## 4 Discussion
[35] also found higher diversity of entomopathogenic fungi in organically farmed soil compared to conventionally treated field sites. [PERSON] et al. [31] reported that there is evidence that plant host associations play an important role in evolutionary divergence within the genus _Metrahizium_. In the USA, _M. brunneum_ is associated with the rhizosphere of shrubs and trees, whereas _M. robertsii_ is found in open fields and grassland [10; 36]. In addition, _M. brunneum_ was only found in agricultural and open field sites when _M. robertsii_ was also present [36]. In contrast, _M. brunneum_ has been reported to be the dominant species in agricultural and grassland fields in Europe [12; 37]. This could also be observed in our field sites in Tyrol, with more than 96.7% of all isolates being _M. brunneum_ (without the applied strain). Although a comparison of the distribution of _Metrahizium_ species already published is difficult due to different sampling techniques, variable distribution patterns of dominant species were found in recent studies. The species _M. anisopliae, M. brunneum_, _M. robertsii_, and _M. pingshaense_ are most frequently isolated [38], and even these species are found with local preferences: _M. pingshaense_ being the most common species found in soil taken from various locations in Japan [39], _M. anisopliae_ in agricultural soil in Brazil [40; 41], and _M. robertsii_ dominating in the USA [10], for example. Other species only occur in restricted areas. _M. flavoviride_, for example, was the most common species found in agricultural fields in Denmark [42]. These global distribution differences of _Metrahizium_ species can also be found on a smaller scale in our test sites--which all had a significantly different _Metrahizium_ population structure. The two chosen regions differ in their climate, landscape and vegetation--the wide-open space in Southeast Styria, 209 m above (Adriatic) sea level (Pannonic climate), and the mountainous region of North-Tyrol (659 m above sea level; Alpine climate). Overall, _M. brunneum_ as well as _M. robertsii_ and _M. lepidiotae_ were isolated as indigenous species. At the sampling sites of Tyrol, most of the isolated colonies were classified as _M. brunneum_, while in Styria, _M. robertsii_ dominated the _Metrahizium_ community. [PERSON] et al. [43] suggested that due to the saprophyic phase of the species, their population genetics shifted in accordance with the ability to grow at low or high temperatures. This would correspond to our preliminary studies on the radial growth of the three species (Table S1) in which growth between 25 \({}^{\circ}\)C and 30 \({}^{\circ}\)C for _M. brunneum_ (negative correlation of temperatures with \(r=-0.559\), \(p<0.05\)) and _M. robertsii_ (\(r=-0.018\), \(p>0.05\)) stagnates or declines and _M. lepidiate_, which only occurs in the warmer region of Styria, showing a larger colony diameter at 30 \({}^{\circ}\)C compared to incubation at 25 \({}^{\circ}\)C (\(r=0.641\), \(p<0.05\)). These findings are supported by [PERSON] et al. (2014), who have reported, that _M. robertsii_ and _M. brunneum_ have different optimal growth temperatures, with _M. robertsii_ preferring higher temperatures than _M. brunneum._ In contrast [PERSON] et al. (2014) have found that certain _Metarhizium_ species are not necessarily dominant in sun exposed habitats but react differently to multiple abiotic factors. Regarding _Metarhizium_ spp. abundance it is well documented that there is a high correlation between temperature, humidity and survival of entomogenic fungi (2014). These natural abiotic factors may have an influence on the survival and development of the _M. brunneum_ production strain in both Austrian regions. Our data suggest that _M. brunneum_ BIPESCO 5 is more persistent when applied in Tyrol. [PERSON] and [PERSON] (2014) summarized that _Metarhizium_ is more common in exposed and regularly disturbed soil but cannot extensively proliferate. In addition, different tillage systems lead to very variable soil densities.