Fungi that infect insects constitute a huge and diverse group, with approximately 1,600 known species 
belonging to 90 genera. The house fly, Musca domestica L. (Diptera: Muscidae), is of great medical 
importance due to its ability to transmit thousands of pathogenic microorganisms, including parasites, 
fungi, bacteria, and viruses. This study was conducted to isolate and characterize the most important 
entomopathogenic fungi and evaluate their efficiency against the house fly Musca domestica L. 
(Diptera: Muscidae). Approximately 50 adult house flies were collected, raised in the laboratory, and 
treated with three concentrations from the fungi Metarhizium anisopliae and Trichoderma harzianum
for seven days in two ways: by mixing with food and by direct spraying of the spore suspension. The 
results of the isolation and diagnosis of fungi confirmed the registration of the two fungi, M. 
anisopliae and Trichoderma harzianum (ID: PP035895 and ID: PP065519). The mortality in insects 
was directly proportional to the suspension concentration of fungal spores. The concentration of 1 x 
10^7 spores/ml showed the highest percentage of mortality in the house fly for both methods. 
Specifically, the mortality in the direct spraying method from the fungus M. anisopliae was 85.7%, 
and by mixing with food was 66.6%. The same concentration (1 x 10^7 spores/ml) with the spore 
suspension of T. harzianum resulted in a mortality rate of 85.7% when mixed with food and 100% 
mortality with the direct spraying method. The results also revealed that T. harzianum spore 
suspension at all concentrations showed higher lethality than M. anisopliae. The study demonstrated 
the sensitivity of adult house flies to the spore suspensions of the studied fungi T. harzianum which 
was superior in increasing the mortality rate, compared to M. anisopliae.