To evaluate the fertility and development of Trichoplusia ni, either larvae, pupae, or adults were exposed to the magnetic field for 24 hours. After exposure, larvae or pupae were allowed to reach the adult stage to evaluate their oviposition rate. From each group (exposed as larvae, pupae or adult), 11 males and 11 females were put in a plastic container for mating.
To assess immunological parameters, third-instar larvae were exposed for 72 hours (Remark EMF-Portal: In the abstract, there is also an exposure period of 48 hours given. However, no results for this are presented in the article or in figures). When larvae reached fourth-instar larvae stadium, the third segment was cut and hemolymph was collected.
|Setup||coil with 552 turns of 1.3-mm diameter copper wire formed a cylindrical solenoid (radius 13.5 cm, length 71 cm); the solenoid was connected to a step-down transformer and to a variable transformer plugged to a 110-V AC source; magnetic field was homogeneous in the middle of the solenoid, so insects were positioned there; temperature with exposure 25 ± 0.1°C and without 24.7 ± 0.1°C; humidity 40%|
|Sham exposure||A sham exposure was conducted.|
No significant differences in the number of ovipositioned eggs and the percentage of hatched larvae were found between exposed and sham exposed animals.
However, differences in immunological parameters were found: The number of hemocytes was significantly decreased in exposed larvae in comparison to sham exposed ones while the number of apoptotic cells was significantly higher with exposure. Additionally, in exposed larvae, the total protein concentration was significantly decreased and the enzyme activity of phenoloxidase was significantly higher compared to sham exposed larvae. The number of granulocytes was significantly decreased and the number of oenocytoids significantly increased in exposed animals compared to unexposed ones (Remark EMF-Portal: not mentioned in the methods section, maybe results are taken from another publication?). The gene expression of the immune markers cecropin, lysozyme, gallerimycin, and pgrp c were downregulated whereas attacin and defensin were upregulated after exposure compared to sham exposure.
The authors conclude that 60 Hz magnetic fields could influence immunological parameters in Trichoplusia ni.