ABSTRACT
Four species of the genus Stylocephalus Ellis, 1912 were recorded and described from beetles in El Fayoum Governorate; S. iongicollis, S. phalloides, S. variabilis and S. eastoni. Both S. phall-oides and S. variabilis were recorded in Zophosis sp. and Pimelia angulata, respectively for the first time in Egypt. Out of 105 Blaps polychresta, 18 [17.14%] were infected with S. longicollis and 57 [54.29%] with S. eastoni. Out of 30 Pimelia angulata, 17 [56.76%] were infected with 5. variabilis and all examined Zophosis sp. [n=67] were infected with S. phalloides. Scanning electron microscopy on S. longicollis revealed morphological features not reported before; three pairs of longitudinal ribs extending from the second fifth till the posterior extremity of old sporont and a minute pore on the anterior tip of epimerite. In S. eastoni, the epimerite-host epithelium relationship revealed that the parasite invades host's gut with the distal part of epimerite. Regarding the gross pathological symptoms, heavily infected hosts showed a sluggish motility, short antennae, swollen abdomen, lack of fat accumulation, and putrid smell in dead beetles