## 4 Discussion  
In this study, we evaluated the feasibility of different biopreparation formulations and their effectiveness in controlling the mortality of _A. mexicana_ ants. The entomopathogenic fungus _B. bassiana_ plays a crucial role as a biological control agent against a wide range of agricultural and forestry pests [40]. It has gained approval for commercial use in various countries [41, 42]. The speed of conidial germination and conidial viability are critical parameters associated with its virulence. Virulence, in this context, is directly associated with EPF capacity to reduce insect mortality, even in the presence of host resistance [43]. Notably, conidial germination is an indispensable process for initiating infection by _B. bassiana_[44]. The genus _Metrahizium_ has been well documented as an effective biocontrol agent against a wide range of insect pests, including leafcutter ants [45, 46, 47]. Similarly, the _Beauveria_ genus is known for producing secondary metabolites with insecticidal properties, such as beauvericin [48]. Furthermore, the genetic variability present in EPF may be one of the factors responsible for the differences in virulence between _B. bassiana_ and _M. anisopliae_[49]. Among the biopreparations evaluated, the MA-Bb1+Diatomin(r) biopreparation exhibited the highest total mortality, achieving 100% mortality in four-week-old _A. mexicana_ ants. These values are higher compared to those reported by [PERSON] et al. [50], who obtained a mortality of 50% in _A. sexdens_ on the third day after inoculation with a suspension of _B. bassiana_ at a concentration of 1.0 \(\times\) 10\({}^{9}\) conidia/mL. [PERSON] et al. [51] mentioned that Diatomin(r) plays a role in dissolving cuticular lipids, facilitating the penetration of fungi through the exoskeleton, and is involved in chemical contact communication processes [52]. [PERSON] et al. [53] conducted a study showing that the combination of surfactants like zeolite, perlite, and vermiculite with fungal conidia of _B. bassiana_ and _M. anisopliae_ exhibited high virulence against _Riptortus pedestrians_ in vivo. Moreover, [PERSON] et al. [54] reported that diatomaceous earth increased the mortality of _T. castaneum_ larvae. In addition, [PERSON] et al. [55] reported an additive effect of _B. bassiana_ when used in conjunction  
Figure 4: The cumulative survival analysis revealed statistically very significant effects of the different biopreparations (log rank: \(\chi^{2}\) = 941.628, \(p\) = 0.0001) in _A. mexicana_ during 15 days of treatment. with diatomaceous earth against adult _R. dominica_ and _S. oryzae_, findings consistent with those reported in this investigation. Furthermore, our Probit analysis revealed significant differences in the median lethal time (LT\({}_{50}\)) between the biopreparations. These findings underscore the importance of considering the rate of action of biological control agents when evaluating their effectiveness in the field. Probit analysis indices such as mean lethal time (LT\({}_{50}\)) are commonly used parameters to evaluate the effectiveness of pest control agents [56]. These findings are similar to those of [PERSON] et al. [57], who observed 100% mortality nine days (216 h) after the application of _M. anisopliae_ against _C. capitata_. This positive association is a phenomenon that was explained by several researchers [58; 59; 60] in the majority of entomopathogenic microbial fungi tested. In this sense, the entomopathogenic capacity is used in the control of social insects such as leafcutter ants [45]. A suitable mean lethal concentration increases the likelihood that an individual infected with either _B. bassiana_ or _M. anisopliae_ will cause the development of mycosis within the colony, thereby reducing the colony's ability to respond to the infection [61; 62]. _M. anisopliae_ is a facultative entomopathogen with a broad host range [63].