In plant pathogenic fungi, as well as in entomogenous fungi, particularly Beauveria bassiana, mycoviruses can spread intraspecifically and interspecifically. Uncertainty exists regarding the prevalence of mycoviruses in Beauveria spp. and their capacity to transfer interspecifically between Beauveria species. In this study, B. bassiana was excluded from the four Beauveria species that were chosen at random for double-stranded RNA (dsRNA) detection. Additionally, employing hyphal anastomosis and a unique insect coinfection transmission technique, the interspecific transmission between B. bassiana, B. amorpha, and B. aranearum was studied using two previously described dsRNA mycoviruses from B. bassiana. According to the findings, dsRNA mycoviruses can transfer interspecifically across various Beauveria species and are present in all Beauveria species. Compared to reverse transmission, B. bassiana’s transmission efficiency to the other two Beauveria species was noticeably higher. In B. amorpha and B. aranearum, both viruses were capable of vertical and stable dissemination, which had an impact on the growth rate and colony morphology.