Study type: Medical/biological study (experimental study)

Reproducibility and Desensitization of the Power Frequency Magnetic Field Effect on Movement of the Common Cutworm Spodoptera Litura. med./bio.

Published in: Entomol Res 2009; 39 (6): 406-409

Aim of study (acc. to author)

To investigate the effect of exposure to an extremely low frequency magnetic field on the movement of the common cutworm Spodoptera litura.

Background/further details

After an acclimatization period of 24 hours in the petri dishes, the larvae (caterpillar) were submitted to one of four experimental schemes:
1.) 1 h without any treatment ("cage control"),
2.) 1 h sham exposure (n=18) + 1 h sham exposure (n=18),
3.) 1 h sham exposure (n=45) + 1 h magnetic field exposure (n=45) and
4.) 1 h sham exposure (n=18) + 1 h magnetic field exposure (n=18) followed by 1 h sham exposure (n=18) + 1 h magnetic field exposure (n=18) followed again by 1 h sham exposure (n=9) + 1 h magnetic field exposure (n=9) .
The fourth experiment was performed to test whether the observed effects are reproducible with the same larvae. All experiments were repeated two or three times.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 60 Hz
Exposure duration: up to 3 hours (à 1 hour exposures, see background/further details)

Exposure 1

Main characteristics
Frequency 60 Hz
Type
Exposure duration up to 3 hours (à 1 hour exposures, see background/further details)
Exposure setup
Exposure source
Chamber larvae were exposed in Petri dishes (35 mm diameter)
Setup rectangular Helmholtz coils, temperature inside the exposure system 25 ± 0.5°C
Sham exposure A sham exposure was conducted.
Additional info intensity of the ambient stray magnetic field was less than 0.05 µT
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT - measured - -

Reference articles

  • Chae KS (2008): An extremely low frequency magnetic field increases unconditioned larval movement of the common cutworm, Spodoptera litura: A novel model for a magnetoreceptive neurobehavioral study.
  • Koh EK et al. (2008): A 60-Hz sinusoidal magnetic field induces apoptosis of prostate cancer cells through reactive oxygen species.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

The magnetic field exposed larvae of the third experiment showed a reduced motor activity in comparison to the sham exposed larvae of the second experiment (not significant). In the fourth experiment, larvae exposed for the first and for the second time showed a significantly decreased motor activity compared to the former sham exposure, respectively. However, larvae exposed for the third time showed no mentionable difference in the motor activity when compared to the former sham exposure.
The authors conclude that exposure to extremely low frequency magnetic fields could affect the motor activity of insect larvae.

Study character:

Study funded by

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