This study investigated the effect of gamma irradiation combined with entomopathogenic fungi (Beauveria bassiana and Paecilomyces lilacinus) on the adult longevity in Galleria mellonella. Three experimental groups were studied: the progeny of F₁ larvae from irradiated parental males, the progeny of F₁ larvae from irradiated parental females, and a control group of unirradiated insects. Results showed that the adult longevity was significantly decreased with increasing irradiation doses. Combining gamma irradiation and entomopathogenic fungi can improve control measures targeted at adult longevity of G. mellonella.