The encyrtid parasitoid, Habrolepis diaspidi (Risbec) (Hymenoptera : Encyrtidea) is one of the most effective parasitoid associated with armored scale insects (Hemiptera: Diaspididiae). This work dealt with the host insect range and the occurance of the parasitoid, H. diaspidi in different localities during 2010 and 2011 in Egypt. The results indicated that the parasitoid, H. diaspidi was reared from 10 species of armored scale insects. The host armored scale insects were Aonidiella aurantii (Maskell), Aonidiella citrina (Coquillett), Aspidiotus nerii Bouche , Chrysomphalus aonidum (L.) , Chrysomphalus dictyospermi (Morgan), Hemiberlesia lataniae (Signoret), Lepidosaphes beckii (Newman), Lepidosaphes pallida (Maskell), Mycetaspis personata (Comstock), Parlatoria ziziphi (Lucas) (Hemiptera: Diaspididiae). Population abundance studies of H. diaspidi were carried out on aforementioned armored scale insects at eight locations in Egypt, being Behira , Beni Seuf, Cairo, Giza, Ismailia , North Sinai, Qalyubiya and Sharqiya .The highest rate of parasitism attained with H. lataniae showed 56.8 and 77.8 % during the first and second years, respectively . While lowest parasitism rates was 14.9 and 17.5 % during the two years under consideration, respectively. As a general trend H. diaspidi was the effective parasitoid attacking armored scale insects in Egypt.