Fall armyworm (FAW) Spodoptera frugiperda is one of the devastating insect pests. It is a polyphagous pest causing economic damage to important cultivated cereal crops such as rice, maize, cotton, sorghum, and various vegetable crops. The first occurrence recorded in Egypt was in 2019. The aim of this study included the study of some biological aspects by using some plant hosts such as maize, sorghum, ricinus and tomato. In general, feeding by maize plants recorded the shortest larval lifespan stage from the 1^st to the 6^th instar, prepupal stage, pupal stage, adult longevity (♀ & ♂), mean fecundity (no. of eggs and hatchability%). Also, the study included the evaluation of the efficiency of some essential oils against the 2^nd and 4^th larval instar of S. frugiperda under laboratory conditions. Generally, results clearly indicated that tested essential oils (Lemongrass oil, Orange oil, Peppermint oil and Linseed oil) varied considerably in their efficiency against the two tested larval instars (2^nd and 4^th) and that higher concentration caused a higher reduction in tested larval instars. Generally, it was obvious that the efficiency of the tested essential oils against the 4^th instar of S. frugiperda remarkably had the same trend as the 2^nd instar with variable values. The efficiency of tested oil can be arranged descending according to the length of LC_50, LC₉₀ and LC₉₅ as follows Lemongrass oil ˃ Orange oil ˃ Peppermint oil ˃ Linseed oil to S. frugiperda after 10 days post treatments.