# The Effect of Exposure to an Electromagnetic Field on Entomopathogenic Fungi
## 1 Introduction  
An electromagnetic field (EMF) is a naturally occurring phenomenon associated with solar activity, cosmic radiation, or lightning [1]. Technological development has caused more and more artificial sources of electromagnetic fields to occur in the human environment [2, 3]. In recent years, the rapid development of mobile communication has been observed, which is associated with an increase in electromagnetic emissions in radio frequencies. While there is considerable research on the impact of EMFs on vertebrates or plants [4, 5, 6, 7, 8], there are relatively few studies showing the impact of this factor on microorganisms. [PERSON] et al. [9] found that 24 and 48 h EMF exposure at a frequency of 2.4 GHz causes increased antibiotic resistance and motility in _Escherichia coli_ 0157H7, as well as enhancing biofilm formation by _Escherichia coli_ 0157H7, _Staphylococcus aureus_, and _Staphylococcus epidermidis_. [PERSON] et al. [10] showed an inconclusive effect of electromagnetic fields emitted by mobile telephony on the microbiota of human skin. In their research, they showed that EMFs can cause both the increased growth and inhibition of bacterial colonies of the _Staphylococcus_ genus: _S. pasteuri, S. Ingdunensis_, and _S. epidermidis_. On the other hand, [PERSON] et al. [11] and [PERSON] et al. [12] found no effect of radio frequency electromagnetic fields on the development of _Salmonella typhimurium_ colonies (TA98, TA100, TA1535, and TA1537) or _Escherichia coli_ (WP2 uvrA) and found no increased frequency of reverse mutations or accelerated DNA degradation of _Escherichia coli_ WP2 and TA102 or _Salmonella typhimurium_ TA98 and TA1535. Of the studies on the impact of EMFs on fungi, the majority have focused on yeast; however, these studies have mainly been concerned with the impact of so-called weak electromagnetic fields. [PERSON] et al. [13] showed that, under exposure to a 60 Hz field, the concentration of intracellular cations of calcium, potassium, sodium, and zinc increased, which could be utilized in bioremediation processes in metal-polluted environments. [PERSON] et al. [14] found that an EMF can cause the loss of yeast cell membrane continuity. The susceptibility of yeast to weak electromagnetic fields was also demonstrated by [PERSON] et al. [15]. These authors noted that the ethanol fermentation of molasses and _Saccharomyces cerevisiae_ under exposure to a 50 Hz field resulted in statistically significantly higher ethanol production than in the control group. [PERSON] at al. [16] showed that a radio-frequency electromagnetic field (RF-EMF) can increase the extracellular level of fungal total proteins and \(\alpha\)-amylase activity in the fungus _Aspergillus oryzae_. [PERSON] et al. [17] proved that an extremely low-frequency oscillating magnetic field can stimulate the growth of a pathogenic strain of _Candida guillermondii_. _C. guillermondii_ showed a tropic response to an applied magnetic field, expressed by the fast growth of its pseudohyphae [17]. [PERSON] et al. [18] reported that exposure to mobile waves may significantly inhibit the mycelium growth of the fungi _Trichophyton metagrophytes_, _Aspergillus niger_, and _Pencillium_ spp. An EMF may not only have an inhibitory effect on fungi but can also stimulate some of their activities. Entomopathogenic fungi (EPFs) are a common group of pathogens in almost all soil environments and play an important role in regulating the pest insect population in agroecosystems. EPFs of the genera _Beauveria_, _Isaria_, and _Metarhizium_ are soil-inhabiting organisms that colonize the plant rhizosphere [19; 20; 21] and may positively affect plant resistance against plant pathogenic microorganisms [22]. These fungi are regarded as important pathogens of insects and other invertebrates [23; 24].