The current study involved isolating two types of fungi associated with mosquito larvae: Aedes aegypti and Culex molestus, which have not previously been recorded in larval infestations. These fungi were used as biological control agents various developmental stages of mosquitoes Culex molestus and Aedes aegypti over different time periods (24, 48, 72, 120 hours). The fungi Lagenidium giganteum and Beauveria bassiana were isolated from naturally infected mosquito larvae and identified in the laboratory. In the pupal stage, the LC50 values were (7.411 × 106, 7.373 × 106) spore/ml for Lagenidium giganteum in Aedes aegypti and Culex molestus, respectively, after 72 hours of treatment. While the LC50 values for Beauveria bassiana were (9.473 × 106, 9.371 × 106) spore/ml for the two mosquito species after the same time period. This indicates the superiority of Lagenidium giganteum in achieving higher mortality rates compared to Beauveria bassiana. Regarding adults, female mosquitoes exhibited greater resistance compared to males. Additionally, males and females of Culex molestus were more sensitive to the fungal suspensions than to Aedes aegypti. LC50 values for females of Aedes aegypti and Culex molestus were (9.108 × 106) and (6.159 × 106) spore/ml, respectively, after 72 hours.