Laboratory and field studies were carried out in Egypt on the biology of Heliothis armigera (Hb.). A list of food-plants is presented. At 27-29 deg C and 50-53% RH, the average duration of the egg, larval, pupal and adult stages, and the preoviposition, oviposition and postoviposition periods, was 3.1, 13.7, 12, 6.2-6.6, 2.8, 4.1 and 0.4 days, respectively. Eggs were usually laid singly, and each female laid an average of 297.8. There were 6 larval instars and 4 generations a year, and the overwintering stage was the fourth-generation pupa. Oviposition, hatching, pupation and feeding are described. The parasites found were Peribaea orbata (Wied.) (Actia aegyptia (Villen.)), Exorista larvarum (L.) (Tachina larvarum), Apanteles ruficrus (Hal.) and Copidosoma sp., which attacked larvae, and Barylypa rufa (Himgr.), which attacked pupae. The predators found were Scolothrips sexmaculatus (Perg.), Orius spp. and Chrysopa carnea Steph., which attacked eggs and first-instar larvae. none