Field experiments were conducted at the Farm Horticulture Services Unit, Gemmiza, Agric. Res. Station (Middle Delta), Santa, Gharbia Governorate, during two successive seasons of 2008 and 2009 to study the occurrence of the spiny boll worm,(SBW), Earias insulana (Boisd.)  in some  its host plants. The hosts were Cotton, Gossypium barbadense L. (Varity Giza 86 ); Maize, Zea maize L. (Pioneer 3062); Khtmia weed, Hibiscus trionum L.; Okra, Hibiscus esculentus L.; Roselle, Hibiscus sabdarifa L. Occurrence period of the SBW larval infestation in the cotton terminal shoots and fruit structures extended from mid May to the end of September and occurred in three peaks. Inthe silk and ears of maize the SBW larval infestation period occurred from late July to late September at one peak. Inbladder capsules, the  larval infestation period started from the first week of June and extended to the third week of September at 2-3 peaks. In okra, it occurredfrom the first week of August and extended to last week of Octoberat 2 peaks. In Roselle, it was recorded from mid September to mid November at 2 peaks. The bladder weed acted as a source of SBW infestation followed by cotton, Maize then okra, and was the most important host in summer for the occurrence of the SBW population. While some other hosts as Roselle acted as source of SBW infestation followed by wintry hosts, which were grown, in Egypt, had the sustain  of  SBW infestation during a critical period of its seasonal history that extended from December to April.