Different concentrations of essential oil of lemon grass, Cymbopogen citratus, were tested for their ovipositional inhibition, antifeedant activity and insecticidal properties against the lesser cotton leafworm, Spodoptera exigua. The results obtained showed that 2% concentration of oil emulsion inhibited egg laying and 0.5% concentration more than reducted by 70% the number of eggs deposited on oviposition sites. 2% concentration acts as a protective concentration against the immature stage by hindering the third instar larvae to feed on treated leaf discs. In addition, the oil emulsion was insecticidal in that percentage mortality was directly proportional to the concentration applied and to the duration of exposure. Older egg masses were more affected by treatment than the newly laid eggs. 2% concentration inhibited hatchability when sprayed on egg masses before hatching. Lemon grass oil effectively controlled S. exigua as an ovicidal and larvicidal agent.
