# The Effect of Exposure to an Electromagnetic Field on Entomopathogenic Fungi
## 4 Discussion  
Exposure to an EMF may affect the growth of fungal mycelia [41]. [PERSON] et al. [42] found that the growth of the mycorrhizal fungus _Pisolichus titorius_ can be stimulated by a low-frequency field of 50 Hz at a density 0.025 and 0.1 mT. This magnetic field also increased the ergosterol content in the fungus mycelium [40]. Ergosterol is a component of fungal cell membranes and is important for fungal growth and their ability to adapt to environmental stresses [43]. Other authors did not find EEMFs to have any effect on fungal growth [44]. It should emphasized that both the type of EMF as well as the type of organism used in the experiment may affect the results [41, 45]. The present study has revealed that exposure to 900 and 1800 MHz EMFs may significantly affect the colony growth of EPFs. However, the effect depends on the EMF frequency and the EPF species. The lower-frequency EMF used in the present experiment significantly affected the linear growth of _M. anisopliae_, _C. fumosorsea_, and _B. bassima_ when they were exposed for seven days to an electromagnetic field. The fungal growth was evaluated not only immediately after the seven days of exposure to the EMF but also seven days after the end of the treatment. Under 900 MHz EMF exposure, the colony diameter was significantly larger than in the untreated control group. This means that the stimulating effect of the lower-frequency EMF was observed not only when it was applied but also as a subsequent effect. The growth of _B. bassima_ was significantly inhibited by the 1800 MHz EMF. The growth of _C. fumosorsea_ and _M. anisopliae_ was also inhibited, but the effect was weaker. [PERSON] et al. [46] found that exposure to a static magnetic field inhibits the mycelia growth of _Fusarium cumorum_. According to [PERSON] and [PERSON] [47], a static magnetic field of 0.1 mT flux density decreased the growth \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{3}{*}{**Treatment**} & \multicolumn{3}{c}{**Fungi Species**} \\  & **Inhibition/Stimulation Coefficient [\%] \(\pm\) SD** \\ \cline{2-4}  & _B. bassima_ & _C. fumosorsea_ & _M. anisopliae_ \\ \hline
900 MHz & 14.3 a \(\pm\) 2.93 & \(-\)21.3 a \(\pm\) 4.96 & 82.5 a \(\pm\) 10.05 \\ \hline
1800 MHz & 60.5 b \(\pm\) 15.40 & \(-\)39.1 a \(\pm\) 9.96 & 28.9 b \(\pm\) 12.95 \\ \hline \end{tabular} Values within particular columns marked with the same letter do not differ significantly (\(p\leq 0.05\)). SD—standard deviation.  
\end{table} 
Table 10: The inhibition/stimulation effect of exposure to 900 and 1800 MHz EMFs on the germ tube lengths of the entomopathogenic fungi _B. bassima_, _C. fumosorsea_, and _M. anisopliae_. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{3}{*}{**Treatment**} & \multicolumn{3}{c}{**Fungi Species**} \\  & **Mortality of Larvae [\%]** & \\ \cline{2-4}  & _B. bassima_ & _C. fumosorsea_ & _M. anisopliae_ \\ \hline Control & 87.5 ab \(\pm\) 4.78 & 80.0 a \(\pm\) 4.08 & 90.0 ab \(\pm\) 4.08 \\ \hline
900 MHz & 87.5 ab \(\pm\) 2.50 & 97.5 b \(\pm\) 2.50 & 90.0 ab \(\pm\) 4.08 \\ \hline
1800 MHz & 67.5 a \(\pm\) 2.50 & 77.5 a \(\pm\) 2.50 & 87.5 ab \(\pm\) 2.50 \\ \hline \end{tabular} Values within particular columns and rows marked with the same letter do not differ significantly (\(p\leq 0.05\)).  
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Table 11: The effect of exposure to 900 and 1800 MHz EMFs on the pathogenicity of _B. bassima_, _C. fumosorsea_, and _M. anisopliae_ against _T. molitor_ larvae. of plant pathogenic fungal colonies. However, other authors have suggested that a static magnetic field may stimulate development of EPFs [32]. [PERSON] et al. [48] concluded that an oscillating magnetic field (OMF) of 60 Hz/220 V and low density values (1-5 mT) stimulate the colony growth and physiology of filamentous fungi. [PERSON] at al. [16] showed that a radio-frequency electromagnetic field (RF-EMF) can enhance vesicle accumulation in the hyphae of the fungus _Aspergillus oryzae_. Vesicles have many functions in the lives of fungi [49; 50; 51].