field affects comb building by worker hornets.

{
  "study_type": "animal",
  "exposure": {
    "band": "ELF",
    "source": "other",
    "frequency_mhz": 0.05,
    "sar_wkg": null,
    "duration": null
  },
  "population": "Oriental hornet workers (kept in an Artificial Breeding Box without a queen)",
  "sample_size": null,
  "outcomes": [
    "Comb building (number of cells)",
    "Eggs per comb",
    "Cell symmetry/morphology (deformed/imperfectly hexagonal cells)",
    "Comb stem morphology (delicate/slender stems)"
  ],
  "main_findings": "Worker hornets exposed in an artificial breeding box to an additional 50 Hz AC magnetic field (B = 50–70 mGauss) built combs differently than controls exposed only to the natural terrestrial magnetic field. Reported effects included 35–55% fewer cells and fewer eggs per comb, disrupted symmetry with deformed/imperfectly hexagonal cells, and more delicate/slender comb stems.",
  "effect_direction": "harm",
  "limitations": [
    "No sample size reported in the abstract.",
    "Exposure duration not reported in the abstract.",
    "Study context is an artificial breeding box without a queen; generalizability to natural colonies is unclear from the abstract.",
    "No statistical methods or variability measures described in the abstract."
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "oriental hornet",
    "worker hornets",
    "comb building",
    "alternating magnetic field",
    "AC magnetic field",
    "50 Hz",
    "ELF magnetic field",
    "brood comb",
    "cell morphology"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.2,
      "reason": "ELF 50 Hz magnetic-field exposure is described, but the setting is experimental/animal rather than a clear occupational scenario."
    }
  ]
}