Spodoptera exigua, beet armyworm is a major agricultural pest in the USA and has recently become a problem pest in tomato production in South Georgia. In 2004, an insecticide efficacy trial was conducted to determine the effect of beet armyworm on tomato yield and to determine a range of infestation levels for 2005 and 2006 artificial infestation trials appropriate for estimating an economic injury level (EIL). A range of 1-40 beet armyworm larva(e) per 25 plants was used in artificial infestation trials to create a population that could cause significant economic damage. An EIL of one beet armyworm larva per 20 tomato plants was determined to prevent economic yield loss in tomato.